Laurence, J.
Oliver Wendell Holmes, Jr.’s, most famous [592]*592maxim — “The life of the law has not been logic: it has been experience”1 — cannot, of course, be taken literally. Law without logic — in the most fundamental sense of objective, practical, and consistent analysis and reasoning — will be law in a vacuum, formless and insubstantial.2 Twice-convicted (of second degree murder) defendant Robert C. Beauchamp has presented us with an intricately woven yet diaphanous fabric of contentions — primarily that the Commonwealth’s use in his second trial of his testimony from his first trial violated his constitutional rights — which is rent by the application of commonsense logic and established legal precedent and which, like a vacuum, lacks substance. A fairly lengthy recitation of the factual and procedural background of the defendant’s present appeal from his most recent conviction is unfortunately necessary to appreciate the threadbare quality of his arguments.3
1. Background. On August 5, 1971, the defendant himself called the Arlington police to report that he had just shot Charles McGrath in the defendant’s third floor apartment in Arlington. Upon their arrival, the police found the victim shot dead and lying on his back, with his keys a few inches from his right hand, on a second floor landing. The landing was situated at the bottom of a flight of stairs that led to a hallway, at the end of which was the defendant’s apartment. The defendant was advised of his Miranda rights upon police entry into his apartment. He told investigating officers that the victim had been blackmailing him and that he had fired in self-defense when the victim attacked him with a large knife during an argument over further blackmail. Released on bail, the defendant fled to California but was soon rearrested and brought to trial on a first degree murder charge in early 1973.
The Commonwealth established at that first trial that the [593]*593victim had been shot five times at close range. Medical evidence indicated that one shot had been fired from behind the victim, apparently as he had turned to escape the fusillade. Two of the bullets had a downward trajectory, as if the shooter had stood over the victim and fired into his chest. No fingerprints were found on the knife allegedly wielded by the victim. A neighbor testified that he had heard the shots, which were not fired in rapid succession but rather with pauses before the third and the fourth shots.
The defendant testified and admitted shooting the victim but claimed he had done so only to protect himself against the victim’s violent knife attack after retreating as far as he could in his apartment. He testified that the origin of the deadly encounter had been the victim’s theft of a national merit scholarship examination in 1966, a copy of which he had given to the defendant. By means of the stolen document, the defendant achieved a high score on the actual examination, obtained a scholarship, and was admitted to a prestigious university. The victim, however, scored poorly on the examination and ended up at a lesser institution. Embittered, the victim proceeded to blackmail the defendant for several years with threats of exposure regarding the stolen exam. The defendant had complied with the extortion until a few days before the fatal incident. On the night of the shooting, a heated fifteen-minute argument took place after the victim had come to the defendant’s apartment to demand more money immediately. When the defendant refused to pay, the victim rushed at the defendant with a foot-long knife (which he held in a napkin) screaming that he was going to plunge it into the defendant as far as he could to kill him. Only after retreating until he was up against a wall, with the knife a few inches from his body, did the defendant, “scared out of [his] mind,” fire several shots in rapid succession from a recently purchased .38 caliber revolver which he somehow was able to retrieve from his open briefcase as he backed away from the uplifted knife. The victim then stumbled out of the apartment.
On February 21, 1973, the jury convicted the defendant of murder in the second degree, for which he received the mandatory sentence of life imprisonment. G. L. c. 265, § 2. The defendant did not appeal his conviction, and in early 1974 he escaped from prison. He was not apprehended until 1981 in California, where he was charged with committing a number of [594]*594Federal crimes. After serving Federal sentences in California and Illinois, he was returned to Massachusetts on a Governor’s warrant. He proceeded to file a series of motions for a new trial alleging various errors in his 1973 trial. One of those claims — that the trial judge’s instructions on self-defense could have been interpreted by the jury to shift the burden of proof on that issue to the defendant — was discerned by the Supreme Judicial Court to be a ground on which the defendant’s conviction should be set aside. Commonwealth v. Beauchamp, 424 Mass. 682 (1997).
The court observed that the law regarding the proper charge with respect to claims of self-defense had changed in the defendant’s favor while he was in hiding from the authorities. Id. at 685, citing Mullaney v. Wilbur, 421 U.S. 684, 704 (1975), and Commonwealth v. Rodriguez, 370 Mass. 684, 687-689 (1976). Although the instructions at his trial had not explicitly stated who had the burden of proof on self-defense and were correct under the then state of the law, the court concluded that, read as a whole, they might have led a reasonable juror to believe that the Commonwealth was not required to prove the absence of self-defense beyond a reasonable doubt, as mandated by the cited cases. Because Rodriguez applied retroactively, even if the defendant had unsuccessfully appealed earlier, his conviction remained susceptible to attack on this ground on collateral review. 424 Mass. at 685-686. The court accordingly remanded the case for a new trial.
Prior to his new trial, on the charge of second degree murder only, the defendant filed a motion to exclude his 1973 testimony, which the Commonwealth had indicated in a motion in limine it intended to introduce in its case-in-chief. As the sole ground for his motion, the defendant reiterated a contention he had begun making in his flurry of new trial motions following his rendition to Massachusetts: namely, that his 1973 testimony had been inaccurate, indeed “perjured,” at the behest of officials of the Federal Bureau of Investigation (FBI), Central Intelligence Agency (CIA), State Department, and White House. The “perjury” had been contrived in order to conceal a complex “scam” by the defendant, the victim, and a third person, with Federal connivance, to defraud and embarrass the Soviet Embassy in Washington by selling it false copies of the so-called “Pentagon Papers.” (See Gravel v. United States, 408 U.S. 606, 608 [1972]; United States v. Liddy, 542 F.2d 76, 78 [595]*595[D.C. Cir. 1976].) The killing had actually occurred, he averred, as a result of the victim’s angry belief that the defendant had cut the victim out of his rightful share of the money mulcted from the Soviets.
The defendant’s motion to exclude requested, in the alternative should his former testimony be introduced, that he be allowed to subpoena and secure the attendance (with public funds) of a large number of out-of-State witnesses. These individuals were vital to his case, the defendant asserted, in order to “explain his inaccurate, former testimony at the first trial,” to verify the “real reasons” behind the victim’s death, and to rebut the Commonwealth’s position that the defendant had recently fabricated his present version of the facts surrounding the killing.4 The defendant also claimed that these witnesses could testify to the “cover-up” associated with the killing, including the “promises and inducements made” to him regarding his testimony at the first trial as well as the clandestine government facilitation of his escape from prison.
Following an evidentiary hearing, the trial judge denied the defendant’s motion in its entirety,5 and the defendant’s retrial proceeded. In his opening, defense counsel presented an outline of the defendant’s self-defense case that essentially tracked the defendant’s 1973 testimony. Nevertheless, counsel attempted during trial to block the use of the prior testimony by arguing that it was hearsay and could be admitted as an exception only [596]*596upon the Commonwealth’s proof of the defendant’s unavailability. See Commonwealth v. Childs, 413 Mass. 252, 260-261 (1992). That hearsay requirement could be satisfied, counsel contended, only if and when the defendant actually refused to testify, by invoking his privilege against self-incrimination when it came time for the defense to put in its case, if any. See Commonwealth v. Ortiz, 393 Mass. 523, 529-530 (1984).
The prosecutor successfully rebuffed this effort, first by citing G. L. c. 233, § 20,6 to establish that the defendant was unavailable; but also by arguing that, in any event, the defendant’s former testimony constituted an admission of a party opponent which is not governed by the hearsay rule and has no unavailability requirement. See Commonwealth v. Marley, 396 Mass. 433, 441 (1985); Liacos, Massachusetts Evidence § 8.8.1 (7th ed. 1999). At no time before or during trial did the defendant or his counsel assert that the admission of the former testimony was irrelevant or would in any way violate his privilege against self-incrimination or his right to remain silent.
Shortly after the Commonwealth began reading his prior testimony into the record,7 the defendant interrupted the proceedings by making a pro se motion for a mistrial. During a hearing outside the jury’s presence, he argued that his counsel had been ineffective and neglectful in preparing for trial by failing to subpoena for authentication certain FBI, CIA, and State Department records allegedly supportive of the revised story (see supra at 594-595) which he urgently wanted to tell the jury. At that point, the defendant’s counsel informed the judge that he had consistently “recommended very strongly” to the defendant that he should not testify at all; telling his changed story, counsel had advised the defendant, would create “a high [597]*597probability” of a guilty verdict on the second degree murder charge.
The defendant nonetheless persisted in his complaint that counsel’s failure to obtain those documents “effectively precluded [him] from testifying on his own behalf,” because they were “absolutely critical” to the case he wanted to present in order to rebut the “perjur[ed]” testimony from his first trial. Without those documents to “corroborate” the admittedly “bizzare[]” details of his new version of events, “the jury would almost certainly find [that] testimony to be not credible.” In sum, the Commonwealth’s use of his former testimony combined with counsel’s documentary neglect had the chilling effect of “denfying] my right to testify in my own defense at my own trial.”8
The judge denied the defendant’s motion for a mistrial, reiterating his pretrial ruling on the admissibility of the defendant’s prior testimony and his refusal to allow the defendant to subpoena numerous Federal witnesses. The judge also took pains to emphasize to the defendant his absolute right to testify. The Commonwealth then completed reading in the defendant’s earlier testimony and rested.9 The defendant filed a motion for a required finding of not guilty of the charged crime of second degree murder. Upon its denial, the defense rested without calling any witnesses. The next day, the jury (having received correct instructions from the judge, including repeated admonitions that the Commonwealth bore the burden of proving beyond a reasonable doubt that the defendant did not act in self-defense) found the defendant guilty of second degree murder.
The defendant raises several issues,10 most vigorously that the trial judge erred in allowing the Commonwealth to introduce [598]*598his “coerced perjured” prior testimony in its case-in-chief. There was no error, however, in that or in any other respect, and we affirm his conviction.11
2. Prior testimony as admission. It is well established that the prior trial testimony of a party, including a criminal defendant, is admissible as substantive evidence at a subsequent trial, regardless of the testifier’s availability. “It is merely a straightforward application of the rule admitting statements of a party-opponent that the testimony of a defendant in a criminal trial will be admissible against him in later trials where a conviction is followed by a reversal and a new trial.” Liacos, Massachusetts Evidence § 8.8.2, at 501. See Commonwealth v. DiMonte, 427 Mass. 233, 243 (1998) (“A party’s admission is excluded by definition from the hearsay rule. Proposed Mass.R.Evid. 801[d][2]”). Therefore, “a defendant’s testimony at a former trial is generally admissible against him if relevant to the current trial.” Commonwealth v. Johnson, 372 Mass. 185, 193 (1977). See Harrison v. United States, 392 U.S. 219, 222 (1968); Commonwealth v. Marley, 396 Mass. at 441; Commonwealth v. Sires, 413 Mass. 292, 305 (1992); Commonwealth v. Cassidy, 29 Mass. App. Ct. 651, 654 n.4 (1990), S.C., 410 Mass. 174 (1991); Commonwealth v. Brusgulis, 41 Mass. App. Ct. 386, 389 (1996); Liacos, Massachusetts Evidence § 8.8.1, at 496-498, & § 8.8.2, at 501; 8 Wigmore, Evidence § 2276(5), at 472-473 (McNaughton rev. ed. 1961); Young, Pollets, & Poreda, Evidence § 804.2, at 213-214 & n.10 (2d ed. 1998); McCormick, Evidence § 301, at 288 (5th ed. 1999).12
As the Commonwealth has demonstrated — and the defendant [599]*599does not challenge — the testimony from the first trial was plainly relevant to the Commonwealth’s burden of proving the absence of self-defense, which it must do beyond a reasonable doubt in a case where self-defense has been put in issue. See Commonwealth v. Rodriguez, 370 Mass. at 687-688; Commonwealth v. Johnson, 426 Mass. 617, 620 (1998); Commonwealth v. Whitman, 430 Mass. 746, 755 (2000). By contrasting the defendant’s description of his and the victim’s actions [600]*600with the testimony of the police and experts regarding those actions and the sequence and angles of the various shots that wounded and ultimately killed the victim, as well as the testimony of the neighbor who heard the pauses between shots, the Commonwealth sought to cast serious doubt on the defendant’s version of the shooting and to persuade the jury that the evidence established a deliberate murder rather than justifiable self-defense.13
3. Prior testimony as hearsay exception. The alternative basis on which the prosecution justified and the judge allowed the introduction of the defendant’s first trial testimony is also well established. Prior recorded testimony of a witness is admissible in a subsequent proceeding if it is rehable and if the witness is currently unavailable to testify.14 Ohio v. Roberts, 448 U.S. 56, 65-66, 74 (1980). Commonwealth v. Mustone, 353 Mass. 490, 492 (1968). Commonwealth v. DiPietro, 373 Mass. 369, 375, 380-386 (1977). Commonwealth v. Bohannon, 385 Mass. 733, 740-741 (1982). Liacos, Massachusetts Evidence §§ 8.4.2, 8.7.1. Such evidence qualifies for the exception “where the prior testimony was given by a person, now unavailable, in a proceeding addressed to substantially the same issues as in the current proceeding, with reasonable opportunity and similar motivation on the prior occasion for cross-examination of the declarant by the party against whom the testimony is now being offered.” Commonwealth v. Meech, 380 Mass. 490, 494 (1980). [601]*601See Commonwealth v. Trigones, 397 Mass. 633, 637-638 (1986); Commonwealth v. Koonce, 418 Mass. 367, 378 n.6 (1994); Commonwealth v. Cyr, 425 Mass. 89, 97 (1997). The Commonwealth may properly introduce a defendant’s earlier testimony as part of its case-in-chief. Commonwealth v. Marley, 396 Mass. at 441. Commonwealth v. Brusgulis, 41 Mass. App. Ct. at 389, and cases cited.
The challenged evidence here could be viewed as prior recorded testimony that satisfied all the requisite criteria for invocation of the hearsay exception. “For purposes of prior recorded testimony, a witness is unavailable if he claims his privilege against self-incrimination and the judge excuses him.” Commonwealth v. Koonce, supra. See Commonwealth v. DiPietro, 373 Mass. at 380-386; Commonwealth v. Canon, 373 Mass. 494, 499-500 (1977), cert. denied, 435 U.S. 933 (1978). The defendant retained his Fifth Amendment privilege against self-incrimination throughout his second trial, explicitly indicating to the judge that he would likely not testify and in fact exercising the privilege by not testifying when given the opportunity at the close of the Commonwealth’s case. Because the Commonwealth could not have called the defendant to the stand, he was “unavailable” to the prosecution (see note 6, supra). The defendant’s prior sworn and transcribed testimony was, additionally, eminently reliable. The first trial involved the very same parties and issues — the same crime was charged and the same claim of self-defense in the same circumstances was raised. The defendant, having voluntarily offered his testimony in the first trial (his implausible claim of having been “coerced” to perjure himself being wholly devoid of record support), cannot now successfully argue that he did not have the fullest possible opportunity to develop that testimony. See Commonwealth v. Meech, 380 Mass. at 494-495 n.7.
4. Constitutional claims, a. “Preclusion” of right to testify. Unable to muster any authorities contradictory to those uniformly supportive of the evidentiary use of his prior testimony, the defendant attempts to persuade us of the novel proposition that, however well established may be the law regarding such use, in his case it was doubly erroneous. It both prevented him from exercising his constitutional right to testify in his own behalf while simultaneously violating his constitutional right not to testify. The first prong of this argument is particularly baseless. The record reveals that the defendant was [602]*602afforded, by explicit judicial invitation, every opportunity to testify, but that the serious risks of doing so — at least by presenting his new, picaresque account of the background to the killing — were obvious to both him and his counsel (see supra at 596-597).15
Further, no authority of which we are or have been made aware suggests that the prosecution’s use of a defendant’s prior testimony in a retrial on the same charge is in any way violative of his constitutional rights. To the contrary, we have rejected the argument that a defendant’s “having testified at the first trial chills his right to testify at retrial” for fear of being inconsistent or appearing less credible. Commonwealth v. Cassidy, 29 Mass. App. Ct. at 654 n.4. “[Tjhis concern is present in all retrials . . . [but] any admissions the defendant may have made in the first trial are admissible for all purposes in a retrial . . . .” Id., citing Commonwealth v. Marley, 396 Mass. at 441.
Perhaps most revealing of the insubstantiality of the defendant’s claim to have been prejudicially precluded from testifying is to suppose that error occurred as alleged: it nonetheless could only have been harmless beyond a reasonable doubt.16 Had the defendant testified as he persistently protested he desired to do regarding the events that led to his fatal altercation with the victim, i.e., to the conspiracy to extort money from the Soviets with official but secret Federal cooperation —• indeed, even had that testimony actually been corroborated at trial by the out-of-State witnesses and documents he had tried to subpoena — it would have been of no assistance to his challenge to the Commonwealth’s evidence demonstrating the absence of legitimate self-defense.
The central issue in the trial was whether the Commonwealth [603]*603proved beyond a reasonable doubt that the defendant either did not have reasonable ground to believe he was in imminent danger of death or serious bodily harm from which he could save himself only by using deadly force; or had not availed himself of all reasonable means to avoid physical combat before resorting to deadly force; or had used excessive force, i.e., more than was reasonably necessary to defend himself in the circumstances. See Commonwealth v. Evans, 390 Mass. 144, 154 n.2 (1983). The precipitating reason for the victim’s alleged knife attack — whether motivated by rage at being denied continued blackmail payments stemming from the stolen exam incident or by fury at feeling cheated of his share of the purportedly extorted Soviet payments — was immaterial to the defendant’s success in convincing the jury of his defense of provocation and self-protection. What actually happened in the defendant’s apartment on the night of August 5, 1971, was the only issue pertinent to the jury’s consideration of his claim of self-defense, not the accidental circumstances that preceded the fateful encounter. On this score, it is “impossible for a mind not disturbed by excessive zeal to see in what respect the defendant was prejudiced.” Commonwealth v. Moore, 379 Mass. 106, 109 (1979), quoting from Commonwealth v. Boyd, 246 Pa. 529, 534-535 (1914).
b. “Violation” of self-incrimination privilege. The defendant’s alternative supposition, that the use of his testimony from the first trial violated his privilege against self-incrimination, also has little, if any, substance. The defendant was not called on to testify, did not testify, and in fact said nothing at the instant trial (as far as the triers of fact were aware). The jury were explicitly instructed by the judge regarding the defendant’s constitutional right to remain silent and the fact that they could draw no negative inferences therefrom. The defendant does not explain how his privilege against self-incrimination could have been violated by its very protected exercise.
Moreover, the self-incrimination issue has been waived by the defendant, since he never raised it or invoked the privilege below in his challenges to the Commonwealth’s introduction of his earlier testimony. See supra at 595-596 and note 5. The privilege is not self-executing. Like any right, constitutional or otherwise, it can be waived, and it has long been deemed waived by voluntary testimony in an earlier proceeding. See Commonwealth v. Judge, 420 Mass. 433, 445 n.8 (1995); Com[604]*604monwealth v. Fallon, 38 Mass. App. Ct. 366, 374-375 (1995), S.C., 423 Mass. 92 (1996).17
Our task, therefore, is to determine, first, whether this is the sort of case, presenting the unusual circumstance of a serious and obvious unpreserved error, which persuades us to exercise our rarely used discretion to avoid a substantial risk of a miscarriage of justice; and, second, if this is such an extraordinary case, whether the defendant has met his heavy burden of clearly demonstrating such a risk. See Commonwealth v. Amirault, 424 Mass. 618, 637-640, 645-646, 650-652 (1997); Commonwealth v. LeFave, 430 Mass. 169, 170, 173-175 (1999); Commonwealth v. Eason, 43 Mass. App. Ct. 114, 133 (1997) (Armstrong, J., dissenting), S.C., 427 Mass. 595 (1998).18
We do not view the defendant’s as one of those rare cases that qualify for the seldom-afforded exception to the waiver rule represented by the substantial risk doctrine. The challenged ruling — admitting a defendant’s prior testimony given under oath as substantive evidence in a subsequent proceeding involving the same parties and issues — was not, as explained in part 4a, supra, error at all under the law of evidence. Consequently, it can hardly be deemed the sort of “serious and obvious error” that furnishes the only occasion for the uncommon exercise of our reserved power to redress a perceived substantial risk of a miscarriage of justice. Amirault, 424 Mass. at 646. The many decisions uniformly upholding exactly what the judge allowed the prosecution to do here preclude such a characterization. See [605]*605authorities cited supra at 598-601.19 The defendant’s objection [606]*606“has long since been foreclosed ... by numerous decisions of this court and other courts.” Commonwealth v. DiPietro, 373 Mass. at 375-376.
Moreover, the defendant’s self-incrimination contention has no legitimate grounding on this record. First, given the thrust of his attempt to exclude his first trial testimony — that it was knowing and deliberate perjury — he cannot now be heard to complain. “[T]he commission of perjury does not fall within the protection afforded compelled self-incriminating statements.” United States v. Babb, 807 F.2d 272, 277 (1st Cir. 1986). Cf. Commonwealth v. D’Amour, 428 Mass. 725, 743 (1999) (“A . . . witness has the option to tell the truth or to remain silent. He . . . does not have the option to lie”).
To the extent the defendant relies on his incantation that such testimony was “coerced,”20 there is no evidentiary basis whatsoever to conclude that he was compelled, in any constitutional or even any commonly understood sense, to testify at his first trial (see supra note 12 and 601). Despite his lengthy list of individuals who could supposedly corroborate his “Soviet scam-Pentagon Papers” story (see note 4, supra), not a single one was ever identified (in any of his motion papers, much less in any affidavit) as having “coerced” him to testify as he did. Nor was the nature or means of the purported “coercion” ever described, let alone established beyond naked assertion.
As previously noted (see note 12, supra), there is nothing to the defendant’s argument that he was “virtually compelled” to testify in the first trial because of the state of the law regarding [607]*607the burden of proof as to self-defense. See Williams v. Florida, 399 U.S. 78, 83-84 (1970) (“The defendant in a criminal trial is frequently forced to testify himself ... in an effort to reduce the risk of conviction. . . . That the defendant faces such a dilemma demanding a choice between complete silence and presenting a defense has never been thought an invasion of the privilege against compelled self-incrimination”). Yet even if the circumstances at bar warranted such a perception, testimony conforming to the procedural requirements of the law is not held to be the result of the sort of “genuine compulsion” and “official[] coerc[ion]” that violate the privilege against self-incrimination. United States v. Washington, 431 U.S. 181, 187-188 (1977) (testimony given under oath pursuant to grand jury subpoena is not so coercively compelled). Compare Williams v. Florida, 399 U.S. at 82-86 (requiring defendant to give prosecution notice of intent to rely on an alibi defense and provide names and addresses of supportive witnesses is not compulsion that violates the privilege); McGautha v. California, 402 U.S. 183, 210-217 (1971) (preclusion of defendant’s mitigation testimony at sentencing if he invokes self-incrimination privilege at trial in which the jury decides guilt and sentence in one process is not the kind of compelled pressure, amounting to coercion or “cruelty,” violative of the privilege); United States v. Nobles, 422 U.S. 225, 233-234 & n.7 (1975) (discovery order requiring disclosure of defense notes of interviews with prosecution witnesses is not compelled self-incrimination); Minnesota v. Murphy, 465 U.S. 420, 427-428 (1984) (testimony voluntarily given under subpoena is not compelled within the meaning of the privilege, even if done without the witness realizing that he may thereby be losing the benefit of the privilege); Colorado v. Connelly, 479 U.S. 157, 170 (1986) (citations omitted) (“The sole concern of the Fifth Amendment. . . is governmental coercion. . . . [T]he Fifth Amendment privilege is not concerned ‘with moral and psychological pressures . . . emanating from sources other than official coercion’ ”). Contrast Mincey v. Arizona, 437 U.S. 385, 398-401 (1978) (reluctant statements by helpless, wounded, drugged suspect lying prostrate in a hospital intensive care ward were involuntary and compelled for constitutional purposes); New Jersey v. Portash, 440 U.S. 450, 459 (1979) (testimony reluctantly given under threat of conviction for contempt is coerced testimony). Cf. Commonwealth v. Harvey, 397 Mass. 351, 356-357 (1986) [608]*608(agency rules requiring police employee to cooperate with internal investigation and testify truthfully do not create self-incrimination compulsion in the absence of “overt threat or direct pressure” from officials in authority).
Even were we to scrutinize this case under the “substantial risk of a miscarriage of justice” lens, we would find no such risk in any event. The defendant’s responsibility for the killing was irrefutable. The Commonwealth’s evidence that a deliberate murder had occurred, rather than an act of self-defense, was strong (see note 13, supra). The first trial testimony was (at least so the defendant asserts) a knowing aspect of counsel’s trial strategy. The issue of self-defense would not have arisen at all if the defendant had declined to testify. Finally, the testimony would inevitably have been used to devastating effect to his credibility as impeachment had the defendant taken the stand with his new tale, as he has consistently and vehemently insisted he would have done had his motion to exclude that testimony been allowed. In that light, we have no serious doubt that the result of the trial would have been the same had the defendant’s prior testimony not been received in evidence in the second trial. On this record, the issue of the defendant’s guilt was fairly (and, we believe, correctly) adjudicated. See Commonwealth v. Amirault, 424 Mass. at 647, 650-651; Commonwealth v. Alphas, 430 Mass. 8, 13 (1999).
5. Other issues, a. Prosecutorial “misconduct.” The several allegedly “misleading” statements made in the prosecutor’s closing argument, unobjected to at trial, were all properly grounded in the evidence and reasonable inferences therefrom and created no error, much less any risk of a miscarriage of justice. See Commonwealth v. Dinkins, 415 Mass. 715, 725 (1993); Commonwealth v. Ashley, 427 Mass. 620, 627 (1998). The reference to there being no issue about the date the defendant purchased the gun he used (almost three weeks before the killing) was based upon a stipulation expressly agreed to (and signed) by the defendant as well as his trial counsel. The prosecutor’s use of the term “ambush” to describe the killing was fairly drawn from evidence indicating that the defendant lured the victim to his apartment (see note 13, supra) and began shooting upon entry of the victim, who was holding his keys rather than a knife and was shot not only while helplessly prostrate but also at angles inconsistent with having rushed toward the defendant. Contrast Commonwealth v. Andrews, 427 [609]*609Mass. 434, 444 (1998). The defendant’s complaint about the prosecutor’s selective reading of the first trial testimony of the neighbor (unavailable at trial) who heard the sequence of the shots rests on a misreading of the neighbor’s unequivocal testimony and a failure to recognize that the omitted portion was of little significance, as well as inadmissible hearsay. Finally, the charge that the prosecutor improperly stressed the pauses between the shots is frivolous, since the evidence solidly backed the prosecutor’s statement that the shots were not fired in rapid succession.21
b. Denial of required finding motions. The defendant concedes that the evidence, properly viewed in the light most favorable to the Commonwealth, permitted the jury to conclude that he shot and killed the victim in circumstances not justifying self-defense. That concession is enough to send the case to the jury, because it recognizes a rational basis for finding the defendant guilty of either second degree murder or the lesser included offense of manslaughter — a determination for the jury on proper instructions, not for the judge. See Commonwealth v. Martinez, 393 Mass. 612, 613-614 (1985); Commonwealth v. Woodward, 427 Mass. 659, 662-663 (1998).22
c. Ineffective assistance of counsel. The defendant posits five instances of ineffective assistance of counsel.23 Two of those claims of ineffectiveness — failure to object to the reading into [610]*610evidence of the defendant’s testimony at his prior trial24 and failure to object to or counter the prosecutor’s “misleading” closing argument — are null because counsel’s objections would have been unavailing, the prior testimony being admissible (see supra at 598-601) and the prosecutorial comments falling within the scope of permissible argument (see supra at 608-609). The defendant could not have been harmed by counsel's supposed inaction in those respects. See Commonwealth v. Brady, 380 Mass. 44, 55-56 (1980); Commonwealth v. Garcia, 34 Mass. App. Ct. 386, 391 (1993).
The other three purported shortcomings of counsel have no merit because they reflect tactical judgments which were not manifestly unreasonable and which the defendant has failed to demonstrate deprived him of an otherwise substantial ground of defense. See Commonwealth v. Saferian, 366 Mass. 89, 96 (1974); Commonwealth v. Rondeau, 378 Mass. 408, 413 (1979); Commonwealth v. Haley, 413 Mass. 770, 775-778 (1992). Failure to have interviewed certain FBI agents who had allegedly investigated the killing of the victim and could strengthen his Pentagon Papers theory was hardly unreasonable, for several reasons: the trial judge’s denial of counsel’s pretrial motion to compel their attendance at trial on the ground of the irrelevance of their testimony; the fact that such agents were not shown to have been percipient witnesses to the killing; the fact that certain heavily redacted and almost indecipherable documents apparently from FBI files relied on by the defendant do not, even if authentic, establish that such agents possessed or conveyed any relevant or admissible information on the self-defense issue; and the tactical decision of trial counsel to present a defense consistent with the defendant’s first trial testimony, [611]*611which squarely raised self-defense and would not have been enhanced even by FBI agents confirming his baroque new story.25
The defendant’s faulting of counsel for stipulating to “highly incriminating’’ evidence against him — namely the knife found in his apartment, the gun he admittedly used in the killing, and the July 13, 1971, date he obtained the gun and his gun permit — is groundless.26 He concedes that all of the stipulated evidence (which had been admitted at the first trial) could have been introduced by reading those portions of the earlier transcript that described or referred to the items. He also fails to indicate any demonstrable prejudice from the stipulation. That he had killed the victim with a gun was never a live issue at trial. That a large knife was found in his apartment could only assist his defense cause, which depended upon the jury accepting his claim that the victim attacked him with a large knife. The stipulated date of his procuring a gun permit and a gun was affirmed by him by signing the stipulation; and there is nothing in the record to support his conjecture that the date might have been earlier, except his own testimony at the first trial (“sometime in June of [19]71”), or that the somewhat later date was significantly more inculpatory.27
The defendant’s contention that the stipulation deprived him of the opportunity to argue that the jury could draw negative inferences from the Commonwealth’s destruction of the [612]*612evidence is not supported by the cases he cites. He has failed to show any culpability on the part of the prosecution — through negligence or otherwise — with respect to the unavailability of the original exhibits. Nor has he presented any argument, much less made a demonstration, that any of this evidence — all of which he had full opportunity to inspect, test, and argue about at his first trial, contrast Commonwealth v. Olszewski, 401 Mass. 749, 753-754 (1988), S.C., 416 Mass. 707 (1993), cert. denied, 513 U.S. 835 (1994) — would (or even might) have been exculpatory or in any way helpful in convincing a jury of his self-defense claim.28
Finally, the defendant’s charge that counsel prejudicially “misrepresented” his case, by making an opening statement outlining the defendant’s self-defense story in a manner consistent with his 1973 testimony, hardly merits further discussion. See supra at 601-603. Counsel’s opening was a reasonable strategy in light of his realization that the Commonwealth would inevitably make the jury aware of that testimony.29
Judgment affirmed.
Orders denying new trial motion and motion for reconsideration affirmed.