M&P M2.0 Accuracy Issues, do to dwell time?

I just finished watching this video below & he talks about the barrel he got from Apex Tactical & how it fixes accuracy issues in the M2.0 M&P do to the dwell time ect, ect....... Isn't this the same issue the 1st gen M&Ps had early on?

[ame="https://www.youtube.com/watch?v=Y199biklz0E"]https://www.youtube.com/watch?v=Y199biklz0E[/ame]

A couple of the changes done to the 2.0 was to lengthen the steel sub-chassis in the frame, and lengthening the front frame rail tabs.

Both of these changes, according to someone from the factory, delays unlocking of the barrel and slide. Increases the dwell (lock) time, compared to the original model. The bullet is now significantly farther from the muzzle before the barrel and slide unlock. These changes were also said to enhance accuracy.

Don't know anything about the APEX barrel. As an armorer, I try to stay within the factory specs, and don't get too involved in competition mods.

Fastbolt said:

A couple of the changes done to the 2.0 was to lengthen the steel sub-chassis in the frame, and lengthening the front frame rail tabs.

Both of these changes, according to someone from the factory, delays unlocking of the barrel and slide. Increases the dwell (lock) time, compared to the original model. The bullet is now significantly farther from the muzzle before the barrel and slide unlock. These changes were also said to enhance accuracy.

Don't know anything about the APEX barrel. As an armorer, I try to stay within the factory specs, and don't get too involved in competition mods.

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Thanks, much appreciated!

I think Apex solves a lot of problems that you could learn your way around. No amount of "upgrades" will make you a better shooter. You'll just miss a little less. Learn to shoot what you have.

ScaryWoody said:

I think Apex solves a lot of problems that you could learn your way around. No amount of "upgrades" will make you a better shooter. You'll just miss a little less. Learn to shoot what you have.

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Yep i get all of that, but no amount of practice is going to make you a better shooter IF what hes saying about barrel lockup/dwell time is true.

Every gun made is a total piece of junk according to somebody on the internet.

gc70 said:

Every gun made is a total piece of junk according to somebody on the internet.

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And most new guns shoot low and left

ScaryWoody said:

No amount of "upgrades" will make you a better shooter.

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This is a common platitude I take issue with. One can train to a very high skill level and with an inaccurate gun still be inadequate. When the equipment is all squared away, then it is all on the shooter.

90% of inaccuracy problems ARE shooter based, not gun based. However, any shooter can progress better and faster with better equipment.

In this case, I have not heard of "accuracy issues" with the new M&P2. Quite the opposite. With a stiffer frame, tighter barrel lock up and longer dwell time compared to the original model, accuracy is improved to a level that exceeds most shooters' abilities.

S&W addressed this issue and has it resolved for a mass manufactured pistol.

Now, can this mass manufactured pistol be improved upon to some degree, probably small, by expensive customized aftermarket parts custom fitted to the gun? Yup. So can almost any off-the-shelf gun, but often the expense is not worth the results if a shooter is just going to stay at an average level.

I have chosen aftermarket parts and expenses and appreciate my guns more. I can afford it and still have $$ left over for training and ammo. Yet I still cannot put a consistent 5-shot cloverleaf on a paper target at 10 yards offhand. My gun will do it from a rest, so I know whom to blame for "innaccuracy".

The best equipment helps you progress to your highest level, but if you are trading $$ on equipment for real progress in training and you don't shoot very well yet, you probably have your priorities backwards.

CB3 said:

This is a common platitude I take issue with. One can train to a very high skill level and with an inaccurate gun still be inadequate. When the equipment is all squared away, then it is all on the shooter.

90% of inaccuracy problems ARE shooter based, not gun based. However, any shooter can progress better and faster with better equipment.

In this case, I have not heard of "accuracy issues" with the new M&P2. Quite the opposite. With a stiffer frame, tighter barrel lock up and longer dwell time compared to the original model, accuracy is improved to a level that exceeds most shooters' abilities.

S&W addressed this issue and has it resolved for a mass manufactured pistol.

Now, can this mass manufactured pistol be improved upon to some degree, probably small, by expensive customized aftermarket parts custom fitted to the gun? Yup. So can almost any off-the-shelf gun, but often the expense is not worth the results if a shooter is just going to stay at an average level.

I have chosen aftermarket parts and expenses and appreciate my guns more. I can afford it and still have $$ left over for training and ammo. Yet I still cannot put a consistent 5-shot cloverleaf on a paper target at 10 yards offhand. My gun will do it from a rest, so I know whom to blame for "innaccuracy".

The best equipment helps you progress to your highest level, but if you are trading $$ on equipment for real progress in training and you don't shoot very well yet, you probably have your priorities backwards.

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Great post, i agree 100%.

FWIW, having listened to different folks from the factory at 5 different M&P pistol armorer classes/recerts, and talking to them about various things between attending the classes, it was primarily some of the 9mm models that were sometimes involved in reports of inconsistent accuracy (meaning from one gun to the next).

The .40/.45 guns were always observed to be quite accurate. The M&P was designed and built around the .40, and I remember the release of the calibers being the .40, then the 9, followed by the .357 and the .45, last. (The M&P 45 had a lot of R&D testing, as it was initially planned as a submission for the suspended/canceled USSOCOM testing in '05, which is why it had an extractor roll pin and a manual safety.)

I handled and fired a fair representative sampling of different "original" M&P 9's, 9c's, VTAC & Pro models which were tack drivers.

I never handled/fired a M&P 357, and the caliber just wasn't in great enough demand to remain in normal production, so I have no immediate familiarity with that caliber in the M&P line.

Fastbolt said:

...Both of these changes, according to someone from the factory, delays unlocking of the barrel and slide. Increases the dwell (lock) time, compared to the original model. The bullet is now significantly farther from the muzzle before the barrel and slide unlock. These changes were also said to enhance accuracy.

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If the bullet is now significantly farther from the muzzle before the barrel and slide unlock, that means it's got farther to go AS they unlock.... That's not going to improve accuracy! Do you think they meant it was farther from the CHAMBER (rather than MUZZLE)? Or did they mean CLOSER to the Muzzle?

Everything I've read and have explored on this subject -- including some lengthy and heavy discussions on other forums with folks who know a lot more than I do -- says that with a Browning short-recoil, locked-breech (BSRLB) semi-auto, additional dwell time isn't likely to matter, as the bullet will be gone before the slide has moved as much 1/10th of an inch or less The slide has to move farther than that to begun unlocking (and tilting)...

Dwell time can affect gun performance where a barrel link is the wrong length (in a 1911), when the lugs in the slide (or on the barrel) are rounded such that the barrel is forced to slip down too early, where the locking blocks or frame abutments are damaged, or where the barrel lug itself isn't right -- but I'm not sure it will matter in guns that work as intended/designed.

If the ammo is the same and the barrel length is the same length, the bullet should be leaving the barrel after the same amount of slide movement, and the bullet will typically be gone before the gun has started to or just as the barrel begins to UNLOCK from the slide Does the M&P 1.0 design allow the slide and barrel to unlock BEFORE the bullet has left the barrel? If so, some extra dwell time might help. I'm not sure that it does unlock like that, however. And even if it does, longer dwell time won't necessarily make the gun MORE accurate, if it was consistently unlocking in the M&P 1.0 version.

More dwell time MIGHT affect felt recoil and how recoil forces are passed to the frame (via the recoil springs pressure against the frame). But we must keep in mind that most of the recoil experienced and passed to the frame occurs AFTER the bullet is gone. I WONDER IF There might be OTHER reasons for these change that have little to do with accuracy?

We should note, too, that not all CS personnel really know what they're talking about on all topics. I've heard some real strange explanations coming from CS personnel over the years. In this case one of them may be giving us a good explanation, and I'm just missing some key technical point that lets me understand what is really happening. (If so, it won't be the first time that's happened.)

"Farther from the muzzle" as in beyond the end of the barrel.

The slide should not move nor the barrel unlock until after the bullet leaves the barrel. You did say that. That's the design.

Apex claims that some M&P 1.0's had slide movement and barrel unlocking before the bullet left the barrel. If this was true, I doubt it was common to all guns as not all were inaccurate. However, it may have been a problem with some guns because of (stacking?) loose tolerances in mass manufacturing. For the barrel to start tilting to unlock before the bullet leaves the barrel is a very, very unusual and unlikely situation. High speed photography shows that the bullet leaves the barrel before the slide moves and the barrel unlocks, if the locking system functions as intended.
Slomo Bullet Exiting Barrel - Mythbusters - YouTube

Tighter tolerances and minor changes in barrel geometry can delay barrel unlocking, but not slide movement (assuming use of the same recoil spring). This is what Apex claims to have done.

The fellow in the original video demonstrates this with the OEM barrel starting to unlock almost as soon as the slide moves back. However, only high speed photography could really confirm if there is barrel unlocking movement before the bullet leaves the barrel. This timing is in milliseconds, and manually demonstrating an event that takes milliseconds is probably not very accurate or scientific.

The Apex barrel appears to unlock only after the slide has moved some distance, thus a longer time after the bullet has left the muzzle. Apex calls this dwell time, although that is a term more correctly applied to gas systems rather than recoil operated systems.

Apex improved accuracy is due more to having a better fitted barrel than increased unlocking time, I believe.

That increased time would significantly improve accuracy in a malfunctioning gun with barrel movement before the bullet exits the barrel. I do not believe this has been a common occurrence or a real "design flaw" other than making tolerances a bit too loose for a small number of guns. Other problems, such as twist rate and barrel quality and dimensions caused more inaccuracy than "dwell" time I suspect. Those were corrected in the 1.0's some time ago and have been further addressed in the 2.0 supposedly.

CB3 said:

This is a common platitude I take issue with. One can train to a very high skill level and with an inaccurate gun still be inadequate. When the equipment is all squared away, then it is all on the shooter.

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THANK YOU!!! I'm getting sick of this cr@p as well. I shoot M&P's well in stock form but then I apex them and go from good to great. I think most people who say this kind of stuff don't have any experience with the products and either can't afford it and are pissy that others can, or are so set in their ways they see anything new as threatening. Its the same cr@p when someone will post a question about some new piece of gear and there's always that one post from the idiot who says "Don't bother, go spend your money on ammo and training" as if thats some kind of Obi-wan Kenobi jedi wisdom. Its not. Get over yourself. If some little accessory or do-dad is gonna make someone feel better about their shooting experience or make them more likely to train some more or have more pride in their gun... I say more power to em!!! and shame on anyone who would belittle that or try to talk down to them for wanting something different.

Sorry ScaryWoody, thats not all directed at you. Pent up aggression...need to go shooting

To the OP, the 2.0's were designed to improve the accuracy over the older ones a bit so the difference that you would see out of the APEX barrel wouldn't be as dramatic with the 2.0's as with the 1.0's in theory. The dwell time is not really a problem per-say but the issue that the APEX barrels seem to address in the 1.0's is that they stay tighter and flatter for a few milliseconds longer before it starts to tilt back giving the bullet a chance to fully exit before its thrown off trajectory. Milliseconds may not sound like much but compare to the cycle of the bullet firing the APEX barrel had something like 100 times more dwell time then the stock barrel. more than you need but....ya know. They addressed that with the 2.0 but its still not what you would call a match grade barrel. The APEX is still going to be an upgrade to the 2.0 because its got a much tighter lock up so shot to shot accuracy is going to be much better. The thing to remember with ultra tight fitting parts and super precision guns is that they are usually not as reliable. they'll drive tacks but a lot of the time are more picky about ammunition. I don't know that I would put an APEX barrel in a defense gun, in a target gun, HELL YEAH!

I haven't done any accuracy tests between my 1.0's and 2.0's yet so I can't say how much they've improved but both are more than accurate enough for defense purposes.

CB3 said:

"Farther from the muzzle" as in beyond the end of the barrel.

The slide should not move nor the barrel unlock until after the bullet leaves the barrel. You did say that. That's the design.

Apex claims that some M&P 1.0's had slide movement and barrel unlocking before the bullet left the barrel. If this was true, I doubt it was common to all guns as not all were inaccurate. However, it may have been a problem with some guns because of (stacking?) loose tolerances in mass manufacturing. For the barrel to start tilting to unlock before the bullet leaves the barrel is a very, very unusual and unlikely situation. High speed photography shows that the bullet leaves the barrel before the slide moves and the barrel unlocks, if the locking system functions as intended.
Slomo Bullet Exiting Barrel - Mythbusters - YouTube

Tighter tolerances and minor changes in barrel geometry can delay barrel unlocking, but not slide movement (assuming use of the same recoil spring). This is what Apex claims to have done.

The fellow in the original video demonstrates this with the OEM barrel starting to unlock almost as soon as the slide moves back. However, only high speed photography could really confirm if there is barrel unlocking movement before the bullet leaves the barrel. This timing is in milliseconds, and manually demonstrating an event that takes milliseconds is probably not very accurate or scientific.

The Apex barrel appears to unlock only after the slide has moved some distance, thus a longer time after the bullet has left the muzzle. Apex calls this dwell time, although that is a term more correctly applied to gas systems rather than recoil operated systems.

Apex improved accuracy is due more to having a better fitted barrel than increased unlocking time, I believe.

That increased time would significantly improve accuracy in a malfunctioning gun with barrel movement before the bullet exits the barrel. I do not believe this has been a common occurrence or a real "design flaw" other than making tolerances a bit too loose for a small number of guns. Other problems, such as twist rate and barrel quality and dimensions caused more inaccuracy than "dwell" time I suspect. Those were corrected in the 1.0's some time ago and have been further addressed in the 2.0 supposedly.

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Sorry, I just reallized that I pretty much just echoed everything you just said

I think you are right on the money. I don't think dwell time is really the right term either. I think maybe the 1.0's unlocking so early maybe was only affecting accuracy by a tiny bit because the bullet was likey already just out of the muzzle by that time. could be some of the gas that was following the bullet was still flowing out when the barrel moves and kind of blows the bullet off trajectory a tiny bit. Dunno...but traditionally a good sample of the 9mm 1.0's were, at best, a 3 in group @25yd gun and some of the samples I've seen with the semi-fit APEX barrels are like 1-1 1/2 inch so that seems to be a pretty good improvement to me. Like you, I think its more to do with being a much tighter fit barrel.

The fellow with whom I spoke in one of the armorer recerts mentioned that in the original M&P's the slide & barrel started to unlock when the bullet was typically only up to several inches out of the muzzle, but in the 2.0 the bullet is significantly further. He offered some numbers, but I don't think I wrote them down, as that sort of trivia is unnecessary from an armorer's perspective, albeit sometimes interesting trivia for owners and enthusiasts.

I'd also not be surprised to discover that sometimes a particular set of tolerances might produce some unexpected issues that are better addressed with some different parts, like a new barrel, perhaps. Or some revised specs/tolerances (new twist rate?). Remember reading about S&W replacing barrels now and again when guns were sent back for complaints about horrible accuracy?

Also, remember that delayed unlocking was something the engineers introduced in the metal-framed TSW's, claiming that it also helped reduce felt recoil compared to the standard 3rd gen's.

Lots of folks like to talk about "match-grade accuracy". The M&P, like the Glock and most other standard plastic pistols, was designed as a service-grade gun.

Longer, heavier slides and slightly lighter triggers in some of the "Practical", "Pro series", etc models may make guns easier to run in some competition venues, but it's not like they advertise them to be able to consistently produce groups of less than 2" at 50 meters.

There are probably always going to be compromises involved in deciding whether someone wants a "combat/service" pistol capable of excellent reliability, especially under adverse, extended conditions ... or a comp gun built to tolerances that are much, much tighter, capable of match-grade accuracy, but maybe not able to always run so well in less-than-optimal conditions.

I'll offer that today's engineers and engineering, with CAD and advanced CNC capabilities, are offering us some phenomenal advances over the state-of-the-art for standard/service grade pistols I was owning and using through the 70's and 80's.

Smakmauz said:

To the OP, the 2.0's were designed to improve the accuracy over the older ones a bit so the difference that you would see out of the APEX barrel wouldn't be as dramatic with the 2.0's as with the 1.0's in theory. The dwell time is not really a problem per-say but the issue that the APEX barrels seem to address in the 1.0's is that they stay tighter and flatter for a few milliseconds longer before it starts to tilt back giving the bullet a chance to fully exit before its thrown off trajectory. Milliseconds may not sound like much but compare to the cycle of the bullet firing the APEX barrel had something like 100 times more dwell time then the stock barrel. more than you need but....ya know. They addressed that with the 2.0 but its still not what you would call a match grade barrel. The APEX is still going to be an upgrade to the 2.0 because its got a much tighter lock up so shot to shot accuracy is going to be much better. The thing to remember with ultra tight fitting parts and super precision guns is that they are usually not as reliable. they'll drive tacks but a lot of the time are more picky about ammunition. I don't know that I would put an APEX barrel in a defense gun, in a target gun, HELL YEAH!

I haven't done any accuracy tests between my 1.0's and 2.0's yet so I can't say how much they've improved but both are more than accurate enough for defense purposes.

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Thanks for the replies everyone!

Fastbolt said:

I'll offer that today's engineers and engineering, with CAD and advanced CNC capabilities, are offering us some phenomenal advances over the state-of-the-art for standard/service grade pistols I was owning and using through the 70's and 80's.

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This i would agree with 100%

Accuracy issues are fixed in the m2.0.
I HAVE RANSOM REST RESULTS TO PROVE IT.
The guys gun in the video looks ridiculous it's no wonder he has issues with all that garb on there.

CB3 is blessed with common sense, experience and communication skills.
I have shot my Shield and Pro9 enough to know they are very accurate and the variable that needs the work is my technique.
I know that my Pro9 5in with the Apex FSS is much easier to shoot than my Shield, but I don't doubt Jerry Miculek could do things with the Shield that I can't do with the Pro9.
Apexing my guns doesn't mean I am hiding deficits in my technique. Lance Armstrong wasn't riding a Huffy and Dale Earnhardt didn't race a Chevy off the showroom floor.

bsmiley said:

CB3 is blessed with common sense, experience and communication skills.
I have shot my Shield and Pro9 enough to know they are very accurate and the variable that needs the work is my technique.
I know that my Pro9 5in with the Apex FSS is much easier to shoot than my Shield, but I don't doubt Jerry Miculek could do things with the Shield that I can't do with the Pro9.
Apexing my guns doesn't mean I am hiding deficits in my technique. Lance Armstrong wasn't riding a Huffy and Dale Earnhardt didn't race a Chevy off the showroom floor.

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Well said!