M&P9 barrel saga

[Tod-13]

<snip>However, this is still a significant improvement over the 8” to 12” groups at 25 yards that members have reported with previous generations of the M&P9<snip>

I had a 2013 Pro CORE that was still doing the 8-12" at 25 yards, so at least some of the current generate guns still have the issue. YMMV, etc. (124 grain ammo)

[ASH556]

No, it's an established standard methodology. You won't find a top level bullseye shooter (or coach) who doesn't understand wobble zone. Shooting from a rest eliminates wobble. It also diminishes the chances (and effect) of trigger jerk and flinch. There's a reason why shooting from a rest (a) turns in better, more consistent results and (b) is used by just about everyone on earth for evaluating accuracy.

As for ignoring fliers, that's fine if you're trying to prove your gun (or your skill) is more accurate than it is. But particularly when we're talking about a model gun that is infamous for having lockup consistency issues, ignoring "fliers" is really just massaging data to get the result you want.

Well, I'm not too proud to eat some crow. I put the pistol on sandbags this weekend and shot a couple 25yd 10-shot groups. The results were revealing. Those "fliers" that I thought were me, weren't. The stupid pistol "throws" a shot or two out of every 10 round group so that what would otherwise be a 2-3" group becomes a 6-8" group.

This weekend's experience leads to this thread. If anyone cares to chime in, I'd appreciate it:

http://pistol-forum.com/showthread.p...794#post159794

[justintime]

Was Todd's m&p dated before these issues? Also are they still just as reliable or has that gone downhill too?

[Tod-13]

Well, I'm not too proud to eat some crow. I put the pistol on sandbags this weekend and shot a couple 25yd 10-shot groups. The results were revealing. Those "fliers" that I thought were me, weren't. The stupid pistol "throws" a shot or two out of every 10 round group so that what would otherwise be a 2-3" group becomes a 6-8" group.

This weekend's experience leads to this thread. If anyone cares to chime in, I'd appreciate it:

http://pistol-forum.com/showthread.p...794#post159794

Mine wasn't throwing a shot or two. It looked liked a shotgun pattern.

[ToddG]

Well, I'm not too proud to eat some crow.

Stick around long enough and you'll see all of us doing that once in a while. Thanks for the honest report.

Was Todd's m&p dated before these issues? Also are they still just as reliable or has that gone downhill too?

The issue "back then" was that the guns would shoot +p ammo accurately and to POA, and weaker ammo (like 115gr practice fodder) very high and not nearly as accurate. Smith put a barrel in mine that shot everything accurately and to the same point of aim, but very high so the gun needed a custom (tall) front sight that they produced from a 3rd gen Smith sight.

[JMS]

I personally think that the twist ain't the only thing they've jimmied with, here. Neither of mine (Feb 2009 and June 2012 guns) have ever been bad shooters, but having seen how much tighter a shooter Thing1 is since I got a fitted barrel....

Smith's only known about and getting told about the other thing for so long that I'd be Jack's complete lack of surprise if they only just got around to finally fixing the lockup thing along with altering the twist, and just continued to refuse to acknowledge that less-than-desirable lockup was a circumstance in the first place.

[98z28]

More data points.

I picked up a new pair of M&P9 full size pistols this week. Both have test fire dates in May 2013 and "single dimple" barrels.

I shot both guns at 25 yards with the stock sights off of a rest*. Each gun saw four different types of ammo: Speer 124 FMJ Lawman, Speer 124+p Gold Dot, American Eagle 147 TMJ, and Federal 147 HST. Each gun fired at least three five-shot groups with each ammunition type.

First gun (serial #HAC**36):

Speer 124 FMJ: ~3.75" max extreme spread. One group went 2". POI ~1" above the front sight.
Speer 124+p GD: ~3" max extreme spread. One group went 1.5". POI ~1" above the front sight.
American Eagle 147 TMJ: ~4" max extreme spread. One group went 2". POI ~2.5" above front sight.
Federal 147 HST: ~4.25" max extreme spread. One group went 1.5". POI ~2.5" above front sight.


Second gun (serial #(serial #HAC**56):

Speer 124 FMJ: ~2" max extreme spread. POI ~2.5" above the front sight.
Speer 124+p GD: ~3" average extreme spread. POI ~2.5" above the front sight.
American Eagle 147 TMJ: ~3.25" max extreme spread. POI ~4" above front sight.
Federal 147 HST: ~6.75" max extreme spread (with one called flier). One group went 2.25". POI ~4" above front sight.

*The "rest" was a backpack full of ammo. I accidentally left the real rest at home and didn't feel like going back to get it as I wasn't expecting much out of the M&P's. Groups were measured with a tape measure and rounded the nearest quarter inch above the actual measurement.

Not the stellar accuracy seen from my Sigs and HK's, but it is consistent between guns and across the ammunition tested. Each gun seems to like 124 grain a little better and shoots 147 grain 1.5" higher. I can work with that.

Next week I'll pick up some CTC grips and do more formal accuracy testing (with a real rest). So far, I'm encouraged.

On a side note, the triggers are the most decent of any stock M&P I have handled. The take up was initially gritty, but smoothed right up with dry-fire. The break is much more of a hard wall than a roll, but it is developing a *slight* roll with dry fire (or maybe I am just getting used to it). It will take some more getting used to. I'm spoiled by the rolling DA Sig trigger. The reset is forceful with a tactile and audible click, without any false reset.

I also picked up a pair of 9mm Shields two weeks ago that show similar accuracy and consistency across the same four ammunition types. The triggers between the Shields and the full size M&P are quite similar, with the Shields' feeling a touch heavier. I don't have a trigger pull gauge to verify that.

[Tamara]

Each gun seems to like 124 grain a little better and shoots 147 grain 1.5" higher.

Slower bullets can be expected to hit higher, so that's all cool.

[wilco423]

Slower bullets can be expected to hit higher, so that's all cool.

Is that as a result of early unlocking or ballistics?

[Tamara]

Is that as a result of early unlocking or ballistics?

Ballistics. Holds true in revolvers. (It seems counter-intuitive, but it's caused by the gun moving more while the round is still in the barrel.)