SPR1

What is the best way to fix it? Thanks

I did not say I shot it using a staging method, it is just a way to describe where in the pull the problem exists. The weight just increase more and the pull is creepier there than I am used to experiencing. If you gave it to the average Joe, he might not even feel it. In the cycle of operation, the cylinder carries up, locks, and then the pull gets creepy. I put another factory Smith mainspring in it and the pull has the same characteristics, just at a lower total weight. On another forum, a guy suggested the width of the hand and it dragging past carry up. Thoughts on that?

I picked up a new in box 20 year old M15 (S&W Heritage series with Turnbull color case hardened frame). The double action pretty much sucked out of the box.... Yes, I am a heathen and I am shooting it..... When I took the factory grips off to wipe it down I discovered some light rust. That helped me rationalize shooting it. I slicked up a few burrs inside, put a 14 pound rebound spring and a different factory mainspring in it. This work has dramatically improved the trigger pull. As has firing and dry firing it about a thousand times. But, since new, the final stacking portion of the pull, where you could stage it, is much more of a creepy, hard, increase in pull than any other Smith I have had. I am wondering if this could be insufficient clearance between the DA sear nose and the trigger? Thoughts?

Just remember the 10-8 test was a statistical sample of one for the "new" barrel, which externally looks exactly like my late 2010 barrel that shot like crap, technically speaking.. However, my KKM barrel turned my M&P into a favorite......

A bit of purple Loctite will allow you to run lower torque without it coming off

If it ever fires with the bolt not locked enough to contain the force (pressure times area) i.e. bolt thrust, it will be a very bad day.

I would first replace the recoil spring assembly if you have not already. Then I would send it back to Smith if that did not work.

I believe the accuracy will degrade before the pistol stops functioning properly. The M&P suffers from early unlocking based on barrel lug geometry. The recoil spring strength will affect how long it stays in battery. I changed my recoil spring at 3500 rds when I noticed vertically displaced fliers from a good shot call. The problem went away and I was back to shooting round groups. I also have a KKM barrel and that cut the group size in half from new. The factory barrel really strung things out vertically, I shot that barrel for around a thousand rounds before switching to the KKM. I hope Smith fixes the accuracy problems soon, because I want another one..... Ps. How many dry fire slide racks do you have on it? That would add to the 1500 rds. If it is not that many, your spring should not be worn out, and I would send it back to Smith.

Source? Not to knock ya, but I have first run of M&P 9pro (with had broken striker pin) and a newer M&P 9pro and both shoot under 3 inches for me with my loads at 25 yards with rest. The early ones, prior to the introduction of the compact were fine. The later ones are hit or miss (pun intentional) for accuracy. That is one reason I got lucky with my drop in barrel, others report no improvement from a drop in. There have been detailed discussions on replacement barrels and M&P problems on M4c and pistol-forum. The early unlocking is actually very broadly known. The best data comes from Randy Lee of Apex tactical fame. He has performed high speed video tests to document the early unlocking and is developing a gunsmith fit Barsto barrel to cure it. This is on the Apex website blog. Like I said, I love the M&P platform. I believe it has incredible potential.

Smith changed the barrel for commonality with the compact and now the full size guns and 5" guns unlock prematurely. Hence the vertical stringing. My 5" sucked out of the box. 5-6" groups at 20-25 yds. I dropped in a KKM barrel and the groups shrank to 2-3", or solid Glock territory. The 115's shoot poorly, Federal 124 AE shoots the best. My understanding is that Smith is working on unscrewing the accuracy problem that they are getting more and more bad press on. I want to buy a 4.25" gun, but won't until they sort it out. That said, I love my 5" Pro, and with the KKM barrel, shoot it better at speed than my Glock 34.

Thanks. I was looking for info on recent 4.25" ones.

How are the recent production ones shooting?

I had occasional problems with the follower hanging up, so I went to take the mag apart to bevel the follower and was somewhat frustrated in trying to get the spring out of the way to remove the baseplate, so..... I dropped a piece of nylon twine down through the mag catch hole, pushed the baseplate over far enough that i could get to the twine and I tied the twine around the most accessible coil. I pulled the twine back up through the hole in the mag body and and the follower slide right off. How do others do this? I also took a small round file to the corners in the baseplate.

I gave my KKM barrel a whirl today. First, I don't think I have ever seen a better finish in a handgun barrel other than possibly my HK's. The rifling does start close to the shoulder, I had to force a reload out that would not allow the barrel to go into battery. These shot into about 1.75", so I can't wait to try them with a shorter OAL. Now, the good news..... it turned patterns into groups! I am a happy camper. It seems to be a consistent 2.5 to 3" gun now at 25yds. Before I would sometimes see 4" plus.

I just ordered one for my 9mm Pro..... fingers crossed.....