645 Accuracy Issues

[Tony2much]

I finally had a chance to take my recently acquired S&W 645 to the range today and I was honestly somewhat disappointed. I punched one ragged 2" hole in my target @ 7 yards with my Springfield XD45 and normally do as well with my full size M&P 45, but couldn't group less than about 6-8" (with a couple of flyers @ 10-12") with my 645 (WWB ammo). I realize it's a different animal all together being solid metal, having different sights (RRWO) and having a very different trigger feel, but I was expecting to do much better.

I noticed that the slide is not as tight to the frame as my other guns and has a tiny bit of side to side play. Is this normal or could this be part of the problem? The gun looks like new otherwise and "functioned" flawlessly, however when I let my wife shoot it, she did have one FTE.

I've heard so many great things about this model in particular and I'm no where near ready to give up on it, (so before you ask, it's not for sale ), but wondering what I can do differently next time. Maybe just more range time to get used to it or possibly something more serious?

 

[kpoesq369]

Did you try new springs? I did that to my 4506 and the groups tightened up considerably. I think the 2 most important are the recoil spring for consistent slide function and the firing pin spring for consistent ignition. Worked well enough I sent away to Wolff's for spring kits for all my autos!

 

[t-bird]

I kinda had the same problem with my 645 back in the summer, but my groups weren't has bad as yours. I hadn't shot it in a couple of years and It took awhile to figure out it was the trigger and not the gun, I've only been shooting my 1911's the last few years. With some practice and range time I can now make one big hole. I've had my 645 for over twenty years now and back in the nineties I put thousands of rds through it with no problems. My was a little loose when I got it and has not changed any over the years. Best of luck and hope this helps some.

 

[Tony2much]

Did you try new springs? I did that to my 4506 and the groups tightened up considerably. I think the 2 most important are the recoil spring for consistent slide function and the firing pin spring for consistent ignition. Worked well enough I sent away to Wolff's for spring kits for all my autos!

I've not replaced anything. I just bought it about a week ago and this was my first outing with it. It essentially looks like a new gun, but now you have me thinking about the springs. While it looks new, I'm sure there has to be at least some fatigue on the springs after being compressed for 20+ years.

I didn't realize that fatigued springs could affect accuracy. I just checked Wolff's and they have the individual springs and kits. Is this something I can do it myself? The recoil spring is obviously an easy replacement, but I've never replaced a firing pin spring (although, I had no problems with light strikes or with the gun not firing).

Thanks!

 

[jimmyj]

Hi:
6-8 inch group at 7 yards ! Flyers at 10-12 inches !
I would consider something beyond springs.
1. muzzle crown
2. barrel set when in battery
3. slide rails
4. loose sights
5. try a different manufacture ammo

 

[Tony2much]

Hi:
6-8 inch group at 7 yards ! Flyers at 10-12 inches !
I would consider something beyond springs.
1. muzzle crown
2. barrel set when in battery
3. slide rails
4. loose sights
5. try a different manufacture ammo

Kinda what I was thinking too Jimmy. It may be something a little more complicated than I am able to fix myself. It's just that the gun looks so darn nice, how could it possibly not be accurate?

I think I am going to change the springs as a matter of just good maintenance and to at least eliminate that possibility, but I will also fall back on some other troubleshooting advice that I've read in previous posts in this forum.

I should probably shoot it from a rest to see if that tightens the groups, as well as let someone else (experienced) shoot it and see how they do. If the accuracy continues to be poor, I may need to send it to S&W service to let them take a look at it.

 

[k22fan]

Hi:
6-8 inch group at 7 yards ! Flyers at 10-12 inches !
I would consider something beyond springs.
[...]

Indeed. Ignoring the flyers that equates to 21" to 29" groups at what used to be the standard pistol range distance of 25 yards. The ONLY explanation for being unable to keep shots on a 25 yard rapid fire target is human error. Other than a trigger job, fiddling with the mechanics of the pistol is pointless. Only three things will help: practice, practice and more practice.

 

[LVSteve]

Was this from a rest? I don't trust my handgun skills enough to pronounce on the accuracy an unfamiliar weapon when shooting offhand.

 

[twin40fives]

The less tight slide was something that I had trouble with on a 645 that I owned. I had 4 at the time and this one in particular, while it looked cosmetically great, had very lousy range performance. The slide rails seemed overgapped for the frame, almost like it was not the original slide or something. If I didn't have the others to compare it to, I may have not seen how well fitted they were supposed to be. The other 3 are solid performers. I let go of the one in question.

 

[KevinCH]

Was this from a rest? I don't trust my handgun skills enough to pronounce on the accuracy an unfamiliar weapon when shooting offhand.

^^^^^^ +1 for this ^^^^^^
I would try shooting the gun on some type of rest, and try different ammunition before I dived in too deep or made any conclusions.

 

[rbert0005]

How does it shoot off of a rest?

Bob

 

[Tony2much]

I only fired it off hand and have not tried a rest yet. The next trip to the range will definitely include a couple more types of ammo and a rest. I am usually a decent shot and do very well with my Springfield XD45 and M&P 45. This is why I'm so concerned. I am having a hard time believing it's all on me, but it is a very different gun from my polymer autos. I'll follow-up with my findings when I go to the range again this weekend.

Thanks for all the responses!