JPucci
Member
New M&P 40c has the dreaded slide "Ker-Chunk!" Has anyone solved this problem yet?
Hey all,
The title says it all...
I have a brand new M&P 40c no thumb safety, no internal lock, but it has a magazine lock that I removed without issue.
The primary observation is an intermittent slide sluggishness/"ker-chunk". When firing, you can feel and see the slide move very slowly back and then forward into battery.
At times, the slide hangs up while chambering the next round with the nose of the round seemingly stuck on the feed ramp followed by a snap into battery a couple of seconds later. For what it's worth, there are no other signs of trouble with this gun...it's very accurate if you can get past this issue.
I've put 270 rounds through her so far out of three 10-round magazines. My usual stress test before putting a pistol into my carry rotation is 250 rounds of mixed ammo followed by a box of my carry ammo, so she's seen 100 rounds of Federal 180gr, 50 rounds of PMC Bronze 180gr, 50 rounds of Herter's 180gr, 50 rounds of Blazer 180gr, and 20 rounds of Federal HST 180gr.
Out of those 270 rounds, I had three failures to feed where I had to manually clear the round, several delayed chamberings, and roughly 30-40% of all rounds displaying the "ker-chunk" sluggishness.
While cycling the slide through full magazines of ammo on the bench, there is a reasonably consistent feature of the 5th through 9th rounds have more resistance to chambering from a manual slide actuation.
Out of approximately 100 "dry cycles" on the bench, I observed 8 failures to feed, where the round was stuck on the feed ramp and several FTE's, although the FTE's don't show up in live firing, so this may just be me not pulling the slide back forcefully enough.
I know that this isn't a new problem and have done a ton of research on it in this and other forums. My best references so far are linked below and discuss all of the observations that I've experienced myself:
http://smith-wessonforum.com/smith-wesson-m-p-pistols/268843-40c-firing-issue.html
http://smith-wessonforum.com/smith-wesson-m-p-pistols/298108-m-p-40c-sluggish-slide.html
These threads are years old though, so I figured I'd start this one to see if anyone got to root cause of this behavior since then.
My best guess right now is that the magazines play a critical role in the behavior of my 40c, so I've got some new ones on order, but did anyone ever figure out if the recoil spring plays a role? I haven't had any premature lock-backs like others have had, so I don't think my slide lock spring is a part of the issue...
Anyway, sorry for the long post. Is there anyone out there that has definitively solved this problem?
Cheers,
- Justin
Hey all,
The title says it all...
I have a brand new M&P 40c no thumb safety, no internal lock, but it has a magazine lock that I removed without issue.
The primary observation is an intermittent slide sluggishness/"ker-chunk". When firing, you can feel and see the slide move very slowly back and then forward into battery.
At times, the slide hangs up while chambering the next round with the nose of the round seemingly stuck on the feed ramp followed by a snap into battery a couple of seconds later. For what it's worth, there are no other signs of trouble with this gun...it's very accurate if you can get past this issue.
I've put 270 rounds through her so far out of three 10-round magazines. My usual stress test before putting a pistol into my carry rotation is 250 rounds of mixed ammo followed by a box of my carry ammo, so she's seen 100 rounds of Federal 180gr, 50 rounds of PMC Bronze 180gr, 50 rounds of Herter's 180gr, 50 rounds of Blazer 180gr, and 20 rounds of Federal HST 180gr.
Out of those 270 rounds, I had three failures to feed where I had to manually clear the round, several delayed chamberings, and roughly 30-40% of all rounds displaying the "ker-chunk" sluggishness.
While cycling the slide through full magazines of ammo on the bench, there is a reasonably consistent feature of the 5th through 9th rounds have more resistance to chambering from a manual slide actuation.
Out of approximately 100 "dry cycles" on the bench, I observed 8 failures to feed, where the round was stuck on the feed ramp and several FTE's, although the FTE's don't show up in live firing, so this may just be me not pulling the slide back forcefully enough.
I know that this isn't a new problem and have done a ton of research on it in this and other forums. My best references so far are linked below and discuss all of the observations that I've experienced myself:
http://smith-wessonforum.com/smith-wesson-m-p-pistols/268843-40c-firing-issue.html
http://smith-wessonforum.com/smith-wesson-m-p-pistols/298108-m-p-40c-sluggish-slide.html
These threads are years old though, so I figured I'd start this one to see if anyone got to root cause of this behavior since then.
My best guess right now is that the magazines play a critical role in the behavior of my 40c, so I've got some new ones on order, but did anyone ever figure out if the recoil spring plays a role? I haven't had any premature lock-backs like others have had, so I don't think my slide lock spring is a part of the issue...
Anyway, sorry for the long post. Is there anyone out there that has definitively solved this problem?
Cheers,
- Justin
