Feed issues with M&P 40

[alphabrace]

Hello,

I am experiencing some issues with rounds not chambering but getting stuck while on the feed ramp. I am reloading

to about 1.120" length and crimping with the Lee bullet seat and crimp die. Rounds check dimensionally just

like factory rounds. Got any ideas on what I can check? I know the loads I am using are on the light side and

I thought that maybe I was not getting enough energy to push slide back long enough to eject spent round and chamber the next. I am using 155 grain plated with 4.2 grain of 231. When a round sticks I just pull slide back and it will then chamber. Anyone know if the bullet seat and crimp die differs from a factory crimp die? I am using LEE dies.

Thanks for your help.

[High Lord Gomer]

I would try the easiest thing first. Is the magazine clean and the spring strong? Eliminate any possible error caused by that.

Do they jam if you cycle them through by hand?

I had bad luck (in .38 Special) trying to seat and crimp on the same die. It resulted in a bulge just below the mouth of the case. I doubt it would be enough to hang up on the feed ramp but it is worth checking. I bought another crimp die and just used the first one to seat and the second one to crimp.

I also have had bad luck crimping too much with plated bullets. For plated I prefer to just get rid of whatever belling I did and bring the case back to straight.

[paul gilman]

I shoot a M&P 40 and find that they are very reliable. What was just said is a good starting point, but I would also chamber check all of my rounds,polish the feed ramp in direction of bullet travel with a wooden dowel of the size of the round, check all of my brass to see if it has been glocked, check and see if their might be a burr on the breach face or extractor that is catching on the round as it is going up the feed ramp.

Hope this will help get you started, the one thing I will say about my M&P is that it is very reliable.

[DougCarden]

Make a dummy round at the longest OAL you can, probably about 1.140 with that bullet. Hand chamber it as fast as you can cycle the slide. If it chambers OK then load up about 5 rounds and try that.

When I load 140gr LTC bullets my OAL is around 1.140 or so with the short bullet. Give that a try and see if it helps...

DougC

[Alfie]

I know the loads I am using are on the light side and I thought that maybe I was not getting enough energy to push slide back long enough to eject spent round and chamber the next.

I suspect that this is your problem but here are a few things to ask yourself:

Will pistol function reliably with other rounds ie - factory rounds?

Have you polished the feed ramp? Did that polishing effort change the angle?

You didn't mention case gauging your rounds. Did you case gauge? Are you possibly using "glocked" brass? If they feed manually you can almost certainly rule this out.

With you light reloads did you also change the recoil spring? My 133 pf loads won't run reliably with a factory recoil spring.

[alphabrace]

I am not sure what "case gauge" is. When you say "do they feed manually" what do you mean? What I do is put one round in the mag, load the mag, pull back the slide, hold for a moment and then release. I noticed that the slide moves forward but does not always completely chamber the round ie the slide is not all the way forward or takes its sweet time getting there. Now if the slide is locked back and I hit the release lever is will slam shut.

[bayoupirate]

If you're going to shoot lighter weight bullets or lighter loads, you're going to have to change the spring.

The gun is set up for standard 180grn factory loads.

Alfie's suggestions are all right on.

(Double check the load data for Max Load First)

Then try loading 20 rounds with 4.4 or 4.5 grains of 231.

Willing to bet you that that little bit more powder will get you over the slide inertia threshold and will cycle dependably.

Seems like that's the easiest thing to try first.

Good luck!

[Alfie]

I am not sure what "case gauge" is. When you say "do they feed manually" what do you mean? What I do is put one round in the mag, load the mag, pull back the slide, hold for a moment and then release. I noticed that the slide moves forward but does not always completely chamber the round ie the slide is not all the way forward or takes its sweet time getting there. Now if the slide is locked back and I hit the release lever is will slam shut.

A case gauge is a device that is manufactured to the specific dimensions of a .40 S&W round. If you reload you own ammo you should buy one because it will pay dividends down the road. If you case gauge your ammo you'll get an idea if the brass will chamber easily. See, there are some pistol that have a chamber that isn't fully supported and during the process of firing the brass will bulge slightly and if you reload that brass without sufficiently re-sizing it you'll end up with ammo that is slightly larger then the chamber of your pistol. This leads to a pistol that doesn't go into battery.

It sounds like this is exactly the issue your facing.

[Alfie]

If you're going to shoot lighter weight bullets or lighter loads, you're going to have to change the spring.

The gun is set up for standard 180grn factory loads.

Alfie's suggestions are all right on.

Yup!

I'm not familiar with the power factor your load is making but it sounds like you're going to have to drop your recoil spring weight.

[alphabrace]

Looks like I am getting a case gauge and a FCD. Anyone use a Lymon brand? I have only used Lee stuff but the Lymon looks good for the money. I like the set screw in the locking ring. Lee uses a nut.

[Alfie]

FCD?

Check out Redding dies also. They make a die called a GRx that does wonders for oversized brass. Thier Competition Die set is also a buy it once and use it for life set.