I have had numerous reloading problems in 9mm, so I reset all my dies today and started from scratch. I am now using Redding carbide sizer, Redding competition seater, and Redding taper crimp on my Hornady LNL AP with the new "univeral" ptx for the powder drop stage.

Previously I had loads which ran fine in a 5906TSW, but completely locked up my 952 and my M&P9c. Today I created some dummy rounds which drop freely into the Wilson case gauge, the 5906TSW barrel, AND the 952's match barrel. But no go on the M&P9c. If I push a little, I can get the round completely chambered, but it doesn't drop in and out like the other three chambers.

I know that technically S&W says you aren't supposed to use reloads, but this is ridiculous. Is is possible that the chamber came out just a bit too small? I have put a few hundred rounds of factory hardball through the pistol and a box of jhp's with no problems, but when it comes to these reloads it is choking. If my rounds fit everything except the 952, I would chalk it up to the match chamber or whatever, but this is not the case.

If I explain all this to S&W do you think they will just fit a new barrel? Does the M&P9c even need it fitted, or is it a drop in? Will they likely want the whole gun back?

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NRA Benefactor Member

All barrels aren't the same as you are finding out. You need to reduce the OAL for the 9c until it drops into the chamber freely. If you want the chamber longer you will have to get it reamed. Good luck with whatever you decide. BTW which bullet are you using? It's possible the bullet profile is wrong for the 9c.

It is just a plain 124 LRN (from Dardascast, probably the Magma mold) I have them seated to 1.100, but in previous experiments I was seating as deep as 1.065 and I was still having feeding problems.

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Googled OAL for 9mm compact. Didn't find much but did find a comment that some of the 9mm compacts are "short-chambered." If that's the case then you have to make the decision to either reduce your OAL's for this pistol or have the chamber reamed. You can contact S&W and see what they suggest. Another possibility would be buying a replacement barrel from Storm Lake.

Hmm, if the barrels for M&P are usually drop in, maybe the factory will just take this one back and send me a different one. I don't want to spend that much on a match grade barrel for my little plinker. I got the M&P9c for fun, so that barrel looks great, but I can't imagine how much more accuracy it would wring out of a 3.5" tupperware gun.

Although I will search the threads to learn more about them. Its great that people are making aftermarket parts for M&P now.

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It could be the LRN bullets your using are hitting the end of the chamber, where FMJ bullets are more tapered and fit down into the chamber. Make sure your reloads are the same OAL as the factory FMJ. I'm sure if you take out the barrel and try the two, you'll be able to see the difference.

Excellent move on the Wilson gauge. The chamber/leade may in fact be a wee bit off. However, the fact that the weapon accepts factory ammo hints that the chamber is within SAAMI specs and the fault is probably with your handloads. The fact that the 952 now accepts your loads suggests you're on the right track.

Have you miked the bullet for diameter? Tried another bullet design? Tried plated bullets? I've had a preference for truncated cone style lead bullets in the 9mm. Most of them have a wider lube groove and produce less leading as well as feeding through almost everything.

They're going to want the entire weapon, but since they're paying the freight both ways, no big deal.

Finally got around to replacing the barrel when Midway had them in stock, and rounds which were tight in the other one drop in and out perfectly. I need to shoot it to confirm functioning, but looks like that is all it needed. Must have been a super tight chamber, and the normal tolerances of ****** 9mm brass and lead bullets must have stacked up too much at times.

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Waste of money. 124gr have a longer ogive. I had a 9mm with the same problem.

I went to my local GS and he ran a reamer in for free. 5 minute job.

Worked fine.. spent my money on more ammo.

Usually it's a matter of little or no throat in these new 9 mm's.
When the chamber ends the rifling begins, the bullet runs into the rifling before it can fully chamber. keep seating the bullet deeper untill it will fully chamber or A gunsmith can fix this easy as pie with a reamer and you can keep the barrel as a back up.
Gary

You got it solved 5 years after running into the problem?
Good for you.

I would have colored the offending cartridge with a magic marker, chambered the round and looked to see where the ink rubbed off.

I expand my 9mm brass with a 38 S&W Lee PTX plug so that I can seat lead bullets without swaging them. That leaves the rim a little wider than the M&P 9 barrel likes it so I run the cartridges through a taper crimp die. The bullets plunk into the barrel with ease after that.