M&P 9mm compact loads?

[KentM]

M&P 9c running AutoComp and 124gr FMJ RN
The Hornady manual shows 4.2 to 4.9gr max and I'm stovepiping with anything less than 4.8. Factory FMJ ammo has no problems. The gun has probably only 300 or so rounds through it, so it is not exceptionally well broken in.

I'm using the Lee carbide three-die set which includes their standard bullet seating die, no additional factory crimping die or anything.

Is this typical for M&P 9c's? I know Hornady has a rep for conservative loads, and the M&P is rated for +P so I'm not worried if I accidentally exceed the 4.9 max by a little, but I'm curious if others have experienced this.

 

[Havok7416]

I have two M&P9cs. Both are flawless with about any ammo I run through them, including special reduced loads.

 

[NWcityguy2]

M&P pistols typically use one recoil spring for both 9mm and 40 S&W. It's a little heavy for 9 and a little light for 40. But, that shouldn't be an issue at your charge weight.

Are there any signs you are low on the pressure side? Sooty cases or maybe lots of unburned powder in the gun? If not, Hodgdon lists on their website higher maximum charges for bullets of that weight. I would recommend you look there for additional load data.

 

[mrawesome22-250]

I don't even bother looking at Hornady's 9x19 data. It is so light it becomes unusable, as you have found out.

 

[Blue68f100]

Try adjusting your OAL to correct your feeding issue.

 

[GooseGestapo]

Hodgdons lists 4.8 as a start load. 5.4max, non +P.
Try increasing powder charge.

 

[bullseye308]

Have you verified your scale with quality check weights?

 

[CMB]

I hope it's ok to say this -

I was once on a mission to find a load that had the least recoil, was still clean burning and accurate. Mainly for the wife to start out with.

Other springs are available of various spring rates. Apex tactical is one good source for M&P Supplies if your looking to fine tune and they are great to work with.

 

[Skeptic13]

Hornady is always extremely conservative on their load data. I would go to the powder manufacturers web site and look at their data.

 

[NWcityguy2]

Other springs are available of various spring rates. Apex tactical is one good source for M&P Supplies if your looking to fine tune and they are great to work with.

You'll just have to grind off the nut at the end of the guide rod and slip on a different spring. But...

I run lighter loads through my M&Ps all the time. I'm agreeing with bullseye308 that the OP should confirm his scale is accurate.

 

[NMexJim]

Not to insult, but check your grip. I had stovepiping problems with my kids until they settled into good grips.

 

[lordpaxman]

My son’s M&P 9 had to go back to the factory as it stovepiped even on factory ammo. You indicated factory ammo didn’t stovepipe so it doesn’t sound like it’s the gun or a limp wrist but just keep those in mind.

The Hornady manual shows 4.2 to 4.9gr max and I'm stovepiping with anything less than 4.8.

COL? By Any chance do you have access to a chrono? The only way to really know how your reloads are performing relative to factory is to chrono them. Autocomp is a relatively slow powder, when I’m loading with slow powders I’m typically near max to see good results. Sounds like you’re there. Good luck.

 

[rfwobbly]

Any velocity data, and/or can you describe the inside of the fired case and gun ?

Autocomp is really designed for 5" barrels with a gas compensator. IMHO, you may have a powder that 's much too slow for your gun. I'm not saying you can't make it work, but it probably won't be optimal or efficient. I bet the inside of the case and gun is sooty black, with particles of powder everywhere.

 

[Charlie98]

I'm using the Lee carbide three-die set which includes their standard bullet seating die, no additional factory crimping die or anything.

But it should have a built in taper crimp in the seat die... which is perfectly adequate.

Autocomp is really designed for 5" barrels with a gas compensator. IMHO, you may have a powder that 's much too slow for your gun. I'm not saying you can't make it work, but it probably won't be optimal or efficient.

I load for both a Kahr CM9 (3.1") and CW9 (3.6") and they take a bit of trial and error to get right. I used BE-86, not a terribly slow powder, but I hit a threshold with it where more powder did not translate to any additional velocity... and hosed me with unburnt (underburnt) powder. A faster powder was definitely in order, and has worked well for me.

 

[mmb617]

My M&P 9 compact is the most reliable gun I own. My plinking loads are nowhere near max with either Titegroup or CFE Pistol and FMJ 115's or 124's. I never have any problems. I have many thousands of rounds through it now but don't remember having many problems with it right out of the box.

 

[Dudedog]

Hodgdon data seems a bit hotter than Hornady
125 GR. SIE FMJ Winchester AutoComp .355" 1.090" 4.7 1055 28,900 PSI 5.2 1120 33,300 PSI

I would be tempted to use their data.

So according to them 4.8 is .1 above start.
So loads lower than their start might explain functioning issues.

 

[AJC1]

Autocomp is slow. Before modifying your gun please try another powder. I load for my neighbor who runs the same pistol, but he is 85. I run 4.0 grains of tightgroup on a 115 bullet. The faster powders may help your gun function more reliably. With your mid range weight a medium fast powder might be the ticket. When troubleshooting the extreme ends of the spectrum are not as easy to resolve.