Cast Bullets in M&P 9

[revchuck]

Folks - I just picked up my new M&P 9 full size and was dropping rounds down the chamber to see if they fit. Factory and handloaded jacketed bullets were no problem. Cast bullet ammo that drops right into the chambers of a Beretta 92, two CZ-75Bs and a SIG P6 didn't quite do so in my M&P. The bullets here are nominally sized .356 and .3565, and could be pushed into the chamber and would chamber from a magazine and extract. The bullets showed no rifling marks, so apparently I've just got a tight throat. If it were a revolver, I'd call it perfect, since that's how bullets are supposed to fit in a round gun, but it's the first time I've had this happen in a bottomfeeder.

Has anyone else had this happen? I can see needing to seat the bullets deeper, but by how much?

I'm going to shoot this ammo as is to see how it works, and if it's really broke or if I should just leave it alone.

Edited September 18, 2008 by revchuck

[DougCarden]

Chuck, I have had no problem with jacketed or lead rounds(115rn and 122/125 fp) loaded to 1.130 in my M&P. I think the 158 LSWC that I got that were sized .356 are shorter....I dont remember...

If you can chamber then and jack it out ok I think you will be good to go

[High Lord Gomer]

What OAL are you using? I've never had that problem and probably a 4th of the 30,000 rounds through my M&P9 have been 129gr LRN that are .356 loaded to 1.125 OAL.

[revchuck]

What OAL are you using? I've never had that problem and probably a 4th of the 30,000 rounds through my M&P9 have been 129gr LRN that are .356 loaded to 1.125 OAL.

I'm using 122 grain LTCs (similar to the Hornady 124 grain FMJ/FPs) loaded to 1.05" and 147 grain LFPs loaded to 1.14".

I'll have a chance to shoot it on Sunday and plan to put 50 rounds of each through the gun, plus about 100 rounds of MG 121 grain IFPs, just for break-in purposes. The 147s are loaded with WSR primers (had a spot shortage of pistol primers at one time), so we'll see how a striker-fired gun handles those.

[rhyrlik]

You should be happy you're getting this nice of a fit in your 9mm. S&W traditionally have tighter bores and throats than Sigs and Berettas. My Beretta has a .359" throat and accepts 38/357 lead revolver bullets without any issues. I had a P226 that had a .360" throat. I could not get it to stop leading.

Edited September 20, 2008 by rhyrlik

[anachronism]

You might just have a slightly tight chamber. If the cast bullets don't show any contact points from chambering, this might be what you're seeing. As mentioned previously, if you can chamber & extract them without difficulty, you should be good to go. If you have any difficulty at all, you could possibly have pressure problems, which you can identify by watching for the usual high pressure indicators.

Edited September 21, 2008 by anachronism

[revchuck]

Update: I got a chance to put a couple hundred rounds down the tube at an indoor range. I shot two mags (34 rounds) of the 147s and one of the 122s - no problems except for one failure to fire due to the use of WSR primers in the 147s; I'm not complaining since the gun was never intended to work with rifle primers. (My SIG P6 popped those WSRs though, even with a reduced power mainspring.)

This gun literally feels like a .22 with the 147s at about a 135 PF. Since I'm about the only one on this forum who doesn't shoot so blindingly fast that I outrun the gun I might have to work with them some more when the 122s run out.