[stalker76z]

I have shot .45 auto in a 1911 configuration for years. I started casting the LEE PRECISION #452-252-SWC, which weighs in at a nominal 242 gr. My data is 5.0 gr of UNIQUE powder with a #350 CCI primer. I calculated this bullet at approximately 775 fps although I plan to chronograph it this Spring when I can get out and shoot regularly.

I would like to purchase a new S&W M&P in .45 ACP but I am wondering if this gun would stand up to the constant pounding from this load, considering that this is a polymer frame with steel rails in the slide and other critical points.

I have used S&W pistols (SS) and revolvers for years along with Colt variants in 1911 design without any trouble. I am also a qualified S&W Academy graduate for both pistols and revolvers------- Just no experience with the "polymers."

I would appreciate anyone with experience with this pistol to please respond.

 

[Range Junkie]

I'm sure that pistol was designed to shoot full pressure duty type loads and many thousands of them. I haven't looked at your data in my manual but just off the top of my head I don't think you are dealing with any serious pressures there. The 45acp operates at some relatively mild pressures anyway as compared to some other chamberings. So, I would think you could shoot your load all you want without any damage to that pistol.

 

[JPaulF]

I do not like plastic pistols. They don't feel good to me and I think they are ugly. Still - I have never seen a verifiable report of any plastic pistol failing due to being worn out, per se. As R.J. said... milder pressures of the .45acp and good user maintenance and common sense should provide you many years of service.

 

[Riposte1]

Being in the firearms instruction business I have seen several plastic pistols broken and blown up. Dont take that as an indictment of them, I see a LOT of them shot (for instance I have seen 3 M-16s blow up and folks don't think they are particularly bad - neither do I). Guns let go from time to time, and when a plactic frame lets go - it lets go!

I have an M&P .45. I have not fired any handloads in it. Indeed I fired perhaps 500 rounds of factory ammo through it and put it away...it will just never be a 1911. But that is a matter of personal taste and how one uses the gun.

I can't say how it would hold up or even function with your load. I did have more malfunctions in my M&P during the first range session than I would have liked - but that does not amount to many - and it got better with use.

I have used both the Lyman Keith (454424 I think?) and the Lee 452-255-RF in 1911s at velocities up to 1000 fps without feeding issues. I use heavier springs for anything over about 800 fps in those weights.

Good luck with the project!

Riposte