+P in M&P 38?

[NSEGE]

I have a 1947 M&P 38 in very nice shape that I prefer as my carry gun these days. I also have some handloads that produce 900 fps w/Hornaday 140 g XTP's and the same load produces 1040 fps with 150 Keith cast bullets in a 4" Colt OP. Are these loads OK for carry in this "transition" M&P?

[murphydog]

K frame .38s first had what was considered to be "modern" heat treatment back in the 1920s, and by report model stamped guns (ca. 1958) had different metal technology such that the factory used to rate all steel K frames as approved for +P .38.

The load you describe does not sound excessive, but if you ask the factory if it is safe in a 70 year old gun with an unknown prior history they will tell you a definite "no". If you see no excessive pressure signs with firing, however, occasional use will probably be perfectly safe, but as noted above caution is a good rule.

If you disclose the powder and charge you are using, one of the handloaders here may be able to quote a pressure and give more information.

[NSEGE]

Well, I did fire a few of both bullets. Load is 6 gr. of VihtaVouri N350, WW case, WW std. primer. Tip the gun up and the cases fall out of the chambers, no other signs of pressure.

By the way, I use VV powders for all my loads w/cast bullets, with one exception: I use IMR 4227 in my Uberti 45 Colt. These are the only single-base powders available for pistols anymore.

[Dpris]

You might get more discussion if you post this in the appropriate revolver section.
This is the M&P pistol section.
Denis

[jakebrake]

I would not do that unless my life absolutely depended on one shot and one shot only.

[cowboy4evr]

NSEIGE , I believe that the " Nobel Sport / Vectan " powders are single base as well . They are quite a bit less expensive and I read good reports from users . Regards, Paul

[epj]

Probably not an issue unless you plan on running thousands or at least hundreds of plus P rounds thru it. Many K frames stood up to 38/44 loads back in the day. The plus P stuff is nowhere near as hot. A box or two isn’t going to destroy the gun.