.356 or .355 diameter 9mm for a SIG MPX

[mstamper]

I have been loading 124 grn 9mm .355 blue bullets for my SIG mpx. I have a fellow shooter says to go to a .356 diameter bullet as the sig barrel would like it better.

 

Can anyone comment on this? is .001 really going to make that big a difference in shooting / recoil / cycling the weapon?

[lcs]

The MPX chamber is short and tight.  Stay with what you have.   If your load is accurate, knocks down steel, and cycles every shot, do not change anything.   

[Acer2428]

Try it. a bag of bullets is cheap. No one going to be able to tell you what your gun is going to like. 

[mstamper]

15 minutes ago, Acer2428 said:

Try it. a bag of bullets is cheap. No one going to be able to tell you what your gun is going to like. 

I get that. I was more wondering if .001 diameter difference in the grand scheme of things is really worth the effort.

 

I know a lot of guys who are running blazer 115 factory plated and love it. I like to reload and like the blue bullets. I also like to not be at the whim of a ammo manufacturer if they decide to change the load or weight or anything else with their rounds and now I have an issue.

[Gregg K]

I'm running .356 Ibejihead bullets in my MPX. I have not seen anything short or tight in my MPX chamber. My PSA is stupid short but not my MPX.

The old school of thought is .355 for hard jacket bullets and .001 over for lead. Tight is better than loose. Some of the PPC shooters run a .355 barrel with .358 bullets for the best accuracy.

Try them in your gun and see how it patterns. My revolvers ran cleaner with larger diameter bullets. If you can make an MPX shoot cleaner and have to clean it less then it would be time well spent testing.

[Les Snyder]

anecdotal... my P35 High Power did not shoot very accurately (two piece factory barrel) with factory loads....when I slugged the barrel, it slugged .356+... loaded with 135grain  38super .357 projectiles it would shoot 50yd Bianchi plates