GP100 cylinder issue

[mulyhuntr]

Picked up a brand new 4" gp100 the other night and the cylinder won't close with pmc bronze .357 magnums, but will with Remington and fiocchi .357's. The pmc rounds won't drop far enough into the cylinder for it to close.

The only difference between the pmc and the others is that they don't have a crimp, so I put a slight roll crimp on them and they drop right in.

My 158gr swc loads are also doing the same thing. The cases are trimmed to min length and bullets seated as far as possible,with a nice crimp, and it's hit or miss whether or not they'll fit. If I don't trim the cases beforehand, they aren't even close.

I measured my cylinder mouths at .356", with two being slightly tighter.

I put 150 rounds through it last night and it shot great.

Is it normal for gp100's to have tight cylinders and be finicky about ammo, or should I get on the phone with ruger?

 

[Snake Plisskin]

No its the PMC ammo, I had the same problem with my GP100 , they work just fine in my Smith's though, so I stay away from them in my GP100.

 

[mulyhuntr]

Ever shoot semi wadcutters in your gp100?

Another interesting thing I just tested is that a 1.284" piece of brass wont fully seat in the cylinder, but ruger's 1.275" test brass will. You'd think brass up to 1.290" max would fit?

 

[Salmoneye]

Rugers do seem to have tighter chambers than S&W (at least in my experience)...

Though they are snug, I actually have a S&W 686 that will chamber Winchester-Western White Box .38 S&W rounds...

None of my Rugers will do that...