9mm OAL in RIA

[dpart77]

Hey Guys

I ran into a little snag today. I was loading up some 9mm rounds I tested the oal in two of my nines (Taurus, S&W M&P) at 1.08in both rounds slid into the barrel and did not engage the rifling. Just for kicks I checked out that oal in my RIA 9mm. To my surprise I had to reduce the OAL to 1.04 in order for the round to not engage the rifling. I am using Missouri 125g small ball over 4.2 grains of Universal. I did some quick math and found that at 1.04" the powder is being compressed by approximately .02". Am I crazy or does this sound Waaaaay to sort for safe shooting? I also ran into the same thing with some 125g FMJ FP I got from Midway a few years ago, they are also very short to properly chamber in the RIA. I know that all gun manufacturers cut their barrels differently but this is kind of strange. Oh, I just tried some factory 147g HPs that will not fully chamber in the RIA. Kind of looks like I will have to use 115g bullets from now on.

Any comments?

Thanks

 

[rfwobbly]

These are the kinds of issues that show up with "short chambered guns" and lead bullets. Don't feel badly, I have a CZ SP-01 that's just as picky. Sometimes they foul on the diameter, sometimes they foul on the rifling. If you'll paint the bullet nose with a felt tip marker and then twist it back and forth in the chamber the offending area will show up easily.

This cartoon will show you what's going on....


You can load these 9x19 cartridges really short and they do good most of the time, but you'll be restricted to those very short OALs. If you want to use longer OALs, then you'll be confined to Round Nose and a couple of rounded ogive Hollow Point like the Gold Dot.

Berry Mfg has a very nice selection of RN and their slender ogive profile will usually allow you to pick the OAL of your choice. In fact if you call them, Berry will send you a 124gr bullet selection kit! Zero and Speer also make very nice HPs that also work well. If the Missouri small ball gave issues, then the Hornady XTP and other sharp shouldered conical FP may not be for you.

Hope this helps.

 

[918v]

You are not engaging the rifling. You are engaging the south edge of the freebore.

 

[LiveLife]

OP maybe experiencing two types of bullet "fouling" with two different bullet types he used:

"I am using Missouri 125g small ball"
1. Maybe hitting the start of freebore with the "rounded" bullet nose base of the 125 gr RN Smallball that's .356" in diameter.

"I also ran into the same thing with some 125g FMJ FP I got from Midway"
2. As indicated by rfwobbly's nice pictures, 125 gr FMJ FP maybe hitting the start of rifling.