Question about reducing the OAL on a 9mm load

[BerksCountyDave]

I'm loading a 125gr flat point lead bullet in 9mm with W231 powder. Hodgdon lists the following load data:

Bullet OAL Start Vel Pressure Max Vel Pressure
125 GR. LCN Winchester 231 .356" 1.125" 3.9 1009 25,700 CUP 4.4 1086 31,200 CUP

I had loaded a bunch of these up at various charges and settled on 4.2gr at an OAL of 1.125". This gave me an average velocity of 1050fps over a buddy's chronograph with no pressure signs. I then proceeded to load about 800 of this load.

However, upon field stripping my pistol (Glock 17L with Lone Wolf barrel) I discovered that almost none of these rounds easily chambered and fell out under their own weight. A couple failed BADLY and would definitely lock the gun up if I were to try and chamber them. I assumed it was a brass dimension issue but it turns out the OAL is too long and the bullet is hitting the rifling.

I played around with a couple of dummy rounds using this same bullet and it turns out the OAL I need to be at to pass the chamber check is 1.069".

So, here's the question. Do you guys think my load of 4.2gr will still be safe as far as pressures go after seating the bullet .056" deeper into the case? I am going to load up 10 each of 3.9, 4.0, 4.1, and 4.2gr and test them at the range this week to be safe, but I just thought I'd see what you guys thought anyway. I REALLY hope it's still a safe load at the deeper seating depth seeing as I have 800 loaded and pulling that many bullets would be absolutely agonizing.

[RemShooter]

1. You are going to raise both pressure and velocity from the current levels by going to the deeper seating depth. Since you are still about 40 fps below what Hodgdon says the max load should produce, you probably still have some room on pressure as well. I would reseat 10 rounds 0.030" deeper and 10 at .060" deeper. Shoot the 030's first across screens and if they are still below about 1,090, try the ones at 060. If they are at or below 1,100 fps, you should be fine. If you really are engaging the rifling, the velocity (and therefore pressure) may not increase as you shorten the rounds and could possibly drop slightly.

2. I am more concerned that you are having to shorten these rounds so severely. The maximum allowable loaded length for 9mm per SAAMI standards is 1.169". If you are getting interference over 1.069" either your bullets have a VERY non-standard profile or your chamber is way too short. This is an issue because ammunition manufacturers are forced to assume that the guns out there comply with SAAMI and would routinely allow their production loaded length to range up to 1.169". If this is engaging the rifling in your barrel, you can run into functioning issues (at least) or high pressure (at the worst). I strongly recommend you have your chamber checked to ensure it doesn't violate the allowable minimum dimensions set for the 9mm Luger.

[max384]

Exactly what Remshooter said. He left me nothing else to say except agree with him.

Remshooter, I tried to rep you, but apparently I recently did because it said I had to spread it around first. Not too shabby for only four posts so far!

[Yoder]

Do you still have the factory Glock barrel? I would install it and see if it makes a difference. I have a standard G17 and have loaded mine to 1.150 without any problems using 115 gr FMJ RN. If they work fine in the Glock barrel maybe the Lone Wolf barrel chamber is too short.