10mm Lead and Coated Lead Question

[kramer]

Small problem. I have issues with reloading Missouri hard cast 180 grainers in both lead and coated lead. Sizing is fine, light crimp with no issues in any factory glock barrel. The problem is with my Glock 20 Storm Lake barrel. They drop into the barrel just fine if I run them at 1.233 OAL but any longer and they don't sit in the chamber deep enough. Definitely not a crimp issue as I have run dummy rounds at 1.240 with excessive crimp just to confirm it's not the issue. This is not an issue with copper jacketed since the lead is .401.

Now at 1.233 the cartridge seats fine and plunks but will not drop free when it turn the barrel over. Problem is that any shorter on the OAL and I'm getting very close to the taper on the bullet.

Any thoughts?

[TSP45ACP]

Check the chamber length dimensions......sounds like it's just a tad bit short.   Maybe within spec, but shorter than your other bbls.

[The_Shadow]

The bullet is making contact at the end of the chamber or the truing cone lead inside the barrel.
Must be a wide nose bullet design.

[kramer]

The bullet is making contact at the end of the chamber or the truing cone lead inside the barrel.
Must be a wide nose bullet design.

So if I can get everything to work perfectly at 1.230 then I'm still over the min OAL I'm good to go? I know the min is 1.2 but even 1.230 seems awfully close to the where the bullet starts to taper.

[The_Shadow]

The lead in the barrel may be cut too shallow for some bullet styles.  There isn't an issues other raising the pressures some, unless working near the upper limits.  A longer lead, can also allow bullets a little more room to jump, thus keeping pressures slightly lower.

One thing I noticed in the Bren Ten barrel was it has about a 1" lead before the rifling starts...

[Quick 2]

The Stromlake barrels don't have as deep of a throat as factory barrels do which may be you problem. The shorter throat does usually increase accuracy but if the bullet setting on the rifling that will raises the pressures. The shape of the bullet also has a lot to do with this. Try to seat the bullet you want to use a little deeper. If it comes down to it you can ream the chamber throat or have it done. But first check your brass to make sure it is the right length. I have seen brand new brass to long. 

[kramer]

The Stromlake barrels don't have as deep of a throat as factory barrels do which may be you problem. The shorter throat does usually increase accuracy but if the bullet setting on the rifling that will raises the pressures. The shape of the bullet also has a lot to do with this. Try to seat the bullet you want to use a little deeper. If it comes down to it you can ream the chamber throat or have it done. But first check your brass to make sure it is the right length. I have seen brand new brass to long.

Thanks this makes sense. I have checked my brass and I'm good with that. I'll try to seat it a bit deeper and see if that changes anything. Thanks

[sqlbullet]

They don't drop in.  Do they fully chamber if you drop a slide on them?

If so, I would just reduce 10% and work back up.  Nothing wrong with engraving on chambering as long as you don't have compromised function.

[kramer]

Ok I've done a little research and found some folks that have had issues with using cast bullets and Storm Lake barrels in 10mm. Apparently it's common to have the throat running a little too short.

The question is whether or not I should have the throat reamed since I bought the barrel to shoot cast as well as the additional chamber support. Otherwise I'd just stick with the factory barrel. What's the cost to have it reamed?

[DM1906]

Send it back to Storm Lake. They may ask for a dummy round to chamber.

[kramer]

Send it back to Storm Lake. They may ask for a dummy round to chamber.

I was thinking of the same thing. I;ll give them a call tomorrow.

[sqlbullet]

What's the cost to have it reamed?

You can buy a reamer for $66.00 and do it yourself.  I would guess if they don't do it free, it will be less than half that.

[DM1906]

I know of several that have been returned for "corrective" reaming, and none were charged (although shipping to them isn't refunded). Most aftermarket barrel distributors offer the same support. If you send a dummy round, use your most troublesome bullet, seated at full 1.260". That should cover any chamber issues you may have.

[kramer]

Update: Sent the barrel back with some dummy rounds seated at 1.260. Two weeks later the barrel shows up in a box with my dummy rounds and no paperwork. It works fine now but I have no idea what they did to it.

[PCFlorida]

LOL, they did the same thing to me a number of years ago with a .45 barrel in a Glock.