Can't chamber 0.400 lead boolts in STI?

[ChrisCbr]

I have an STI Edge 40 S&W. Actually built up from a short block kit from Brownells. Long story short, cast boolits (180gr, powder coated and sized to 0.400) will not chamber in my STI correctly (crimp etc is fine). It's as though the chamber tightens slightly towards the throat. The only way I can get reliable chambering is to run the loaded ammo through the Lee factory crimp die which has problem due to slight swaging of the boolit.

So, is this a known matter and are there suitable chamber and or throating reamers to sort this barrel out?

[bobthenailer]

IF you have a gunsmith fit match barrel ? they are usually slightly short chambered or also some stock factory or pre fit match barrels may need the throat/lead lengthened to accept cast Jacketed my be OK, you may have to use a finishing reamer to recut lead/throat or even chamber demsions just a few thousands .

[runfiverun]

does it chamber the same boolit without the powder coating?

most of the newstyle pistols come without throats now days.
I dunno who or why or whatever but I guess it saves a nickel or sumthin, but it has kept me from buying a few new ones.

[bigarm]

Interesting. I have a factory STI Edge and it chambers my powder coated 200 grain bullets with no problem. In fact, I load them long at 1.18.

[Iron Mike Golf]

Maybe use a Sharpie or some Dykem on the boolit and case and see exactly where the contact point is?

[Blammer]

brass too long?

[Moonie]

I'm thinking it might be a crimp issue, measure a cartridge that will fit and one that won't at different places on the cartridges and compare the results. I'm sure you will find the one that won't fit is either under or over crimped.

[fredj338]

Check OAL, make sure you are not into the rifling. If it will chamber a .0400" jacketed, it should chamber the same dia lead bullet.

[Jupiter7]

IF you have a gunsmith fit match barrel ? they are usually slightly short chambered or also some stock factory or pre fit match barrels may need the throat/lead lengthened to accept cast Jacketed my be OK, you may have to use a finishing reamer to recut lead/throat or even chamber demsions just a few thousands .

I think you're onto something. If this was a factory STI barrel sold as a part it is short chambered. They need to be chambered and throated.
My factory built eagle will feed wide meplat bullets powder coated sized .401 at 1.18 all day.

[ChrisCbr]

Throating is good, I can chamber out to 30.70mm OAL. I suspect the reamer I used to finish the barrel (it was short chambered) is very conservative. Perhaps ok for jacketed ammo. Catches up on the case mouth and section where the projectile is seated when almost chambered. The round goes in backwards fine.

[bhn22]

forgive my asking, but jacketed ammo functions fine? If so, check and make certain your cast bullets are seating straight in the cases. I've seen a number of instances where the bullets are slightly tilted in the case, and that doesn't work well with tight chambers.

[ChrisCbr]

Jacketed bullets are sized similar to 0.398" so chamber without issue. Ammo loaded with jacketed bullets can also be run safely through the Lee factory crimp die as a general rule. But no, the lead is loaded straight but thanks for the thought.

[MT Chambers]

Use your "LEE Factory crimp die" and crimp the **** out of it.

[ChrisCbr]

Results in key holing and flyers due to swaging of the lead projectiles....

[bhn22]

It sounds like you've covered the bases. A slightly more generous chamber may be necessary.

[ChrisCbr]

Yeah, that's my thought also. Good to check though, thanks for the feedback!

[DougGuy]

I often have to make a piloted aluminum lap and use compound to finish what the throating reamer started. Some barrels exhibit a springy quality in that I can use the same exact reamer that I -just- got done reaming a cylinder with, and a .4525" pin gage goes right through the throat where the reamer just cut, but some .45 ACP barrels will let the reamer cut the rifling then the same pin gage won't go into the throat. Seen it more than once, the flutes act like an expanding mandrel when they are cutting the rifling and they leave just a hair of the rifling in the barrel and this will stop the pin gage from going in the throat, it will also stop a boolit from going in the throat.

For these barrels I make me a custom piloted aluminum lap and use fine valve grinding compound to lap out the nubs of the rifling where the reamer didn't cut them all the way off. Gotta do what you gotta do.