Shooting .454 bullets in .457 cylinder throats. Problems?

[Gunfreak25]

Long story short, using this surplus swede wood bullet powder in 45 colt. My Uberti replica has .457 throats and a .452 barrel but my biggest mould can only muster .454. So that's what i've been loading tumble alox lubed over 8-9 grains of this Swedish powder. Before I get the usual disclaimer on unknown powder usage and darwinism, this has been approached with great prudence and a lot of research on the use of this stuff. It burns very close to Unique and others here and abroad have had great success. Plus I have 15 pounds of it. It works very well, and the pistol shoots straight as can be.

My theory is the bullets are too small for a tight seal in the throats and once the primer pops and unseats the bullet, pressure just isn't there to reliably ignite the powder. So i don't think it's a powder issue, but I'd like your guy's take on this. It also suffers from light primer strikes but that's being worked on soon. Plus I believe a primer either ignites or doesn't kind of thing, regardless of how light or hard it's hit. I could be completely wrong there though, and this is contributing to the issue.

No high pressure signs, 8 to 9 grains giving light sooty loads with about 1 grain of unburned powder left in each case after firing (the bore as well). Using 250 grain Lyman 454190 mainly. Around 11 bhn

[Outpost75]

Try softer alloy, 6-8 BHN, such as 1:40 or 1:30 tin-lead, or 50-50 plumbers lead and wheelweights.

Your 11 BHN is unnecessarily hard for standard pressure loads in the .45 Colt.

Heavier crimp may help the ignition issue, but I think the real solution is to try a throat-sized bullet.

[Silver Jack Hammer]

I've read your post and I'm not sure what you're asking, are you experiencing unburnt powder and asking about the primer?

I have Colt's 3rd Gen's with the same .457"/.452" dimensions and the 454190 rolled in Alox over a medium dollop of Unique works with wheelwright alloy. Maybe it shouldn't or maybe there's better things out there but it works.

Uberti's replicas are so accurate they've cut the dimensions to the Army specs when they were handing these shootin' irons out for use with black powder on the frontier. Hence not only are the cylinder throats oversized but the chambers have a slight taper to ease ejection with black powder fouling in a dusty environment in the not highly trained hands of those who treat these guns as issued rather than purchased.

I neck resize for the Colt's, crimp at 1.6" COL and use a standard primer. I don't anneal my Starline brass. If you crimp the 454190 with too long a COL you may not be maximising your neck tension and potentially increasing your unburnt powder reside.

All in all if your boolits are hitting center in good groups then I'd just shoot it as is. I've run these guns with heavy use and not cleaned them for months just to try to make them jam. They were designed by men who fought in battle and wanted their troops to be equipped with the best arm in the worst moment.

sounds like your 11 BHN should be about right for the pressures you are running.

The .45 Colt's has a cavernous case capacity but I've found fast burning powder provides good accuracy and clean burning. Powder slower than Unique provides good accuracy with more unburnt powder but unburnt powder doesn't affect how the gun runs.

[Silver Jack Hammer]

I've found the 454190 is sized best to .454" and my current Dillon expander plug / powder funnel preps the cases for seating without undue deformation of the base of the bullet.

I did have RCBS cut me a custom seater plug that might help align the bullet a little more squarely than the stock seater plug. -Or maybe I wasted $30.00.

[str8wal]

primer pops and unseats the bullet

Crimp?

[Gunfreak25]

Thank you for the comments. I am using a firm roll crimp with the 454190's. No crimp groove so I seat past the ogive and roll crimp. Regular or magnum primers makes no difference in my case.

I just don't want to damage the bore with those unburned powder flakes being jack hammered into the rifling.
If I recall powder granules can be very hard.

[9.3X62AL]

If I recall powder granules can be very hard.

I thought about this after I read it. My thoughts are that if the powder kernels are going to embed in anything, it would be into the far-softer-than-barrel-steel bullet metal. In any event, I think the bullet's passage pushes out any debris in the barrel in front of it. What we see in the barrel as powder debris is remnants of the prior shot, and little if any more.

[Piedmont]

There is always some gas leakage past the bullet when you shoot a gun. Remember those slow motion shots in Guns & Blammo? So I think any powder would be blown away before the bullet got there.

[scattershot]

If the primer goes off and doesn't ignite the powder, I would suspect the powder. Those wooden bullets were a wartime expedient for practice ammo in WWII, and may not have been stored properly for all these years.

Your other question, about the bullets, I have a S&W M25 in .45 Colt with the large throats, amd it does fine with .454 bullets. They have to be pretty soft, though.

Good luck!

[DougGuy]

My Uberti has .4565" throats and I use 9.0gr HS6 under the 454190 sized to .456" in 50/50+2% alloy with SPG lube. I had to make a custom expander plug to get the neck tension right but the gun shoots lights out and never leads, it leaves a tiny bit of powder and lube residue in the bore and that's it. You can get that mold to drop at .457" and size to .456" or whatever will go through the throats. I honed out a Lee die to .456" and that worked great. That cylinder should have fairly even throats since they don't cut cylinders the same way Ruger does.

I think the bullet's passage pushes out any debris in the barrel in front of it. What we see in the barrel as powder debris is remnants of the prior shot, and little if any more.

Exactly. A "seasoned" bore it is, and can provide lube to the front side of the bearing surface as the boolit travels. I never clean mine they are what is called a "black bore" when there is enough residue in there to turn a patch dark gray almost black with residue, this is both a desirable and PERFECT condition for shooting cast.