Why do bullets keep keyholing out of my Ruger Blackhawk?

Okay, some background info:

I test-fired this gun before buying it, with .38 Special +P 125 gr. JHPs. It seemed fine. The very night I bought it my house was destroyed in a fire (this was back in Feb.). My guns more-or-less survived, but most got rusted, including the Blackhawk. A friend scrubbed the rust off of it, and I Duracoated it to preserve it as a functional gun. (What the hell, at least it still worked!) I did have to disassemble and reassemble it at least a dozen times because the timing was off after the fire. Turned out the plunger on the side of the hammer that activates the cylinder latch was bent. I also installed a heavier Wolff hammer spring, a lighter trigger spring, and a Hogue monogrip.
So anyway, I have been back to the range several times with this gun, and every time it has keyholed bullets. Now, the only bullets I've fired though it since the fire have been 158 gr LSWC in 38 Spec cases. The first time it was with 3.0 gr Red Dot, the second it was 4.6 gr Unique. I adjusted the crimp for the second load, but the keyholing was still there, and very obvious after 15 yards. The bullets were Hornady, the brass various range pickups, but thoroughly cleaned.

I HAVE checked the crown, the forcing cone, and the mouth of all the cylinders, very closely. If they have ANY problems at all, they are microscopic. The bore also has no obvious problems. It's like a mirror, and I'm sure there is no Duracoating or rust in either the bore or the cylinder. I also fired the same ammunition through my Rossi 38, and it didn't keyhole then.

I'm almost out of ideas. But I did load up some .357 Mag cases with 125 gr JHPs and 6 gr of Unique (basically the same baillistics as the load I fired before I bought it.) If it still keyholes these, I might just get rid of it.

But, before I do something rash, has anyone ever experienced keyholing of 38s in a 357, or keyholing in a Ruger Blackhawlk, when it was NOT attributable to crown or barrel problems? What were the causes?

MikeJackmin said:

> I did have to disassemble and reassemble it at least a dozen times because the timing was off after the fire.

I'm no expert, but this suggests a serious safety issue.

Any gun that has been exposed to a fire may have become hot enough to alter the properties of the steel. If this gun became hot enough to set it out of time, that means it was hot enough to distort the small parts inside.

That may very well be hot enough to weaken the cylinder or the barrel, too.

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Oh, I thought of that. I did have it checked out, though I suppose I could've gone a bit further down that road than I did. The gun was never directly exposed to fire; it was in a gun safe that was in a room that caught on fire. Flames never touched the guns, though it did get hot enough inside the safe to partially melt plastic bottles in there.
I don't think the heat was the cause of the bent part, either. The plunger in question is extremely small and thin, and it is in the very center of the gun's mechanism. It would be highly unlikely for the heat at the center of the gun to be so high as to warp metal, but leave the plastic grips unaffected. I think I just bent the plunger when I took the gun apart to replace the springs.
I have fired at least 100 rounds through it since the fire, though they were all as described, and not hot. The timing is fine, and the lockup is tight. I don't intend to fire full-throttle 357 Mag rounds out of it.

moxie said:

Could be overcrimping deforming the bullets a bit. Those are relatively light loads and probably don't need any crimp at all to prevent bullet jump under recoil. Try just enough "crimp" to remove the flare from the expander step and to allow chambering of the round.

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Tried that. I tried firing the same loads both crimped and non-crimped, and it keyholed both. :banghead:

Jim Watson said:

You have "checked" the forcing cone? How?
Slug the barrel and see if there is a tight spot under the barrel threads. A lot of revolvers have constrictions there from the barrels being torqued in too tight and it is not good for performance.

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I examined it as closely as possible with a flashlight and magnifying glass. It appeared uniform.

It sounds like slugging the barrel is a pretty common prescription. I was hoping to avoid that. *sigh* Guess I'll just suck it up and do it.

Confederate said:

Whatever it is, I'd like to know, so don't keep us hanging!

How old is the Ruger, BTW? Is it stainless or blued?

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The gun is blued, made in 1982. I have other news: I tried shooting it one last time before slugging the barrel, with the +P 125 gr JHP load I mentioned above, and it DID NOT keyhole! I tried it at 15 and 25 yards, and got nice clean holes at both distances.
I now believe BCRider was right; it has to be those Hornady bullets, although it's possible the cases used may be a factor. (The 125 gr JHPs were in 357 Mag cases, while all others i tried were in 38 Special cases.) I'm loading up some 125 grain LRN at different velocities in both cases and trying those out too.