Problem with security six; keyholing

[Sacramento Johnson]

Hi!
I recently picked up a used 2 3/4 inch barrel security six, cleaned it thoroughly (barrel was clean) and then took it to the range yesterday. I put some buffalo bore 38 spec.+Ps; the 158 grain with gas checks, through it, and out of 18 rounds, the last eight appeared to keyhole at 8 yards. The accurrancy of the first 10 wasn't much, either, but atleast went through the paper straight. Afterwards, I looked in the barrel, and the fouling streaks seemed to not match the groves/lands, but veer off them the last 3/4 inch of the barrel.
This is my first 'six', and am wondering if the barrel is no good.
(I've shot this ammo out of newer Ruger models/revolvers without any problems.)
I've never had this problem before with any revolvers or ammo (factory or handload). Thanks!

 

[dbarale]

Either the barrel is heavily fouled with lead deposits or it is bulged. You're gonna have to clean it really well before you can determine what's going on.

 

[Pinecone]

+1 with dbarale! Clean all of that leading out of the barrel and take a real good look at your "forcing" cone. Problems here will also cause your "keyholing"!..........................Dick :wink:

 

[protoolman]

I agree that a full cleaning is in order to start. I would also look at the bullets and see if they are sized to .358 correctly. Also try shooting a different brand of bullet either lead or jacketed and see if they peform well. You may have a bulged barrel but I doubt it, don't get discouraged just work through it.

 

[Sacramento Johnson]

Hi!
There was no lead in the barrel or forcing cone initially; I made sure of that when I initially cleaned it. As for leading now, didn't see any significant leading at the forcing cone; will look closer there and especially at the distal barrel when I clean it. (As for leading, this ammo, with it's copper gas check, hasn't leaded other barrels up in the past.)

 

[dbarale]

Really interesting. Any chance you could take some pics of the forcing cone and bore?
Also, is the gun chambered for .38 or 357? Any crud in the chambers? Any chance that you could retrive one of the fired bullets?
I'm wondering if the gas check cup is somehow getting damaged before entering the barrel creating a really weird "flight pattern"?
How is the accuracy with other loads?

 

[arfmel]

+1 for trying some other ammunition. Particularly something with no gas check.

 

[Sacramento Johnson]

Hi all,
Well, I cleaned it up today, and there wasn't any leading in either the cylinder (no significant crud, either), or barrel (including the forcing cone). What I did find were several small spots of corrosion in the barrel distally that I had missed seeing earlier. (sorry, I can't do pictures) No bulge noted to the naked eye or touch.
I'm waiting for some different self defense ammo to come in next week. I'll try it with that ammo (Remington Golden Sabers 38 spec +P), and see how it shoots. Either way, will give some thought to sending it to Ruger for a rebarrel.
(BTW, it's a 357.)

 

[dbarale]

Could the specs of corrosion actually be copper fouling? That would explain why you missed them earlier and could definitely be related to the keyholing.
Long shot here but I wonder if the gas check cup is getting caught on the shoulder in the chambers?
You mentioned using the same ammo in other guns, were those chambered in .38 or .357?

 

[Sacramento Johnson]

Hi,
These spots aren't on the edges of the lands like I've seen in other barrels after shooting jacketed ammo.

I don't know about the gas check coming off in the cylinder. I do remember one late shot on the target whereby there was a crisp round hole merged with a jagged oblong one; it made me think the gas check and lead bullet had separated, and gone through the target next to each other. None of the rest of the keyholed shots looked like that.

All the other Ruger revolvers that I fired this ammo in were 357.

 

[Doxadude]

Not that I can be of much help with your problem... but I was curious... do you work in medicine?

 

[dbarale]

Not that I can be of much help with your problem... but I was curious... do you work in medicine?

LOL, I was "distally" wondering the same thing...

 

[winchesterbilly]

Not to act like I know anything, But I'd try shooting standard velocity rounds thru it. It sounds like the bullets are tumbling. It just may be that the bullet at high velocity in that snub barrel is not stabilizing by the time it leaves the barrel. Again, JMHO!!! Good luck! :?

 

[Sacramento Johnson]

Hi all,
Yes, Doxadude and dbarale, I do work in medicine!

I can't imagine that the velocity would be the culprit, as the revolver is marked 357 (and thus should be able to handle fairly high bullet velocity as found in 357 ammo), unless there was also significant metal wear in the barrel (which may be the case).
I'll test out some different 38 spec +P ammo next week, hopefully.