Cactus Plains bullets keyholing in my 357 Mag

[Garand]

I recently had a problem with Cactus Plains .38/.357 130 grain RN keyholing and Bruce (who owns Cactus) and I discussed it frequently since I'm a member at his club. He blamed my heavy crimp, I said the bullets didn't like Red Dot, I changed powders and the problem went away. Same thing happened with his 9mm 147 gr bullets about 10 years ago, same solution try a different powder.

In my Cowboy pistols I'm using 4.1 grains of Unique pushing a Cactus 158 gr RNFP and with my Cowboy Rifles I'm using 5.1 grains of Unique pushing a cactus 158 gr RNFP, both have given me no problems. I've been using Bruce's bullets for 21 years now.

 

[buckbrush]

.355 Is way to small for a .38/.357, it is to small for any 9mm I have used also.

 

[Boomer]

Keyholing aside, a revolver's best accuracy is realized when the bullet diameter matches the chamber throat diameter. Measure your chamber throats and go from there.

 

[Slapshot]

I'm a bit new at this, is the chamber throat the end of the cylinder, in front of the barrel?

 

[Boomer]

I'm a bit new at this, is the chamber throat the end of the cylinder, in front of the barrel?

Yes, the chamber throat is the portion of the chamber at the front of the cylinder. Where the bullet enters the bore is the forcing cone which if one pictures it in exaggerated terms, looks like the opening of a funnel .

 

[kjohn]

The keyholers are "warning shots".