Cylinder Gap on Ruger Super Blackhawks?

[jam66]

Does Cylinder gap on a Ruger Super Blackhawk affect accuracy? Say if one revolver has a cylinger gap of .0025" and th other is .004" , is the .0025" gap going to make one more accurate? Does the Gap affect velocity? Whats the normal range for a SBH?

 

[airwin]

Hi jam66, as I know, the cylinder gap has only little or no effect for precision. The measurements given by you are great and very closely, I've never seen a Ruger revolver whitch had such a narrow gap. Usually a gap of 0.06 is fine and common, for Ruger revolvers rather more. For good accurracy is more important the alignment of barrel and cylinder and an accurate, tightly throat. The gap affects the velocity only slightly, because when the powder is burning in the cartridge there is so much gas excess that the gap hardly plays a role.

 

[airwin]

One more thing: There are several factors which are important for the precision of a revolver. Very important is the barrel too. I had now three SRH and all of them has had a barrel-problem. Their barrel was in the thread-area too tight. Which results to a poor precision, because the projectile in the first part of the barrel is compressed too tightly and then it only has a poor guideance. I believe that this is a bug in production at Ruger. I suspect that the rifling will be pressed in after the final fabrication of the threaded area. So the threaded area is thinner as the other part of barrel and also more "elastic". After the knob-rifling the barrel-tube at the threaded area will contract back more than the thick-barrel part. If the barrel has the same inside diameter, you can check by pushing a lead projectile through the barrel. In this way, you can realize where the bullet will stuck. I hope you can understand what I mean, I´m not so good in English...

 

[Lee Martin]

Velocity, yes. Accurary, no. Most Rugers run from 0.003 on the tight side to 0.006 - 0.007" on the high end (though I've seen wider). I have a stainless Super that gauges at 0.007", the cylinder to bore is 0.005" on alignment, and the barrel shipped really rough. And guess what? The gun groups like there's no tomorrow.

 

[mindustrial]

I had a S&W model 10 with a barrel gap big enough you could sling a cat through it (it was over .010") It still shot tight groups.

The Dan Wesson SuperMags came with .002" shim stock to set gap, the .357 mags just had .006" shims. Higher pressures with slower burning powder should create more velocity variations with a large cylinder gap than a small one. Obviously, velocity deviations could impact accuracy

 

[airwin]

I meant of course 0,006!

 

[Chuck 100 yd]

airwin , Your English is good enough to understand, don't apologize for it.
I wish I could communicate in more than one language! :mrgreen:

 

[brushunter]

I can add .....Last summer I bought a new Ruger, 45C , Bisley B.H. from a member on the classifieds. After picking it up , I proceded to measure it. The throats were all a consistent 451.5 ...all six. However the cylinder gap was .009 ....well I was really deflated. But I figured I'd shoot it before I griped too much. With my loads ( 255 gr cast and 250 XTPs ) it shoots 1 to 2 inch grps at 25 yds.......and very little leading from the cast bullets. And according to my chrony , the velocity seems to be on par with what the manuals say I should be getting.....actually most are a little faster. Go figure :?

regards , brushunter