Bullet/Cylinder size relationship

23 February 2004, 04:26

Will 0.4325 cylinder be an issue with a 0.431+ bullet cast medium hard. Loads will be such to yeild 1000-1450 fps with 429421 and some GC based bullets of comparable weight!
Where can I find some good info on the net with the bullet/throat (barrel) realtionship discussed?

23 February 2004, 05:00

Chargar

Under the conditions you describe in your poste, I would expect the bullet so slug up/expand/obdurate the .0015" necessary to fill the cylinder throats and give good accuracy. This subject has pretty well be done to death on the interenet but if you have missed it, go to Sixgunner.com and ask you question on either "the Campfire" or in the Forums under "handguns". You will get plenty of replies and plenty of good information.

23 February 2004, 05:03

felix

Louis, for every reasonable boolit size there is a powder/primer combo that will make the gun shoot well. The number of trials to find that magic combo goes way up as the boolit becomes smaller in relation to the cylinder exit holes. But, it can be done with lots of patience. Who knows, you might get lucky right off. ... felix

23 February 2004, 05:35

aladin

Quote:

Will 0.4325 cylinder be an issue with a 0.431+ bullet cast medium hard. Loads will be such to yeild 1000-1450 fps with 429421 and some GC based bullets of comparable weight!
Where can I find some good info on the net with the bullet/throat (barrel) realtionship discussed?

Medium hard sticks out. Something on the order of aged ww alloy or linotype? Your talking the throat dia or the actual cylinder measurement at the bullet's loaded placement in the cylinder?

Goes to obturation of the slug which would fill the gap. The Q is what happens to the slug pre-obturation. Say your using a relatively fast fuel for a ww alloy slug at 35,000 CUP. Bullet movement is minimized before the slug swells up and hopefully maximizing your accuracy potential-- IF less misalignment of the bullet to bore center is accomplished. The slower fuel of course does the opposite-- a more gradual rise to peak pressure and the hammer drop is delayed.

If two of your cylinders are much different in dia you'd have the makings of a good experiment-- firing groups otta the tight vs largest fit.

A cast bullet's potential accuracy is almost always maximized by a fit only allowing the bullet forward movement. Side to side play introduces the variable of the bullet entering the rifling barrel at an off angle-- which isn't obviously condusive to accuracy. I've seen glaring exceptions though in rifles-- but this isn't common.