Jacketed bullets slightly smaller than the bore -- what happens?

[Thirties]

What is the effect of shooting slightly smaller jacketed bullets, say .003" smaller than the bore?

I'm thinking here of a Ruger Single Six revolver in .32mag. I now use .314" plated or lead bullets. They are slightly oversize as per normal for lead bullets.

But what if I used the Speer "Plinker" bullets which are .308" diameter, jacketed with a soft lead tip?

What would be the effect of using these slightly undersized jacketed bullets? I am not too concerned about any leading here. I'm mostly wondering what actually happens when you shoot an undersize bullet. Does the velocity go way down and the flash increase?

I'm just curious if any of you have tried such things. Or would a .308" bullet in a .32mag revolver be close enough in diameter to be unremarkable?

 

[Sunray]

The bullet will not get enough purchase on the rifling to impart adequate spin, so the accuracy will stink. Chances are the bullets will tumble as well causing keyholing. Slug the bore to find out its exact diameter. T/C Contenders apparently are bored to .308" for the .32 Mag. This may help some. http://www.reloadbench.com/cartridges/p32hr.html

 

[Thirties]

Sunray, thanks for the clear explanation . . . maybe those plinkers are not for me and my .32mag, eh.

 

[ClarkEMyers]

Try'em first, easy to bump'em up if you want

The Speer plinker has been bumped up in various dies bought and improvised for plinking in slightly larger bores for years. Suggest trying them first they run soft and may well work - minie balls killed a lot of people out of oversize bores with black powder to slug them up.

Word is that quite often a soft bullet will bump up nicely in the chamber throat and forcing cone - don't know about that, I don't have super vision but I do know performance is often but not always acceptable depending on performance and standards.

 

[Ben Shepherd]

Sometimes it'll work. My blackhawk convertible 357/9mm will hold 4" at 25 yards with 9mm slugs. That's a .355 slug in a .357 bore. Good enough I suppose.

Try it out, who knows your gun might shoot them OK.

 

[Thirties]

Thanks for the replies . . . for sure I'll be trying a few. I'll compare my results to ammo loaded with fatter jacketed bullets that I have.