Barrel bore information - harder than I thought

[xwray]

I have been searching without success for what I thought would be a simple search on the web... I guess I'm not couching the search terms properly.

What I'm trying to find is a table/chart that provides the max/min barrel bore dimensions for the various calibers. What I'm trying to achieve is to be able to reasonably confirm if a suppressor mounted on a threaded barrel is sufficiently aligned to ensure minimal chance for a baffle strike before firing the suppressed gun for the first time.

My 73 year old optics will not focus properly to allow eyeballing through the bore which I'm not sure I'd trust in any event. I thought if I got the proper sized drill rod I could insert it into the barrel far enough to provide for a stable mount and then checking to ensure that the drill rod is sufficiently centered with the suppressor bore at its exit.

I realize this is not very scientific and certainly not mechanically accurate to the Nth degree but it ought to give me more assurance than I have now.

Any feedback will be much appreciated.

 

[rcmodel]

First of all, I don't know much about suppressors.
But I do know about threading barrels.

Perhaps the best way would be to dial indicate it in a lathe after the threads are cut.
Any run-out would be easily measured with a dial indicator (or eyeballed) while spinning it.

A bore dia range rod would also work I suppose.
But the rifling depth would make a range rod undersized to the true bullet diameter.

You could miss the can with a .300" rod that would go down the bore.
But maybe not with a .308" bullet!

rc

 

[Jim Watson]

Go to SAAMI
http://www.saami.org/specifications_and_information/publications/index.cfm

This is a price list for print publications but when you click on the title like
ANSI/SAAMI Centerfire Rifle
it will bring up a PDF of the book.

Go to the section on Standard Velocity and Pressure barrels.
The standard bore and groove diameters will be given, with a tolerance, normally +.0005", - 0".
Production line barrels are seldom held that close but this is the only place I know of to look.

As rc says, if you make a near bore diameter range rod, you would have to be watching for diametral clearance for the groove diameter bullet. Most suppressors have a good deal more clearance than that, so it ought to be possible to check.

Or you could just have the suppressor company install their product and depend on their quality and "customer service" if it doesn't work.

 

[xwray]

Thank you gentlemen...this was a big help