headspace

[twoshooter]

I am new to this so I need some input. I have a new factory sb2 receiver and barrel. The headspace on the new gun appears to be .002, it will close on a piece of light weight typing paper and that can be pulled free if carefully done without tearing the paper. The new barrel is a 444. I have other barrels, a shotgun barrel-20ga, and a 243 rifle barrel. They will close on a .007 business card and hold it tightly, showing a 005/006 increase in headspace. This is about like a cylinder gap in a revolver. The barrels seem to make complete contact on the barrel lug with the locking mechanism. So, how much headspace is too much? Should the .005 pose a problem? I will use the same cases and can just necksize when reloading, the 243 load I use is a starting load producing around 39k psi, and I use standard cheap field loads in the 20ga, no magnum stuff. I plan to do some test firing from a rest before actually shooting it in the field.

[trotterlg]

In general you would not want more than .006.  Probably .010 is OK, remember the headspace is the gap to the breach face plus the headspace built into the rifle by the depth of chamber or rim cut depth.  Larry

[quickdtoo]

Headspace and barrel to frame gap isn't the same thing, if it has a .007" gap between the barrel and frame, it likely may have even more headspace, .006" is the SAAMI maximum acceptable spec. Read the barrel fitting info in the FAQs, ideally a barrel should lock up tight on anything you place between the barrel and standing breech, I have lots of rifles that will lock up tight on aluminum foil which is .0005" thick. If the barrel is tight on the frame without the forend on when the action is closed, shoot it and see how it does, accuracy will tell you if there's problem.

Tim