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lwink
11-30-2009, 01:36 AM
On my new .308 fresh out of the workshop I got a COAL measurement (very crudely) of 2.835". Is that too long to be safe? The bolt seems to close firmly on the go gauge from forster and I can't seem to close it (may be able to with a swift hit from the palm, but haven't tried that) with a piece of scotch tape, so I thought all was well, but that measurement seems to be much longer than many I've heard of in the 2.635"=2.7xx" range. Any ideas for me? Maybe I measured wrong -- I think I've seen a thread on here before for do it yourself chamber measuring with no special tools, but can't seem to find it. I'm a beginner so please tell me anything you can about this issue and advice for measuring more accurately without getting the tool for it. Thanks.

GaCop
11-30-2009, 07:23 AM
How are you measuring COAL? I use the Stoney Point (now Hornady) and measure to the ogive of the bullet, not the tip. 2.835" doesn't seem excessive if that's to the tip of the bullet.

You could take a fired/sized case, cut the neck on opposite sides with dremel or hack saw and expand neck until it just holds a bullet slightly snug, chamber and then carefully remove the cartridge. Measure to bullet tip and you'll be close to max length to lands. Measuring to the tip is inaccurate because bullets vary in length from base to tip but you'll be close.

LG
11-30-2009, 08:50 AM
It's important to remember that even if headspace is the same, COAL will vary depending on the shape of the bullet, i.e. different bullets will result in different COAL measurements. Also different barrels might result in different COAL because the throat length varies from barrel to barrel.