I just got a new magazine tube for my Mossberg 500a Persuader.  Is there a headspace spec for the gun?  Who would have 12ga headspace gauges?

Don't sweat the headspace on a shotgun. Here's why -
There is a recess in the barrel hood/extension that the locking lug in the bolt locks into when the action is closed. If the locking lug in the bolt locks into the recess in the barrel, your headspace is OK.

Most of the shotguns have excessive headspace anyway, but unless it's way off, it's not a problem. Shotguns have fairly low chamber pressures, compared to rifles. I have never seen a shotshell hull seperation due to excessive headspace.

Brownells sells the gauges. But I wouldn't buy one unless you want to drive yourself crazy wondering why all your shotguns have excessive headspace.

Thanks,
Lee
]www.thearmsroom.com[url/]
Thanks.

Wait a minute!  Doesn't a shotgun headspace on the rim?