Are throat erosion gauges rifle make-specific or only caliber-specific

[judaspriest]

I am going to try to buy a decent used rifle at a show and want to be able to check its condition as much as possible. For that, I want to get a throat erosion gauge for the caliber. Do these depend on the rifle at all (specific make or action type) or only on the caliber?

I am also bringing headspace gauges. Any other tools I might need?

Thanks

JP

 

[Strongbad]

I did a quick search and the only ones I could find were for service rifles which stands to reason.

If it's a bolt gun (or any gun for that matter) and you're that concerned about it, have a gunsmith check it with a scope. That's the best way to tell. If you have the luxury of that option.

 

[skinewmexico]

Buy a Stoney Point gauge, and you can tell where the lands in your throat start. But if you don't have a reference point from when it was new, it won't tell you anything. If it's a milsurp, headspace gauges would tell you if it was safe or not.

And that would be a lot of headspace gauges to take to a gun show.

 

[Slamfire]

Throat erosion is kind of a relative thing. If you have gages for service rifles then you can compare between service rifles for throat wear. And there are muzzle gages.

I have gaged a number of factory new Garands. These CMP rifles pop up at the range, and you would be surprized to find that a new Garand will throat a 1.5. So will a new GI chrome lined M1a barrel. I have one of those. Might have throated a "2".

But for rifles other than Service rifles, determing how many rounds have been through a barrel will be hard. Some absolutely new 98 Mauser barrels have very deep throats. All depends on the reamer profile.

If you could take the barrel off, you will see on a moderately used barrel that the lands are almost at the surface of the grooves. But you can't see that detail when the barrel is attached to a receiver. Your eye is too far away. Only really becomes obvious on a barrel at the end of its useful life.

Hey, clean the barrel out, look for pits, shadows. If the rifling has nice square edges, the muzzle crown is nice and sharp, you are good to go.

 

[Onmilo]

Throat erosion guages are generally available for ..223/5.56, .308/7.62X51, .30/06, and .300 Winchester Magnum.

If you really want to see what is going on in a whole bunch of different caliber rifles a better, though far more expensive option, is an optical magnifying borescope.
A good one with infinity focus ability will set you back about $750.00

Unless you are planning on buying a whole bunch of rifles or are planning on starting up your own gunshop, I wouldn't become too terribly concerned with throat wear.
You can rebarrel most rifles for less than $300.00 if they really need it and most don't.

 

[Swampy]

I want to get a throat erosion gauge for the caliber. Do these depend on the rifle at all (specific make or action type) or only on the caliber?

The only throat erosion gauges I'm aware of are USGI gauges made for the '03 Spfld and the M1 Rifle. Unfortunately, they are rifle specific. Neither will work for the other as they index off the back edge of the chamber opening, which is miles apart on the '03 and the M1.

Best,
Swampy

Garands forever