What do muzzle and throat readings mean?
What do muzzle and throat readings mean?
The condition of the rifling at the muzzle and the crown have far more meaning than a few thousandths of wear at the throat. With a throat reading of 5, you’ll usually see about 2 or 3 thousandths of wear at the muzzle. This amount of wear at the muzzle will account for losses in accuracy.
What is throat erosion on a rifle?
If you aren’t familiar with the term, throat erosion is just the throat of the chamber eroding down the barrel. This increases the distance the bullet must travel after leaving the brass case before it contacts the lands of the rifling. When measured next to a new barrel, the throat on this barrel had eroded nearly .
What is the bore size on an M1 Garand?
M1 Garand
| U.S. Rifle, Caliber .30, M1 | |
|---|---|
| Barrel length | 24 in (609.6 mm) |
| Cartridge | .30-06 Springfield (7.62×63mm) 7.62×51mm NATO (.308 Winchester) (Postwar use by U.S. Navy) |
| Action | Gas-operated, rotating bolt |
| Rate of fire | 40–50 rounds/min |
What is muzzle gauge?
Muzzle Gauge is Calibrated in Thousandths of an Inch Observe where the muzzle “falls” on the gauge. 0.0 indicates a . 300 diameter bore, that is, . 30 caliber, new, perfect.
What wears out a rifle barrel?
Barrel wear in a centerfire rifle is almost exclusively due to throat erosion (cracks and roughness in the first 3-4 inches ahead of the chamber caused by heat, flame, and pressure). An additional 500-plus rounds may not seem like much, but it will add up over the course of a few barrels.
How fast does a barrel erode?
The lands eroding 0.0100” over 143 rounds equates to an average of 0.00699 per 100 rounds (0.0100” ÷ 143 round count × 100 = 0.00699″ per 100).
What is barrel throat?
In firearms, freebore (also free-bore, free bore, or throat) is the portion of the gun barrel between the chamber and the rifled section of the barrel bore.
How heavy is an M1 Garand?
9.5 pounds
Weighing only 9.5 pounds, it had a rigidly-supported barrel and fired semi-automatically from an eight-shot clip. The Army officially adopted the M1 in 1936, with the Marine Corp and Navy following by 1940. A true patriot, Garand offered this amazing gun to the government royalty free.