Te 2-4

[daengmei]

Maybe someone can help me understand. A parts kit lists a barrel as excellent and states the throat erosion is 2-4. This is a .308 barrel with a Bm-59 kit. I'm not familiar with the TE specs so what do I see?

[country gent]

The military used a Throat gage to see what a rifles throat was it was a round shaft with short handle on the bac end and taperd end that went into the bore. It had graduations down the side from 0-10 I believe. This showed how far the throat was burned out. Ive seen very few 0 or ones even on new barrels. 2-4 is good and should perform well for awhile. This tool helped give armorers an idea of what barrels needed replaced before going into storage with out shooting each and every rifle. I believe the military had them in 308 and 30-06 maybe now there is a 5.56 version now also. These gages were simply inserted by hand into the chamber till they stopped and the graduations read at the end of the chamber.

[daengmei]

Thank you, I really didn't know what condition the numbers meant, and not seeing 0 or 1 on new tells me a lot.
Jim

[Half Dog]

People on this message board amaze me with their knowledge. It's like...How in the world did you know that?

[country gent]

After 25 or so years NRA high power rifle service rifle competitor ( m1 Garand M14/M1A and starting on AR15 when MS took me out) Ive not only seen them but have one in 30 cal in my tool kit. It gives a good idea of what the throat is in you barrel.They dont give a definate yea or nay on a barrel but in the military and 1000s of rifles being checked its better than shooting groups from each rifle. Once I made high master the X ring count at 600 determined barrel changes more than the bore scope or throat gage. My big match rifle was chambered with a short throat, 155 grn sierra at mag length on the M1A. it read just over zero on my gage when new. I always wanted to make one up for 243 win but was afraid the results would scare me. LOL