throat wear

[bench]

How many thousands of throat wear is considered bad and time to start thinking about a new barrel.
In chasing my bullet seating depth to lands is starting to get longer.

 

[Dusty Stevens]

How many thousands of throat wear is considered bad and time to start thinking about a new barrel.
In chasing my bullet seating depth to lands is starting to get longer.

Itll either get too long or itll stop shooting. When either happens youll get the feeling you need another barrel then. Until then keep on shootin it.

 

[retired]

when it stops shooting is a good clue

Itll either get too long or itll stop shooting. When either happens youll get the feeling you need another barrel then. Until then keep on shootin it.

 

[Dusty Stevens]

when it stops shooting is a good clue

Or if the bullet in the neck cant reach the lands. That happens sometimes with the .130+ freebore dashers and a real good shooting barrel youre in no hurry to get rid of

 

[expiper]

a bbl wears out in a lineal direction and in a radial direction as well,,,,,it depends on the cal-twist-bullet wt and bearing surface-and velocity,,,,usually I wont put a bbl in the car or on an airplane and take it to a national match with more than 2,000 rds of wear,,,,the thing that makes em shoot wild is when the hole gets so big that the lands do not grip the bullet sufficently and the bullet scoots down the bore without adequate stabalizing/spin.....usually this occours for me when throat erosion is ~.080",,,Roger

 

[ShootDots]

I recently had a barrel in .260A.I. that went real south in 1050 rounds. After a complete and thorough scrubbing down to the bone, my bore-cam showed REAL firecracking to the point the edges of the conventional rifling were "broken-off", for lack of better terminology. The grooves were so bad they looked like alligator hide, for approximately 7 inches! Needless to say the rifle had a hard time holding a ten-ring, much less getting into the X ring with any sort of regularity. I had another 260A.I. that went over 1800 rounds before the accuracy fell off. So, from MY perspective, it is NOT a matter of how far throat erosion may or may not be 10 thousandths or 40 thousandths, it becomes a matter of when the accuracy falls off, no matter the erosion, to where whatever discipline you are engaging in, you no longer become competitive.. That is my idea of when a barrel needs to be replaced...

 

[Bart B.]

Here's a decent table of match rifle barrel life based on bore capacity which is 1 grain of powder for each square millimeter of bore cross section area......

Charge weights at bore capacity get 3000 rounds of accurate life. 40% more powder cuts life to half, 1500 rounds. Double the powder charge and barrel life is one fourth, 750 rounds.

Barrel starts out shooting 1/4 moa average then degrades 50% to 3/8 MOA average. That's been Sierra Bullets' standard for test barrels as well as many top ranked competitors.