Not sure if my barrel is shot out or not!

[CanusLatransSnpr]

I'm shootin an old S&W 1500 .243 Win. with a 10" twist barrel that is 21-22" long. At 100 yds. the best groups I can get are 2-2.5" and that is while I'm doing my part. The C.O.L. with my Hornady tool is 2.784". I don't know if this barrel is long throated from the factory? Can't imagine with the slower twist, atleast compared to other factory tubes! Is this C.O.L. long or average. I don't have a bore scope so I really have no way of inspecting the throat area for erosion. I've seen shot out take off barrels so I know what they look like. Any help would be great! Thanks, Mike

By the way, I didn't have any bullets keyholing or anything like that. Just really crappy and inconsistent groups!

 

[watercam]

Assuming you are using bullets of 100 g. or less, give the barrel a good cleaning and polish with both JB products. If you have less than 1500 rounds through it that should help. I have a barrel on a match rifle that gets 1000 rounds a year and still going after 2000. Consider lapping with a patched brush and 600 grit lapping compound after all the other cleaning. About ten passes in the throat and four or five through the length of the barrel.

 

[Yellow11]

Assuming you are using a square tail bullet i.e. a tip that is NOT overlong for its weight. Have you check the crown?

I had a similar problem with a .243 that I had owned for 30 years... It cost me £15 to have the crown re-cut and the rifle then carried on as if new!

 

[CanusLatransSnpr]

I've been shooting 55 and 70 Nosler BT which are boat tails. Not shooting a real heavy bullet. This is for Coyotes not deer. I havn't given the crown a real good look. That may be the problem. It shot alot better before but now its kind of wild.

 

[CanusLatransSnpr]

Good call JH! I checked the crown of the barrel this evening and it looks kind of chewed up where the bullet exits. Not a nice smooth transition like the rest of my rifles. I inherited this rifle from a good friend of mines father after he passed away early this summer. It sat in his cabinet with no scope on it. Maybe Joe knew something about this rifle that neither his son or I knew. I'm digressing from the subject though! While inspecting the crown I noticed some rust pitting in the rifling in the end of the barrel, must have happend while it sat in Joe's cabinet. So it looks like I'm gonna have to have this rifle rebarreled. Darn! LOL! I'll keep it 6mm of some sort but, not sure what to have it chambered in though!

 

[fdshuster]

If there are more than 1200 to 1500 rds. fired thru the barrel, I'd expect to see heavy fire-cracking in front of the throat, with poor groups, mainly involving more and more unexplained "wild shots". Heavy copper fouling is also another indication of a barrel that is "done"/ time to be replaced. Keeping very careful records, I shot out a Douglas CM 243, and had to replace it at 1400 rds. Ditto for the Shilen SS that replaced it. Actually accuracy began to go shortly after 800 to 900 rds., about the same time heavier copper fouling began. All this was watched and verified with my Hawkeye borescope. Another reason the 6BR remains my #1 favorite 6mm chambering.