rifle accuracy and a dirty barrel?

[vash]

drove out this morning before work..took the AM off actually.

got some $$ non-toxic ammo for CA hunting. i shot two weeks ago and got 3/8th groups with bread/butter lead ammo. i wanted to confirm that my 257 Weatherby liked the Barnes TTSX ammo.

the first shot was perfect. it all went nuts right after that. 2" groupings. i dont think i ever recall a worst group shot by me.

all i did last time was run a bore snake down the thing because someone (my brother) took my good cleaning rod. it "looked" clean.

the range guy thinks the first copper round fouled the already dirty barrel. he isnt a fan of the bore-snake.

i'm gonna go and buy a new one-piece cleaning rod after work and go after the barrel with powder and copper solvent.

would a dirty barrel take a sub MOA barrel and turn it into a 2" scatter gun?

[Bill Douglas]

My thoughts are the gun just doesn't like the ammo, and the first shot was just lucky.

[flipper35]

What Bill said. Is this the same grain you normally shoot? If not that changes the rpm of the bullet for the rate of twist you have. Could also be the longer bullet causing the issue if it is longer than what your particular spoon likes.

[vash]

Originally Posted by Bill Douglas

My thoughts are the gun just doesn't like the ammo, and the first shot was just lucky.

oh. let me add:

i did fire a few of the original rounds. same 2" groups..something happened.

[flipper35]

So you cleaned the bore and shot a few rounds to get it back into shape? Were you shooting non-jacketed rounds before? I don't think the copper should foul it any more than a regular copper jacketed round.

[id10t]

ive had several rifles that grouped larger with new/different ammo. one needed about 20 rounds to settle in. Ive seen the same when shooting a clean bore.

But Id bet it is the nonlead ammo no stabilizing properly.

[cabmandone]

Originally Posted by vash

drove out this morning before work..took the AM off actually.

got some $$ non-toxic ammo for CA hunting. i shot two weeks ago and got 3/8th groups with bread/butter lead ammo. i wanted to confirm that my 257 Weatherby liked the Barnes TTSX ammo.

the first shot was perfect. it all went nuts right after that. 2" groupings. i dont think i ever recall a worst group shot by me.

all i did last time was run a bore snake down the thing because someone (my brother) took my good cleaning rod. it "looked" clean.

the range guy thinks the first copper round fouled the already dirty barrel. he isnt a fan of the bore-snake.

i'm gonna go and buy a new one-piece cleaning rod after work and go after the barrel with powder and copper solvent.

would a dirty barrel take a sub MOA barrel and turn it into a 2" scatter gun?

Copper fouling does some weird stuff. My 22/250 actually likes the barrel a bit fouled. I'll normally clean the bore, then go to the range and shoot 10 or so rounds through it. My gun seems to loosen up a bit when I clean it but then goes to quarter groups at 100 yds once a few rounds go through it. Another thing you might consider is checking your barrel temp to see if it's heating up. If you have a heavy barrel this isn't normally a problem but on a standard barrel it can affect the groups as well.

[Borders Reivers]

Cold Bore Shot

Cold Bore Shot is the most important single thing to know about any rifle, most widely overlooked and least often documented.

Either you can place THAT SHOT where you want it when you want it or that rifle is useless as a precision tool and becomes an area weapon.

Virtually every firearm's point of impact moves as the barrel heats up.

Yes I have some with cryo'ed barrels that move less, but they all move.

I ALWAYS leave barrels fouled. That's why they are called "Fouling Shots". Clean barrels are anathema to accurate, repeatable Cold Bore Shots.

FYI: I placed fourth in Unlimited Rifle at the 2000 Fifty-Caliber World Championships at The Whittington Center, .50BMG at 1000 yards.