Accuracy went south

[chet]

the last few times out at the range i notice my accuracy is getting worse especially in the last 500 rounds or so, gun is a savage model 10 in a 6.5 creedmoor, barrel has approx 1700 rounds thru it, my buddy has the same gun with over 2000 rounds and his accuracy is still good. i know every barrel is different ect, so before i give up on it, i was thinking of different OAL of a loaded cartridge, mainly i have been shooting anywhere between touching lands and as far a .040 off the lands. has anyone been down this road and tried something and revived the accuracy. i am going to try loading .050 to .070 off the lands. tried 140SMK, 140 ELD, 140 Nosler RDF, 130 TMK, 130 Norma Golden Target, and the new 130 nosler 130 RDF, some 123 SMK. there are a few others in there somewhere, mainly used H4350, some Varget with the 130, and recently been trying Superformance powder. groups used to be around 7/8" and few 3/4" at 200yds recently groups are around 1 1/2 and some larger. i have changed it into 2 different stocks, the only thing i did not try was another scope, the scope is a Sightron SIII 8x32x56. so before i finally give up on this barrel, any thoughts what to try. no copper in barrel i cleaned it well after 50 shots.

thanks
chet

 

[ShootDots]

No doubt about it, copper is a destroyer of accuracy. However, the REAL culprit is HARD CARBON! I know you said it was well cleaned>>>it may in fact be. If that is the case you probably need a new barrel. BUT you need to find out. I would "JB" the barrel really well, including ensuring NO carbon ring has formed. Then check your seating depth on the really clean barrel with your bullet. Load up your cases with the load that shot well previously and see what happens. If it does, you have solved your dilemma. If not, you know where the problem lies. I had a .260 Ackley barrel that went south at 1100 rounds. I have NO IDEA why, but it did! I suspect it was bad barrel steel. Not a bad barrel, as it shot well up to the very end>>>it is just that the "end" came several hundred rounds sooner than normal. The 6.5 Creedmoor is not that far behind a .260A.I. so it may just end up being a burned out barrel!

 

[Tim s]

Jumping at far, have you had checked with a borescope for a carbon ring at the end of the throat ?

 

[headhunter1111]

I would go through your dies and press just to be sure nothing loosened up that could be giving you excess runout, and if you turn your necks, check thickness and neck bushings, not trying to question your reloading habits, i just have made too many blunders myself, then wondered why my rifle decided to act squirrelly.

 

[T-shooter]

Most likely carbon and copper deposits. Different bullets and different powders can cause a faster accumulation of deposits.

 

[Capt. Oblivious]

I would go through your dies and press just to be sure nothing loosened

Start here and then have a look for carbon, a lose seater and a "flared" open seating stem almost cost me a new barrel

 

[dkhunt14]

Even though your buddy has the same gun, doesn't mean you are going to get as many rounds out of it. Many factors can change the round count. The biggest factor probably being rate of fire. If you heat it up by firing too fast, it will go away faster. That's why prairie dog hunters take more then one gun. You can burn one out in a few hours. The other big factor is amount of powder and kind. Some powders are just harder on barrels.

My guess is your barrel is probably shot or very near it. A good cleaning like Ben said might help it. Matt

 

[Texas10]

You mention changing stocks, maybe it's time to revisit torquing the action screws. With use, it's possible it's changed.

http://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/

https://savagearms.zendesk.com/hc/e...What-is-the-torque-spec-for-my-action-screws-

I was also wondering how much the throat has eroded over the 1700 rounds? And have you found it necessary to "chase the lands" in your seating depth over time?

 

[chet]

Jumping at far, have you had checked with a borescope for a carbon ring at the end of the throat ?

not 100% up to date about this carbon ring, how is it removed, resolved ect.

chet

 

[Milo 2.0]

Is there a pressure dump or velocity decrease with the problem also?

 

[Tim s]

not 100% up to date about this carbon ring, how is it removed, resolved ect.

chet

It can be a major issue. Typically it is removed with something like IOSSO on a brush worked just at the end of the chamber

 

[chet]

It can be a major issue. Typically it is removed with something like IOSSO on a brush worked just at the end of the chamber

i don't Iosso, but i do have JB Bore paste, going to do it again, i did it this morning, i feel i should do it one more time, maybe this time hook the cleaning rod to a sawzall, LOL


chet

 

[dkhunt14]

i don't Iosso, but i do have JB Bore paste, going to do it again, i did it this morning, i feel i should do it one more time, maybe this time hook the cleaning rod to a sawzall, LOL


chet

Soaking it with C4 will help. I let it soak for days. Matt

 

[Shynloco]

Chet,
Just out of curiosity, have you measured how much throat/rifling degradation you have in that barrel as compared to when you first started shooting that rifle? A quick way to see is to take a shot casing - resize it and start to seat a bullet that you have records on. Then close the bolt and let the rifle seat the bullet the rest of the way. Measure the Ojive (hopefully you have that measurement from before - I seat all my bullets by Ojive setting and not OAL measurement). Besides the cleaning other have advised, this suggested seating method gives you an idea how much the throat/rifling has degraded that is caused by several factors. Just an idea But 1500 -2000 rds in a 6.5 IMHO (and depending on the loads you've been shooting) is about right for an accuracy drop off in a 6.5. Good luck.

Alex

 

[370bc]

I JB bore pasted 2 of my barrels that I was having bullets getting stuck in the barrel. I think I did 3 or 4 sets of cleaning. After that, I realized how bad the bore had been in. The patches after the last treatment were going down the barrel like glass. Im going to remember that! My accuracy went back to normal too. All of this thx to the members here on the br!! Thx again guys!

 

[Capt. Oblivious]

not 100% up to date about this carbon ring, how is it removed, resolved ect.

chet

After your done with you normal cleaning take a jag or undersized brush and put a patch on it. I rub some Kroil into the patch and then put Iosso or JB on the patch. Short stroke the first 6 inches of the barrel and then push it out through your barrel. Now I use a old cleaning rod (chopped about 12") in a drill and screw on a over size nylon brush, put some Iosso or JB on the brush and slowly spin it just in the throat area for a minute or so. Now push a couple dry patches through the bore to remove most of the paste and then flush it with your carbon cleaner. Patch it dry and make sure there is no trace of any paste left anywhere in you rifle and you will never see a carbon ring, obviously use a bore guide to keep everything out off all the small places.

When I only did the Iosso every couple 100 rounds I used to let the Carbon cleaner sit in there a long time to try and get it soft and it took some "drilling" to get back on to steel. Now I push Kroil down the barrel as soon as fired my last shot and when I get home do my normal cleaning and then the Iosso every time. My "effort" of pushing patches down the barrel is minimal and the barrels clean up in no time.