Need help! Rifle shootimg way off!

[smokin502]

Where should I look for a carbon build up or ring? I never experienced anything like this before.

 

[MagnumManiac]

Before looking for a carbon ring, when you say you blew a primer, have you had any pierced primers previously?
I have had several rifles come across my bench that had a pierced primer and blown primers that suddenly gave erratic accuracy. The culprit every single time was either the pierced piece of primer cup stuck inside the bolt body or the crud from the blown primer. Dismantle the bolt, remove the firing pin assembly and flush the inside of the bolt with a carbon solvent and blow it out with compressed air.
Check the firing pin spring carefully, the pieces my be stuck in the coils.
If this checks out, then check the extractor and ejector, a blown primer can stick the ejector in place and you won't see it.
Check and double check the ejector, push it all the way in.

Cheers.

 

[Deleted member 107796]

1000-1500 rounds, cleaning every 50-100 rounds and then you blew a primer. That's a lot of copper buildup, especially for the round with the blown primer. I'd do a good copper removal. Good luck and let us know how it goes.

 

[smokin502]

1000-1500 rounds, cleaning every 50-100 rounds and then you blew a primer. That's a lot of copper buildup, especially for the round with the blown primer. I'd do a good copper removal. Good luck and let us know how it goes.

1k-1.5k total rounds. I usually go shooting with my sons and they shoot 50-100 rds while out. I'll bring it home and clean before putting away.

 

[Calvin45]

More info might help...the round that blew a primer...factory or handload? One of many like it or a new round to try? If it's a factory round or an established load of yours there's no reason it should be primer popping.

the carbon ring theory is most plausible however I want to rule out another gremlin. Is it at all possible you had a bore obstruction that caused a crazy pressure spike that caused a primer to fail/leave? Snow or mud or dirt in the muzzle? It can happen with braked guns no different than others. It is bad for them just the same. It could explain the blown primer round AND subsequent loss of accuracy with bullets that are still stable if it damaged the brake or especially the crown of the rifle.

just to be different my moneys on this haha.

 

[Old Rooster]

Bolt face looks normal. Not sure where a carbon ring would be but this gun gets about 50 to 100 rounds tops then gets clean pretty good. Not sure. Bore scope is too large to fit inside this barrel.

Someone I know used to glue his primers in and keep using them until one came apart and messed up his bolt face.
To check if your bolt face was damaged and got a high spot you can clean the bolt face real good and use a sharpie and blacked the whole bolt face and shoot 5 to 10 rounds and pull bolt and look if there is a high spot then you found the culprit but a gunsmith can fix that.
Plus what magnum maniac said
Old Rooster

 

[smokin502]

More info might help...the round that blew a primer...factory or handload? One of many like it or a new round to try? If it's a factory round or an established load of yours there's no reason it should be primer popping.

the carbon ring theory is most plausible however I want to rule out another gremlin. Is it at all possible you had a bore obstruction that caused a crazy pressure spike that caused a primer to fail/leave? Snow or mud or dirt in the muzzle? It can happen with braked guns no different than others. It is bad for them just the same. It could explain the blown primer round AND subsequent loss of accuracy with bullets that are still stable if it damaged the brake or especially the crown of the rifle.

just to be different my moneys on this haha.

The primer that blew was handload. It was an anomaly. Loaded the same rounds for years, then pop. The primer pocket was all black and the primer came out. I did find it. I was at an indoor range, so obstruction. It was instant. Right after the primer blew out it hasn't shot the same since. I have some good ideas to check, so thanks guys. I'll post after

 

[Hard rock]

The primer that blew was handload. It was an anomaly. Loaded the same rounds for years, then pop. The primer pocket was all black and the primer came out. I did find it. I was at an indoor range, so obstruction. It was instant. Right after the primer blew out it hasn't shot the same since. I have some good ideas to check, so thanks guys. I'll post after

I wouldn't rule out excessive head space until verified die might have moved but could be a number of things check seating die too

 

[matt_3479]

It does sound like a carbon ring a bit. Even with you cleaning it as often as you do, you may be not working that area enough or breaking down the carbon at the flash point touch's barrel. I know 2-3 years ago shooting my full custom 6 creed it just was too easy. On friendly match day (group of guys once a year) my rifle was just hammering for the first half of the day and then all of a sudden a wild dramatic shift in impact and velocity and group size occurred. To the point where my door was telling me 180-250 fps faster meaning my 105's were travelling 3300-3400fps. I couldn't hit the broad side of a barn. Clean it and nothing. Bought a bore scope, cleaned it right and back into .3's-.4's

 

[nksmfamjp]

2 questions.

1) Do you have fired cases from before and after the blown primer incident? How does their case base to datum length compare? Trying to confirm lug setback.

2) Do you have the blown primer case? Did it's case head expand excessively.

 

[jarnold37]

It does sound like a carbon ring a bit. Even with you cleaning it as often as you do, you may be not working that area enough or breaking down the carbon at the flash point touch's barrel. I know 2-3 years ago shooting my full custom 6 creed it just was too easy. On friendly match day (group of guys once a year) my rifle was just hammering for the first half of the day and then all of a sudden a wild dramatic shift in impact and velocity and group size occurred. To the point where my door was telling me 180-250 fps faster meaning my 105's were travelling 3300-3400fps. I couldn't hit the broad side of a barn. Clean it and nothing. Bought a bore scope, cleaned it right and back into .3's-.4's

Over the years I have had pressure spikes and loss of accuracy and never with new brass. Always with brass reloaded more than once. Took a long time to discover that neck grip on the bullet was extreme. I had some cartridges that gripped so tight that couldnt pull bullets in the press gripped with side cutters. Yes, I had blown primers. One of the most important steps in reloading that is not mentioned that much. I make sure I keep necks annealed which gives consistent neck tension.

 

[DDWing]

I have a Remington 700 204 ruger. I've had it for about 10+years. Nothing done to it with the exception of a better stock and muzzle break. It has a varmint profile barrel. This gun shoots normally like a laser. But this last time I had a round blow out a primer and now the bullet placement are everywhere. So bad I sent my scope in thinking the reticle was jacked up somehow. It came back as no issues found. Went today and bullets are again all over the target. If I were to guess how many rounds I have through the barrel, I would say about 1000 to 1500. Most factory loads too. I measured about 8 inches off at 100 yards. About 3.5 inches at 25 yards. Any suggestions are appreciated.

I had the same problem with a 6.5 Grendel. The rifle would shoot quarter inch groups consistently, then all of a sudden it started shooting all over the place. I checked every thing on the rifle except the muzzle brake. It was still tightened securely, but the rounds started hitting the top of it on exit. I changed the brake out, and it has been consistent every since then.

 

[capona]

I'm not buying the carbon ring theory when it went bad immediately following the primer blowout. Doesn't make sense.
Take the bolt apart, take the muzzle brake off. You got something cruddy jammed somewhere as a result of the primer blowout.

 

[epags]

Always change one variable at a time or you will never know what the problem was.
IMO: Start by removing muzzle brake and shoot with factory ammo to see if that is the problem.