Need help! Rifle shootimg way off!

[smokin502]

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.

 

[Hugnot]

I have had stuff like that happen - catastrophic sudden failure(s).

1000-1500 rounds should not be the end of barrel life.

Should I have to go thru this:

Alignment of muzzle brake - try shooting it without brake..
Is the rifle a 12 twist, this is marginal for some 40 grain bullets, check out bullet length suitability for your rifles twist.
Excessive fouling or damage in barrel - clean it up good & have it checked out with a bore scope.
Check out scope mounting/rings.
Try different loads with shorter bullets & less pressure/velocity.
Check out targets looking for elliptical bullet holes.
Check out usual stock stuff - screw tension, bedding, barrel/ stock contact.

 

[smokin502]

It has a 24" barrel, 1/12 twist. I clean everything as soon as I get home. I have both 32 and 40, both used to shoot super straight. I was shooting factory ammo today. Holes are perfect circles. I'm missing something and can't figure it out.

 

[26Reload]

Carbon ring....?

 

[Gunpowder]

Carbon ring....?

My guess too, a bore cam will tell the tale.

 

[Old Rooster]

How is your bolt face?

 

[smokin502]

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.

 

[Hugnot]

I did not include an inspection of the crown - like look for dings or damage. That or the brake might be causing the problem. Check out the crown & try without the brake. Might try a good scrubbing with JB just in front of chamber.

 

[HARPERC]

Hugnot hit all the points. n spite of being told the scope was good try another one, I have been misinformed about such things before.

Sudden pressure spike, followed by loss of accuracy suggest its in the bore. Get a good look at it. Clean to bare metal, look again.

A carbon ring is high on my list.

 

[L.Sherm]

Buy a Teslong there cheap everybody should have one to check on carbon rings and barrel for your cleaning regime if nothing else.
I dont know what boresope you have but just about everyone that I know of fit down a 20 cal barrel.
Hugnot and Harperc hit on some great points.

 

[david g ranes]

First thing I would do is clean the internals of the bolt hard telling what got in there blowing a primer something could of changed the way the firing pin is striking the primer if nothing else hose it out with carb cleaner blow it out with air and try again. David

 

[LaHunter]

Blowing that primer out and your accuracy going south immediately makes me think carbon ring and / or mechanical failure like scope or scope mounting system
It's already been mentioned but you brake could be an issue also

 

[Lefty7mmstw]

1500 rounds of rather steamy stuff is possibly enough to start moving metal inside of your brake enough for bullet strikes, assuming the brake was a rather close fit to start with. I had that happen to my Browning Boss 300win twice. The first time I cut a bit of metal out and she was fine for another few hundred rounds. The second time I scrapped the Boss and went CR as I had bit chatter and chewed up the inside of the brake a bit.
I suspect the blow out was a separate incident and may have just pushed the rifle over the edge. Assuming the rifle is mechanically sound, everything is tight (including nothing odd with your bedding), and your scope is good I would look inside your brake.

 

[Creedmoor shooter]

My money is on a carbon ring. I had a carbon ring once and while it wasn't quite to this extent, my accuracy definitely was bad and my pressures went up. Even if you clean every 50 to 100 rounds if your not using something to attack that carbon it will still build up