Emergency! Please help.

[400Bullelk]

I have a 300 RUM, it is a Remington 700, I had a Vias muzzlebrake added, stock bedded and pillared(sp). It was shooting better than 3/4" groups two weeks ago. Walked it out to a 1000 yards. It was dialed in. I am in the middle of a limited entry mule deer hunt. I let my buddy try and shoot a coyote in a field, let him know to aim low, gun is zeroed at 300 yards. He shoots high a couple of times. I shoot it, and it won't keep a group. Check the scope and take it too the range where there is a guy who puts them in a vice. He shoots it and again it is all over the place. So, its either the bullets or the gun. The bullets that I am shooting were loaded up the same time as the bullets that were so accurate, so I am pretty sure that its not the bullets. So I am worried that its the rifle. Does anyone have any experience with this? I am going to call a couple gunsmiths tomorrow, but thought I would throw it out here first. The group is now bigger than 4" and I am shooting 200g Accubonds and 95g of Rutumbo. No pressure signs.

 

[7STDUBBERU]

Double check ALL of the screws on the rifle. Scope rings and mounts and the action screws. I had a similar experience and changed the scope out thinking it had gone bad , just to find the action screws loose.

 

[Broz]

Here is a check list of what I would do.

Check action screws.

Check for loose scope base or rings

Clean the barrel with Boretec eliminator.

Swap out the scope.

I have had two Leupolds and one Redfield do this to me.

Hope this helps.

Jeff

 

[400Bullelk]

Having the dude put it in a vise I guess took out the scope issues. I did a double check to make sure everything was tight. I just checked the two screws that hold the action to the stock, and they are tight. I just don't understand how a rifle can go from tack driver to **** overnight.

 

[Loki Dog]

I believe I would check the diameter bore on the muzzle brake. If the bullets are scrapping, even if for powder residue. This will cause the grouping to change. Hope this helps. Loki

 

[Eaglet]

Just about everything has been covered...

Check and make sure no debris or dirt has gotten into the chamber, specially inside where bolt lugs fit into.

Look at the bolt head, make sure there's not brass shavings there, clean

with a brush even if you don't see anything. This alone could be your problem.

Good Luck!!!

 

[Broz]

Having the dude put it in a vise I guess took out the scope issues.

I don't see how, explain this vice you put it in. I took it to be a leadsled.

Jeff

 

[BryanLitz]

How many rounds thru the barrel? Could it be shot out?
Bad copper fouling, especially at the muzzle can cause precision to go to hell. If you can remove the break (or if you can see without removing it) look in your crown for bright orange copper fouling. If it's there in your crown, it could be the culprit.
Good luck,
-Bryan

 

[400Bullelk]

Its one of the sight in vises, that rock when shot. the dude does it for a living. So the rifle is aiming at the same spot. I cleaned the rifle, but not the bolt, just the barrel. I will clean the bolt, and chamber and throat really well. I pulled the muzzlebrake off and it is clean, the crown is clean as well. I use the Barnes copper remover, follow the instructions, and then check with a q-tip to make sure all the copper is gone. I am going to take some manufactured ammo next time, to see how it groups. I have put about 200 rounds through it. It has gotten hot, but I let it cool before shooting it. I have heard when you shoot out a barrel, it goes from like 1" groups to 1-1/4" groups, not .75" to 4"?

 

[Boss Hoss]

I some all cases the addition of a brake will change the harmonics of the barrel. If not done perfectly the addition of a brake will really screw up an otherwise great shooting rifle. The could be a damaged crown or the brake is not concentric for example. It may just be as simple as starting over with your load development because of the change in harmonics. Maybe the action is in a bind causing stress ---- lots of things to check in the process. Good luck!

 

[406pat]

I'd take a really hard look at EVERY screw associated with the scope. I had a similar problem with my .300 RUM.Thought I looked everything over and just when I though everything was tight, I was pushing on an Uncle Mikes scope cover and the scope base started to move. apparently it was just loose enough to wiggle a bit when firing but not when I was checking everything. I swear I torqued that thing 5 times to check it but it still came loose. I took every screw out and used some locktite on all of them (rings and bases) and groups dropped right back into .5-.3 where they were at first.

Things like that are the reason I love tinkering with stuff. Soooo frustrating when you can't figure it out but when you finally get it you feel like Einstein cracking relativity!

 

[bigbuck]

Having the dude put it in a vise I guess took out the scope issues. I did a double check to make sure everything was tight. I just checked the two screws that hold the action to the stock, and they are tight. I just don't understand how a rifle can go from tack driver to **** overnight.

I just wanted to make mention of this "having a dude to put it in a vice took out the scope issues" Not so if the scope has pooped then it want make a difference if it's sand bags a vice or prone the gun want shoot. I would swap that scope with a friends scope if I had to the reason I say this is I had a 22-250 that would shoot lights out and I could not get it to hit with no load! decided to send it back to ruger and had them put a new barrel on it got it back and it was my scope

 

[Mikecr]

To clarify..

I had a Vias muzzlebrake added, stock bedded and pillared. It was shooting better than 3/4" groups two weeks ago.

Was it shooting so well before or after all the changes?

The bullets that I am shooting were loaded up the same time as the bullets that were so accurate, so I am pretty sure that its not the bullets. I am shooting 200g Accubonds and 95g of Rutumbo

Are the bullets and load shooting badly EXACTLY the same as shot well before?

 

[nevada]

I just wanted to make mention of this "having a dude to put it in a vice took out the scope issues" Not so if the scope has pooped then it want make a difference if it's sand bags a vice or prone the gun want shoot. I would swap that scope with a friends scope if I had to the reason I say this is I had a 22-250 that would shoot lights out and I could not get it to hit with no load! decided to send it back to ruger and had them put a new barrel on it got it back and it was my scope

if its clamped in a vice...you could pull the scope off. it would have no bearing on where the rifle is shooting.