I recently had a custom 300 win mag made 28in barrel and its a kreiger with a mussle brake. when I first got the gun I used 70.5 grains of H 4831sc with a serria 200 macth king and was getting bullet hole in bullet hole with it being one thou off lance. Then I went to the Amax 208 the bullet I what to use the gun started to lose accurcy and got worce with every shot ,no matter what seating deth or what powder. I went back to the serrias and they lost ther accurcy, There is only 200 hundred rounds through the barrel it will be burned out before one finds the fix talk to the gun smith and hes at a loss . Is it possible a bad barrel , HELP.
trouble shooting 300 win
- Thread starter cooter 1
- Start date
- Location
- Saskatchewan
If you go back to the load that works and its still a problem... I would check screws, bolts, nuts, base, rings, then if that still doesn't work, try a different scope. Then try it without the muzzle brake. There maybe something out of place with the break since they are machined to very tight tolerances.
That's what I would do before blaming the barrel. good luck
That's what I would do before blaming the barrel. good luck
Besides the things mentioned above...
I would start with a very clean barrel (no copper) then keep shooting it. You should be able to get 300-400 rounds out of it before cleaning it again. Have you taken the action out of the stock? There may be some solvents that have leaked down into the bedding. This will make an accurate rifle spray the target.
I do not shoot A-Max bullets because I never had any luck with them. However a friend of mine uses them (155 gr) and finds they work best in his rifle jammed into the lands.
I would start with a very clean barrel (no copper) then keep shooting it. You should be able to get 300-400 rounds out of it before cleaning it again. Have you taken the action out of the stock? There may be some solvents that have leaked down into the bedding. This will make an accurate rifle spray the target.
I do not shoot A-Max bullets because I never had any luck with them. However a friend of mine uses them (155 gr) and finds they work best in his rifle jammed into the lands.
6mm Shooter
CGN Regular
- Location
- White City, SK
Its sounds like something is loose on the gun or in the scope.
1) clean properly. Many different products, but try overnight with wipe-out and plug the barrel with a bore mop. Remember the throat is the area most likely to be fouled and least likely to be cleaned properly. Examine the crown for ANY signs of damage! (maybe ask the gunsmith to do this)
2) torque your action screws properly and evenly
3) remove the scope and check that the base is mounted securely and torqued properly. Ensure that the scope rings are firmly in place. (I use blue loc-tite)
If these don't work, try a different scope or let another experienced shooter try grouping with it.
You need to re-establish the point of first land contact. after 200 rounds with this cartridge, it has almost certainly changed.
Barrels don't go from being one-hole to shot-out in 200 rounds unless you over-heated the barrel.
2) torque your action screws properly and evenly
3) remove the scope and check that the base is mounted securely and torqued properly. Ensure that the scope rings are firmly in place. (I use blue loc-tite)
If these don't work, try a different scope or let another experienced shooter try grouping with it.
You need to re-establish the point of first land contact. after 200 rounds with this cartridge, it has almost certainly changed.
Barrels don't go from being one-hole to shot-out in 200 rounds unless you over-heated the barrel.
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Thanks for all the advice but I have done all of the above from screws tight to different scope its a nightforce so I didnt think it was the prop, cleaning the hole bit , the only thing I did was the brake was not on true ,the gun was jumping side ways the ports on this are on the sides and top to recoil the gun back and down to stay on target when I talk to the gun smith he had locktight it on and said to heat the break with a paint stripper gun and turn it . The heat was on the brake not the barrel thats the only thing that was done to it. But thats when things started happening I suggested that to him but he said it didnt matter what angle its at . I thought it was me but shot two other target rifles of mine same mickmillon stocks ,triggers and scopes, 1/4 inch no prop. The barrel was never heated from shooting 5 shot groups to 6shots on a ladder for loads
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Take the brake right off and see how it shoots. The barrel must still have a proper crown on it -even with the brake - and if it is suddenly shooting poorly, I would suspect that if it isn't your load, then the crown is a possible cause.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Take a bullet and put it into the front end of the brake. How much room do you have? Most brakes have a 20 thou clearance. I have seen brakes that were just over calibre.
Now if the brake is cockeyed AND the exit hole is tight, guess what....
Your bullets may be hitting the brake. Is there copper fouling on the brake exit hole?
Another simple check is to look from the chamber out to the brake. There should be no shadows at the front and the view of the exit hole should be nice and round.
A brake needs to be solidly mounted AND concentric with the bore. 20 thou is usually plenty to get the bullet out of the brake before recoil causes the brake to get in the way.
If you have checked everything else for tightness (not overly tight ie crushing), and the optics is sound, that would be my next spot to check.
Another check you can make is see how far away your lands are from your loaded rd. I expect that your bullet will fully engrave in the lands LONG before it leaves the case neck but you just never know.
Jerry
Now if the brake is cockeyed AND the exit hole is tight, guess what....
Your bullets may be hitting the brake. Is there copper fouling on the brake exit hole?
Another simple check is to look from the chamber out to the brake. There should be no shadows at the front and the view of the exit hole should be nice and round.
A brake needs to be solidly mounted AND concentric with the bore. 20 thou is usually plenty to get the bullet out of the brake before recoil causes the brake to get in the way.
If you have checked everything else for tightness (not overly tight ie crushing), and the optics is sound, that would be my next spot to check.
Another check you can make is see how far away your lands are from your loaded rd. I expect that your bullet will fully engrave in the lands LONG before it leaves the case neck but you just never know.
Jerry
I have witnessed a crooked brake as described first hand.
The gun would display great accuracy, for about 4 out of 5 shots on average. Just when I was getting to the hair-pulling stage I noticed there was a copper smear on one side of the brake exit hole and no smear on the other. I unscrewed the brake and tried it again, problem solved.
I got the threads cut off and the barrel recrowned, never a problem again.
checked the hole on the brake with calipers, hole diamater is 8.98 and the bullet is7.78 diff 1.20 and I cleaned the gun again so cant tell about the copper if its on the side of the brake Ill have to heat the brake to take it off its a ##### to clean with that thing super glued on
juanvaldez
CGN Ultra frequent flyer
- Location
- Sudbury, Ontario
I wood bet it is the break. it is an big concidence that you just hapen to turn the brack and then your groops go to shlitz
send it back to the builder before you do anything!!! let him take the brake off if it is that tight. you don't want to fark it up, then the blame lies with you. it is a long time till spring, do it right. obviously you paid to have a precision rifle built and that is what you should have, if you wanted something that would shoot 1 -2 " groups you could have saved yourself a couple grand and bought a factory rifle. don't give the smith ( and i use the term loosely) any excuse to push the blame on you.
I agree with Bingo1010, send it back and let him(smith) fix the problem. You don't pay that kind of money for a paper weight. That way if something happens when he takes the brake off he has to fix it or replace it. If you start messing with it he( smith) can use that as a excuss and blame you, then he might not stand behind his work.
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- Location
- Vancouver Island BC
If the problem lies with the muzzle brake, then honing it out to a slightly larger diameter would solve any bullet yaw from contact with the brake.Better yet,take the sissy thing off and get the rifle recrowned.
