I have a friend that has 338win mag that he had rebarreled. The gun cold will put 2 bullets touching and then through one 1.5" to the right. Then it may jump back to the left or further to the right. It will also go in a square about 4"s with bullets in the four corners. After 60 rounds and 2 different scopes it seems to be better, but once hot it starts to through them in the square partten again. I have never seen anything like this before. He said that while cleaning the barrel he noticed the machine marks in the barrel are about gone. This barrel had some machine marks from reaming, that were in the button lines. Need some advice on this one.

STARTING BIGBORE,
Welcome aboard. Several things might contribute to the problem. First, after two shots your friend may start backing away from the gun due to recoil. I'll list the procedure I follow. Give the rifle a thorough cleaning, Check screws, stock-scope base-scope rings. check bedding, especially the barrel channel. Consider having the action and chamber area of the stock glass bedded. I doubt if the tool marks in the bore were the cause, had they been, I doubt if the first two shots would be touching. The fact that the first two shots are touching eliminates the locking lugs being uneven or the stock cracked. I hope that this is of some help. Let us know what happens. Good luck.

[ 10-04-2002, 08:48: Message edited by: BigBob ]

The lugs were trued and laped. The action is glass bedded and the barrel floated. All screws are tight (maybe too tight) scope rings trued, it has been tried with 2 different scopes. It seems to be a heat related problem, as it warms up it starts throughing lead every where. Although it is in that strange square partten, after the first 2 then to the right then maybe back on the same line then into it's square partten. It is the stranrest thing I have seen. I have had bad shooters in the past, but I could blame it somthing. (He is a vey good shot usualy, also not on one day this was done on 2 diffreent days)

Its possible the barrel wasn't properly stress relieved at the factory. When it heats up the nodal vibrations of the barrel become inconsistent and cause the bullets to fly everywhere. You might try adding a pressure point under the tip of the forearm. Use some paper or electricians tape. Not all rifles benefit from free floating the barrel. Some will shoot better with pressure under the forend.

My Ruger 77 in 338 and a custom M98 in 270 both went thru the exercise of being free floated first due to stringing and then (wanting to shrink group size) having the forward 1 1/2" end of the stock glass bedded to add a pressure point the results were outstanding - both rifles will shoot 1/2" groups if I do my part and for the most part are immune to the barrel heating up. What I have noticed, especially in the 270, is that it will shoot a wider variety of loads better than when it was free floated. Good Luck

I would also recommend adding a temporary pressure point and experimenting with it. I cured a very similar problem on a Howa .30-06 by replacing the flexible plastic stock with a very stiff fg/kevlar Bell & Carlson stock. The combination of proper bedding (which your friend's rifle already has) and a solid pressure point at the tip of the stock got my groups down to a consistent 1/2 MOA @ 100 yds.

Thanks, that is what we thought we would try. (pressure point that is)It has a very stiff stock
(laminated) the barrel is heavy and stiff too. I talked to him and he said it seems to be getting better the moer rounds he shoots through it. I have a new 338 on a mauser that I built we will try on Sunday, here's hopping. If any one has any other thoughts we would thank you for them. This is great to have experience helping you.

Thanks for the help, My friends gun is shooting about 1.5" groups in the tipical triangle. Now working up some hand loads will proabably make it better. My new 338 shot about 2" with floated barrel, with pressure point added it shoots .75" with factory rounds .
Thanks again for the help.