I have been tinkering with my 7mmRM and trying to concentrate on top accuracy instead of all out velocity. I have found a couple loads that seem pretty accurate( sub moa) in my Model 70 however it seems to start placing shots all over after aprox. 12 shots. Should accuracy degrade that quickly or is there a different cause to my problem. I don't think its an overheated barrel as I let it sit for an hour and then started shooting again with 2-3" groups.
Steve

Some rifles shoot well only when clean -- they give good results with the first 3-shot group, less good results with the second one, and still poorer results with the third group. Others shoot well only when dirty. From the results you describe, I suspect that your rifle likes to be clean.

As mentioned above, some guns just shoot better or worse than others after they get fouled a little. I would assume that since the gun in question is a 7mm magnum, and is for hunting, this should not pose a real problem. How many shots do you get to fire on a hunting trip, usually.

Back to the problem, though. I own two identical Remington 700VS rifles chambered in 22-250. In regard to shooting when fouled they are complete opposites! One of them just seems to shoot fine for quite a number of shots. (As in 75 or a 100 while shooting prairie dogs before cleaning.) Sure, the accuracy goes away after a while, but the change is gradual and not too bad.

The second rifle, however, is quite different. Like your gun, in about a dozen shots the accuracy just goes to hell. When REALLY clean this barrel will shoot under a half inch groups, after about a dozen rounds it is a inch and half gun. I considered putting on a new barrel, but decided to experiment some. You know what solved the problem? Switching to moly coated bullets cured this headache for me. I have sat at the range and shot 60 rounds through this gun; (allowing it to cool properly between groups), the last group I shot was the best of the bunch, about a half inch! Problem solved, I do not know why and I don't care, I just shoot moly coated bullets in that gun ALWAYS.

R F

For the cost of a boresnake give it a try. Maybe pull it through the barrel every 8-10 shots??
It extends my shooting sessions!

Is your barrel free floating? If not the stock could be your problem.

BH - Was the gun new when you acquired it? Did you do a break in on the barrel? If the bore is exceptionally rough accuracy goes away quick.

Geezer

Rough barrel. My 300RUM does the same. It sucks. Barrel is rougher than a cob and gets so copper fouled after 10 rounds, it takes me over 2 hours with Sweets to get it all out. So I took to a smith and saw a horribly rough barrel. You can do two things, rebarrel, which I am going to do, try JB abresive bore polish with about 500 to 600 strokes, or shoot it and don't worry about it. Take it to a good smith and borescope it. You will see.

RF-I'll have to take a look at the moly just for the heck of it. I know it's a hunting rifle but its nice to have confidence in shot placement.

This gun is free floated so stock pressure shouldn't be an issue. I bought the gun in '91 for an elk hunt and didn't know much then about proper break in (more like 20 shots between cleanings) I might have to look into a bore snake if the moly trick doesn't work.

BH - If all else fails and you don't wish to re-barrel, a good barrel break in procedure (there are a number of them) might, at least, extend your cleaning requirements to something more acceptable to you. For what it's worth...

Geezer
This barrel has about 500 shots through it now. About 300 of which have come this year with my interest in reloading. What barrel break in would be possible at this point? I've seen those bullets that are supposed to be coated with an abrasive but I'm not sure about the net effect on barrel life and accuracy.

NO!!!!!!!!!!!. Stay away from Tubbs Final Finish kit. It ruined my barrel. I wanted to smooth out my barrel, due to the copper fouling and borescoping at the Gunsmith showed very rough. So I tried the final finish kit. It rounded off all my edges on my rifling.

Most rifles get off 3 shots of thier best accuracy and then need to cool down 5 minutes per shot.

BH - Most custom barrel manufacturers recommend a break in that are pretty much the same. I've used it on all my acquisitions regardless of new or used and it works for me. You'll need:

1- Patience
2- 60 rounds. I use either cheap factory ammo in the brand case I prefer (60 once fireds when done) or use handloads of mixed/odd brass; bullets that you may have tried but not liked; any any powder that gets the bullet down range. Find a load 10% off max and load 60. You are NOT interested in speed or accuracy, they just have to go bang safely.
3- Cleaning stuff: Strong copper solvent (Sweets, CR-10, bore paste...) Regular cleaning solvent (Butch's, Hoppes 9 or Copper solvent, Shooter's Choice...) Nylon brushes, cleaning rod, bore guide and MANY patches.
4- Other guns to shoot during this 'endeavor'.
5- Did I mention patience?

Do this:

1- Clean the barrel thoroughly. This procedure works best if the barrel is squeeky clean between steps.
2- Fire one round and clean.
**To clean: Use strong copper solvent/paste according to direction. Then use lighter duty solvent to get the remains of the serious solvent out of the barrel. YES!! This takes time. See step #4 above. Remember: The cleaner the barrel the better.
3- Continue 'one & clean' for 10 rounds.
4- Then do 2 shots & clean for 20 rounds
5- Then 3 shots and clean for 30 rounds.
**If you must do this in more than one session, I generally soak the clean barrel with Kroil and leave until next session.

You should notice the barrel cleaning up quicker and easier as you go, hopefully. Consider that an indication of progress. Most all of the barrels I've done this to shoot straight and long between cleanings. And the majority of them have never seen a bore brush. If at the end of this procedure you still have a problem, see other parts of this forum under 'barrel replacement' for you will have tried everything I can think of.

Geezer