300 wsm headaches

[HPBTMTCH]

Last year a friend bought an expensive rifle chambered for the 300 wsm, he brought it over and wanted a load built for his alaska hunting trip. I started with RL 22 and 168 gr. barnes triple shocks, and nosler 180 gr. accubonds, it shot these like the high dollar rifle it was, no problems. Most loads going under half MOA. This year he said it would not shoot a group under 3 inches. I thought that was a bit strange so i told him to bring it back and i would check it out. Sure enough i shot his loads and it would throw flyers all over the place. He said he lost or shot last years rounds and could not find the fired brass. He did have the same powder and lot #bullets though. I loaded 3 rounds and thought they seated with very little effort, so i checked if i could turn the bullet with my fingers and suprisingly i could. The dies are from redding but are`nt the bushing style. I measured the brass and it went 12. 5 to 13 thousanths. Thats pretty thin. Bought 100 more new brass and it measured 15 to 15.5 thousanths and figured i had the problem solved, not so. It still shot flyers. I looked at the barrel, and it was fouled bad. Ran patches for 8 hours and let it soak over night. Ran more patches and it showed rust under the copper, it`s stainless so who would have guessed. After several JB patches it looked clean. Back to shooting. Now it would bughole 2 and the 3rd would be out about 2 inches, no problem you think, right? but the 4th round would land where the 3rd went the #5 would be in the same hole and # 6 would be 2 inches farther than that, and they would walk around, never going in the same place, without moving the scope. Changed scopes, checked mounts, same. Retightened stock bolts to specs and checked bedding, nothing wrong. After many expensive componets down range could not get it and gave up. The bore looks shiny, but could the rust have changed something? Cleaning it showed no exessive copper fouling, nor does it make it shoot better. So with the hunting trip in days he buys a rem. 700 in 300 wsm, and it starts again, this thing won`t shoot either. Finally i stumble on some leftover 200 grain sierra gamekings, with win wmr primers and RL22, it shoots these into .4`s, and the 10 round group went under an inch !! But it is so picky that 3 rounds with fed 215 primers went out to 1.6 inches. Oh well, it likes one load and thats it. But it does shoot one load, me, i`m just glad it`s over, lol.

["yote"]

That's why I got rid of mine. It was the most problematic round that I have ever tried to re-load. And that was in a Tikka. My 2 other Tikkas (223 &308 ) are great !!!. The 300wsm has no re-loading flexibility in my book. I have heard similar reports from the other WSM's.

[gd357]

HPBTMTCH,

Did he send the gun back to have it checked out? I'd think that they could be able to tell him if something was wrong with the bore (or any other issues with the gun).

gd

[Jack]

" The bore looks shiny, but could the rust have changed something?"
My guess would be that even though the bore looks shiny, the rust slightly roughened the bore surface. The result of that would be more friction, and increased pressure for the load you've been using.
You might try working DOWN from that load in small increments. When you reach pressure similar to what you were getting pre rust, it may group better.
Clearly, the rifle needs to be cleaned more often than your friend is doing.

[6.5x53.5]

Wow, I recently aquried a Savage in 300 wsm I have loading data via Lymans. I also had a quanity of older Norma 204. In my very first attempt I concidered the max load for a fastest burning powder H-380, checked the slowest IMR, that being 4350 compramised between the two and attempted a N204 65gr charge with a Sierra 150gr spitzer loading only 5 ( strippings a chore) I took it to my hole and proceeded to punch a sub moa group this with circa 55 Model Perfect Herters standard #120 primers. I was ONE lucky guy or this problem has not yet appeared. I was under the impression with all the hooplaw saying what promise it held for future wildcaters it was a rather forgiving magnum load round, what with the new PPC design factors and such. I DO HAVE TO KEEP THE CHAMBER CLEAN!
I will be following this thread for some time YOU HAVE MY INTREST.
6.5x53.5

DO NOT ATTEMPT THIS KIND OF LOADING ALLWAYS USE AN ACCEPTED LOADING DATA SOURCE AND WHERE APPLICABLE ALWAYS USE THE RECOMMENDED STARTING LOADS! WORK YOUR LOADS UP FROM THERE. ITS NOT WORTH LOOSING YOUR HEAD OVER!!!

[HPBTMTCH]

GD, nope still sitting in the safe as far as i know, lol. Jack, yes i went up and down, cleaned after each round for a few groups, still did`nt make any difference. The fact it shot so good last year and then to go away this year puzzles me to no end. I have never had a rifle walk around like this one without the scope being junk or lose, it would be over 8 inches from where it started. And with the only thing different being the brass. He even bought 3 boxes of different factory rounds, and could not get groups under 2 inches. Loaded the fired factory brass, that did`nt help either. And the laugher here is the new remmy would`nt do any better with the factory rounds either. Put the scope on my .308 and it shot 10 rounds under 2 inches at 200 yards, which is a typical group for it. I was`nt aware that there was a problem with the 300 wsm, but after this i doubt i run out and buy one anytime soon, lol.

[Rapier]

HPBTM,
The description sounds like the barrel is still fouled.

The first thing I do with a new bought, used gun, is to plug the chamber neck with a dowel and fill the barrel with Shooter's Choice. I let it soak for one full week. Normally with a stiff bronze brush, I get 1/4 inch long chunks of copper jacket out of the barrel after a week. The gun then shoots like the day it was made... 99% of the time. You might try this, at this point you have little to loose.

Ed

[Classicvette63]

You could possibly try one of those Outer's Foul Out electronic gizmos. I have one and you would not beleive the stuff that comes out of a "clean" barrel. Doesn't take very long to use either. Just make sure the ground wire is not touching the barrel, lest you lose the blueing where the wire is touching. Don't ask me how I know this.

[Mike Moss]

The 300 WSM is as accurate or more so than any other cartridge in it's size range. Currently its the favorite 30 cal magnum for long range shooting. So that puts the accuracy mumbo jumbo aside.

Besides it's usually the gun and most cartridges will shoot bullets well from a good gun.

It only takes one thing to throw the accuracy off in a gun. At present the fouled bore and possible damage to it seems to be the easiest to work on.

Not sure if you used an abrasive to also clean the bore but if not do so. Get some Rem. Bore Cleaner or JB's or something. I like to put it on a cut patch over a bristle brush and not a bronze brush. You can go back and forth with it and the chemical removers.

To look for fouling near the muzzle shine a penlight down it. To see even better hold a Q tip in the bore when shining the light. (you guys thought your bores were clean huh?)

When in a serious off season test like this I try to stay with Sierra bullets.

Once the defect is found test it with other bullets but if it's the fouling keep it really clean. I too like the Outers Foul Out but just try the abrasives for now.

What make of custom is it? You might call the maker and tell the story. He might have some insight. I always suspect the crown and if that was damaged I would send it back to the maker before voiding the warrantee expressed or not.

[Catfish]

If the rifle has a wooden stock the stock may have dried out in the safe and put some different presure points on the barrel. Can you run a dollar bill under the barrel?

[HPBTMTCH]

The rifle is from H-S precision, and is free floated with the aluminum bedding block. I hand lapped the barrel with polishing compound from the david tubb kit. Barrel got pretty warm, so i`m sure it does not have any carbon or copper fouling now. Shot it again, the group shape changed but it did`nt help the size much. I told him to call H-S and talk to them.

[Cossack]

If the barrel is in fact fouled, try some Wipe Out and let it soak all night, won't hurt the barrel and will clean all the crud out.
Shooting copper bullets (Barnes) over leaded bores is a recipe for super fouled barrels. Always clean the barrel down to steel after every shooting session for best results and, especially, shoot copper loads from a clean barrel.
But check the crown for dings. I just had a rifle in here that was doing the same thing. The crown had a barely noticeable ding that I observed with a magnifying glass. A brass round headed wood screw coated with JB paste and chucked in a drill polished it up and accuracy returned.