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Re barrel to 7WSM

fireguyty

Sergeant
Full Member
Minuteman
Jul 24, 2010
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Las Vegas
Guys,
I have a factory Remington 700 XCR in 300 WSM with a chamber that has .5" of free bore. Remington says that they do this to keep novice reloaders from blowing up their guns.

Needless to say that after trying around 50 different reloads and factory ammo and can't get better than around a 2.5" group at 100 yards. I am done with it and want to re barrel to 7 WSM.

I want to shoot the 180 grain Berger. What twist, length of barrel etc would you all recommend?

Thanks!
 
Re: Re barrel to 7WSM

Merely changing the chambering does not guarantee resolution of your perceived problem. You need to make sure the gunsmith doing the work uses a reamer that matches the specs of what you desire the chamber to be.

My smith was building a 7 RUM, only to find the SAAMI reamer had a freebore half way down the bore when it came in with a copy of the print. He decided to scrap the RUM idea, go with a 7 WSM, and custom spec'd the reamer to his dimensions around the 180 Berger.
 
Re: Re barrel to 7WSM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">Merely changing the chambering does not guarantee resolution of your perceived problem. You need to make sure the gunsmith doing the work uses a reamer that matches the specs of what you desire the chamber to be.

My smith was building a 7 RUM, only to find the SAAMI reamer had a freebore half way down the bore when it came in with a copy of the print. He decided to scrap the RUM idea, go with a 7 WSM, and custom spec'd the reamer to his dimensions around the 180 Berger.</div></div>

I appreciate this reply for the good information, but am confused about the "perceived problem" part. Are you saying that a rifle shooting 2.5" at 100 yards is not a problem, or that the half inch of free bore may not be the issue? I know that I have provided very little info about that problem, but if you have a recommendation on fixing my accuracy issues I'd sure appreciate it.

I have been reloading for years and venture to say that I am pretty good, so I don't think its the ammo. I have tried 5 different bullets, 6 different powders in various weights, and 2 different primers. I have tried 4 different kinds of factory ammo. I have restocked the rifle to a Bell and Carlson LTR thinking that that flimsy plastic stock may share the blame, but saw no improvement. I swapped out the scope, rings, and bases thinking that this may also be the problem.

If I missed something please make a recommendation.
 
Re: Re barrel to 7WSM

Here are some thoughts...

A rifle is a system and many factors contribute to accuracy or the lack thereof. A rifle with a long throat can still shoot well, so the long throat may or may not be your issue.

You haven't mentioned whether or not you bedded the rifle and polished the crown. I would check into those two areas.

Over cleaning a rifle can cause this. Rifles with rough factory barrels may need quite a few rounds down range before the rifle settles down and starts to group. As to groups, a 3 round group is a more reasonable test than long strings with light barrels.

A fair test of your rifle would be done with match grade ammo and match bullets. You might see how it shoots with SMK or A-Max after you clean up the crown.

TC
 
Re: Re barrel to 7WSM

i would order up the Krieger 1-9 heavy palma that brunos has listed for sale, then call my smith and get my name on the list asap


K1143 Krieger Barrel 7mm 1-9tw #14 HV Palma @ 31" 1.250 x .900


but that is me, I HATE waiting on guns
 
Re: Re barrel to 7WSM

"I have a factory Remington 700 XCR in 300 WSM with a chamber that has .5" of free bore. Remington says that they do this to keep novice reloaders from blowing up their guns. "

If you cannot 100% prove that the "problem" with the rifle is the freebore, then in my book that is perceived.

Do I think the freebore is causing your 2.5" groups? NO - but, if you are going to re-barrel and think freebore is one of the things you want to address, then I was trying to draw your attention to the fact that reamer dimensions need to be taken into account, or you could very well end up with another funnel throated magnum.

Does that make more sense?
 
Re: Re barrel to 7WSM

I would bet with some work on the barrel that it could shoot pretty well but i have a feeling you just want a new barrel in another caliber. Im all for the 7WSM. IMHO, go make your perfect barrel on Kriegers website and then order it. I would have an MTU countour made at 24" finished length but thats just me. If it's supposed to be a hunting rifle i'd suggest either having a shorter barrel made of the same contour (maybe 22 inches?) and have it fluted, or just have a slightly lighter contour made.

Regards,
Dylan
 
Re: Re barrel to 7WSM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mwroseberry</div><div class="ubbcode-body">1 in 8 twist if you're wanting to run the 180 bergers. But with a WSM you might as well try the 210s also.

Good luck,
Merritt </div></div>

Sorry Merrit you only need a 9 twist do not use the 8 twists they actualy are a backwards step also the 210's are a 30 cal projectile and he said he wanted to rebarrel to 7mm and that is a good move. i would get a barrel at least 24" long i have both a 22" and 3 barrels 28-31" in 7mm Rem SAUm and it is actualy a better case i believe for target shooting and also hunting as the case is shorter you can seat the longer projectiles out further allowing the case capacity to be maximised and to get the projectile further out of the doghnut. i have been using both Rem cases and Norma 300 Rem SAUm cases necked down and am getting over 10 shots per case and winning state championships at 1000 to 1200 yards with the longer barrels in my target rifle i am using a Rock 5r 9 twist at the moment and it is an awsome barrel.
 
Re: Re barrel to 7WSM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">"I have a factory Remington 700 XCR in 300 WSM with a chamber that has .5" of free bore. Remington says that they do this to keep novice reloaders from blowing up their guns. "

If you cannot 100% prove that the "problem" with the rifle is the freebore, then in my book that is perceived.

Do I think the freebore is causing your 2.5" groups? NO - but, if you are going to re-barrel and think freebore is one of the things you want to address, then I was trying to draw your attention to the fact that reamer dimensions need to be taken into account, or you could very well end up with another funnel throated magnum.

Does that make more sense?</div></div>

Yeah, I understood your point about the reamer, and now I see your point about the fact that I can not prove that the freebore is causing the problem, but I feel as though I have trouble shot it pretty well.

Top Cat, the barrel has a factory installed muzzle break and so polishing crown or better yet having it recrowned is not a cost effective option. No it is not bedded, just bolted to the B&C. As far as match bullets go: I have tried 168 SMK, and 155 Scenar, along with two others.

As far as the free bore goes I don't think I have explained the issue well enough. Using a Stoney Point, the plunger is sticking out of the mouth of the case by about 5 mm. The bullet is literally jumping the entire length of its self before it hits the lands.
 
Re: Re barrel to 7WSM

What you need to look for is a gunsmith that understands the issues with 7wsm and has a reamer that is throated for the bullets you want to use. I suggest you call GA Precision.

Barrels can be found fairly easily. Correct throat depth seems to be harder to find. You are going to have to pick a bullet and load it to fit your magazine, then find a gunsmith with a reamer that length (or buy one for your gunsmith or have your gunsmith buy one). Anyway, you need the bullet, the magazine length, the oal and the reamer to all work together.

GA Precision has a reamer that is made for the Bergers, if you want to use those bullets they can do it. Or so I am told.
 
Re: Re barrel to 7WSM

The WSMs and the RUMs are not the first chamberings to hit the market with funnel throat spec chambers from the makers. Weatherby is famous for this.

The problem comes in with factory ammo. It is generally considered to be true that if you move away from the funnel throat long freebore chamber in a Weatherby to a "match" dimension neck/throat/straight section, you give up the ability to shoot factory ammo at safe pressures.

This is the reason my smith abandoned the 7 RUM. He did not want to continue down this path of the "funnel throat magnum", and built the rifle around what was considered "the best" magnum available now, the 7 WSM, and "the best" bullet, the 180 gr Berger. He had done Weatherby-based long range hunting rifles long before the current rage. The 7 WSM case just becomes the mule at this point, SAAMI specs and factory ammo for the chambering be damned.

Just understand the ramifications of the various paths in front of you before you venture down one is all I'm getting at.