I recently picked up a Winchester M70 Extreme Weather chambered in 300 WSM, manufactured in 2017, but looks almost new. It appears very lightly used, put a bore scope down it, threading all looks fine, no issues to note and it was a good deal so I bought it. Grabbed 3 different boxes of ammo from sportsman's, all Federals, 165 gr, 180gr, and 200 gr. Long story short they all shot terrible, like 3"+ at 100 yds. I have quite a few 212 ELDX's and 210 VLD's and both IMR 4350 an H4350. Anyone have some loads that they use or have experience with accuracy issues in the M70 300 WSM? If you load the 210 VLD's what COAL are you guys at so I can have a rough idea where I should start. Thanks in advance.
Loads for 300 WSM? M70 Extreme Weather
- Thread starter ktsmith29
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It has Warne steel rings and a Warn pic rail. Bedding is just the factory bedding. i did put it on the mill and clean it up a bit because there was some residual bedding material in contact with the barrel. I will eventually re-bed it, but even with the poor factory bedding I was surprised at how bad it shot. The barrel is completely free floating now and the action screws are torqued to spec. I also swapped scopes and same issue so not the scope.
Does seem like something is out of wack. For 3” groups with that variety of ammo I’d be wary myself. Any torque on the action now that you’ve cleaned up the factory bedding?
I’d pull a book load with H4350 and get the 212’s in as close as you can to the lands and see what happens as a test. Usually they’re incredibly easy bullets to tune so if those are spraying something has to be amiss.
I’d pull a book load with H4350 and get the 212’s in as close as you can to the lands and see what happens as a test. Usually they’re incredibly easy bullets to tune so if those are spraying something has to be amiss.
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I agree with Scotty. Something seems amiss, and that should be sorted out before investing money, time, and effort in load development.
Last week my gunsmith showed me a Win. Super Grade M70 that had been brought in because it won't group. It turned out that the chamber was out of alignment with the bore.
I had a 300 WSM once in which the bolt face wasn't square to the bore.
Do you have a reliable gunsmith where you can take it to be checked out?
Last week my gunsmith showed me a Win. Super Grade M70 that had been brought in because it won't group. It turned out that the chamber was out of alignment with the bore.
I had a 300 WSM once in which the bolt face wasn't square to the bore.
Do you have a reliable gunsmith where you can take it to be checked out?
Ralt71
Handloader
- Jun 6, 2025
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- 401
Nothing I can add here that these guys haven't already touched on. If it won't shoot 180's from factory ammo in a tight group it's most likely an equipment issues for sure. My 300 wsm all shoot well, it's a fantastic caliber.
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