Home Forums Reloading Big Game Rifles 300 WinMag - Seating Depth/magazine length question

I agree with FH and that is what I have used in the 300 Win mag as a very good place to start with a 300 WM.

Also agree regarding the longish throats and why factories do it.That said it has caused me some issues in M70 Classics.I have seen some accuracy issues with lighter bullets. The 180's and up seem to jump the distance and shoot well;in some rifles 165's did not do so well.This issue of making a jump to the lands is no big deal if the throat is cut with a good reamer IME but factory dimensions of the throat can be a bit sloppy....some will shoot and some won't.

Also deep seating can cause tension issues with SOME bullets in the short necks of a 300 WM.

The solution for the M70's was to change out the mag box,follower,ejector,etc for 300 H&H-length.This allowed seatin closer to the lands(not too close!) and just made life easier.I figure if you can have the magazine length you might as well get it and use it.

Let me rephrase my self, I used a max load of 75g of the two I loaded. I typically don't use book max, so I followed the preceding load which was 75.0g, the next step down.

Bob
About lengthening the magazine with the 300H&H magazine, follower etc, how do you get around the feed ramp if it's a standard length action? I'm curious about this option as well.

"my bullets are having to make an (almost) 1/4" jump to get to the lands...Is this normal behavior for rifle companies (mine, Ruger 77) to throat this round way out there, while restricted ultimately from the magazine well?"

Yes. ??

might check if wyatts makes an extended mag for your ruger. had one installed in my 700p so i could seat my 300rum out farther

boomtube, please add to your response so I can understand where you're coming from.

My experience is that rifle companies understand cartridges like the 6.5x55 Swedish Mauser, which needs a long action, fast twist to accomodate longer/heavier bullets. They could have put the Swede into a short action, but they didn't, for a reason.
Any insight into why the 300 WinMag wasn't designed into a Magnum action rather than a Long Action?
Thanks.

stxhunter, thanks for the lead, I'm going to look into this if or when I find that bullet seating is resulting in my poor accuracy. This will be a project that will miss this year's hunting season, no doubt.

kcT: On the M70,there is no feed ramp issue;it is already configured for the 300 Win mag.A M70 Classic action of 30/06-length is long enough,as it comes, for any H&H-length round.But in 300 WM,338,7RM,etc,they put a 30/06 length magazine box(actually there is a block in the magazine).

If you swap out the M70 Classic parts,(box,follower,bolt stop and ejector)for H&H length,there is no modification done to the feed ramp,no metal removed from the action itself.

I just had a custom rifle built on a Classic action originally chambered for the 270 Win.It has been converted to handle a belted magnum loaded to H&H length.You can do this with any M70 Classic of 30/06 length, ie build a 375H&H length cartridge on them;a nice thing about the design.

I think it can be done with a Ruger,but not quite so easily,and may require additional work...I am not certain as I have never had it done.