338 Lapua or 300 Win Mag to 7mm Rem Mag conversion

[glennjames]

I am looking to build a 7mm Mag to shoot 1000-1200 yds but would also like to have the opportunity if the need arises (and we all know it will) to be able to push out a little further. Can I take the savage 338 lapua or 300 win mag and swap barrels and bolt face and achieve my goal?

Thanks in advance
New member here and I did a search but did not find exactly what I was looking for. I saw where there were some trying to go from 7mm Mag to 338LM, but I personally would not want to go smaller to bigger caliber.

[Redandwhite_72]

A 300wm should have the same bolt face as a 7mm rem mag, if I'm not mistaken. So you could just swap barrels and not change the bolt head. And if you want closer to the lapua you could do a 338 edge and still not change the bolt head, just the barrel. But unless you buy a dedicated 338 lapua action, it will be a single shot with either an edge or lapua, without some machining and most guys here won't recommend a lapua on a standard action.

[lrshooting]

I wouldn't stick the lapua on anythng other than a magnum or specifically designed action for the 338...Then again, it looks like you were saying swapping barrels from a 338 down to a 7mm remmy so I dont see why not. You would have to find a bolt head for it though...

[nso123]

Are you specifically wanting both a 7mm and a larger caliber? If not, you might be best served by looking at the 300WM with a 208gr bullet. It will get you well beyond 1000.

[Hotolds442]

Start with the 300WM, and all you'll need is a barrel and headspace gauges for belted magnums. Very simple.
Start with the 338LM and you'll need a barrel and bolt face, extractor, ejector, springs, pin, and ball. Add a set of headspace gauges for each and you'd be set providing the 7/300 will stay in the 338 magazine without issue.
Its not hard to figure out which route would be the easiest.

[glennjames]

Well here is what has transpired. I actually found a used Savage 110 7mm mag that I am going to use as the donor action and bolt. I am going to sell the barrel if at all possible (or just put it in the corner) and get a new stock, rail and 26-28 in. barrel. Work up a load with Hornady 162 gr a-max and see what happens. Any recommendations on load data for this rig? I actually have some Retumbo on hand. What brass to buy? Last question i promise.
Does anybody know what brass does Black Hills use in their 7mm Rem Mag Black Hills Gold 162gr. A-Max Polymer Tip Ammo?
Thanks for all the replies and help!!
You gentlemen are GREAT!!

[WinnieTheBoom]

Lapua brass if you can find it, followed by Remington/Norma/etc. .300 wm is about the smallest I would try to use with Retumbo, it's a realllyyyyy slow burning powder and was really meant for the big big calibers. It will work but I'd be willing to be that you'd be much better suited with H-1000, RL-22, 25, etc.

As a parting note, please do NOT try to shoehorn a .338 into that action, it is not going to end well. I would, however, recommend necking down a 300 win mag to accept a 7mm projectile, because that will get you out well beyond 1,500 yards if/when the need arises.

good luck.