Rem 700 RUM action safe for Lapua/Norma

[Shane Lindsey]

For now it will stay as a RUM.

I had the Wyatt's mag cut, but because I failed to research properly, I had the 3.85 cut instead of the 4". I thought I could buy a new bolt and go Norma for the shorter length. It shoots great now with the 245, but not what I had hoped for with regards to velocity. Hoping the shorter, fatter case would get a little more.

Guess I'll save some $$$ and if really wanting that cartridge, spend the money...

Thanks for the input gents...

 

[MagnumManiac]

The thing I am seeing in this discussion is that folks are suggesting removing material from the feed ramp.
THIS IS COMPLETELY INCORRECT!

Nobody is suggesting this, but I do know it is done by those not familiar with action conversions.
True, it's not necessary with a Wyatt's box.
As to the feed ramp being altered for feeding…I'll leave that aspect up to you.

Cheers.

 

[meatyrem]

Or. Just go 338edge and be done with it. You wanna go 338 anyway and if you have a rum then you already have the cases.

 

[tobnpr]

The concerns with using cartridges like the Lapua Magnum with .587 boltfaces on standard magnum long actions is the increased bolt thrust, with the lugs and abutments being beefier to handle it.

Bolt thrust is a function of casehead diameter and pressure. Even thought the .338 LM has lower pressure than the .300 RUM, it still has higher bolt thrust due to the .587 boltface.

I have not ever handled one of the factory M700's in .338 LM. I tried to purchase one through Brownell's years ago- they were unavailable- but I was told they are not the same as the standard LA's. I do know for a fact, that Savage boltheads on their .338 LM's have beefier lugs.

As a riflesmith I will not build a .338 LM on a standard LA not designed for it.
Is this "overly" conservative? Perhaps- but it'll be my *** on the block if you have a case separation due to lug setback 1,000 rounds down the tube.

That said- I look at this sorta like Titanium actions. Not practical for high-round count applications like target shooting, fine for light use hunting. This is a function of round count- the lugs pounding into the abutments with greater force than they were designed to withstand can cause plastic deformation/permanent setback. On a high-round count rifle, that setback- if not monitored/measured- can eventually case headspace to increase to a potentially dangerous length.

I'll add food for thought...
Try to find a barrel maker that'll sell you a prefit in .338 Lapua Magnum. Most do not offer them, and that's for a reason.

JMO, worth what ya paid for it.

 

[sp6x6]

Cody on here has a 338 NM,built on one I believe and doesnt push it hard.And he has a custom , that he pushes harder.When I was doing load work, I talked with Glen,owner off Defiance.Had some sticky bolt,he chewed me out for pushing it there.Their custom action,he said that is alot of pressure if I take it there on my action,warned me to back off

 

[ARlife4me]

This was my concern. Bigger case, wasn't sure if they lugs were beefier on that type of action by design.

I have 2 savage 110 (1 300wm and 1 338lm) and both bolt lugs measure the same.

 

[Shane Lindsey]

So I took a totally different approach. I bought a 338 Sherman prefit. Will snug it up on my 110 action and voila, I have a 338. My woods it is more than adequate.

I figured I have a good bit of time before any barrel is ready for a change.

Thanks all. Will do an Edge/RUM or what ever this action was designed for. IF Lapua/Norma is in the cards, I will seek the appropriate action for the duty.

Good luck this year...

 

[Shane Lindsey]

So I took a totally different approach. I bought a 338 Sherman prefit. Will snug it up on my 110 action and voila, I have a 338. My woods it is more than adequate.

I figured I have a good bit of time before any barrel is ready for a change.

Thanks all. Will do an Edge/RUM or what ever this action was designed for. IF Lapua/Norma is in the cards, I will seek the appropriate action for the duty.

Good luck this year...

@shortgrass. That is with that action I got from you...

 

[shortgrass]

Just my 2 cents... I f I was going to build a 338Lapua, Rogue or NM, I'd be seeking out a custom action designed for these larger diameter cartridges. They feature larger diameter bolts and larger diameter threads (and a barrel with a larger diameter 1.35" shank}. My thoughts are, "I want the absolute" if I'm going this route. If the 'best' accuracy node is near the top (in pressures) I don't want to have the sticky bolt or other potential issues to contend with. Sure, several production produced actions have been offered for the Lapua and many have been converted by gunsmiths or a pre-fit installed by a hobbyist, and that is up to each individual. My whole train of thought is, "I would want to be able to take full advantage of the chambering, without having to potentially sacrifice because I used a 'lessor' action." I'd not want one on a common production action just to be able to say, "I have one." Just as a side note, I think I have changed out more extractors on Rem 700s chambered in UMs, than in any other of the common chamberings.