Howdy folks-

I have an extra Rem. 700 in 7mm rem mag. laying around. I have been considering rebarreling it to .338 RUM. Will it just require a new barrel, or will I need a new magazine box as well?

Does anyone have any thoughts pro or con about the round. I am also considering building the rifle up as a 358 STA. Which would you choose?

Thanks in advance for your responses.

Gib

Gib,

A mate of mine had a Rem 700 Stainless in 7mm Remington rebarreled to 300 Ultra and it works fine although it only holds two shots in the magazine. I think you can buy a magazine box from Brownells like Rem uses for the Ultras. On the other hand some people on the forum have said that the rails of the action need to be altered.

I have had three barrels in 358 STA. I think the 358 STA is better than the 338 Ultra if you want play around with barrels of different groove diameter and different twists as well play with reduced loads with pistol bullets.

But for a gun just to shoot the calibre's standard loads I would prefer the 338 Rem Ultra.

Mike

My first 300ultra was built from a 7mm mag action.The rails need to opened up slightly for proper feeding and the magazine insert needs to be modified or replaced to hold the third round.The rifle feeds just as well as my second 300ultra which was built on a factory ultramag action.I considered the 358sta but in the end chose to have a 338x8mmremmag built instead due to a better selection of .338" bullets being available.This was before the ultramag was available or I would have chosen the 338ultramag.

[ 05-23-2003, 17:47: Message edited by: stubblejumper ]

The .358 STA is going to be a little simpler to build on your 700. All it takes is a new barrel, with no work on the magazine, feed rails, etc.

If you prefer the .338 bore, the .338/8mm Rem Mag would be an excellent choice. It's velocities will run virtually equal to the .338 RUM, and it also requires no alterations other than a new barrel. In fact, if you are satisfied with Remington barrels, it's cheap and easy to find a .338 Win Mag take-off and have it rechambered and fitted to your action. This would be extremely economical.

Putting a 300 Ultra mag on a standard 700 is a piece of cake but I found the 375 to be a bit more of a problem to get reliable feeding. The 338 shouldn't be as bad as the 375 but may be a little more trouble than the 300. Regards, Bill

I have built a switch barrel M-700 in calibers .257 wby through .338 Rum ( five magnum barrels to be exact and a spare 30-06 bolt for cartrtidges of that rim diameter ( .306/35 whelen etc.)) . This is an easy conversion only requiring a new mag box and a sako extractor. The .338 Rum is an extremely accurate cartridge easily capable of exceeding the .338 Lapua.-Rob

Will a 338 Ultra reamer cleanup a 338 Lapua chamber?

Gib,

It makes more sense to just sell the 7mm Mag and buy a .338 RUM. If you remove the barrel from that action you are throwing away it's value and just spending money on modifying it for the longer round.

You can get a new gun right away too and have a warrantee rather than waiting for it to get done.

Also rebarreled guns don't bring squat on the market. Just run the numbers.

If you buy a factory 338 ultra you will have a factory rifle with factory barrel and factory performance.If you have the action trued and a quality barrel installed and properly bedded you will have a much higher quality rifle with a much better potential for accuracy.You also can specify the length,countour and twist rate of the barrel and the type of bedding you desire.