338 caliber questions

[benny1]

Does anyone have any experience with improving the 338 rum or anything about the 338 stw

 

[MudRunner2005]

I'm pretty sure there is a .338 RUM Imp.

And the .338 STW is actually called the .338/8mm Rem Mag. But I personally like .338 STW better. Sounds more like a hotrod caliber.

 

[Deleted member 46119]

There is a 338 RUM 'Improved' I think its called a Jared and is based on a 300 RUM shoulder blown out and forward. I'll try to look it up later.

 

[MudRunner2005]

There is a 338 RUM 'Improved' I think its called a Jared and is based on a 300 RUM shoulder blown out and forward. I'll try to look it up later.

I think you mean Jarrett, as in Kenny Jarrett the gunsmith and wildcatter.

 

[Deleted member 46119]

I think you mean Jarrett, as in Kenny Jarrett the gunsmith and wildcatter.

Yes.

 

[azsugarbear]

Kirby Allen has a wildcat called the 338 Allen Express. The design utilizes the 338 Lapua case, with his design blowing out the side walls of the case, moving the shoulder forward and finally changing the angle of the shoulder. His improved version gets another 100-150 fps or so with 300 gr. bullets over the standard 338 Lapua cartridge.

 

[J E Custom]

Does anyone have any experience with improving the 338 rum or anything about the 338 stw

There is a 338 AI RUM PT@G Has the reamers in stock. the advantage of the 338 AI rum is that it has identical case capacity as the 338 Lapua and does not need a special bolt face/extractor.

The 338/8mm Rem (STW) is also a very good wildcat but does not have the case capacity of the 338 AI RUM.

The fact that the 338/8mm STW has a belt is of no concern to me. they are proven shooters.

J E CUSTOM

 

[benny1]

Thanks guys for your input I've a 338 rum and love it but I'm trying to find something else to play with comparable ballistics or better that can be built on mag bolt face and long action so if I can get lapua ballistics on this I'm interested thanks agin for the feed back

 

[Cold Trigger Finger]

The 338 Edge is just a necked up 300 RUM. A friend built one and it is very impressive. I have no idea why Remington didn't just do that from the start with the 338 RUM. I've had a 338 RUM also and I really like the round but would have preferred if they would have just necked up the 300 and called it good.

 

[J E Custom]

The 338 Edge is just a necked up 300 RUM. A friend built one and it is very impressive. I have no idea why Remington didn't just do that from the start with the 338 RUM. I've had a 338 RUM also and I really like the round but would have preferred if they would have just necked up the 300 and called it good.

The 338 RUM has the optimum powder capacity for a 26" barrel. The 338 EDGE can utilize a 28''
or 30'' inch barrel , so if you are going to build a 338 with a long barrel them go with a 338/300 RUM.

The factory was not going to build a 338 sporter with anything longer than a 26'' barrel so they shortened the case for best performance in there rifles.

The 338 RUM is very close to the same case capacity as the 338 Lapua and is its ballistic twin If loaded to SAMME pressures.

Before they became hard to get I used the 375 RUM cases necked down to 338, especially if they needed to be fire formed to a wildcat (It was easier to size them down to 338 diameter and load).

If I were going to build on a Remington I would prefer the 338 AI RUM for bolt face size and mag length.

If I were going to use a Weatherby Mark 5 action, I would go with a 338 Lapua Improved for the case strength and the larger bolt size. Plus the MK5 has a very long magazine length.

J E CUSTOM

 

[azsugarbear]

An additional reason for making the 338 RUM shorter was safety. The shorter chambering of the 338 RUM precludes the possibility of someone mistakenly loading a 300 RUM into the chamber.

 

[Cold Trigger Finger]

Aparantly it was very common to find slightly used 338 RUM model 700 s in gun shops in Washington and Oregon not too long after they first came out guys would buy them, get ringed real good or just get their bell rung from the recoil and then trade them for a standard cart rifle or a 7 or 300 mag. .
Most guys can't take a moderate amount of recoil.
Mine was nice and light and I kept it that way by putting a Leupold M8 fixed 4 power on it. Where I lived at the time was over run with brown bear and I was after a nice light deer rifle that would keep big bears off me. A guy I was hunting with totally ruined a chance for me to try it out on a good size bear then the next spring another friend REALLY wanted the rifle and I was on to the 375 Ruger so I sold it.

 

[Cold Trigger Finger]

But even with the 26" barrel I could have got more velocity with the 275 grain bullets that I shot in it. And the 300 gr bullets would have been benefited from more powder capacity . .
I also found that it wouldn't have been too hard to get the 550 CZ action to feed it and the Edge.
The factory 250 gr Swift A Frame load chronographed 2950 fps with less than 25 fps variation. I got the 275 s up to 2900 fps with H1000 or 7828 . I wanted to try Retumbo but sold it before I got some.
If I was going to build a mile shooter I would start with a Richardson+Roberts action and have Matt build a 338 Edge probably with a 28" barrel with one of those jet engine brakes on it. Have Matt mill as much moa into the square bridges as he could and make them Picatinny bases.