338 rum rifle build?

[oltmann]

I have to think the brass issues you mentioned are the ones I had?

Don't worry, it's easy to reload for if you take your time and do it right. I have fired a couple hundred reloads from 300 RUM necked up to 338 without issue.

I recently got hasty while setting up my dies on someone else's press and undersized(shortened) the brass, this lead to case stretch and seperation.

I also had to switch to 375 rum brass because it was all I could find. This brass is going to require more prep since it is being sized down. Now that I'm back on track, I don't anticipate any more problems.

 

[lamiglas]

Thank you all for the information. it was good to hear input from guys who really know there stuff. I did alot of research on this gun before now and decided the edge was the rifle I wanted. my only recent concerns have been explained here and with additional research. I no longer have any hesitation with this choice. thanks again!

 

[highridge1]

I would go with the 338 Ultra if you decide the rifles isn't right for you alot more guys know what a 338 ultra is over the 338 edge and you could more easily recover your investment.Also what does the 338 edge bring to the table that the338 ultra can't do?? Nothing as far as I am concerned.If you really want to step it up more go the 338-378 then you clearly have a gain ballistically.I don't quite get all this 338 edge hype.

 

[rolly]

Still learning here, but why neck up a 300 RUM to 338 if there is a 338 RUM? What characteristics make the necked up version better than the factory round? If necking up a 300RUM to 338 makes it better, why not neck the 338RUM to 416?


Since I don't yet reload, I may do the same project just starting with the 338RUM and "upgrade" with a rebarrel to 338 Edge later if needed......if in fact it's needed..

 

[highridge1]

But really how would it be a upgrade? The 338 ultra mag is a fantastic round and extremely accurate.I really don't see any advantage to turning a 338 ultra into a 338 edge in fact I think it makes no sense at all..

 

[Bigcat_hunter]

Still learning here, but why neck up a 300 RUM to 338 if there is a 338 RUM? What characteristics make the necked up version better than the factory round? If necking up a 300RUM to 338 makes it better, why not neck the 338RUM to 416?


Since I don't yet reload, I may do the same project just starting with the 338RUM and "upgrade" with a rebarrel to 338 Edge later if needed......if in fact it's needed..

The factory 338 RUM brass is a little shorter than the 300 RUM brass. But I also don't see much of an advantage between a 338 RUM and a 338 Edge as highridge1 stated. Most guys run about 92 grains of 1000 with there 338 edge and thats what I run with my 338 RUM. If I had a 30" tube I would probably get close to the same velocity. Although you are limited to remington Brass with a 338 RUM.

 

[rolly]

Ahh...I didn't know it was a shorter case. Thanks.

Either way, I've seen good and bad written for either. Since I don't reload at all, the 338 RUM is probably where I'll start.

 

[J E Custom]

I don't want to hijack this thread but what kind of velocity does the 338 Edge
produce with a 225gr and the 250gr AB with a 26" tube?

J E CUSTOM

 

[Long Time Long Ranger]

J E , I don't see where your highjacking the thread. Looks like a good question to me. I have built and shot bunches of both of these over the chrono. 200 grain bullet averages about 3300 fps. 225 about 3150 fps and 250 about 3050 fps and these are the hottest you want to shoot them safely with any brass life. The difference between individual barrels could make either the 338 ultra or the 338-300 ultra faster but the latter usually is just a tad faster. Just not much difference. My old 340 wby shoots the 250 at 3000 fps so just not much difference between any of these. The guy with the most accurate one of these has the best one to tell you the truth.

 

[Lightvarmint]

Hello,

My one fully custom repeater that I use during the rut in Missouri is a Hall Express in 338 RUM w/ 225 Accubonds at 3220 and loaded to function in the magazine for running shots. Basically unlimited brass life at these pressures (still on the first set of brass)..... I had the reamer set up to engage the lands at the magazine box length and the rifle likes the bullets .030 off the lands. Very accurate and lethal combination.

Now if you really want something impressive, take a look at this....... We have a 30/378 that we shoot .900+ BC Henson bullets at 3274.9 fps. When you crunch the numbers on this comparing it to the 338 Allen Magnum using 300 SMKs at the velocity that Kirby recently posted on this website (for his 5 shot case reloading pressure level which is the same criteria in the 30/378), you will find that this 220 grain high BC Henson bullet SURPASSES the bigger 300 SMK at 1700 yards in KINETIC energy, is running 252 fps faster than the 300 SMK and has 13.5 FEET LESS DROP at that same yardage as compared to the 300 SMK fired out of the 338 Allen Magnum.

At 3000 yards the velocity is 1065.8 for the 220 grain Henson bullet and 936.3 for the 300SMK.

All of this with 40 or so grains less powder using the 30/378 Weatherby case versus the Allen Magnum case.

To me, this is impressive............. And MUCH MORE efficient!

James

 

[J E Custom]

Thanks Long Time Long Ranger , Thats what I though but I
dont own a 300/338 so I didn't want to quote the reloading
manuals that are not allways accurate.

My 338 RUM is built on a Weatherby mark 5 with a 26'' Lilja
and my velocitys are 3162ft/sec with a 225 AB and 3012 with
a 250 AB and these are not MAX loads.

So there is realy not much difference in the two after all.

I am a bigtime fan of the 340 Weatherby and use to load 250gr
partitions to just over 3000 ft/sec without problems.

So I'm sticking with my 338 rum.
J E CUSTOM

 

[Long Time Long Ranger]

That 340 wby is a great cartridge and I can't understand why it never took off and the 338 ultra is all of a suddun a world beater. Just not much difference performance wise and we have had the 340 for over 40 years. I remember when 7828 powder came out it really turned on my 340 for long range elk shooting the 250 gameking at 3020 fps. At that time it was the highest BC bullet I could get. 30 years ago that was a very impressive load for elk. I know mine impressed a few! The ultra will definitely outperform it but not by much when your talking about that much power.

Lightvarmint, Looks like your loads are right in the range. What length barrel are you shooting in your ultramag? My personal 338-300 ultramags shoot the 200 grain ballistic tips at 3350 fps with a 28" barrel and that is a very definite max load with about three shots per brass.

 

[Lightvarmint]

Hello,

My barrel is a 28" Hart 10" twist. The major reason I chose the ultra mag over the other offerings for my magnum bolt face repeater was due to the belt. I don't like the belts. The belts seem more fussy even with the accuracy innovation belt tool as it adds another step to the reloading process.

James

 

[Long Time Long Ranger]

I went down to the basement and sifted through some boxes of my old loads from several years back just to check my memory on this to make sure I had it right. I found loads on two 338 Lapua's with 26" barrels. The accuracy loads averaged 3476 with the 200 grain ballistic tip. Accuracy load was 106 grains of WMR and the bullet seated on the lands. The average of eleven 338-300 ultramags that I could find data on averaged 3358 fps with max accuracy loads and the 200 grain ballistic tip. This was with various powders but they all maxed right in there. The barrels on the ultras varied between 28"-30". The max loads on the Lapuas averaged about 2-4 grains more of the same powder. When I find data on other bullets I will put it in here. The Lapua, which is a shortenned 416 Rigby, fell right between the 338-300 ultramags and my full size 338-416 rigby's and 338-378 weatherby's.

Other interesting data I found was my little pet 358 ultramag shooting 225 grain ballistic tips at 3419 fps with a 7 fps extreme spread on a 5 shot group. The group was 3 6/8" at 650 yards. That is an elk killing machine. This is a hart barrel with 1-16 twist and the weatherby freebore in it which is probably the difference with the high velocity.

For comparison my pet 338 gibbs accuracy load shot the 200 ballistic tip at 3068 fps. This is all you can get out of a 30-06 case. This was with H-414 powder.

I have boxes of data on all kinds of wildcats I have done over 35 or so years. I need to get it all together in book form for easy access. I guess now retired and a shattered leg might be time to start that process.

I found my long range coyote load for my 240 gibbs shooting the 70 grain ballistic tip at 4226 fps and my 257 STW antelope killing load of 3987 fps with the 100 grain Barnes. This really got to be fun reading.