338 ULTRAMAG----Barrel / Bullet selection??

[ultramagbrion]

My next project is a Long Range toy simmilar to the AR-30

I just picked up a SS 700 Remmy BDL in 7MM RUM....Im going to build a 338 Ultramag in a barrel block skeleton stock.

With a diameter of 1.250 + .......length and twist are my questions.I want to smack steel at 1000yds plus.


So........what do you good folks suggest for length and twist and what VLD bullets in .338 around 200-250gr do you suggest??

 

[Rust]

Been playing with the RUMs in .300 and .338 since they first came out. Decided against monkeying with the .300 and made the .338 my project rifle.

Right off the bat I settled on a 250 gr Lapua Scenar,better BC than the 250 gr SMK, less recoil than the .300 SMK), RL-25 right around 94-95 gr or whatever produces a muzzle velocity in the range of 2950 fps,which seems to be a good accuracy velocity for the Lapua Scenars in 6.5, .30 nd .338 diameters thus far) and a Winchester primer. Extremely accurate even out of the original factory Sendero-SF, even when it still had that awful J-lock. It should carry out to about 1,500 to 1,600 yards supersonic.

Once you've got a good load, stop playing around, you won't find anything suddenly magically better. Lots of folks will tell you their load,much like their dog) is better than yours but as long as you've got decent ES/SD numbers, leave it be.

1-10 twist is just fine. And I had no problem hitting 2950 fps out of the original 26" factory barrel, matter of fact, it would do a good but more but the accuracy node was at 2950 fps. You don't need a truck axle diameter straight barrel either unless you plan on putting about 10 lbs of lead in the butt end the balance will be poor and yes balance still counts when using rests, a bipod or bags.

Basically what I'm suggesting is keeping it fairly uncomplicated, which makes it a bit easier to hit goals, like it worked the first time and not only that it worked well. Complicated tends to take money and,just as important to me nowdays) time with sometimes less than a successful outcome.

 

[ballistic64]

I went ahead and ordered a Rock Creek .338 1-10" with a finish length of 30",#8 1000yd contour) when Rock Crk. hosted a group buy on another forum.Ive always wanted to do a 338 project and couldnt pass up the prices Paul gave for the buy,especially with what steel prices have done the past couple years.Im still undecided about which 338 Im going to do,but with Nosler selling 300rum brass the 338-300rum is pretty tempting.

 

[ultramagbrion]

................ what I'm suggesting is keeping it fairly uncomplicated, which makes it a bit easier to hit goals, like it worked the first time and not only that it worked well. Complicated tends to take money and,just as important to me nowdays) time with sometimes less than a successful outcome.

Good advice. Im not looking at doing much more than a rebarrel and playing with the stock trigger. I may send the action to Tannel to have him blueprint it propper.
As far as the stock goes......Im a firm believer in barrel block styles, and Ill build the stock myself.Ive been sketching ideas for a year now in my head.

 

[ultramagbrion]

Im still undecided about which 338 Im going to do,but with Nosler selling 300rum brass the 338-300rum is pretty tempting.

I cant see paying the astronomical $$ folks get for their 338 Lapua brass

The small edge the Lapua gets from their 338 isnt enough to sway me from the RUMs.....and the Wetherbys are out of the question.

Ive liked the Ultramags since their inception.

 

[acloco]

I did the same as Ballistic - Rock barrel in 338. I went with a 33" barrel though. Will finish at 31.5 to 32 + the muzzle brake.

 

[varmint]

Brion,

I agree with you on the .338 LM. I build a .338 RUM with a 30" barrel and I get more vel. with it than all the loads I have seen for the .338LM, so why would I want to pay the high price for that brass,and you may have a hard time finding it around in the US. .338 RUM is every where and don't cost a arm & and leg to buy.The thing that gets me is why would you want to burn a 100& some grains of powder to get,FPS) whtat I can load with under a 100grs of powder.Just my 2 cents. Tim

 

[ultramagbrion]

Brion,

.The thing that gets me is why would you want to burn a 100& some grains of powder to get,FPS) whtat I can load with under a 100grs of powder.Just my 2 cents. Tim

Tis what I was thinking too.

......like I said.Its a toy. I cant compete with the 50 cal guys,one of those is the next build) and its overkill for 1000 yd benchrest.

I really just like the big guns....and I can do it without spending a ton of cash.

While the realistic factor is very low........the cool factor is right up there.

 

[Rust]

Simplicity. Cool factor used to appeal to me a lot more and back then I ended up shooting less as there always seemed to be just one more thing that needed to be addressed. Matter of fact, there are still a few cool factor projects sitting in various corners gathering dust.

Just bought a factory 700 in .308 just to have something to go out and shoot, a lot. First time out two loads printed around just over 1/2 moa. Of course the barrel is a little slow, and it really picky about those loads, and the trigger needs a little work, and the stock could have 3/4" shorter LOP... but the bottom line is I was shooting it the day after I bought it.

 

[ultramagbrion]

Simplicity. Cool factor used to appeal to me a lot more and back then I ended up shooting less as there always seemed to be just one more thing that................. ,snip)..................... but the bottom line is I was shooting it the day after I bought it.

Is it practical ? No.
Can I shoot it now? No.
Do I care? Obviously not.

I have a Savage 12 Varmint that I can shoot now.,And a dozen others that are also fun and accurate)
My 6BR is almost done......and it will be practical.

My next project WILL BE this 338 RUM. And I dont have a problem with it. And if you thing THATS impractical.....I'll be building a 50 after that,if I dont go with a 6.5RUM


But thanks for your input just the same.

 

[bama110]

ultra,

I am a 338 RUM fan also. I just built a modified 338 edge. The Edge is a 300 RUM necked up to 338 it gives you more powder capacity. The edge will shoot with a Lapua. Either way I can not wait to shoot mine and I am sure you are the same.

FYI I set mine up for 300 grains by making the throat longer this also increase powder capacity. I should get 3000FPS with a 300gr. This gives a 20moa drop at 1000.

 

[dennisinaz]

I had Pacific grind me a reamer in .340 WBY that allows me to seat 300 SMKs out to the bottom of the neck but tight enough that I can still shoot regular bullets accurately too.

I have a 1-12 Schneider #5 contour and it handles all the 250s I've thrown through it no problem. I haven't tried the Lapua so I don't know what it will do. I get 3200 fps with Norma powders and 250 grain hunting bullets. This is 33-378 velocities in a normal factory rifle.

It does prefer 200s and 225s for gilt edge accuracy so I would suggest at least a 1-11 if you are going to shoot 250s. Since 1-10 will shoot 300s you really don't need more than 1-11 and it's easier to hot-rod the slower the twist.

 

[biglonnie204]

its all about the cool factor and the motto "he who dies with the most toys wins"