New 338 is Finally Done! :)

[BigDMT]

I thought I'd show you folks a couple pics of the new 338-375 Ruger rifle I just got done building, and perhaps pick the brains of some of you that may have experience with this caliber. Looking for load data specifically, but any other input is much appreciated. I have the 250gr Berger Elite Hunter bullets on hand and that is the only weight I plan on shooting out of this rifle. Will be used mainly for hunting deer and elk.

Haven't fired one round through her yet, so I still need to break the barrel in then begin load development. Case capacity of the 338-375 Ruger is 1 gr of H2O more than the 340 Weatherby, so I believe I could start with medium load data pertaining to that caliber and work my way up. But would appreciate any info on loads used specifically for the 338-375R. Perhaps even pet loads for the 340 Weatherby using 250gr bullets. Thanks Folks

Action: Remington 700 Stainless Magnum, lapped and blueprinted to barrel,
Barrel: Brux Stainless .338, 1 in 10", Rem Sendero contour, finished at 26"
Stock: Bell & Carlson A2 Medalist, full aluminum skeleton, black with gray web
Optics: Bushnell Elite Tactical 4.5-30x50mm
Other: Timney "flat trigger" @ 1.5 lbs, Badger Ordinance .316" recoil lug,
Blackhawk one piece scope base, Burris Tactical rings, bipod, sling,
PTG Speedlock firing pin assembly and bolt shroud,
Full action bedding with Devcon Steel Puddy.

PS: I know, I know...I need to cut my grass lol!

 

[Terry]

Good looking gun.

 

[MrMajestic]

Nice Rig! Hope the Neighbors don't call the Cops! ;D

 

[BigDMT]

Nice Rig! Hope the Neighbors don't call the Cops! ;D

lol! not in Montana

 

[barnesuser28]

Awesome rifle, i like the bolt fluting and skeletonizing (i just realized how weird of a word that is : LOL). I plan on putting that stock on our next build that should be chambered already. Ironically also off the 375 ruger case, but a 30 cal variant.

 

[BigDMT]

Awesome rifle, i like the bolt fluting and skeletonizing (i just realized how weird of a word that is : LOL). I plan on putting that stock on our next build that should be chambered already. Ironically also off the 375 ruger case, but a 30 cal variant.

With some heavyweight VLD bullets, I'm sure the 30 cal version will be one mean long range machine

 

[barnesuser28]

Awesome rifle, i like the bolt fluting and skeletonizing (i just realized how weird of a word that is : LOL). I plan on putting that stock on our next build that should be chambered already. Ironically also off the 375 ruger case, but a 30 cal variant.

With some heavyweight VLD bullets, I'm sure the 30 cal version will be one mean long range machine

Thats what i am planning! I am going to try the 210 ALR and get some custom bullets made in the 208-228 grain range. Have fun with your rig and let us know how it shoots!

 

[BigDMT]

Will do. I'll be back home on the 29th and I'm going to start breaking in the barrel right away so I can get it done and start running her through the paces with various powders.

 

[BigDMT]

I was talking about loads with a member through PMs and he said he was able to achieve 2925 fps with a 250gr bullet from a 340 WBY with a 26" barrel. So I hope to hit right around 2950-3000 fps with my chambering in an identical 26" barrel since it has slightly larger case capacity and is supposedly more efficient at burning powder. At the speeds I am expecting to see fired at the 4000 ft elevation where I will be load testing and in 40 degree temp, ballistics calculators estimate that my 250gr Berger VLD bullet will only drop approximately 20 MOA at 1000 yards and still be packing a massive 2150+ ft lbs of energy. And those calculator estimates could end up being even better since most of my actual hunting areas reside at elevations from 5000-7000 feet. Either way, that ought to make for a nice freezer packer

One thing that concerns me is whether or not I will see more pressure earlier on than the 340 WBY chambering due to lack of freebore.....

I've got a sneaky feeling that this rifle is gonna shine with charges of RL-22 or RL-17...

 

[BoydAllen]

I have helped a friend work up loads for two custom .338 Lapuas. We worked with a full reloading setup, chronograph, and flags at the range, on more than one occasion. The powder that worked well for him was Retumbo. We used Federal 215 primers, and 250 gr. SMKs. Both rifles have muzzle brakes. On the lighter rifle (quite light for the caliber) we ran into an issue that took some work to figure out. It would throw shots a little, and it turned out to be the rear bag was too hard. After much frustration, I had him try a group with no rear bag and it went away. The funny thing was, although our reloaded ammo was very straight, and the charges were done with a Chargemaster, it would not happen with new brass, only with brass that had been fired and reloaded. Strange. The bag had worked well for all of his other rifles. Because I didn't want him to develop a flinch from all of the load testing at the bench, I loaned him my PAST strap on magnum recoil shield. I think that he still has it, he really liked the extra protection for long range sessions. Another friend has a top of the line, BAT actioned single shot long range elk rifle that is chambered in a variant of the .338 Lapua that has (if I remember correctly) a 37 degree shoulder angle. It is a Dave Kiff design. That rifle has the very best components that money can buy, and my friend is a very good shot and reloader. He has a second barrel in the .30 caliber version of the same case. While both are accurate, the .338 was a lot easier to get to shoot to the high standard that he was looking for from the build. He has one five shot group that went just under a quarter of an inch. I have looked at it, and it was accurately measured. Watching him shoot the rifle, he shows absolutely no reaction to the recoil, and has perfect follow through. The rifle has a muzzle brake, a good pad, and a mercury recoil device in the butt, but it still packs a whollop (sp?).

 

[wboggs]

Many years ago P.O. Ackley rebored and rechambered my .300 H&H. to a .340 Wby. He experimented with a standard chamber and the freebore on the exact same rifle. He told me that the freebore did not increase velocity but only took more powder to reach the same velocity. In the final version he throated for the freebore because of the factory ammo. In those days we used Win. .375 H&H brass to make the .340 because it was harder than the factory brass. All his experiments were based on equal pressures.

 

[BigDMT]

I believe that Retumbo may be a bit too slow for the 338-375Ruger. But if I can get my hands on some, I will give it a try. I say that because because from what I've read about the 375R, it seems to act kind of like a "short mag" Lapua. By that I mean that it comes close to the larger case's velocities with less powder. And generally the best speeds in short mags are found around the RL-22 burn rates. But of course that is just my speculation from past experiences with short mag style cartridges.

 

[BoydAllen]

I did it again. I saw the .338 and skipped right over the second part. I must have Lapua on the brain.

 

[BigDMT]

I did it again. I saw the .338 and skipped right over the second part. I must have Lapua on the brain.

;D no biggie, still valuable input. Especially with the part about the fliers being caused by the rear bag. Thank you.

 

[BigDMT]

Put the first 5 rounds thru her last night to start barrel break-in. Just picked up some cheap Speer 200gr Hot Cor bullets for break-in/fowlers. Loaded them at about mid level of 340 WBY data using H4831 and man oh man does she have a bark!

After feeling the amount of recoil with mildly loaded 200gr bullets, I really am wondering if I will be able to effectively manage the recoil with hotter loaded 250gr bullets? I really really really don't want to, but she might end up wearing a brake. Ill know today after I finish single shot break-in and fire my first groups with the 250gr Bergers...

 

[barnesuser28]

Let us know how that goes! How is she cleaning up? Do you have a brake in mind if you do decide to have one put on?

 

[BoydAllen]

There is no way that I would shoot that without a break, and double hearing protection.

 

[BigDMT]

I was very pressed for time because of other things I had to get done today. But I was able to finish up my single shot / clean round of break-in and got to shoot two different 3 shot / clean groups before the day was over. The barrel is cleaning up very nicely. Only solvent soaked Remington 10X and Pro Shot patches were needed to fully remove all carbon and copper after each 3 shot group (with one fouling shot before each group).

Fortunately I could not notice any difference in recoil between the 200gr and 250gr bullets. They all just kick like a summ bit**! So I think I can manage without a muzzle break...just barely

Below are photos of the two 3 shot groups I was able to get off today. She shows a lot of promise. Have three more 3 shot groups to do tomorrow and break-in will be complete. This thing is definitely gonna be a hard hittin' tack driver when I get done with it.

Groups are fired with .073" jump to the lands so they fit in my magazine and GM215M primers. Grid squares on target are 1". Chronograph was set all the way out to 20 ft in front of the muzzle to avoid any muzzle blast interference.

82gr RL-22 / 2920fps / .552" CTC greatest spread


72gr RL - 17 / 2750 fps / .614" CTC greatest spread


The two groups are respectable and plenty good enough for hunting, but I like sub 1/2 MOA or better with any modern bolt rifle I own, so we're definitely not done. But considering the circumstances, the groups are very good.
By circumstances I mean;
1. Enormous amount of recoil, so you really have to hold onto her tight which wiggles the reticle a little bit on 30X.
2. Brass shoulders are fire-forming during these tests.
4. Necks are not turned because they need to fire-form first.
3. Barrel is completely cleaned before each group, with only one fouling shot before each group. Then let barrel fully cool, and fire 3 shots for group in quick succession.

The RL22 group was very nice and shows great speed potential with about a 2920 fps avg. The RL17 was loaded extremely safe because I am creating this load myself from burn rate charts. I will increase it's speed gradually in future load testing. Neither load showed any signs of pressure on the brass, so I think 3000 fps is definitely within reach.

And to think, all that speed and only from a 26" barrel that can be shot without a brake and in a standard length action....Look out 338 Lapua, little brother is hittin' the gym he's right on your tail

 

[BigDMT]

Got my last 3 groups shot today.
RL-19 shot very well, but could use a bump in speed. Group was .470" CTC. Picture below.

IMR7828 was fast at 2980 fps, but not that accurate (as always seems to be my result with that powder). Group was only 1.475" CTC. Also had ejector marks on all the brass. A clear sign that 7828 is creating too much pressure to achieve that speed. Won't be testing again, so no picture posted of group.

Hornady Superformance was no good in any way, speed or accuracy, so that powder will not be tested again. No picture posted of group.

80gr RL-19, 2890 fps, .470" CTC (wood on backer was blowing out paper so I had to tape it back together)


After my first 5 load tests during break-in/fire forming, the verdict for test powders is RL-17, RL-19, and RL-22.
I have some RL-25 as well, but have not tried it. Might give it a shot before I start fine tuning the other powders to decide the winner. All further load testing will be conducted at 400 yards.

 

[wboggs]

Great groups with a rifle shooting a 250gr. 2900-3000fps. Interesting that you get that accuracy with
0.073" jump. You are a very good man to shoot those groups from sitting with only a little wiggle in the reticle at 30x.
Very impressive, you have a superb hunting rifle.
Bill