First Long Range Build Completed

[longarm338]

Double checked with a second chrony and the b.c. and drop values are spot on out to 400 yards which is the furthest I've ran the combo so far. The speeds are correct. Part of the speed comes from the modified throat allowing for longer coals, and higher powder charges. H2o capacity is only 2 gr less than the 338 win mag and the case is considerably stronger. Another is the 27 inch barrel helps squeek out every bit from this very effecient case. Cases are at 4 reloads so far and primer pockets are just as tight as they were new.

 

[338sniper]

With numbers like that I may as well scrap my .338 warthog. I'm getting 2934fps with 99.5gr of RL-33 & 300 SMK's out of a 28" barrel.

 

[longarm338]

You could go with a cross canyon arms short mag. Ita basically an ackley improved wsm case. That will get you very close to RUM type speeds with the right bullets. It seens as though some of the Cutting Edge bullets you can run a good bit faster than their lead core counterparts due to the short bearing surface and the fact that only the band touches the bottom of the groves. I think 250 gr is about the upper limit for reasonable spees with this case as it doesn't have the boiler room the larger 338's have much like how a 308 comes pretty close to the 30-06 up until you start getting past 155 gr where the 06 starts to rapidly pull away. Some of my loads come within 150 fps or less of the laupa but once you get past 250 gr velocity starts to fall off pretty rapidly. That's where the larger cases shine. The goal of this project wasn't shear power but effeciency through carefull loading practices and effecient bullet design and to mag feed in a standard sized action. If I ever feel the need for more power or have to start chasing the lands, I can easily rechamber to one of the larger 338's. Just did some more playing around with the 225 gr MTH and with them kissing the lands over 65 gr of RL17, netting just over 2900 fps, shot this 200 yard group today. With a bc of .64 it runs right with the lapua with a 250 gr smk at 1000 yards.

 

[longarm338]

I'm gonna be running these guys next. Its an older single feed design that CE no longer produces on a regular basis. They are full bore and do not have a bore rider hense the sealtite band being so close to the case mouth. There is very little bullet in the case and have a hollow base, so they make the most out of available case capacity. 65 gr of RL17 is running them right at 2900 fps. There might be room for a little bit of improvement but I don't know yet. Possibly another grain or so. I ran them 25 thousandths off the lands and they shot moa. This rifle likes its bullets as close to the lands as possible so I'm gonna try that next.

 

[mitch260]

Sounds like a cool project. Impressive velocities for sure. I think those 250 Lazers will be tough to beat in that set-up.

 

[longarm338]

Well all testing has been completed and I'm very happy with where this project ended up. I'm definitely hooked on long range shooting and will be doing many more builds like this in the near future. I am taking all the knowledge I gained and will be improving on them in upcoming builds. To fund future projects, the prototype here is going up for sale. Its had about 200 rounds through it so far. PM me if anyone's interested

 

[Timber338]

Great thread somehow missed it until now. I've got a 338-300 wsm built on a short action as a light weight Elk rifle and absolutely love it. Cool to see what you've done with this cartridge in a long range platform. Nice work!

Have you started any new builds yet?

 

[harleybug]

I wonder if there is a 338-300 saum.