Short barreled 338s

yorke-1

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You should be able to easily hit 2700 fps with a 285 from a 20" 338 Lapua with the right load. I get 2700 fps with a 260gr bullet from an 18" barreled 338/375 Ruger with H100-v. I get 300gr OTMs to 2875 fps from a 20" barreled 338 SnipeTac running a relatively mild charge of H50bmg.
 
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I developed a wildcat 338 MKS that shoots a 300 grain bullet at over 2400 fps. out of a 18" barrel. It is a Ruger 375 necked down and shorted to 2.75" so it runs through a standard action. About 4000 Ft lbs. I would like someone to test it in a longer barrel.
 

backyardsniper

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Pottsville, ky
I'm thinking very seriously about trying a 20" I have a decent supply of H1000, Rl33, and Ramshot LRT. I also have a good bit of H4831sc which I have had a lot of success with in the 250gr bullet class. This should be a good experiment. Once I have all the other parts if it Doesn't workout all I'll have to do is get it rebarreled with a longer barrel but I think i'll give this 20" 338 Lapua a shot
 

North Idaho Hunter

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I would research desert tech forums - lots of 338 lapua’s running real short 18” barrels out of that covert platform.
 

Mazdayasna

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I have built many 338's for different purposes and for the 338 Lapua you are going to be limited to 24 to 26'' barrels for any performance. The smallest and lightest 338 that is still a performer is the 338 RCM (A short mag that does well at 22" of barrel. The 338 rum is the ballistic equal to the Lapua using less powder but when you get to this level a 26" minimum barrel length is needed to get any real performance. I would recommend using 250 grain Bullets for this class of cartridge. Then there are the cartridges that consume 115 or more grains of powder and they need at least 28 to 30" barrels or as stated, they become flame throwers and not only waist lots of powder they also erode barrels fast from pushing un-burnt powder all the way through the barrel.

The 338 RCM will push a 225 grain to 2700 + with the 22" barrel. the 338 RUM will push a 250 grain to 3000 ft/sec in a 26" barrel and the Lapua will do 2900+.

The short mags use less faster burning powder to reach the max pressures in shorter barrels so you might consider an Improved short mag on a short action with a 24" barrel to save overall rifle length.

Big High velocity bullets need longer barrels to reach their potential unfortunately.

J E CUSTOM
Considering his application, "short barrel" and the desire to use .338 Lapua Brass, why wouldn't he be better off going up to .375? "375-338 Lapua Improved"
 

J E Custom

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Considering his application, "short barrel" and the desire to use .338 Lapua Brass, why wouldn't he be better off going up to .375? "375-338 Lapua Improved"
Longer cartridges need longer actions and normally have more case capacity requiring more slow burning powder that needs a longer barrel. The short mags are very efficient at getting velocity with limited barrel length.

They also don't need long barrels to get velocity. They do however use about the same amount of powder as their counter part but in a much more compact package. The poster wanted the shortest barrel/rifle possible and the short mag in a short action will do both.

I have both the short and long action 338's and all tho the short mag cant compete with the wildcat 338 Texan, It does push a 200 grain bullet @ 2850 fr/sec and the 225 @ 2700+ in a 23" barrel.

Just an Idea

J E CUSTOM
 

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