338 Lapua Mag barrel

[hammertyme]

From what I have just read in your posts, it appears that you have a firm grasp on the math and what you want. I agree that the Lapua round with a 20" barrel would be a super cartridge and would pretty much burn all the correct powder in a 20 inch barrel. If someone did not have the reamer and did not want me to test the 338 X 378Weatherby imp. in a handgun I would have gone the Lapua Imp route myself.

Neal

 

[vballcop1]

Thanks Neal. I didn't look up the ballistics on your thunder stick, but it sounds like quite the impressive hand cannon. 17 inches isn't a common barrel length for that round. Did you ever compare the velocities of a longer barrel to see what you lost? Like I was saying about the sako...the military standard for submission into the testing was grouping beyond my hunting/1000yd goals. I don't remember the exact details, but I'm talking measured groups past 1500 yds plus. This isn't custum ammo either. Black Hills I believe. I just figured that if a major manufacturer was working this direction it must be relatively plausible. Tactically speaking I'm sure the addition of a supressor makes the short barrel a benifit. I however am looking at packing/hiking/humping this thing up and down mountains.

 

[hammertyme]

Working the numbers mind you as the reamers were just made, I figure I am loosing between 400 and 500fps with the shorter barrel. But, The 378 Weatherby case holds way more powder than the Lapua and because of that case capacity I am limited on powders I can use. Up side is there is an awesome amount of shearing gasses so recoil is very managable with the brake. Send me an e-mail if you wish and I will send you a picture.

[email protected]

I have a friend that is building a 338Lapua on a 20" pistol barrel. He figures he can get 3000fps with 225 grain Accubonds. I agree as I am certain that I can do the same with the 245 grain Lehigh bullet.

Neal

 

[vballcop1]

Thanks Neal! I would love to see the pics. My Email is [email protected] I hope your friend gets his gun running. I would love to hear what sort of results he gets. I'm going to direct my attention toward the short barrel and try to get some answers from some of the barrel manufacturers. Thanks again and keep them flying straight! Darren.

 

[dougm]

Hi, I'm the fella Neal was speaking about who is building the .338 Lapua handgun.

I chose a 20 inch barrel length (plus brake) as it seemed to provide the velocity I was looking for. According to Necco's Accu Load I should burn just over 99% of the powder (IMR 4831) when shooting 225 grain bullets. If I push it a bit harder (around 53K psi) I can burn a bit more (around 99.27%).

My velocity goal is 2900 fps as a minimum with the 225 grain bullets which will equal a 338 win mag rifle (typical barrel length of 24"). Could I have just chambered in .338 Winny and stuck a 24" tube on it, sure, but where is the fun in that!! I'll probably get closer to 3K in velocity and the extra capacity will help when shooting 250's and even 300's if I want to.
Seriously, when we are talking about short barrels (in my case for a pistol) efficiencies are out the window. It's all about horse power. Are the gains dimenishing, sure, but there is some gain.

I ordered a Bartlein barrel, and after talking with them we decided on a 1:12 twist. Remember, I'm not planning on shooting 300 grain bullets all that much and according to the twist calculator I used and Bartlein's calculations, a 1:12 worked the best for 225 and 180's. We were going to go with a 1:10 but felt it was too far from the 1:15 (which showed as ideal for I believe the 180's) so we went with the 1:12. If I was going to shoot the 300's a lot I would have went with the 1:10 or maybe even a 1:9 but not sure how the 180's would have done with the 1:9.

Right now I'm waiting on the action (Stiller Tac338) and the barrel, but I do have the Patriot Arms Fat Bastard brake. This brake is amazing! I watched a video with an 8 year old boy shooting a .338 Lapua tactical rifle and it bumped his shoulder like a .243 with no muzzle rise.

Good luck with your project, you will have to keep us posted.

 

[nothenpersonal]

i know im a newcomer, but i have too say one thing to the 20 inch barrel, personally if your gonna throw bullets at any distance, stay away from the 20 inch, and go with 26 or better... I have a 308 savage, 175 grain bullet, bullet flys geat up too 600 yards.. after that i cant hit a 4by8 sheet of plywood at 700 yards. ouch. A fusion factory bullet will fly just as far as the reloads, but falls off its face after that.. My brother is flinging bullets at 1760 yards with his 338 ultra mag.. sweet...

 

[nolo263]

I have seen two 338 lapua's with 20 inch barrels. I helped set up the loads and shot one of them yesterday and it chrono'd at 2750 with 300 smk's, we then tested this speed to 1000 yards just to make sure. I liked it so much, I picked up a AI-AWSM in .338 lapua today and the first thing I am going to do is send it to Jared Joplin and have the same 20" barrel he put on my buddies rifle put on mine. Oh and accuracy was insane, the only draw back I saw was the percusion but I could live with that seeing the gain in portability.

 

[nothenpersonal]

I have seen two 338 lapua's with 20 inch barrels. I helped set up the loads and shot one of them yesterday and it chrono'd at 2750 with 300 smk's, we then tested this speed to 1000 yards just to make sure. I liked it so much, I picked up a AI-AWSM in .338 lapua today and the first thing I am going to do is send it to Jared Joplin and have the same 20" barrel he put on my buddies rifle put on mine. Oh and accuracy was insane, the only draw back I saw was the percusion but I could live with that seeing the gain in portability.

Was that a custom barrell 20 inch?? What twist?? Mine was a factory, but I still cant believe that a 308 even with a twenty incher no matter what twist would not fly well after 600 yards.. the bullet started tumbling between 650 and 700 yards. ***.

 

[nolo263]

Was that a custom barrell 20 inch?? What twist?? Mine was a factory, but I still cant believe that a 308 even with a twenty incher no matter what twist would not fly well after 600 yards.. the bullet started tumbling between 650 and 700 yards. ***.

Actually 4 or 5 of the .308's we use past 1000 are 20 inch barrels, mine is 22" we are shooting 155 scenars but I have seen it also done with 175smk's, Infact one of my buddies rifle is a 18" barrel and he has no problem to 1000 yards.
The 18 incher was a factory Rem. 5r cut to 18 inches, He was using fed. gold match 175's. The other rifles including mine are all customs,

My 6.5x47 lapua is a 22" barrel made by GA precision. 1 in 8.5 twist rock barrel. I am shooting 130 bergers at 2970fps.

My 300 wsm is 24" fn spr and it is a freaking hammer at 1000 yards, 190 bergers at 3000fps.

I used to think short barrels sucked until I started using them. Less weight, easier handling and they can still get it done at long range.


Before somebody calls ********. You can call preston at surgeon, jared at patriot, George at GA, and I can keep on with the customs that me and my buddies have had built. The 338 lapua with the 20" barrel was built by Patriot (Ask him about the .338 he built for Tom B in Laredo)..

 

[JPRITT]

A 20" barrel on a Accuarcy International 338 LM?!! I think I just threw up a little in my mouth. LOL to each his own but I couldnt imagine doing that to such a fine specimen.

 

[nothenpersonal]

Actually 4 or 5 of the .308's we use past 1000 are 20 inch barrels, mine is 22" we are shooting 155 scenars but I have seen it also done with 175smk's, Infact one of my buddies rifle is a 18" barrel and he has no problem to 1000 yards.
The 18 incher was a factory Rem. 5r cut to 18 inches, He was using fed. gold match 175's. The other rifles including mine are all customs,

My 6.5x47 lapua is a 22" barrel made by GA precision. 1 in 8.5 twist rock barrel. I am shooting 130 bergers at 2970fps.

My 300 wsm is 24" fn spr and it is a freaking hammer at 1000 yards, 190 bergers at 3000fps.

I used to think short barrels sucked until I started using them. Less weight, easier handling and they can still get it done at long range.


Before somebody calls ********. You can call preston at surgeon, jared at patriot, George at GA, and I can keep on with the customs that me and my buddies have had built. The 338 lapua with the 20" barrel was built by Patriot (Ask him about the .338 he built for Tom B in Laredo)..

Well, Either way,, i used a factory bullet, fusion, 165 grain, that shoots like a monster , that made it too 600, and i used a 175 grain sierra handload, that shot like a monster up too 600 as well, and after that it tumbled worse than a tumble weed in texas and arizona.. Im working on building a 6.5x284.
I would still like too know the twist in both of them barrels you were talking about.

 

[AJ Peacock]

According to Quickload, using a 300SMK behind H-1000, your velocity drop from a 26" barrel to a 20" barrel is around 150fps. Most of the powder is burned by the 20" mark, but the barrel exit pressure is pretty high. The bad part of that will be a big muzzle blast, on the bright side, a brake will probably work really well

I've found that a high muzzle pressure can really magnify any problems with bullet bases/muzzle crowns.

My guess is that a 20"LM will probably top out less than 2550fps with a 300SMK

AJ

 

[VTi]

AJ -- Could you run the same thing for a 23" bbl? Does the mv basically decrease linearly? i.e. 25fps/in? Would you mind also running it with 96.0gr Retumbo?

Thank you sir.

 

[AJ Peacock]

The H-1000 load I used was 89gr (106% load density) for a 66.8k PSI and the following velocities
20" 2553fps
23" 2640fps
26" 2712fps

96gr Retumbo gives the following
20" 2660fps
23" 2747fps
26" 2819fps

But it shows 96gr retumbo is 113% load density, so you may not be able to get that much in there. It also shows an above recommended pressure of 73k psi

90gr Retumbo gives a 105% load density and the following velocities
20" 2546fps
23" 2577fps
26" 2652fps
with a moderate pressure of 57.5K psi


Hope this helps.
AJ