Fiftydriver
Official LRH Sponsor
You can get that and more with the 338 Allen Xpress or 338 Terminator and do it with 10 grains less powder, dramatically superior brass in every way and in a much shorter oal in ammo.
Big 338’s
- Thread starter westcoasthunter
- Start date
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One of the problems of being in Canada is access to Brass for something like a 338 Allen Express. Can it be made from readily available brass of another cartridge?
i just found your website and found out the 338 Lapua is the parent case. I think I will do some more research into this. Thanks for the heads up.
Fiftydriver
Official LRH Sponsor
You can simply fire standard 338 lapua ammo to form brass. And it actually shoots pretty darn well most of the time.
Have not noticed, mag fed or not. If single shot is ok...... I had a 338/378 Wby, SAAMI reamer with all that freebore, seated close to the lands, that pushed that big Berger right along. Couple down sides to it....
IMO, of course.
1. Brass. Proprietary. And soft. And expensive. Still, I was getting over 20 loads out of em.
2. Seemed kinda finicky to load for, tho that may have been the build.
Got 3111 with RE33, in a work up from a small amount of powder given me. No signs of over pressure. Looking at notes, I ran right around 3050, shoveling Retumbo in it. Way faster than a Lapooaa. Not sure about the Improved....but that seems like ALOT of improving!
It had a 31in Lilja 10 twist barrel.
And,......wow! What a machine! Wish I'd known, I'd never have fooled with that darned Wby!
Fiftydriver
Official LRH Sponsor
Only reason i know because when i was starting the R&D for my 7mm Allen Mag, 300 Allen Xpress and 338 Allen Xpress, i had been playing with some versions of the 30-378 and 338-378 wby. Had built several test rifles and customer rifles in the 30 and 338 Kahn which is the big weatherby with conventional 35 degree shoulder. At that time, nearly 20 years ago no (WOW!) it was claimed that the Kahn would improve accuracy and performance slightly over the standard wby.
the kicker however was that one had to compete against the freebore throat design of the weatherby rounds. I found that with similar barrel lengths the standard wby design would slightly outperform the Kahn simply because the Kahn was designed for accuracy and as such used a conventional accuracy minded throat design. Greatly improved accuracy and consistency but not ideal for max fps numbers.
seeing this, i had no desire to simply make minor tweaks to the big weatherby and slap my name on the "NEW" design. With my first three wildcat releases, the 257 Allen Magnum, 6.5 Allen Magnum and 270 Allen Magnum, they were head and shoulders above the performance level of any other chambering in these calibers.
maintaining this advantage in the larger caliber families would be much more difficult. Which is also one reason i came up with the Alle Xpress line of wildcats.
i new the big weatherby case was just to large for the 7mm bore, even with the 200 gr wildcat bullets that i had waiting to test. I also knew from my years playing with the Kahn that the norma and weatherby cases were not overly strong in the case head.
i also knew that the lapua brand of 338 lapua cases were extremely strong and much shorter then the big wby. So started there. In all honesty, i most think the 7mm Allen Magnum was the 4th release from my line of wildcats and while that is true as far as being commerically available to order, the 300 Allen Xpress was the first of my lapua class wildcats i tested as i wanted a head to head comparision with the 30-378 wby.
had a friend with a mark V rifle with a 26" barrel so i made up a test rifle on one of my blueprinted Rem 700 chrome moly receivers with a same length lilja 10 twist 6 groove.
when both were loaded to what i could perceive as very similar pressure limits with the 200 gr accubond which i used for testing, i found that my 300 AX produced roughly the same velocity then the big wby round. And did it with roughly 10 grains less powder and a dramatically shorter OAL possible……. I was very impressed.
now many will just say i loaded my 300 AX to higher pressures and that would have some truth to it. However, when i did my initial testing, i knew the lapua brand case had the strength to support far more chamber pressure then the rem 700 or any other factory receiver should ever be subjected to long term. As such, for my testing, i used the much softer norma brand of lapua brass. This brass would show primer pocket loosening dramatically sooner then the lapua brand brass to make sure my recommended loads to customers would be safe in their rifles.
my testing consisted of loading each rifle up with a starting load, then increasing powder charge 1/2 grain at a time to the point that i could feel the very first hints of the primer pocket loosening on the first firing. I would repeat this five times with five virgin brass and record the load that reached this point. Most were very consistent. then i would reduce that load by one full grain and consider that the max working load for that system. Starting load would be 5% off that load.
then i would repeat this test with the formed norma brass in my 300 AX. This brass was formed using the corn meal forming method so for all intent and purpose, still high pressure load virgin brass.
this same performance level held true for my 338 AX vs the 338-378 and eventually the 375 AX vs the 378 wby. In every test, my rounds would match the much larger wby design..
some had said that the larger wby would have an advantage with really heavy for caliber bullets, i did not see that with the 230 gr or old 240 gr smk in the 30 cals and did not see that with the 300 gr smk in the 338 caliber, the 300 gr smk was about the only game in town back then!!
the 7mm AM had nothing really to compare to, it was head and shoulders above any other 7mm back then and still today. In fact back then the 7mm RUM was much more popular and was its closes competition yet still 125-150 fps short even though it had only slightly less case capacity then my 7mm AM. Again, case quality and strength were the real advantages.
then we moved into the age of my Raptor receiver and i transitioned away from rebuilding factory receivers and only offered my lapua based wildcats on my custom receivers or other custom receivers designed for the lapua class of chamberings. this decision came mainly from an incident where a SUPPOSED cartridge collector asked for and purchased dummy rounds of all my wildcats. Said he was a collected and wanted to add my rounds to his collection.
turned out he was a rifle builder, took my dummy rounds, had reamers made on them and started building and selling rifles in my wildcats. This came to my attention when he had improperly built a rifle for one of his customers in my 7mm AM based on a Savage M110 receiver. He had retained the barrel lock nut design which kept the barrel shank small. He was also using a button pulled barrel which were known to be relatively soft.
rifle eventually blew up due to some over aggressive loading and put the guy in the hospital along with his spotter. I was nearly included in that lawsuit as this *** had told everyone he was only using my recommended loads and build procedures….
luckily i saved all the emails with this guy where i told him specifically i do not recommend chambering my lapua based rounds in any commercial receivers. I also provided him with load data specs and it was proven during the discovery stage of the suit that the ammo had been loaded to much higher levels then i ever recommended. My saved email conversations kept me out of that mess. However it did push me to go with my Raptor receivers to avoid any future issues.
once i had my Raptor receivers designed, tested and in production, i retested all my lapua based wildcats with lapua brass to the same pressure limits. Load up until the first hint of primer pocket loosening, then drop one full grain and consider that absolute max working pressures for that combo.
what i found with my dramatically stronger Raptor rifles and eventually Stalker rifles is that i would now get 50-100 fps more velocity then the big Wby cases and get this with significantly longer brass life. Solid 150-200 fps over the RUM class rifles. Will not even mention the nosler cartridges which are STW class performance at best. Good rounds but not the "Biggest Bull in the Herd" as their adds claim.
so after all that, the lapua based wildcats can easily match or exceed the big wby rounds in same length barrels and do so with less powder usage.
now, there are some minor conditions that need to be followed. If you use a traditional Ackley Imp design on the lapua case, meaning same shoulder angle and case body taper, you will usually run into case extraction issues well before you reach max working pressures of the case. In a softer steel barrel like a button pulled barrel, this will be a bigger issue with sticky extraction, especially as brass gets more firings on it and looses some of its elastic properties.
my design, started with the AI case body taper specs but i quickly found this issue, as such, Case body taper was increased slightly to allow great extraction right up to max working pressures. This is critically needed on these larger diameter cases.
here about guys shooting the 338 lapua AI all the time getting great performance but after cases get 3-4 firings on them, they pretty much need to pound on the bolt handle to open it and extract the case…. The Ackley Improved design was NEVER intended for use on anything larger then the standard 0.470" head diameter cases, even belted mag case diameter is pushing it in PO Ackleys own words.
anyway, sorry for the long rant. Just wanted to offer my testing experience and why many of my wildcats are based on the Lapua parent case over the big wby.
I know your set on the 338 Terminator but I have had Excellent results with sever 338 Edge rifles from 10.6 pounds to 19.6 for my Elr Rig.
No way would I build a 16 pound rifle for hunting ... you must be a Younger tougher Man ! Lol
I been there dont that .
I shot my last Elk at 1244 yards with that 10.6 pound Carbon barrel 338 Edge . I only had H-1000 powder at the time .
It was pushing the 300 gr berger at 2884 ft.per.sec. I'm positive I could get alot more Velocity with the Nv570.
There is so many choices now for a big 338 ! It's a Caliber I will never be without a few of !
I have a buddy that Shawn Carloc just built him a 338 Edge +P on a 30 " barrel..he is getting 3147 ft.per.sec with a 300 gr berger ! That's almost 300 ft.per.sec faster than mine . Wow !!
Anyway Good Luck in your Choice !
Rum Man
No way would I build a 16 pound rifle for hunting ... you must be a Younger tougher Man ! Lol
I been there dont that .
I shot my last Elk at 1244 yards with that 10.6 pound Carbon barrel 338 Edge . I only had H-1000 powder at the time .
It was pushing the 300 gr berger at 2884 ft.per.sec. I'm positive I could get alot more Velocity with the Nv570.
There is so many choices now for a big 338 ! It's a Caliber I will never be without a few of !
I have a buddy that Shawn Carloc just built him a 338 Edge +P on a 30 " barrel..he is getting 3147 ft.per.sec with a 300 gr berger ! That's almost 300 ft.per.sec faster than mine . Wow !!
Anyway Good Luck in your Choice !
Rum Man
I will always have a soft spot for the Edge. I remember the 300gr SMK days and the Exbal program lol. My dads R Bros Edge still shoots in the same hole 2000 rounds later. That SMK killed a lot of game WAY out there at 2820 muzzle velocity. Old Faithful ha
westcoasthunter
Well-Known Member
I did think about the edge but I already have the action for the lapua bolt face.
Bghunter338
Well-Known Member
Well a long time in the waiting game and she's finally done 
. Here's a picture that I got of her complete.
. Here's a picture that I got of her complete. 
Alex Wheeler
Well-Known Member
The 338 lapua imp is one of my favorites. They tune up around 2950 in a 26 inch barrel. You can barely fit them in a 4 inch box but throated properly for a 300 berger they are pretty long.
Brother, you already know my offer.Well a long time in the waiting game and she's finally done
View attachment 454485
Bghunter338
Well-Known Member
If I was only a little bit closer lolBrother, you already know my offer.
