Barrel for ELR with an AIAXMC

[M67]

Hi all,

I'll start (re) introducing myself, - as far as shooting goes - i started shooting competitively in 1980, and have been touching most disciplines that use rifled barrels. Norwegian, and won a couple of F-Class nationals, shot both PRS WCs, going to Cameo.
My main interest was always long range, and the longer the better.
I bought my first 338LM in 2009 and we had a sort of start to an ELR thing here in Norway, shot a few matches (nothing past 2500m), but it died, and PRS came along - but now we see matches coming up, and it looks fun, as it used to.

Since i bought an AIAXMC mostly for the heck of it a few years back (and used it, w. the 260Rem barrel in Bitche - i have an AI and a 338LM barrel - the typical 27" Palma profile AI 338 barrel. Shot it quite a bit at 1250, and and a little at 1600m.
I have pondered custom stuff, modern ELR cartridges and even 416Barrett, shot a couple, and yada... To expensive, too much fuss - and my old Barnard could hold its own out quite far.
The AI however is a bit too tactical, barrel is "thin", at 27" i get not enough speed, accuracy is fair w. Berger 300 (its everything short of "very good") it groups within a moa at 1000m or at least almost... But SD/ES issues, besides its light, etc - in short i do not find it optimal for ELR work, and it absolutely does not shoot brass/copper bullets.

So my gunsmith has these two blanks. Lilja 9" twist. 30 and 32" long. I plan to not use the magazine for this, but seat bullets just short of the donout area, and then also get some more case volume. I have thougt of an 338LM improved, but i doubt it - for ease of everything.
Main concern and reason for this post is twofold.

- What profile? What length? 32" MTU? Anyone done a stepped barrel, thinner in front of the handguard? Flutes? (yes for looks ) Speed, stiffness. balance? Someone must know where is the optimum?
- Barrel and bullets - will the Lilja shoot solids? Tell me about solids? Warners, Peregrines? We do have a supply issue her in Norway, and Bergers are not always to be had - today i shoot 285gr ELDMs. They are not bad, but i want solids, and we also face a lead ban. And Peregrines we have ready access to

Anyone has a thought on anything concerning an AIAX in 338LM for ELR? Everything is appreciated. And solids.

K

 

[mojavejim]

I've used my AI AXMC with the standard 27" factory barrel at several ELR match's. 300 hybrids are my go to @ 2820-2850. The shoots I missed wasn't because of the barrel profile. I'd say go shoot your barrel out (until the lead ban) & then decide what you want, but if you are just wanting something new, the twist rate for the intended bullet used would be my biggest concern. Bartlein with their gain twist seems to be a bit easier to tune.

 

[M67]

Du you get 2850fps on the 300gr Hybrids from the factory 27"? Even 2700 more or less erases the bottom stamp on my cases... Also precision is not as good as at lower velocities. I run them around 2650fps - which is actually right on the max according to the Vihtavuori tables .

K

 

[mojavejim]

yes w/H1000 & n570. I was getting a little bit of primer flow before having the firing pin turned down & all my bolts bushed. I have over 4 firings on Lapua brass with no issues. I've tried 250 hybrids & 285eld's but have best results w/300 hybrids & 300smk's both running over 2800. But I'm not getting any ejector swipe mark at all if I keep it under 2850. Maybe I just got a fast barrel, not sure about the bigger 30mm tenon barrels but the 27mm in north America are Bartlein blanks or were a few years ago. I'll PM you the charge I'm using that happens to be the same with about the same speed but the H1000 gives me really good ES.

 

[M67]

I went and ordered an 37XC barrel...

K

 

[GIXXER2000]

Not a bad choice what length barrel and twist did you go??

 

[M67]

Not a bad choice what length barrel and twist did you go??

The blank is 1.350x37", 8" twist. Now i am wondering about profile, brake, and what bullet to choose.
- considering a more or less straight 1.20 or 1.25, just keep the 1.35 at the chamber. Any thoughts?
- Area 419 Sidewinder is the current favorite, I have good experience with the Hellfire in 6 and 6.5mm
- I'll start with the Peregrine 393gr "Glider", it is the only LR 375 bullet that can be bought off the shelf here in Norway. Occasionally A-Tips are in some shop, but i dont know if they handle the 8" twist. Will import Flatlines or Lazers if the Peregrine wont fly.

 

[GIXXER2000]

I run the Terminator T5 on my 375CT and it works great. Also the APA Fat Bastard is a good choice since it's self timing. My barrel is 1-7.5 twist 36in and goes from1.460 straight tapper to 1.375 at 36in. I shoot 400 CE Lazer never cared for the Flatline's as the cost vs performance was not there. The new Berger 410 Hybrid will be out out about summer time. I talked with Berger at Shot Show and they tested them in a 1-7 twist barrel over 3200 FPS and they did fly apart so that may be an option later down the road.

 

[bunny too]

I went with a 33XC from Southern Precision. 33" 1 in 9.3, Bartlien 400 MODBB.

 

[M67]

Nice! What profile is the barrel?

K

 

[bunny too]

Nice! What profile is the barrel?

K

I copied the AXMC 2018 barrel profile.

 

[M67]

So the brake became an APW, and the current scope is the SuB 5-20x50 US. AIAXMC and a looong Krieger barrel.

I got some 393 Peregrines, a BC from Pieter Meyer (0.491 G7) and used Tubbs load data going up to 119grs of N570. Very good accuracy right away, and after a 5 shot ladder (115-119gr) and 3 3rd groups at 300m we went into the hills with 30 rounds.
A few rounds at 900m but quite boring hitting the 40x40 every time with little effort. Except when i was filming...

1230m it was, and wind on the top had us hold 1.5-2mrads and varying so not 100% hitrate, but high - and at the 40x40 at 1000m, 100%. Så quite happy with that.


But 1200m is hardly ELR, and there is one thing and that is ES - 16-17m/s of ES still (was 30 on the first day), and just hoping for it to go down. Trying 121gr today, at 300m


K