Testing Berger new 338 OTM hybrid/338 win mag --Need Input

[CADDIE5]

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new Berger 338 cal 250 gr Hybrid - testers needed
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Got my 338 OTM bullets tonite for testing. Bullet length is 1.6285". I will be testing them in a 338 win mag rifle 1-10 twist 26" barrel. Powders available are IMR 4064,IMR 4350, Reloder 17, and H4831sc on hand. Do fellow shooters think I should add Re19 to the mix. Any accuracy loads/nodes/powders that 338 win mag shooters have before I start loading? I will be doing ladder testing at 300 yds and varying seating depth.Thanks Steve

 

[Charles E]

IIRC, Rel-17 is that single-base Swiss-made powder. Probably would be best to try a double-base powder, either Alliant or Vihta. I'd imagine even Rel-22 or N-560 would be worth a look for highest velocity (before, I predict, you settle on 4350 or H-4831-SC. BTW, don't believe there is a short-cut in IMR 4831?).

If the 250 hybrids are like the 300 hybrids, try about .020 off the lands. I found the best charge for the 300 Sierras in my rifle also worked well for the 300 hybrids; though this was in a larger chambering.

Let us know, please.

 

[CADDIE5]

Berger 338 OTM Hybrid test results for 338 win mag

Like Tarey, I was chosen to test the Berger 338 OTM hybrid bullets. The rifle I used was my 338 win mag elk rifle-- a Mauser 98 action, 26" Mcgowen barrel with 4 magnaported slots, in a McMillan fiberglass stock that is glass and pillar bedded. Scope is a Leupold 4.5x14x50mm scope with a Bulzeye pro 3.5 eyepiece.
I will present my results in an excel spreadsheet. Shot the rifle with a 100yd zero at 300yds so that I would not shoot my chrony. Used 3 target frames- one for each powder used-just shifted bulls bag to line up on each target. My son, Steve jr., recorded velocity, conditions, and shot pattern-- this way my only job was to shoot and call my shots. Saw the target results after we pulled down targets to go home. Therefore the ladder test is a drop POI. Shooter is firing uphill to targets because of pits. I let barrel cool for 5 minutes after each 5 shot string. Didn't clean barrel during testing. Did not adjust for wind changes. Bullet's vertical is fantastic when velocity similar. Loads are conservative because I had no experience loading 250gr match hybrids. All rounds single loaded and fired--box mag length is 3.34" --rounds seated for coal of 3.64" which is 0.050" off the lands. Ammo loaded on Forster press, RCBS sm. base die, Forster ultraseating die. Used CCI 250M primers. New 338 win Winchester brass. Primer holes done with KM tool and seated with KM tool with dial indicator. Forster seating die caused tip to flatten ever so slightly-- did not affect accuracy. ISRA range is in Illinois. I liked these bullets and would use for hunting at longer range shots if a close shot did not present itself on elk, moose, etc. Thanks Berger and Michelle Gallagher for the opportunity to test these bullets. The short bearing surface makes tuning easy and can push loads more than Nosler 210 gr partition or Barnes 225 gr tsx or ttsx bullets.