Barrett MRAD 338 and 300 WIN

[senna.bra]

Hi all,

I just got a Barrett MRAD in 338 and 300 win mag conversion too. If you own one, and you would like to share you "pet" load please list it here. I know every rifle is different, but I had some really good luck replicating a load I got from another forum member on my SCAR heavy too.

I will work up and load and will be glad to post results.

Thank you all very much!

SC

 

[diverdon]

Tag, I have shot mine mostly with the .308 barrel on for that I used FGM 175 with about 1/2 moa results. I have not broke cherry on the .300 WM yet. I started load development for the .338. Retumbo and all kinds of bullets seemed better than moa but did not really find a optimum length before I switched to .308.

 

[senna.bra]

Cool, looks like I am not alone. I hope this will benefit others as well...

 

[Holtz]

You are not alone. I've had my MRAD in .338LM for a couple years & finally got the .300wm barrel & conversion kit. Have several loads developed for both & will get back to you with specifics when I have a little more time. In general terms, for the .338 I shoot Berger 250 & 300 grain vld's using Retumbo & found 208 Amax with H-1000 is great for the .300wm. I also have a BORS on top. More later. Holtz

 

[senna.bra]

Holtz, thanks man. Please post your data. I get my rifle next week and I am going to try 208 AMAX and 230gr Bergers for the 300. I might shoot the Lapua 250gr with the 338 but I haven't done enought research yet.

Regards,

SC

 

[LawnMM]

Mine seems very pressure tolerant in 338, I'm over/around max depending on who's data you look at but I'm getting 2799fps with Hornady 285 HPBTs loaded to 2.715 over 94.4gr of Retumbo. SD9 and ES was 21 I think...

Work up to it but my rifle seems to like it!

 

[Clark]

I have 338WM, 300WM, and 7mmRM reamers. In building those rifles I try to get a lifetime supply of brass and headspace for the longest case space to end of belt.

In no wind, if the rifles with scope and bipod were all 10 pounds, the 7mmRM with 140 gr boat tails is going to shoot the best at 500 yards in the hands of putz's like me.
But if in no wind the rifle with scope and bipod is 18 pounds, the 300WM with ~220 gr boat tails is going to shoot the best at 500 yards in the hands of a good long range competitor.
But in gusty crosswinds, the 338WM with the heaviest bullet that can be stabilized will do best.

 

[senna.bra]

Thanks for the data. Please confirm if you loading these for your Barrett. If you have a custom rig is cool, just be specific.


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[morganlamprecht]

just jumping in on this for the future...got my MRAD in .308 a couple weeks ago and will be adding the .338LM conversion soon...rifle shoots and feels awesome

 

[GIXXER2000]

I don't have the MRAD I shoot the PSR but I just started working up a load for the new long range 210 SMK for my .300 win and it shoot great. Best group was .387 100 yards and 3.91 in group at 500. I have a friend who shoots a DTA and his results are very close to mine. They also work very good at 1000 yards. Best group on paper at a 1000 yards was 8.79 inches. I was using the 220 SMK but the 210 have a better BC and for me are more accurate. Good luck it is so nice to have a multi barrel system!!

 

[senna.bra]

just jumping in on this for the future...got my MRAD in .308 a couple weeks ago and will be adding the .338LM conversion soon...rifle shoots and feels awesome

Good deal... Have you tried Lapua cases, Sierra 175gr and Varget yet? Any rifle that I use this combo works great. I run my 175gr SMK in 308 around 2,600 FPS.


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[morganlamprecht]

Good deal... Have you tried Lapua cases, Sierra 175gr and Varget yet? Any rifle that I use this combo works great. I run my 175gr SMK in 308 around 2,600 FPS.


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you got it! i currently run 43.1 gr of varget under 178 amaxs or 175 SMKs in lapua brass and they both shoot great and have the same 100 yd zero...also run 175s over 42 gr of 4064...both loads shoot right @ 1" @ 200 yds...ill get a chance to stretch it out to 1k in a couple weeks then run in the MRAD in 2 upcoming matches. Bout to put it thru its paces lol

 

[Holtz]

A couple things first. I found that when developing a load for shooting beyond 500 yds, that correct BC & MV entered into my BORS library plus using & full length resizing die with a bushing made a huge difference. Matt in the BORS section of Barrett was a big help in developing accurate BC numbers for me. My MV numbers are from a Magneto Speed chrono. I am lucky enough to be able to shoot out to 1800+ yds using a garbage can as a target with consistent hits with the .338 barrel. Four other friends shot right after me, all with hits using my MRAD. Have only stretched the .300wm barrel out to 1000 yds with consistent hits on the same can.
here's a couple numbers to start with:
.338LM
Lapua brass
Fed 215M primers
250 grain Bergers Tactical
96 grains Retumbo powder-CAUTION!! Way over recommended, but zero pressure signs in my MRAD
MV is 2900 fps

.338LM
Lapua brass
Fed 215M primer
300 grain Berger Hybrid Tactical
92 grains Retumbo powder
2720 MV

.300WM
Winchester & Hornady brass
Fed 215M primer
Hornady 208 AMAX bullet
77 grains of H-1000. No pressure signs
MV of 2900 fps
That should give you something to start with hopefully. I should add also that both barrels are suppressed with a suppressor from Elite Iron here in Montana. Same suppressor fits both barrels.
finally, thankfully, I have a custom .308 and it likes 175 grain SMK's with 43.5 grains of Varget or 43.8 grains of 4895.
time to get back to reloading. Holtz

 

[senna.bra]

Good deal, Holtz. Could you please add the barrel length as well?

 

[Holtz]

they are both 24" fluted.

 

[senna.bra]

Ok, so it only took me 37 rounds to find a excellent load in 300 win mag.

This load is above max but with no pressure in my rifle, so start at lot lower.

Barrett MRAD only
24" barrel 1-10 twist
300 win mag
230gr OTM Berger
Winchester case
76.6gr H1000
2828 OAL from Ogive

Velocity at 2750fps
1/2 MOA

Going to stretch it to 1,000 next weekend.


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[senna.bra]

forgot to add a photo of the target...


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[smschulz]

We NEED more gun porn!

 

[senna.bra]

We NEED more gun porn!

Chocolate- peanut butter...

 

[senna.bra]

Found another similar good load.

This one is using Nosler 300 win mag brass, thus less internal capacity than Winchester brass.

Barrett MRAD only
24" barrel 1-10 twist
300 win mag
230gr OTM Berger
Nosler case
75gr H1000
2828 OAL from Ogive

Velocity at 2750fps
1/2 MOA

 

[jkonzal]

I almost never see it mentioned, but if you can find some, try RL-25 for your 338LM loads. I get 2951fps with 91gr under 300gr SMK's. Mine is a 98B with 30" Kreiger tube.

 

[senna.bra]

I almost never see it mentioned, but if you can find some, try RL-25 for your 338LM loads. I get 2951fps with 91gr under 300gr SMK's. Mine is a 98B with 30" Kreiger tube.

Thanks! BTW- How were you able to fit a Krieger on your 98B?

 

[jkonzal]

A good gunsmith!!! ;O)

 

[senna.bra]

A good gunsmith!!! ;O)

Ok... Who did the work?


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