Curious About Building 338 AR

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  • BigRick

    Hooligan #15
    Aug 7, 2012
    1,141
    Southern Maryland
    I'm lucky enough to have a friend that has a DRD in 338 and it's fun to shoot and very accurate. It's hell on brass. I've tried to reload his brass and long story short it ain't happening. If you want a 338 Lapua in AR platform and don't care to reload it's a great rifle. If you want to reload your 3 dollar plus for each piece of brass get a bolt gun. I have 2 a sako trg 42 and savage 110 in 338. Both are good rifles the Sako is a much better rifle but is 4 times the cost.
     

    brianns

    Ultimate Member
    MDS Supporter
    Dec 29, 2015
    3,643
    Montgomery County
    That would be built in the ar10 platform right?


    Sent from my iPhone using Tapatalk
    Either AR10 or DPMS pattern AR308. You need to know for the gas tube length. I think there are some 30-06 ARs but those probably have a different magazine. But I think the .338Federal is supposed to work in the 308 magazine.
     

    4g64loser

    Bad influence
    Jan 18, 2007
    6,490
    maryland
    The 338 Lapua is a super magnum cartridge. I witnessed a woman get the ole scope ring eye shooting one of them. I spoke to her just recently and you can still see that “perfect” ring around her eye.
    I cannot imagine how tough a 338 semi auto Lapua Magnum could be on the shell casing. How much will one stretch?
    Stretch is a headspace issue. More frequently I see ejector swipe, damage from the barrel extension, etc on cases shot in gasguns.
     

    4g64loser

    Bad influence
    Jan 18, 2007
    6,490
    maryland
    How many times would you think the 338 Lapua Magnum would have in a semi-auto?
    Highly variable depending on how the headspace is controlled (that's on the MFG) and how well the timing is controlled. I've reloaded the 300wm that comes put of my friends Noreen. Biggest issue there is damage from the extraction/ejection. Case necks get dinged. Sometimes the shoulders too. The 338LM case had a significantly thicker head design than conventional magnums. I would guess that damage from most semis would be to the neck and.shoulder area.

    My friend was an early Grendel adopter. He was not able to reload his cases. A LOT of work later (new rifle after a lot of wasted time trying to fix the old one) he now.gets five to ten load.cycles, depending on what load he is running. His 123s use a slower burning powder and even with the adjustable gas system, carrier weights, and buffer.system it is still a bit much. His 90 and 100gr nosler loads, the cases last much longer as his powder choice is more appropriate to the AR system.
     

    U.S.SFC_RET

    Ultimate Member
    Dec 8, 2005
    6,819
    Highly variable depending on how the headspace is controlled (that's on the MFG) and how well the timing is controlled. I've reloaded the 300wm that comes put of my friends Noreen. Biggest issue there is damage from the extraction/ejection. Case necks get dinged. Sometimes the shoulders too. The 338LM case had a significantly thicker head design than conventional magnums. I would guess that damage from most semis would be to the neck and.shoulder area.

    My friend was an early Grendel adopter. He was not able to reload his cases. A LOT of work later (new rifle after a lot of wasted time trying to fix the old one) he now.gets five to ten load.cycles, depending on what load he is running. His 123s use a slower burning powder and even with the adjustable gas system, carrier weights, and buffer.system it is still a bit much. His 90 and 100gr nosler loads, the cases last much longer as his powder choice is more appropriate to the AR system.
    So it would be better to reload the 338 Lapua magnum for a bolt gun.
     

    4g64loser

    Bad influence
    Jan 18, 2007
    6,490
    maryland
    So it would be better to reload the 338 Lapua magnum for a bolt gun.
    It's better to load pretty much anything in a bolt gun. You can avoid sizing the body at all (neck only or, my preference, a.bushing neck bump die) and achieve exceptional case life with minimal trimming over life.cycle. If you use an ejectorless or mechanical ejector design action, you can also eliminate the "neck ding" that plunger guns give when the case.mouth impacts the action under the force of the ejector spring as the case clears the chamber.

    The nonstandard case head/web design of the 338LM does resist case growth better than many of its peers, in any action type. Lapua scaled this design down to the 6.5x47mm case with similar success.
     

    Rocinante

    Active Member
    Jul 19, 2018
    182
    Eastern Shore
    Is it possible to build a .338 Lapua ar? I’m curious as I’m almost done with my 300blackout build and needed something else to try my hand at. Send links to parts if you know any.


    Sent from my iPhone using Tapatalk
    You'd have to go with either a proprietary design for the round to accommodate the magwell, such as a Noreen Bad News, or mate a bolt action upper to a standard lower such as a UPR-15/10.

    Otherwise, 8.6 blackout is your answer.
     

    Rondeezy

    Active Member
    Aug 25, 2022
    404
    College Park
    You'd have to go with either a proprietary design for the round to accommodate the magwell, such as a Noreen Bad News, or mate a bolt action upper to a standard lower such as a UPR-15/10.

    Otherwise, 8.6 blackout is your answer.

    Yea I did a lot more searching and looks like if I want to do the ar platform I can go with this 6500$ Bad News form Noreen , but building one semi auto is dead in the water. Looks like I’m gonna go with the Ruger precision 338 for a 1/3 of that.
    4c73b8eb9982bbaa853182da5db8736b.jpg



    Sent from my iPhone using Tapatalk
     

    4g64loser

    Bad influence
    Jan 18, 2007
    6,490
    maryland
    Yea I did a lot more searching and looks like if I want to do the ar platform I can go with this 6500$ Bad News form Noreen , but building one semi auto is dead in the water. Looks like I’m gonna go with the Ruger precision 338 for a 1/3 of that.
    4c73b8eb9982bbaa853182da5db8736b.jpg



    Sent from my iPhone using Tapatalk
    The Noreen is semi auto. I've shot them.
     

    4g64loser

    Bad influence
    Jan 18, 2007
    6,490
    maryland
    Yea it’s one of the few I found & will result in being divorced if my wife notices I paid 6500$ for an ar


    Sent from my iPhone using Tapatalk
    Don't tell her?

    In all seriousness, I am a bolt gun snob and would definitely be building myself a sweet rig if I was regularly (more than every quarter) able to shoot past 1000yds. As it stands, 1k is my functional max unless I drive 4 to 6 hours. Thus I stick to cases with less than 60gr of powder capacity. Currently, my heaviest charge is 45.6gr in my 308. If my shooting situation changes, I'll build a 375 chey tac like the one a buddy has. Was at black bear and 2k is literally not a challenge.
     

    Allen65

    Ultimate Member
    MDS Supporter
    Jun 29, 2013
    7,145
    Anne Arundel County
    Yea I did a lot more searching and looks like if I want to do the ar platform I can go with this 6500$ Bad News form Noreen , but building one semi auto is dead in the water. Looks like I’m gonna go with the Ruger precision 338 for a 1/3 of that.


    Sent from my iPhone using Tapatalk
    These guys are advertising a 338LM AR for "only" $5,450:
    https://www.fddefense.com/rifles/fd338/

    I've never seen one in person, though.

    I had a BN-36 for a while, but ended up selling it. Just too much of a novelty item. Most of the parts other than the stock and trigger group were AR-ish, but proprietary so there was only one source for spares and magazines. And if they went belly-up, the rifle would eventually be a paperweight unless I machined my own replacements..
     

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