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to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 3:23 pm
by etownguy
I bought a .243win upper for my AR10 only because I have several hundred rounds and no guns to shoot them haha.. the lower is a SI-Defense forged matched upper and lower, the new upper is a Bear Creek Arsenal. the curvature of the lower and upper do not match if I sand off just a bit from this BCA upper I could get them to go together no problem. but then I lose any hopes of any warranty work if it doesn't work somehow. I can cycle the action even with it not pinning so I know that part will work.



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Re: to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 3:36 pm
by WLJ
etownguy wrote:
Fri Apr 28, 2023 3:23 pm
I bought a .243win upper for my AR10
Actually what you have there is a LR-308 (aka DPMS) pattern not AR-10. Sorry to be picky but which is which does come into play when ordering parts.
But anyway
Kind of weird the upper did not fit right. Either the upper or the lower is off.

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Re: to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 3:41 pm
by etownguy
true true it's just always been easier to call it a AR-10 instead of a LR 308 DPMS Gen 1 lol. I'm sure the lower isn't 100% in spec because it is a matched set to the .308 upper I have for it. but from everything I've seen parts compatibility with the big frame guns has always been rough. because of all the variations.

Re: to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 3:46 pm
by WLJ
Sorry, got bit a couple of time by online retailers saying a part was for a AR-10 when it was actually for a LR-308. Been anal on the matter since.

Re: to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 5:28 pm
by etownguy
It's not as uneven as the photo makes it look I just took more finish off one side. but now it fits like a glove no rattle or anything!

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Re: to sand fit or not?? AR10 incompatibility

Posted: Fri Apr 28, 2023 5:32 pm
by WLJ
Hope it works out okay.
Welcome to the wonderful world of just about every company in the LR-308/AR-10 world doing it their way.

Re: to sand fit or not?? AR10 incompatibility

Posted: Mon Jul 24, 2023 2:31 pm
by WLJ
WLJ wrote:
Fri Apr 28, 2023 3:46 pm
Sorry, got bit a couple of time by online retailers saying a part was for a AR-10 when it was actually for a LR-308. Been anal on the matter since.
And I got bit again

Add another item to the list of stuff advertised for AR-10 but is for a LR-308.
Three piece gas rings. Even says AR-10 right on the package. After fighting them it turns out not all three will fit and after trying to find the right google search combo of words come to find out it not just me, you can get two on but not all three.
Have to get the Mcfarland one piece gas rings for the AR-10..

just placed an order with Armalite

Re: to sand fit or not?? AR10 incompatibility

Posted: Mon Jul 24, 2023 2:47 pm
by badvoltron
Ive been kind of wanting a ruger sfar lately, digging that new smaller pattern they came up with, ive got a buddy with one. Seems like they are having some teething issues but coming along.