UBR on an AR-10

[firefighter238]

Looking for a cheaper solution to mounting the Magpul UBR to a DPMS compatible AR 10 lower. The biggest recommendation I can find online is to sped $125 on a Slash Heavy Buffer. Seems WAY to high for me. Suggestions?

[thvigil11]

I had an old 9mm buffer that I used. Its one of the steel heavy 9mm buffers, I had to cut it down about .5", i don't recall the exact amount. Redrilled the pinholes for the rubber piece. Then I used two tungsten buffers out of an old H2. The total weight came up to be 5.3oz. For me it was cheap because everything was in the spare parts bin. If you bought everything I think you'd still be about half of what a slashes would cost you.

[ray1970]

Doesn't the UBR use a standard carbine buffer/spring setup?

I know I've seen AR-10s with standard collapsible stocks.

Can't you just use whatever they put in those?

[thvigil11]

Doesn't the UBR use a standard carbine buffer/spring setup?

I know I've seen AR-10s with standard collapsible stocks.

Can't you just use whatever they put in those?

Longer bolt (ar10) inside a standard buffer tube requires a shorter buffer. Other option with normal stocks is to use an ar10 carbine tube, but a UBR is only available with an ar15 length tube.

[Delfuego]

You could try a H3 buffer and an adjustable gas block. Tubbs CS springs have always done me well in the past too.

[thvigil11]

You could try a H3 buffer and an adjustable gas block. Tubbs CS springs have always done me well in the past too.

A normal ar15 carbine buffer is too long to use with 308 bolt and a UBR tube. He needs a short 308 buffer. The DPMS 308 ones are short, but light weight. The Slash one is also short, but is equal to an h3 in weight. He was looking for a cheaper solution to cashing out for the Slash buffer.

[Delfuego]

A normal ar15 carbine buffer is too long to use with 308 bolt and a UBR tube.

Roger that.

I didn't realize the UBR had a shorter tube. The DPMS CAR-10 buffer and an adjustable gas block would work, but he's still gonna spend $125-$150 on either. AR308 are way over gassed to begin with, no cheap solution eh?

[firefighter238]

Thanks for all the input! I'm going to try to machine down a standard carbine buffer and see how that works. If that doesn't work I have a 9mm buffer that I'll try to cut down. Either way I'll post details.

[Skully]

I had a standard AR15 issue UBR on my DPMS pattern 308 and it worked just fine for me.

No special anything, other than buffer and buffer spring for a 308 carbine, which incidentally came with my 308 lower when I bought it.


Use a little Google Foo and you will see a lot of examples.

Maybe the Armalite AR10 uses something special?

Doesn't the UBR use a standard carbine buffer/spring setup?

I know I've seen AR-10s with standard collapsible stocks.

Can't you just use whatever they put in those?

Longer bolt (ar10) inside a standard buffer tube requires a shorter buffer. Other option with normal stocks is to use an ar10 carbine tube, but a UBR is only available with an ar15 length tube.

You are correct Ray, you win the prize!

Not sure what the rest of you guys are all talking about or smoking????



So in review, you CAN use your UBR, your just need the 308 CARBINE buffer and buffer spring.




What I had, a CMMG MK3 308 carbine lower.

[Skully]

Here Firefighter saved you the trouble of searching.


Rainier arms buffer spring $8.95

DPMS .308 Carbine Length Buffer Spring
DPMS 308 carbine buffer spring which can be used in conjunction with the DPMS 308 carbine buffer in standard sized AR15 buffer tubes. This combination allows you to use the AR15 buffer tube which is slightly shorter than the AR10 buffer tubes.

308 Carbine Buffer $34.95

DPMS .308 carbine buffer
DPMS 308 carbine buffer which can be used in conjunction with the DPMS 308 carbine buffer spring in standard sized AR15 buffer tubes. This combination allows you to use the AR15 buffer tube which is slightly shorter than the AR10 buffer tubes.