LR-308 buffer tube (receiver extension) posibilites?

[RichM]

I'm starting my build-up of a Fulton Armory FAR-308 (DPMS pattern lower).
Will a Armalite receiver extension (7 3/4 inch buffer tube) work on the DPMS pattern lower while using an AR-15 CAR buffer (3.250 inch)?

Or, will the bolt carrier impact the buffer retaining pin or rear of the lower receiver requiring the 7 inch AR-15 CAR receiver extension while using an LR-308 carrier and bolt?

And, what spring would be needed if the Armalite tube and 3.250 inch buffer combination is workable?

My logic is that this will open a great deal of options for different buffer weights, anywhere from 3.0 ounces to 7.9 oz buffers and hopefully a variety of spring rates from Wollfe and Sprinco. better to tune the action for variety of loads and configurations while maintaining the greatest possible comparability.

Thanks.

Rich

[Plasman]

You can use an AR10 or VLTOR A5 receiver extension with a DPMS pattern lower. Just make sure you use an AR10 spring and a standard AR-15-length buffer.

My PWS MK216 came with a longer PWS enhanced receiver extension, AR10 length spring, and AR-15 buffer.

[Bushytale]

RichM, to answer your question, yes the Armalite AR10 carbine rec. ext. will work using a car length buffer. Just use the Armalite AR10 carbine spring.

I am running the Vltor 10A5SR rec. ext.(also 7 3/4 in.) and H3 buffer with an Armalite AR10 carbine spring all from DSG Arms. My Bushmaster ORC came with the 7 inch rec. ext., short buffer (2 1/2 in.)(3.8 oz.) and short spring. The buffer was to light. My thinking was like yours about the simplicity of the std. carbine length buffers and the tried and true Armalite rec. ext. length.

Bushmaster LR308 is a DPMS receiver, bolt and carrier.

Good luck with your build.

[RichM]

RichM, to answer your question, yes the Armalite AR10 carbine rec. ext. will work using a car length buffer. Just use the Armalite AR10 carbine spring.

I am running the Vltor 10A5SR rec. ext.(also 7 3/4 in.) and H3 buffer with an Armalite AR10 carbine spring all from DSG Arms. My Bushmaster ORC came with the 7 inch rec. ext., short buffer (2 1/2 in.)(3.8 oz.) and short spring. The buffer was to light. My thinking was like yours about the simplicity of the std. carbine length buffers and the tried and true Armalite rec. ext. length.

Bushmaster LR308 is a DPMS receiver, bolt and carrier.

Good luck with your build.

Thank you for the validation Bushytale.
Did you notice any changes in cycling or recoil going to the heavier buffer and different spring compared to the stock setup?
I'm playing with the idea of ordering the XH buffer (8.5 ounce 3.250 inch) from Heavybufffers.com.

I have a lot of reading to do over the next few months while this frankenstein-build comes together.

[Plasman]

Did you notice any changes in cycling or recoil going to the heavier buffer and different spring compared to the stock setup?
I'm playing with the idea of ordering the XH buffer (8.5 ounce 3.250 inch) from Heavybufffers.com.

You will certainly notice a difference in cycling and recoil with a heavier buffer. My friend has a DPMS-pattern gun with Slash's XH CAR buffer and that thing has a slow recoil impulse and you can tell it's cycling slowly (too slowly for my taste). It also practically drops the brass right next to you. I tried his XH buffer in my PWS and it had a similar effect. I've changed my buffer from a standard AR-15 CAR buffer to an H3 (5.4-5.6oz) to soften the recoil impulse.

[Clint]

I would use:
VLTOR or Armalite RE10/A5/AR10 tube
CAR H3 Buffer
AR10 CAR spring

That is the "factory" AR10 CAR setup.

[VIP3R 237]

I would use:
VLTOR or Armalite RE10/A5/AR10 tube
CAR H3 Buffer
AR10 CAR spring

That is the "factory" AR10 CAR setup.

So what is the length of the AR10 CAR spring?

[Clint]

Around 14"

The same spring is used for AR10 rifle and CAR stocks.

http://www.armalite.com/ItemForm.asp...b-7f2ec6d594ce

http://heavybuffers.com/reference.html

So what is the length of the AR10 CAR spring?

[Bushytale]

The Armalite springs that I got from DSG measured 13.5 in. long, had 35 coils and a wire dia. of .072.

The heavier buffer along with the longer rec. ext. and spring smoothed out the recoil cycle and cured an extraction issue. I would start with an H3 buffer and see how it works. An XH 8.5 oz. buffer seems like overkill.

With the 16 in. medium weight barrel and a PWS FSC30 comp. it shoots real smooth with RG surplus.

[mic2377]

I would use:
VLTOR or Armalite RE10/A5/AR10 tube
CAR H3 Buffer
AR10 CAR spring

That is the "factory" AR10 CAR setup.

+2 on this setup. I have one with this exact configuration (A5/H3/CAR spring), and it runs great with 100% reliability. Ejects at the 5 o'clock position, 6-8 ft. I have also used a DPMS carbine buffer spring with no difference in operation as well.

The extra heavy buffers are a bandaid for an overgassed gun, IMO. 308 AR's have plenty of bolt mass, and a H3 provides ample "buffering" ability.