Buffer, Spring, Tube set up will this work???

[AR-Ghost]

I'm new to the 308 world and I'm building my first 308AR. I think I've gone through and picked out some great parts but I'm still just a bit confused on the whole buffer set up! Here's what I'm working with SI Defense gen 4 receiver set, Rainier arms 20" S.S. match grade barrel, RA NiB BCG, Troy LP gas block (rifle length) magpul PRS, A2 buffer tube, tubb CS flat wire spring, and a Spikes tactical ST-T2 carbine buffer which weighs 4.3 Oz! I've ordered most of the parts but I didn't want to waste the time or money on the buffer assembly if it's not going to work! Any input would be greatly appreciated thanks.

[blue109]

You need a rifle buffer/spring for the PRS. 308 specific. The carbine won't work. Most in here will recommend slash heavy buffers. If you can't swing the price tag a standard DPMS 308 rifle buffer/spring will be fine and not very expensive.

[Robocop1051]

Blue is right. All your parts sound great, you just have to change to a rifle length buffer instead of the carbine length.

Technically you want an A1 buffer tube, although most people don't know the difference between an A1 and an A2.

If you get an A2, you'll need a spacer to fill a gap between the PRS stock and the tube. Most A2 tubes come with those spacers.

[blue109]

I was under the impression all rifle buffer tubes were A1? The addition of the spacer allows the longer A2 stock to fit. The PRS doesn't require a spacer so the standard buffer tube is A-ok.

[AR-Ghost]

Ok thanks so I need a rifle buffer not a car. And the A1 and A2 tubes are the ame the A2 just comes with a spacer which isn't needed for the PRS I'm planning on using. Now the heavy buffers are right around a 100 which is only 30 more between the buffer and spring I was planning on. Should I go wih the standard AR-10 spring in the kit or any one had good results with the tubb cs flat wire springs?

[imschur]

I have moved away from the flat wire springs in favor of Armalite AR10 springs. Also available at Rainier

 

"One spring to rule them all"

[AR-Ghost]

Is that the spring the heavy buffer will come with?

[AR-Ghost]

I guess one more question! So is the buffer supposed to bottom out in the tube is that why you can't use a car buffer in rifle tubes? I guess I was under the impression the spring caught the buffer that's why I was originally thinking it was the weight was the main thing to worry about not the length.

[mineralman55]

Going thru the parts gathering here. I've decided to go with the Magpul ACS mil-spec buttstock. I've got a DPMS LR-308 buffer spring and the standard DPMS LR-308 buffer. Will these work with the Magpul ACS?

[blue109]

Going thru the parts gathering here. I've decided to go with the Magpul ACS mil-spec buttstock. I've got a DPMS LR-308 buffer spring and the standard DPMS LR-308 buffer. Will these work with the Magpul ACS?

as long as they are the carbine spring and buffer and not the rifle spring and buffer, yes. awesome stock though. i have 2.

[FaRKle!]

Going thru the parts gathering here. I've decided to go with the Magpul ACS mil-spec buttstock. I've got a DPMS LR-308 buffer spring and the standard DPMS LR-308 buffer. Will these work with the Magpul ACS?

 

Your stock compatibility is based upon the receiver extension (buffer tube) you use. Is yours mil-spec or commercial-spec diameter? Based upon that you need to get the mil-spec or commercial-spec ACS stock.

Edited August 2, 2013 by FaRKle!

[survivalshop]

ACS is a carbine stock & will need all Carbine parts . Carbine receiver extension , carbine spring & buffer .

 

Rifle stock type parts will not work.

[markdavidson]

I guess one more question! So is the buffer supposed to bottom out in the tube is that why you can't use a car buffer in rifle tubes? I guess I was under the impression the spring caught the buffer that's why I was originally thinking it was the weight was the main thing to worry about not the length.

My understanding is yes...If you use a CAR buffer in a rifle tube, the BCG will be allowed to crash into the receiver.

The BCG needs to come back past the "bolt  hold open", but not far enough to make contact with the back end of the receiver

[eagle10]

I use the Tubb CS spring along with Slash's Heavy Tungsten buffer and I love it! My rifle recoil is less than my AR15, incredible and I have had other people shoot it now and they also agree it's awesome. I know some disagree with the combo, just my .2c.......

[shibiwan]

I swapped the CAR length buffer on my CMMG MK3 to a rifle length "A2" buffer tube so that I could put on the Magpul PRS stock. I used a standard DPMS 308 sized buffer and the matching spring in order for everything to work properly.

 

The recoil has definitely been reduced a good amount, and my next project will be to make a heavy buffer and compensator for it.

 

-S