AR buffer question...

[95wrangler]

Im building a 300 blackout pistol with a 9-10.5 inch barrel (haven't made up my mind yet) and am using a fixed stock buffer tube and Sig brace for balance. My question is what buffer and spring would I use? I will eventually be suppressing it and running sub and super sonic ammo. Im assuming Id use a rifle length spring but are there different weight springs? Do I need a carbine or heavy buffer? So much to learn building franken ARs! If you could, can you also explain why Id use one over the other so I may learn more? Thanks ahead of time!

 

[sipherblitz]

springs are usually the same more or less.. the buffer weight is where most changes will occur. Unfortunately I haven't built a blackout gun so I can't give you specifics. go to you local gun shop and start asking some questions.

 

[95wrangler]

Well my Google fu improved and now my question is do I use a rifle buffer and spring or use a spacer and carbine setup and which buffer?

 

[bmbutch]

Mine is 8.5 on SBR lower, running Spikes Heavy Buffer. Did have to upgrade extractor spring & install o-ring, now runs awesome!

 

[Trigger Time]

Buy a KAK industries pistol tube and then use a regular spring and a carbine buffer or a heavy buffer (whichever one). no spacer needed

 

[95wrangler]

I wanted a longer tube that's why I didn't buy a pistol tube. I already have the sig brace and rifle length tube.

 

[Ericpwp]

I think you need the rifle buffer for the increased length in the tube.

Edit:I cannot find the post I read that addressed this.

 

[95wrangler]

From what Im reading elsewhere, I have to use the rifle spring. As far as buffer I think I can use any carbine buffer, you just cant use a rifle buffer in a carbine tube. Bad things happen. The diameters are all the same, the rifle buffer weighs in at 5 oz. while carbine buffers weigh in anywhere from 2.6 to 5.8 (ish) oz.

Now that Im getting parts in hand, I may have to rethink this. The rifle tube screws all the way to the receiver so I cant use the endplate I wanted and still have the tube retain the buffer retainer plunger. I may have to sell some new parts and just settle for the KAK tube. Its only an inch shorter. (That's what I tell her!)