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Sunday, March 24, 2013

Speculation: building a 300 Blackout SBR.

I'm starting to research putting together an upper. Not sure if I'm going to go through with it - I'm in the brainstorming stage. Chris suggested I look at going for 300 Blackout, since I've also entertained getting a suppressor.

The problem I'm encountering right now: what in the world is the deal with buffer weights? I don't care quite as much about the tube length - I'm still getting an adjustable rifle stock for it. Lead the blind, will ya? Do I need a lighter weight buffer, or can I stick with the standard weight?

I'm still doing my research, but dang there's a lot of conflicting information out there. My brain hurts. :)

Oh, does anyone know anything about this item?


Expect more questions as I attempt to navigate through planning this build. I'm an idiot when it comes to this sort of thing, and I suspect I'll come across more mental roadblocks.

9 comments:

Old NFO said...

Buffer weight depends on whether you're firing blackout or full power rounds... And AAC does build good stuff! Pricy, but good!

Laura said...

Pretty sure I'd stick to Blackout. Would that mean a lower weight buffer would be fine? I found this particular one, and thinking it might be an ideal option...opinions?

ZerCool said...

I'm running a standard carbine buffer in the Pale Horse, which is 300BLK, carbine gassed, and an 18" barrel.

Wally's advice to me was essentially "start with standard carbine, and adjust if needed".

Firing milspec 5.56 from the same lower *might* want an H/2/3 buffer, depending on cycling.

Vuurwappen blog (sp?) has a really good post with video on it.

Laura said...

Hmm. Okay. Chris said I'd have to start with something lighter because of the short barrel. I'll check out that post later. Thanks. :)

Wally said...

Run a "H" carbine buffer with a 10" 300BLK, and stock carbine spring.

I build all of my semi-auto SBRs this way (MGs go for the H2 buffer).

Never had any trouble to get a 10" 300 to run happily with sub or super sonic, suppressed or not. 16" (with carbine gas systems) can be a little more sensitive to run with all ammo loads. But even then an H buffer is required.


blatant pimp : If you need a 10" 300 bbl, I have a few here, leftovers from the guns that didn't go to NY.....

Laura said...

Thanks for the info!

I...may email you. Soon. After payday.

Alan said...

I'm trying to build a 300 blackout SBR too. I'd be interested in what you wind up with.

Laura said...

Alan, i'll keep ya posted. :)

Charlie said...

General rule of thumb is run with a standard buffer at first, then adjust as necessary. Observe primer strikes and ejection patterns to see if you are overgassed/short stroking. Anything at about 12 o'clock to 2 o'clock ejection tends to be overgassed, 3 o'clock to 4 o'clock is ideal, and 5 o'clock is a short stroke. Of course, there are variations depending on what kind of ammo you use, etc., but it's a decent base line to start with.