looking to do a 10.5" barrel AR pistol w/ a folder on it.  I already have most of the parts together but I still need to decide what chambering.  This is a superlight build w/ light BCG and magnesium allow receivers and handguard.  Want it so its short w/ suppressor, fast in the hands and easy to lug around discretely in a bag when I take it out of the house w/ me.  

I have a suppressor, a shorter 30 cal can already.  

could do a 556, but thinking about wilson 762x40.  The x40 woudl be more power, would suppress better, especially w/ my suppressor, could be used for brush hunting too (someday).  I'm not thriled how x40 is not so popular, w/ only one source of ammo but so long as there is one source of ammo I'm comfortable w/ it.

I alreay have a similar 5.45 upper & surplus ammo I can use for blasting/training whatever, so I'm not too concerned about hte high cost of the x40 factory ammo.  

The only thing that gives me pause is just getting into a new & proprietary chambering.  Worth is???

300 blackout is really caught on but its pretty wimpy.  I supposed it is better than 556 out of very short barrels for power an suppress ability, but 10.5" is the absolute min length and it hardly seems worht it going to 300 blackout for > 8" barrels to me...

I don't agree than 10.5 is the min for blackout. I would strongly recommend an 8" blackout as you do not reload. Alternatively, I'd recommend a 6.8. The x40 is nice, but you need to hand load for it. Especially in short barrels (using lil gun rather than 1680).

I was saying that 10.5 was the minimum for this handguard i have.  

I agree that 8" is a good length for blackout and probably x40.  

So you are that the powder wilson uses in their x40 loads  is a slower burning powder not well suited for short barrels?

I am aware that the 6.8 is more powerful than BO even out of short barrels...

I was looking at the  parts again... Perhaps a  ca 8" would be better, every inch counts when you are trying to drop weight and make the suppressed gun manageable.  

anyone have a source for a Light weight ca 8" 6.8 barrel??

Thx

IF you are set on a magnesium receiver, Mag Tactical has blems for 75.00 now.

Black and FDE

MagTac Stripped lowers

(Not affiliated nor do I own one.)

If you have no intention of shooting suppressed subsonic, I'd highly recommend a 6.8 SBR as they do have an edge in mv and ke over other double stack ar15 cartridge options. Add to that the fact that many manufacturers produce 6.8 ammo and it can be found at many sporting goods stores.  Ammo availability is a huge plus for the 6.8 and the 7.62x40WT simply cannot compete with that aspect.

And the 300 performs far better from an 8" barrel than 5.56 does.  It may not be "the powerhouse" of .223 variants but it does remarkably well for what it is.

A 110gr TAC-TX fired from 300 sbr is a potent round that I wouldn't necessarily call wimpy, especially when used in close quarters.

ymmv

yes, I have a set of them, and a KMR.  Wanint to make th ebuild as light as possible, and short.  Just wish the law tac folder didnt' weigh tso damn much

6.8 is great in that it is good for short barrels, suppresses well, is powerful and has decent external ballistics too.  Unless you are talking about hand loader only boutique chamberings perhaps, it really is the best SBR general purpose chambering.  The main drawback to it is that the ammo weights up to half again more than 556 and the magazines lower capacity heavier.  Of course, the Six8 LWRC project is pretty sweet w/ the lightweight 30 rd magazines.


The end purpose woudl be a short handi suppressed home defense rifle/ and a light concealable travel/bag gun and that doesn't give up ammo capacity or have much of a weight compared to over 556.  

For something that is efficient from shorter barrels, can suppress well for HD, uses light weight magazines and receivers.  x40 would be better, but only if loaded w/ lill gun I guess, and I'm not reloading yet nor have time to lear soon.  So, I'll probably end up with 300 BO, it sure as shit is am improvement over 556 from very short barrels, and suppresses great.  I suppose it can also be suitable for hogging w/ a few loads.

yes, I called, all their factory ammo is loaded w/ accurate 1680.  The do however have handy handloading tables on their site w/ five different powders including lil gun so it would be pretty easy to load. Unfortunately, the only 110 g bullet is the TSX.

How hard would it be for a total newb to learn how to load up some rounds per published data w/ brass that is already converted and sized?  I know that reloading fired rifle brass is a lot of work w/ many steps, but is the learning curve very steep is the brass is already sized and you are just using published loads?

all i run in my x40 is the 110 vmax and sp with excellent results.

with 1680 start at 24.5 and work up.

results?  Like terminal performance???

fuck it!  I think I'm gonna do it in 8.5"

I'll just get a little factory ammo for now and get some lil gun and prepped brass and load other ammo out later.  30 BO just seems like such a waste of case capacity for silly subsonicry.

say, w/ the powder used by wilson, which of their ammo would be best to get for short barrel? heavier or lighter?

http://shopwilsoncombat.com/762x40-WT/products/418/

ETA: hang on, better look at the 277 wolverine...