1/4 Circle 10 Lower

[Troutburger]

So I received my QC10 AR lower today. 

 

Here is my question.  Which upper to go with?

 

I can order a lone wolf upper and the bolt has already been modified for about $700, but I don't like the short quad rail on this one.

Or

I can order a CMMG upper with a keymod rail that I like better than the LW rail for for about $630.  But I will either have to re-profile the bolt my self or spend $40 getting it done.

 

Any other glock ready uppers recommended?

 

How big of a deal is it to fit the bolt?  I have a dremel, and some files.... 

 

[MacGyver]

I put my upper together myself for exactly this reason.  I couldn't find what I wanted.

 

I'm running a custom 9-3/4" barrel by ADCO to ensure that my suppressor mounts up appropriately with the KAC URXIII rail.  I modified my bolt myself - but that's not a step I'd recommend without a milling machine.  I'd probably just send the bolt to someone like ADCO to get it done.  

[Troutburger]

I'm still flip flopping over carbine vs pistol vs SBR too. 

This is ridiculous too many decisions. 

 

I can find a dozen AR15 uppers I like in ten minutes, but i'm all messed up over a 9mm lol. 

[MacGyver]

I couldn't find any real compelling reason to do a longer barrel on the 9mm.  In my mind, it ought to be a pistol or SBR.

[Lumber_Jack]

Just SBR that sucker and get a suppressor while you're at it. A suppressed sub 10" 9mm AR is what wet dreams are made of

[Dolomite_supafly]

With a 9mm you have to go to the extremes. Either it needs to have a 4" barrel or a 16" barrel, anything in between is senseless. 4" barrel will keep most ammunition subsonic while 16" barrel will deliver 357 magnum performance but anywhere in the middle and you get neither.

 

If it were me, and I have spent many a night thinking about the 1/4C10 lowers, I would get a 4" barrel with a rail that will fit over the 9mm suppressor that this thing begs for.

 

I will say from the pictures that the lowers are designed to match up with billet uppers. I cannot remember which billet but I think it says on their website. Matter of fact I would just get the bolt from them, you cannot buy and have machined cheaper.

 

The only, and I mean ONLY, reason I do not have one yet is this year there will be a US manufactured 9mm AK. I am saving every red cent I can to make sure I can get one when they become available. And when I do get one it will have a suppressor.

[Smith]

With a 9mm you have to go to the extremes. Either it needs to have a 4" barrel or a 16" barrel, anything in between is senseless. 4" barrel will keep most ammunition subsonic while 16" barrel will deliver 357 magnum performance but anywhere in the middle and you get neither.

How can that be? Everything I've seen says 9mm maxes out velocity wise around 10"-11". After that the gain is negligible and starts scrubbing speed around 16" and up.

Even thought I read in another thread that at 10+", a factory subsonic load will go super sonic(?)

One reason I went with a 10.5" Edited March 5, 2015 by Smith

[Dolomite_supafly]

Depends on the rounds but most are still gaining at 16". The vast majority of rounds are still making significant gains between 10" and 16".

 

If I am going to go with something less than 16" it will be way less than 16" so everything I shoot will be subsonic.

 

http://www.ballisticsbytheinch.com/9luger.html

[Troutburger]

Yeah the bummer is QC10 bolts are out of stock. I cant find their suggested upper anywhere on the site. 

 

I actually want a carbine and a suppressed SBR, so that adds to the decision. 

 

I figure since I cast 9mm bullets a 9mm carbine is a good way to stay in ammo during the now common droughts. 

[Jct1911]

Their lower is machined to match the Vltor mur upper profile. For me, I'd wait and get the parts from QC10. Too many variables in pistol AR configurations to chance it working with other manufacturers stuff. Only guys I would trust would be RMW or MaconArmory for a DI upper, but that is not in option in 9mm. I'll eventually get a .40 build done with a QC lower, .40 gets a good boost from barrel length also.