PDA

View Full Version : 7.5" BBL AR ammo choices?


DJ Urbanovsky
09-05-2014, 17:32
Did the research, used the search function, etc...

Application is a 7.5" BBL, 5.56 chambered, 1/8.

I know velocity is going to take a hit with a BBL this short. Gun needs to fold up and fit into a particular bag without separating upper and lower. Reach in, grab, unfold stock, disengage safety, up.

I do realize that 6.8 and .300 Blackout might be better options for a BBL this short, but I am standardized on 5.56 for all of my guns.

Based on what I've gleaned here and out on the Interwebs machine (mostly here, though), I have narrowed it down to the following three options for this specific application.

1) MK 262 77GR OTM. Silver State Armory with SMK or Black Hills.

2) Le Mas / RBCD?

3) DRT 79GR Terminal Shock. I believe Buck mentioned these in a previous thread.

My question is, do you guys feel like these are valid choices for this application, and are there any options that aren't on my radar that I should be evaluating?

I know there are considerations like range and barrier blindness... I'm looking for something that's well balanced, and that will hit as far out as possible.

Thanks for your help!

The Reaper
09-05-2014, 19:05
I don't think the specialty ammo offers any appreciable terminal performance increase from a pistol barrel.

Even the lightweight rounds will be near or below the fragmentation threshold, which means head/CNS shots will be required beyond 25 meters.

I would just buy M193 and use the money saved for practice ammo.

Learn to put the bullet where it needs to be.

A short pistol is not going to be as good as a rifle for extended engagements.

There is a tradeoff, especially if you want to go small.

TR

DJ Urbanovsky
09-06-2014, 17:24
Thanks buddy.

Roger all that. Training good! :lifter

I've got standard 16" for rifles, and then 12.5" and now this 7.5" for the pistols. Just got the 7.5" together this afternoon. Will hit the range this week, ring it out, and see how it performs (and if I can hit with it). Hope it runs half as good as it looks!

Minimum recommended barrel length to achieve fragmentation with MK 262 is 10.5", yes?

Considering procuring a chrono to see what kind of velocity I'm getting out of that 7.5".




I don't think the specialty ammo offers any appreciable terminal performance increase from a pistol barrel.

Even the lightweight rounds will be near or below the fragmentation threshold, which means head/CNS shots will be required beyond 25 meters.

I would just buy M193 and use the money saved for practice ammo.

Learn to put the bullet where it needs to be.

A short pistol is not going to be as good as a rifle for extended engagements.

There is a tradeoff, especially if you want to go small.

TR

DJ Urbanovsky
09-26-2014, 14:03
Range report on the 7.5": 246 rounds fired, combination of MK262 and SS109, zero malfunctions, hits with MK262 out to 300 yards with T1 Micro clone. No magnification. Did not have chronograph, so not certain of muzzle velocity or how fast bullets are going by the time they get out that far. Pretty impressed with the performance of this upper. Am tempted to put a variable optic up top and see how far out I can reach with this thing.

The MK262 came from Silver State Armory. My only real gripe with this ammo is that it doesn't have primer sealant.

Ambush Master
09-26-2014, 18:01
Gun needs to fold up and fit into a particular bag without separating upper and lower. Reach in, grab, unfold stock, disengage safety, up.



If this has a Shoulder Stock, it becomes an SBR (Short Barrel Rifle) which carries the same Restrictions and Registration Requirements as a Machinegun or Sawed-off Shotgun!! Be very careful here!!!

Later
Martin

DJ Urbanovsky
09-26-2014, 19:39
Ambushed again! ;)

Spot on. Details matter, and I misspoke, Martin. By "stock," what I meant to say was "pistol buffer tube equipped with SIG brace." This receiver has never been assembled as a rifle, nor has it ever had a stock attached. If BATFE would like to pay me a visit, they will discover 100% compliance and it will be a very boring visit for them. I even keep a copy of three different BATFE letters pertaining to AR pistols in the case with the pistol.


If this has a Shoulder Stock, it becomes an SBR (Short Barrel Rifle) which carries the same Restrictions and Registration Requirements as a Machinegun or Sawed-off Shotgun!! Be very careful here!!!

Later
Martin