Building an AR15 in 7.62x39 SBR....

[Mexican_Hippie]

If others have different experience let me know. I'm always open to cheaper options I may not know about.

 

[texas skeeter]

Thanks for the info Hippie.

 

[texas skeeter]

I'm still for it. Try it out and let us know

I will because I guess I'm a gluten for punishment. LOL Ill post pics and a report of final product weather good or bad...

 

[Se7en62]

I'm going to do the same and report back on my Sharps 25-45 AR. I just have to do it now out of principle...

 

[The Lox]

The Mk47 T is our entry level MUTANT designed to be a budget friendly offering, giving you the opportunity to upgrade as you see fit. The Mk47 T offers the modularity of the AR-15 giving you the opportunity to readily upgrade your trigger, pistol grip, and stock to your preference. The Mk47 T features all new mid-sized receivers based on our Mk3 platform carved from billet 7075-T6 aluminum. The Mk47 T was designed to harnesses the power and reliability of the 7.62x39 cartridge utilizing a robust bolt also based off our Mk3. The unique Mk47 lower receiver readily accepts all standard AK Magazines. Every rifle comes equipped with a 30rd AK PMAG and CMMG's lifetime quality guarantee.

Available January 2015

[/URL]
CMMG Mk47 MUTANT T:


Caliber:*7.62x39mm

Barrel:*16.1" Medium Taper Profile 4140 SBN
.311 Groove Diameter, 6 Groove Rifling

Muzzle:*A2 compensator
Threaded 5/8-24

Hand Guard:*CMMG RKM15 KeyMod

Upper Receiver:*7075-T6 AL

Lower Receiver:*7075-T6 AL

Trigger:*CMMG Single Stage Mil-Spec Style

Furniture:*Mil-Spec 6-Position Collapsible Stock, A2 Pistol Grip

Weight:*7 pounds (unloaded)

Length:*32.75 inches (stock collapsed)

Magazine:*Magpul PMAG® 30 AK/AKM MOE®

MSRP:*$1,499.95

Just save your self the trouble and buy one of these. Reviews seem to be positive.

After handling one of these at the last fun show I went to, this is what I am going to do. I sold my Saiga rifle because I wasn't really into the platform. Kept all my ammo and mags, so those will all work and this rifle was just awesome to think about using in the future.

 

[Se7en62]

Since we touched on the .300 BLK and I am championing the .25x45, I wanted to include something pertaining to their ballistics. If someone else wants to add the same for the 7.62x39, I'd be interested to know them, but I'm not holding my breath that they're any better.

Sharps .25x45
SD: .188
87 Grain bullet at 2885 fps muzzle Velocity with a BC of .300
Energy at Muzzle: 1608 ft-lb
Drops to 1010 ft-lb at 200 yards
Sight it in at 100 yards and it drops 4.8" at 200 yards.

.300 AAC Blackout
SD: .188
125 grain bullet at 2250 fps muzzle velocity with a BC of .366
Energy at Muzzle: 1405 ft-lb
Drops to 1007 ft-lb at 160 yards
Sight in at 100 yards and it drops 8" at 200 yards.

 

[Mexican_Hippie]

That's more apples to apples.

Both look fine on deer out to 200yds w supersonic loads.

 

[Younggun]

Interesting comparison.

One thing to note, numbers don't equal real world results. And I would be more concerned with the real world results of the .25-45. Gonna check out the cartridge.

But an example of numbers not always panning out:

I have a 1911 chambered in .22 TCM. It has the same muzzle energy as .45 ACP. I would prefer the .45 ACP as a defense round over the 40gr 22TCM, and I don't even care for .45 all that much. It's simply the fact that energy numbers aren't always equal to real world benefits.

 

[Younggun]

One other question on the .25-45 Sharps


The OP is looking at an SBR but the posted velocities seem to be in line with a 20" test barrel. The design of the cartridge seems to match those that are more suited to longer barrels.

Is their any velocity info for SBRs. With such a light bullet, velocity will be critical to making it effective. Going from a 20" to a 10" barrel could turn the tables when it comes to external ballistics.

 

[Saltyag2010]

Skeeter- here is a YouTube video of 7.62x39 out of a 16" barrel, 11.5" and 7".
[video]https://m.youtube.com/watch?v=lbgAh9-sCDQ[/video]

Kinetic Energy = mass x velocity x velocity of I remember right. Plus cheap ammo makes me happy.

 

[texas skeeter]

Whoo Hoo Great video Salty. It looks like the 11" barrel is the one for me. With Saker can i'm a thinkin....

 

[texas skeeter]

And I had a good laugh at how the gentleman tried talking me into building some kind of "Quigley Down Under" rifle.

 

[itchin]

What is a quigley down under rifle? I look forward to your "my 7.62x39 ar won't cycle" thread. There are many.

 

[Younggun]

He's referring to the movie "Quigley Down Under". Good movie, but the caliber used was not .25-45.

 

[texas skeeter]

I would suggest a Sharps 25-45.

This was what made me think of that movie QDU. And Yes Youngin I know it was not the same caliber.

 

[Se7en62]

What is a quigley down under rifle? I look forward to your "my 7.62x39 ar won't cycle" thread. There are many.

This +1

 

[texas skeeter]

I look forward to your "my 7.62x39 ar won't cycle" thread. There are many.

OK Negative Nancy, we'll see how it goes...

 

[Younggun]

This was what made me think of that movie QDU. And Yes Youngin I know it was not the same caliber.

I wouldn't mind having an actual Quigley rifle, just because.

 

[Se7en62]

Hahaha, I had to look it up for context. The Quigley rifle you guys are referring to is a 1874 Sharps Buffalo...they're available in 45/70 or 45-110 Caliber and start at $3,464.

That nothing like the Sharps 25-45.

 

[Rebel]

Shiloh Rifle :: Sharps Rifles :: 1874 Rifles :: 1874 SHARPS BUFFALO - "QUIGLEY®"

Fair warning: The theme music to Quigley Down Under plays on that page. The media controls are in the top left of the screen.