New project 300 Blackout 10.5" pistol

[MK111]

I just decided to build a AR 15 10.5" pistol with a Sig arm brace. I'll put a red dot scope on it with a lazer and good light. Plus I'll be getting a suppressor for it.
Why just because I can and don't have one.
I was going to build a AR 15 in 22 TCM but after research the reliable function isn't there. Plus it's damn expensive with buying a magazine adapter and modified magazines. Then even at that it may end up being a high priced single shot most of the time.
I'm selling off all my 22 Mag rifles and switched to the Rock Island bolt action in 22 TCM. The 22 TCM is a hell of a round at 2800 fps out of the rifle and reloadable. At that it beats the hell out of the 22 Mag round and a whole lot cheaper to shoot.
Last year I traded off my ATV that I hadn't ridden in 10-12 yrs for a AR 15 pistol with Sig arm brace in 9MM that uses Glock magazines. Now that compact firearm ready rocks and is 100% function.
Working for a ammo company has it's benefits of free 2nds ammo.

 

[Dustinb80]

Keep us updated with pics Frank. Good luck

 

[MK111]

Forgot to mention the ammo CO. sent me 30 caliber 200 gr plated bullets to work up a sub sonic load for the 300 Blackout. The 1st loading functions 100% just waiting for the suppressor for function testing and test for FPS. We used to load a 220 gr sub sonic load so a 200 gr load was rather easy test loading.

 

["J"]

Forgot to mention the ammo CO. sent me 30 caliber 200 gr plated bullets to work up a sub sonic load for the 300 Blackout. The 1st loading functions 100% just waiting for the suppressor for function testing and test for FPS. We used to load a 220 gr sub sonic load so a 200 gr load was rather easy test loading.

How you liking the plated bullets Frank?

 

[OO2]

Sounds like a cool project!

Selling 22Mag? You got my attention

 

[hickslawns]

That sounds like a fun gun Frank! I like the idea of the 9mm using Glock magazines too.

 

[MK111]

How you liking the plated bullets Frank?

The ammo Co. uses plated bullets for all the pistol rounds.
Most plated bullets must be kept at less than 1200 FPS.
The 30 caliber 200 gr look good and loaded OK. Plus all the test rounds at or near subsonic speeds about 1050 FPS functioned 100% in semi auto mode. The main test until the suppressor gets here was for function. Putting the suppressor changes everything. Put when I developed the 220 gr sub sonic it worked full auto suppressed.

I've shot 22 mag for years and had almost every rifle made except the Savage. Mossberg, Brno, HK 300 auto. I've sold them all except the HK 300 auto and that's for sale now at Lima gunshow.
The 22 TCM rifle has replaced the 22 mag rifle and I can load what I want and shoot cheaper with a faster better round than the 22 mag. That's another project I'll be working on when the weather breaks.

 

[MK111]

That sounds like a fun gun Frank! I like the idea of the 9mm using Glock magazines too.

It's a great compact firearm. The Class 3 FFL Dealer just converted the same pistol I have to full auto suppressed and brought it over for me to shoot and that got my attention. It ran full auto with 100% function. I never wanted a full auto but that will make a great addition to my house defense gun. LOL

 

[Ohiosam]

I've been thinking of a similar build. Build it now as a pistol. Then if they remove suppressors from the NFA I'd pin and weld a suppressor on that gets me to 16" and add a Carbine stock.

 

[MK111]

Today while my trimming equipment was running smoothly I decided to prep 500 300 BO cases.
I already had the case cut down and sized from once fire 5.56 military cases.
I used my RCBS case prep machine that is motorized.
1. used the inside primer pockets debur tool to remover inside flash hole bur.
2. used the outside neck debur cutter to remove trimming burr.
3. used the inside neck debut cutter to remove trimming burr.
4. used primer pocket military crimp remover.

All 4 of these steps are not necessary as the carbide trimming tool makes a nice clean cut and the primer pocket was swaged to remove the military crimp. But doing these 4 case prep steps goes back to my NRA big bore shooting and long range PD shooting to wring out every little bit for accuracy.
I'm doing 1000 case for a once in a life time case prep event.

 

[MK111]

I case prepped another 500 cases today for the 300 BO. That gives me 1000 cases ready to reload.
I've done my main research on getting a 300 BO pistol. Looks like I'll be buying a 10.5" upper threaded for a suppressor and a pistol lower.
When you buy a upper and lower together as a complete firearm that raises the price $150-200. Hell I can push the 2 pins in for that and that $150-200 can be spent a a good sight.

 

[MK111]

That sounds like a fun gun Frank! I like the idea of the 9mm using Glock magazines too.

Here's my 9MM AR pistol that uses Glock magazines.
I installed the SIG arm brace ordered direct from SIG for $112 delievered.
Also installed the hand guard stop so I couldn't move my hand too far forward and shoot my fingers off. Important.
The red dot sight I bought from my grandson when he upgraded his 3 gun rifle sight.

It's my house defense gun with 3-30 round magazines. It's a fun practice gun as I get all the 9MM 2nds ammo from the ammo company I want.

 

[hickslawns]

That is cool! Have fun with it Frank.

 

[Ohiosam]

That's a great looking AR!

 

[Hedgelj]

Hey Frank,

You might look into a smaller barrel...if i recall correctly the 300BO was designed for complete powder burn at 8.5".

The biggest problem i have read about suppressing them is making sure the gas port isn't too large. AAC seems to be the go to company for uppers that run flawlessly suppressed or un suppressed.

 

[MK111]

Hey Frank,

You might look into a smaller barrel...if i recall correctly the 300BO was designed for complete powder burn at 8.5".

The biggest problem i have read about suppressing them is making sure the gas port isn't too large. AAC seems to be the go to company for uppers that run flawlessly suppressed or un suppressed.

Advised by a Class 3 dealer go nothing less than 10.5" suppressed or the internal baffles will destory from heat. He has everything suppressed. We used his 2 uppers for testing and both worked OK. He ruined a shorter barrel rifle already.
Almost all problems with suppressed guns is the ammo. I had a real time learning curve 3 yrs ago doing the R&D load development for the 300 BO. I got it to 100% semi auto, full auto, semi auto suppressed, and full auto suppressed.

 

[Hedgelj]

Advised by a Class 3 dealer go nothing less than 10.5" suppressed or the internal baffles will destory from heat. He has everything suppressed. We used his 2 uppers for testing and both worked OK. He ruined a shorter barrel rifle already.
Almost all problems with suppressed guns is the ammo. I had a real time learning curve 3 yrs ago doing the R&D load development for the 300 BO. I got it to 100% semi auto, full auto, semi auto suppressed, and full auto suppressed.

The minimum length is dependent on the suppressor manufacturer. That is dependent upon what the baffles are made of and how the entire thing is assembled.

Ammunition is one part of the equation in how an AR15 will run. It's not the entire equation.

 

[Hedgelj]

Here is an example of a very solidly built suppressor which has minimums much less than 10.5.

 

[Jackalope]

Here's my 9MM AR pistol that uses Glock magazines.
I installed the SIG arm brace ordered direct from SIG for $112 delievered.
Also installed the hand guard stop so I couldn't move my hand too far forward and shoot my fingers off. Important.
The red dot sight I bought from my grandson when he upgraded his 3 gun rifle sight.

It's my house defense gun with 3-30 round magazines. It's a fun practice gun as I get all the 9MM 2nds ammo from the ammo company I want.

Me likey! I once had a kel-tek sub 2000 in 9mm and it was a blast to shoot. Junk built POS but it was fun on the range.

If you don't mind what's the recipe for that gun. I feel a build coming on.

 

[hickslawns]

Me likey! I once had a kel-tek sub 2000 in 9mm and it was a blast to shoot. Junk built POS but it was fun on the range.

If you don't mind what's the recipe for that gun. I feel a build coming on.

I had a Sub 2000 as well in 9mm. Looked and felt like a toy. I will never own anything Kel-Tec again in my life. How to adjust the front sight pin? Just bend it some with your fingers. Good thought on the design. Lacking in the quality department. It was priced accordingly though.