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It’s Piss Off an Anti-Gunner Day: Black Friday Budget 300 Blk Frankengun

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You may have just heard the President’s new directives on gun control by way of executive order and are wondering how any of them have any possibility of stopping “gun massacres.” You know, the ones he claims have him so incensed, that bring him to tears. Yeah, not one of these proposed orders will have a detrimental effect on crime. So, maybe you should celebrate by buying or building a new Frankengun just to make those NICS checks jump a little higher this month and let him know how you really feel!


We are always a sucker for a good deal on a new firearm. Black Friday and Cyber Monday brought those out in spades.

Rather than buy a new gun, we sought to build a 300 Blackout Frankengun-style pistol with what we could source from the internet. This is a firearm simply for conducting testing on the types of products you love to read about, so our requirements were simple: a pistol length barrel, folding iron sights and a decent sling mount to haul it out to BLM land because there is no feeling in the world like being 200 yards from your truck and kit setting up a target and seeing a brass buzzard check to see if your vehicle door is open!

The best deal on complete upper receivers (less bolt, carrier and charging handle) came from Radical Firearms by way of AIM Surplus for $209 including shipping. This was no bare bones upper, we had an ejection port, forward assist, M4 feed ramps, stainless gas tube, low profile block, the company's rail system and a 8.5″ barrel.

For a lower receiver, we found a great deal with Karri's Guns. A complete pistol lower including buffer and action spring for $129 delivered. As luck would have it we got serial number 500!

We procured our bolt carrier group from It was an Anderson Arms version for $89.99 shipped.

At this point had a working gun for just over $425, so we looked at some other small upgrades. We found the standard bird cage flash hider to be lacking. After all, the point of an 8.5″ 300 BO is to run a can on it. As the only can we had in the house was an AAC 762-SD, we quickly called in to for a 51T Blackout Flash hider for $75 delivered. When we test other silencers in the future we will reach out to Silencer Shop for any adapters we need as they seem to have better stock (and lower prices) than the manufacturers and with the impending fight against implementation of 41P, we want to support a company that has skin in the game!


We have more AR magazines than most police departments, but wanted to try something new out and Freedom Munitions had Hex Mags for $11.99 with free shipping, so we snagged one up before they ran out.

When it came time for a sling attachment we replaced the standard end plate with one from TX3 for 420 shipped. This end plate comes with standard sling loop attachments, but can be had with QD sockets or without attachments at all.


The reason for that is the rear end of the end plate holds a takedown tool that can be used to push out stubborn pivot pins. It locks in and is retained by a magnet and makes the chore of taking down a stubborn pivot pin seemingly effortless.


Sig Sauer had us covered with a Sig Brace that came out to $80 shipped with 20% off and free shipping and we snagged a set of Magpul MBUIS and rail sections at Cabelas on Employee Discount night with an additional 5% off for Veterans for about $69 out the door.

We had our pistol together in less than 30 minutes once all the parts came in. We ran out to the range and performed a test fire with a single loaded round. The rifle fired and the bolt locked rearward on the empty magazine. So far so good.

Three rounds in the magazine gave us a malfunction. The empty did not kick out far enough and got caught up with a fresh round. This happened 3 more times until we threw our silencer on.

The 762-SD made the pistol function, because as we all know, silencers solve 90% of gas problems in the AR platform (thank you Mr. Hollister).

However, what if we had the need to run the gun without the can?

The block was centered and the tube was not bent. A call in to Radical Firearms assured us that they would take a look at it and rectify it with no problem, but we tend to be resourceful and like figuring things out on our own. Great customer service there.

We considered a Noveske KX-3 type brake, but knew it would cause a lot of unnecessary ass pain due to how those brakes need to be timed and we did not cherish the thought of changing brakes every time we want to run a can.

Then we remembered Simplistic Shooting Solutions and had them ship us a QD Brake shield which attached to the 51T. I asked the owner of the company if it would add enough back pressure to help cycle the action and he admitted that it might, but they had never specifically tested for that.


About a week after Christmas our blast shield arrived via USPS. We threaded it on and ran back to the range with 200 rounds of 300 BO.

Every round, both super and subsonic cycled flawlessly. If you have been wondering about this device (and they make a YHM version as well) it will help cycle a problem gas system.


We are into this test pistol for just south of $700 and it looks to be a sound platform with which to test rounds, optics, lights, lasers and silencers. Best of all, some anti probably thinks we used an “internet loophole” and is having a stroke because we bought more than 12 rounds of ammunition in a 90 day period.

Some things, money can't buy.

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