300 AAC Blackout Build - Finally!

[mtlcafan79]

Actually, it's the other way around. I don't think a .223 would chamber in 300 BLK (at least not go into battery - too long). However, a 300 BLK would chamber in a .223 and that would be a .308 going down a .223 barrel.

 

[BradMacc82]

Where there's an idiot, there's a way...

 

[pitpawten]

I notice the bottom of the brass on that casing is missing, gas has to go somewhere....wrong end of the barrel for my tastes!

 

[Praeger]

Now we know how long a 220gr .223 bullet is . . .

 

[pitpawten]

Now we know how long a 220gr .223 bullet is . . .

Who knew, now you can fireform bullets too...Now you can easily switch between .223 and 300blk interchangeably after each shot!

 

[BradMacc82]

I notice the bottom of the brass on that casing is missing, gas has to go somewhere....wrong end of the barrel for my tastes!

It was sheared off when the person was milling the barrel to show the results of someone not paying attention.

 

[j8064]

Back to the Original Thread Topic:

The BBTOH delivered a long-anticipated package today. I wonder what it could possibly be?

The new upper and lower mate perfectly. They like each other.
The carry handle/rear sight and front sight seem to be in alignment.

The time has come to get this bad girl to the range!

 

[Marauder]

Good luck at the range.

 

[Sticky]

Now we know how long a 220gr .223 bullet is . . .

 

[j8064]

Beagle Inspection Complete...

I learned a long time ago my builds and restorations shoot better if they pass a final beagle inspection. The noses know.

I can check that box. Patty approved this build with a little help from Kasey.

We're GTG!



EDIT:
It took a while for me to figure out why Patty was so focused on the magazine. After reviewing the inspection pics I now understand. She was verifying the distinct aroma of that mag having come from WV!

What a smart beagle.

 

[j8064]

99 Blackout Rounds in the Box...

Well, I had 100 test rounds loaded. Original plan was to save them all for tomorrow's range trip. But when the Tourons staying a few doors down began setting off loud fireworks (beagles went crazy), I figured one Blackout round into my hill wouldn't be noticed...

The rifle functioned perfectly and the spent case made from a cut down .223 looks like it should.

I'm ready for the range tomorrow!

 

[Mooseman]

I will settle for taking the second shot with the new build. Can I ring the gong?

 

[j8064]

I will settle for taking the second shot with the new build. Can I ring the gong?

The gong is already afraid!

 

[Mooseman]

The gong is already afraid!

I checked this evening. They are still hanging. We will have to keep Stan away from them.

 

[j8064]

I checked this evening. They are still hanging. We will have to keep Stan away from them.

If he brings that Mosin he better bring some bungie cords too....

 

[Mooseman]

If he brings that Mosin he better bring some bungie cords too....

I'm hoping he packs his tool kit.

 

[Mooseman]

The upper was great.

 

[j8064]

The upper was definitely worth waiting for. But there were some issues at its debut today.

First, after cycling the first round the trigger locked. To free it we had to rotate the safety. Then it would fire. When I got the lower back on the bench I quickly spotted the problem. Somehow during assembly I installed the trigger spring looped over the top of the trigger tang instead of underneath where it belongs. What was happening is the disconnector was catching on the spring when live fire cycled the bolt. Rotating the safety would release the disconnector so the trigger would reset.
That DA faux pas is now fixed.

Second, a couple of my loads were hanging up in the chamber and not allowing the bolt to go into full battery. I’ve had that happen before with 223 reloads. The solution for 223 was to run the cases through a small base sizing die vs. a standard die. Since the 300 BLK cases are built from 223’s the same small base die will work on them. I ran today's cases through the 223 SB die and then the 300 BLK sizing die. As expected, the SB die took the bases down quite a bit further. It adds a step to the reloading process, but it should do the trick.

With the exception of the rounds that wouldn't chamber all the 150 and 180 gr FMJ test rounds shot beautifully. Even my cast loads worked well. To my surprise the upper liked the 110 gr RN FMJ's. With a heavier charge of H110 behind them the 110's were zooming.

More testing ahead, but for the price this upper was a terrific entry into 300 BLK.

 

[Marauder]

Nice shooting, I really like my 300Blk.

 

[Mooseman]

I still think that you should have stopped after the first shot. Right in the center of the red, I would have quit while I was ahead.