.243 LBC, another AR build and intro

[aftCG]

Greetings. I thought I had been a forum member here before but I guess I just lurked and drooled a lot. I have managed to find some great information for loading and caring for my bolt rifles (.243 Win and .22 PPC) and I guess it's time I make some posts.

In the past I've built a number of AR15 rifles but all of them have been in .223 and nothing out of the ordinary. This particular rifle is a .243 LBC, which is a 6PPC with the shoulder moved forward a touch.

The barrel and bolt are from Black Hole Weaponry in Moses Lake, WA and I assembled it all on a Mega billet upper and lower, with other bits and pieces to fill it out. I had to pirate glass from one of my bolt rifles, a Nikon 4-16 x 42 SF that has served me well enough.

I bought the .243 LBC because I wanted to build something for longer distance work that was light enough to carry, and still be legal for deer. I'd seen posts of people claiming very tiny groups and that always gets my attention too.

So far I've not enjoyed any single hole targets with it. It's really not shooting any better than any of the .223 ARs I've built and dialed in. I've tried various combinations of bullets and powder that brought other people luck but so far it's been happiest with the 87 Vmax pushed by Varget and another load of 58 Vmax being pushed by N133.

I'm curious if others in this forum have been shooting this round, and what kind of luck you've had with it. By its pedigree it should be quite a round.

 

[Rtheurer]

Wow
I thought I was up to speed on most of the AR cartridges out there but have to admit I have not heard one single thing about this one.

If you can give me the internal Volume of the brass in water weight ( 32gr of H2O) and what your loaded round is from Base to tip of bullet I can run some Quick load info for you, since Im bored out of my scull.

I have a 6mm Fat Rat wich is a 6mm version of the 6.5 Grendel and the 6MM AR, AR turbo and turbo 40 are all varients off the grendal. They fall in from that 6PPC family too.
I shoot alot heavier bullets for Matches like the 87gr to 107gr stuff. Shoots very well. But like you said Ihave a 223 that will shoot just as well...... it just has less wind drift at the 600 yard line.

Nice buttstock Assy. Whose is that?

RT

 

[6brxdude]

I too am shooting a Fat Rat in an AR15 platform. I built the rifle for coyotes so I went with a Kreiger 1 in 10 twist barrel at 20". My go to load so far after much testing is using CFE223, CCI 450 primers and the 70 grain Nosler BT. Very accurate and according to my Magneto speed chrono the bullets are doing 3385 fps with less than 20fps deviation in a 10 shot string.......I'm very happy!
Good luck with your rifle and loads


Kevin

 

[aftCG]

RT,
Thanks for the offer. The 243 LBC is identical to the 6mm AR. It's just a 6.5 Grendel necked to 6mm. I don't even have dies, I'm just using 6PPC dies moved up enough to chamber the brass.

I would welcome any input as far as loads to pursue.

 

[aftCG]

The butt stock is a Magpul UBR. It's rock solid.

Hey 6brx, where did you get your barrel from? I have put a bit over 150 rounds through my tube and haven't had anything to get too excited about. I just shot it this afternoon and got a 5 shot group in .78" which is the best it's ever done.

Unfortunately the adjacent loads in the same ladder were much less consistent.

I have most of a box of 95 grain Bergers, so if either of you have a recipe for that I'd be happy to hear it.

 

[Rtheurer]

Havnt played with the Berger 95gr VLD's yet. The big winer in my gun as I mentioned some where here before was the 87gr Berger VLD hunting bullet with either CFE 223 or Reloader 15. Both just under 3000fps.

Would be a great 1:10 twist option if you wen that route.

Tried the sierra 95gr Match Kings and Berger 90's but neither shot well in my barrel... not as good as the 87's anyway. I have a bunch of 95gr VLD's I use for a 243 AI in coyote rifle that a re smoken along at around 3500fps... Do the math on that one!
Just seemed the 95gr VLD's looked a little long to get them to work as they took up alot of case space when set at Magazine length. Hence the 87Berger and Hornady's

RT

 

[Rtheurer]

Also forgot to say that I just put a Mega Ambi lower reciever together as well. Very nice to have the bolt release on the right side by the mag release button for what I do. Shooting out of a sling on the left arm kinda prohibits doing anything on the left side of the reciever without alot of movement.. difficult.

Very well made product as well. So far so good.

RT

 

[aftCG]

My turn to scratch my head. I've never heard of CFE 223 powder but I do have some RL15. I'll see if I can secure some 87 Berger's

 

[6brxdude]

Aftcg,
Lee Weels the smith who built my upper had the Kreiger in stock when I rdered my upper.


Kevin

 

[Shooterman]

I recently acquired a 6mm RAT. Not sure what your twist rate is but mine is a 7.5. I have not shot too many loads but I did have good luck with the 87VMAX and 87 Hornady HPBT, using 8208, BR4. 4 out of the last 5 groups shot just over .5" I have tried the 95 SMK, 75 VMAX, and Varget. All those combinations have not shot as well as the first load above.

For my next loads I am going to try some 450's and Wolf KVB-223 primers. I read that someone else had good luck with AR Comp in the Grendel wildcats.