Building AR for long range

I see a Spikes "M4 NO PROVISION UPPER". It looks very similar to the slick side uppers I used to get. Again, not sure how much they might add to accuracy, if any, but they certainly don't seem to hurt.

Yes, I've used the same methods to bed 10-22, 77-22 and AR barrels (blue loc-tite).
 
I've been shooting 77hr smks out of an 18" ballistic advantage barrel. I've shot multiple sub moa groups at 500 with it but never really pushed it beyond that. I don't think you can load the heavier bullets in a 223 because they end up being way too long, the way I understand it at least. Never tried. Have 1000 77s and 3 or 4 pounds of staball 6.5 to load up and push it a little farther this year.
 
I've been shooting 77hr smks out of an 18" ballistic advantage barrel. I've shot multiple sub moa groups at 500 with it but never really pushed it beyond that. I don't think you can load the heavier bullets in a 223 because they end up being way too long, the way I understand it at least. Never tried. Have 1000 77s and 3 or 4 pounds of staball 6.5 to load up and push it a little farther this year.
You should try some CFE223 with the 77 SMK you will get more velocity than StaBALL 6.5.
 
The BCM uppers barrel extension bore is slightly undersize, and requires heating the receiver to install the barrel. I have had great luck with this, and in my 12.5" DD barrel have no problem hitting 10" steel at 415 yards, using M193 55gr. The setup seems accurate, but its still new and primer availability is hindering my load development. Use good parts and and a good torque wrench for the barrel nut and you should be close to as accurate as any bolt gun. I do agree with 600 yards being a more realistic limit for reliable accuracy, over that you may start to loose accuracy with unstable bullets as they will affected by the transition from supersonic to subsonic velocities.


I came from the same background, with lots of bolt gun experience, and got into the AR game later, but the process is the same to be honest. Biggest differences you will notice is you cant neck size, so brass life is less, and COAL is dictated by the magazine, and the ejection process can make brass more difficult to read. Good parts, and careful assembly of the upper is what is going to make the biggest difference, and performance is the same as bolt guns, longer barrels for more velocity. 1 in 7" twist will be what you are looking for to reliable stabilize the 77+ gr bullets.
 
We found the Bravo Company uppers to be some of the best. They are heat-to-fit. And the faces are pretty true. They clean up nicely with 0.001 skim cut when chucked up in the lathe.


20210406_231804.jpg


For precision, the barrel/chamber is the top enabler in the AR15 system. The accuracy belongs to the trigger puller.
 
I can't speak to LR AR shooting but I built a varmint rig with a BCM upper and X-Caliber barrel. I did all the machining and improved the mating surfaces across the board. At 100 yards, it prints groups 1/4" and less everyday. I haven't had the chance to stretch it out. I was a skeptic that an AR could shoot that well. I'm glad I tried it.

For LR shooting, I hear the gas system is the weak link in creating a wider ES. If I was going to build an LR AR 15, I'd go with the ARC or 6mm Turbo. Preferably, step up to the AR 10 platform and shoot a 6mm creed.
 
I've been shooting 77hr smks out of an 18" ballistic advantage barrel. I've shot multiple sub moa groups at 500 with it but never really pushed it beyond that. I don't think you can load the heavier bullets in a 223 because they end up being way too long, the way I understand it at least. Never tried. Have 1000 77s and 3 or 4 pounds of staball 6.5 to load up and push it a little farther this year.
Can we expand this to consider the 6.5's and more importantly ( to me at least), the 7.62?. Please. Can we get the AR platform accurate to 1 K yards?
 
If you want to go to 1000 yards, I'd recommend a better LR cartridge than .223. Doing all that work, spending all that money...might as well have a solid plan in place as far as the cartridge before starting. If you still want it to be .224 caliber, look into .224 Valkyrie maybe. Or the 6mm ARC or 6.5 Grendel. Good luck and hope you love it.
 
Warning! This thread is more than 4 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top