223 AR reloading/bullet weight/twist help

[postal]

I just bought my first 2 lowers. Havent decided on uppers yet.

I want to rig one as a free float long barrel scoped precision rifle. Up to 600 yds. Stainless 18" or 20" barrell.

I cant figure out what bullet weight is best to 600 yds that will fit an AR mag.

I know 75 gr AMAX will NOT fit....

What weight Amax/Vmax should I be looking at for 600 yd performance that will fit AR mag length, and what twist should I get to stabilize that weight?

I prefer to use Varget if it will work with lower bullet weights.

Or maybe point me to a good site that discusses 3 gun AR's and ammo?

They probably cover the info I'm looking for.

Thanks!
Postal!

[NiteQwill]

Why limit yourself to Hornady bullets? Why not try Sierra, Berger, etc. among all others. Try all kinds of bullets, powders, and primers.

You can easily do 600 yards with the right equipment (and shooter).

Varget is a good powder to start with with the bullet weights you are using. It works fine with 55 gr plinking rounds. It just doesn't meter well for me, that's all.

75 gr AMAX will work if you single-shot/load your rifle. Or, if you're lucky, you can load to mag length or 2.250", whichever gets you there. Just don't "force it" to make it fit and watch for pressure signs.

My setup that gets me 600-650 yards: 18" WOA barrel. 24.5 gr Varget. 2.250" OAL. LC brass 1.750". Hornady 75gr VMAX. CCI 450.

(don't use my recipe without first, developing your own load from the bottom.)

[Fjold]

Why limit yourself to Varget? It's a bulky powder that takes a compressed load to get max velocity with a 75 grain bullet.

If you try something like H4895 you can use a smaller volume of powder, get the same velocity and make it easier to load to magazine length.

If you want to shoot long range, I always recommend the 7.7" twist in case you ever want to single load the 80 grain bullets for 1,000 yards.

[postal]

I -just- bought 2 lowers... dont pick them up until Sat. I dont have any 223 or AR platforms yet.

I come from 308 precision rifle -bolt action- background, and use varget for 308.

It would just be convenient to use the same powder for 308 and 223. If I *need* a faster powder, I can deal with it, but would prefer to use the powder I always have on hand.

I use SMK 175 in 308 with varget. I've heard many good things about, and know a few competitors using hornady Amax in 308, so I *plan* on going with Amax/Vmax 223.... but it isnt set in stone.

I dont have a midrange semi rifle. 600 and beyond- as far as I'm concerned, is all 308 (or better) bolt action territory which I already have covered.

With 2 lowers, I intend to setup them for- 1- 16 inch short M4 wannabe for close in to 2-300yds max. red dot with backup irons or iron only 2- "varminter style" longer stainless barrel for tiny groups and reach out to 600 ish yds max with scope. BUIS not needed.

Other projectiles are a consideration but I'd prefer to stick with Amax Vmax for cost to performance, and if I can... stick with varget so I only have to stock 1 powder for rifle ammo. I dont know if this is realistic, trying to feed a 16 and 20 ish barrels. AI can see a 16 needing a faster powder.

I do not intend to single load an AR. If I *need* long range performance, I have the bolt action 308, so I'm looking for bullet weight and twist rate that hopefully works with varget for decent midrange performance that will fit mag length. I'm not even that concerned about getting to 600. Even 4/500 would make me happy.

I hope that better explains what I hope to accomplish.

Any advice?

Thanks!
Postal!

[sig808]

Arf and brianenos should have all the info you need.

[NotEnufGarage]

Skip the 18" and go for a 20", 22" or 24" barrel for more velocity.

Should be able to get there with 75 grain HPBT and you won't have to seat them as deep as the A-Max's, but you can seat the A-Max to 2.260" if neccessary.

TAC meters better than Varget and I've shot 69's and 75's out to 600 with it. It also isn't quite as bulky.

1/7 or 1/8 twist barrel, at the most. Some 1/9's can shoot the long bullets, but why risk it?

[vinny_land]

I -just- bought 2 lowers... dont pick them up until Sat. I dont have any 223 or AR platforms yet.

With 2 lowers, I intend to setup them for- 1- 16 inch short M4 wannabe for close in to 2-300yds max. red dot with backup irons or iron only 2- "varminter style" longer stainless barrel for tiny groups and reach out to 600 ish yds max with scope. BUIS not needed.

Postal!

This is exactly what I have in my 'toolbox'. Havent had a chance to push my RRA Predator Pursuit upper more than 400 yards and Im still trying to find the right load for it. Currently focused with the precision aspect and have had good luck (sub-moa) with 60gr Hornady V-max. Bought a box of 70gr Berger bullets...really need to get back on those.

[ocabj]

I've been using the 77gr Lapua Scenar for my short line ammo ("Across the Course" matches). I think the G7 BC is only slightly better than all other 75/77gr BTHP out there. But the one thing I like about Lapua is the quality control. The consistency and cleanliness of the meplats are top notch.

[the86d]

I do not know where I got this and I am unsure of it's accuracy, but longer barrels give higher velocity, and I found this:


Correct me/this if it is wrong, or it is your graphic...

If you want to attach an M7 bayonet without some goofy rigging connector, you need a 20" barrel... if not then don't.

[NotEnufGarage]

The longer the barrel, the longer the gas has to time to accellerate the bullet, hence more velocity. I did some comparisons between my 16" and 20" uppers with 75gr HPBT's and chrono'd 300 - 350 FPS more velocity out of the 20" barrel. That can translate into a lot less drop at 600 yds.

[postal]

Vinny!!!!!! SEE!!!!!???? Thats what I'm talking about!!!! I want 2 in those types of configurations.


Thanks all for the info. I think I got a good understanding on this now. Sounds like the 1:8 is a good choice. though 1:7 might be better.

Not enough garage. Yeah, longer the barrel the higher the vel. Thats why I run a 26" on my 308. It's interesting to see your vel difference between these 2 lengths, however, a huge variable is the the quality of the barrel, and the tightness of the chamber cut. A sloppy chamber with a long throat will drop a lot of vel. So I think its very interesting to see your drop from 20 to 16", but realistically, every barrel manufacturer would be different.

I know a lot of powders meter better than varget, but the stability to temperature changes make it highly desirable for precision rifle. I dont need to worry too much about hot or cold days- there isnt too much vel difference. Sure, the air pressure changes from temp, but muzzle vel is pretty consistent with varget.

Thanks all.