Loading for 6x45/6mm-223

[Yankeefan]

Is anyone loading for this round in an AR15 and not a bolt gun? I ran a search that yielded lots of bolt gun info but little to none on the AR side.

I'm just wondering what powder you are getting the best results with and what bullets you are using.

I am just waiting on my 18" black hole weaponry barrel to arrive (hopefully within the week) then I can start load work up. Right now we are going to start with 87gr hornady amax using varget powder.

Just curious as to what other are using.

 

[armorpl8chikn]

Re: Loading for 6x45/6mm-223

I have no experience with this one in an AR but I have had several 6TCU( virtually same cartridge) barrels in a Thompson Contender, carbine and pistol.
I have a new barrel I just shot for the first time Saturday. I think you will find Varget to be a bit too slow for this cartridge, especialy with the lighter bullets needed to make magazine length. I was convinced I would be able to use Vraget for my 105gr AMax bullets but after some judicious study it appears I was wrong.
Look to powders such as H335,WW748(this one is likely to be a real eye opener), H322, H4895,blc-2, IMR4320,3031,4198. I guess with the AR you are looking for well metering pwders....in that case I would look no further than H322 and WW748.

 

[1lnbrdg]

Re: Loading for 6x45/6mm-223

I used H-4895 with very good results for the 69gr bullets. My barrel was only a 1/10-twist. It was a take-off from a guy that couldn't figure out why his .223 shot so horribly. The 1/7-twist Colt take-off barrel I put back on for him shot just fine for the blasting he was doing.

The 69gr bullets would shoot 1/2 min groups at 200 yds and did well on yotes.

What twist is your barrel?

 

[thespecialist]

Re: Loading for 6x45/6mm-223

I'm running a Blackhole 24" 1/10 twist 6x45 barrel on my recent build. If you ordered the 1/10 twist you may not be able to run those 87gr VMax's, mine hates the 87gr BTHP's with a passion. 70gr Speer TNT's though, they shoot lights out with IMR8208. Single digit ES, and can be easily pushed over 3,000 fps in my barrel but lose some accuracy past 2900.

That being said, I just finished putting on another barrel from BHW, a 6x45 1/9" twist that should handle the 87gr Berger VLD's just fine.

I've been able to reach well over 2900fps with IMR8208 under the Hornady 87gr BTHP's and 3,000+ has been reported using Reloader15. I do run mine over standard mag length though, at 2.345". H&K mags will let you load to 2.300" with no feeding problems whatsoever, or you can trim the front out of a 20 round USGI mag to allow 5-8 rounds to feed at up to 2.350". FWIW, the 70gr TNT loads I have worked up are 100fps faster now than at the standard mag length of 2.260", all other load specs are identical other than that.

Great powders for it from my personal experience are H335, IMR8208, and H4895 with my personal nod going to 8208. Varget has gotten piss poor speeds, but decent accuracy for most who tried it and Rl 15 gives pretty good accuracy and screaming speeds if you're willing to play on the edge. IMR 8208 data is available from Hodgdon's website for the 6x45, as well as H4895 data.

 

[Yankeefan]

Re: Loading for 6x45/6mm-223

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 1lnbrdg</div><div class="ubbcode-body">
What twist is your barrel?</div></div>

I ordered the 1/9 twist barrel so I could use the lighter bullets.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: thespecialist</div><div class="ubbcode-body">
.....Great powders for it from my personal experience are H335, IMR8208, and H4895 with my personal nod going to 8208. H4895 data.... </div></div>

IMR 8208 huh? I hadn't even considered that one yet. Thanks!

 

[thespecialist]

Re: Loading for 6x45/6mm-223

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Yankeefan</div><div class="ubbcode-body">

IMR 8208 huh? I hadn't even considered that one yet. Thanks! </div></div>

Be prepared to fill that case up if you use 8208. LC or Winchester brass will give you a few tenths grains more capacity, and with IMR 8208 you'll want all the case capacity you can get. I honestly don't think you could get enough of it under most bullets to get pressure signs in the 6x45.

I know I've been north of 27gr with the 87gr BTHP's and never saw any hint of high pressures.