SMK's and Varget in a AR 10 T

[ClayDirt]

Got a new AR10T with 20" 1-11.25 twist 20" stainless match barrel. Worked up a couple of different loads. All were 168 smk with Varget powder. Started my charge at 40.5 and ended at 42.5. All were horrible groups, at best 2.5 Moa.

I had a box of hornady Tap 155gr so I decided to see exactly what they would do. The TAPs tightened my groups to about 1 Moa.

Is 42.5 grs of Varget enough to stablize the 168 SMKs?

According to the Sierra loading guide that I have they are about .5 gr from being max charge. On the other hand Hogodon data says 45 grs is max.

Anybody have any same experiences?

 

[Bugholes]

Re: SMK's and Varget in a AR 10 T

42.5 of varget sounds kinda light to me. I would expect that to be running in the 2500 fps range. Not saying to disregard loading manual info but I would think you could keep going up in charge weight.
Or try the 155 hornady bullet

 

[snewhouse]

Re: SMK's and Varget in a AR 10 T

I use 46gn varget with 168smk in a rem 700 with 26" barrel and 1 in 12 twist for sub moa groups. with a 11.25 barell you might consider 175smk and 45 gn varget. I use that in my mil spec 5r with 11.25 twist 24" barrel

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T



I gave the Hogodon data more more look see and it actually says that 46 grs of Varget with 168 SMK is max. I am going to turn the heat up and see were that takes me before I abandon the 168 gr bullet.

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T

I did try 175 gr VLD Berger's staying underneath their max charge with about the same result as the 168 smk. I do understand that the SMK and the VLD are a completely different animal though and I will try the 175 smk's at some point.

 

[snewhouse]

Re: SMK's and Varget in a AR 10 T

A lot depends on the max range you are looking to shoot. If you are looking at 1000 yards than 175 are way to go but 500 or less the 168 do just fine.

 

[sinister]

Re: SMK's and Varget in a AR 10 T

The sweet spot for 168s and 175 with Varget is 44 grains, military or commercial brass.

Sierra's data book tends to be low, Lyman's 49th Edition is about the best in the industry.

Varget can vary a little between year-to-year lots, so I try to buy 8-pound jugs to maintain data values.

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sinister</div><div class="ubbcode-body">The sweet spot for 168s and 175 with Varget is 44 grains, military or commercial brass.

Sierra's data book tends to be low, Lyman's 49th Edition is about the best in the industry.

Varget can vary a little between year-to-year lots, so I try to buy 8-pound jugs to maintain data values. </div></div>

I will have to pick one up.

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T

RL15 is definately on the to get list. By the way thanks for the how to write up on the stress free bedding.

 

[m1ajunkie]

Re: SMK's and Varget in a AR 10 T

I have found the same issue in my hornady 7th edition manual. Compared to charges that people are using on the various forums, the 7th edition is very light.

I have decided to that starting in about the middle of the hornady data seems to be a good starting point and then working up. What I plan to do next range trip is chrono some FGMM 175's and then get my handloads with 175smks and varget to roughly the same velocities. (Assuming no pressure signs)

I have found that most load between 43-44gr of varget with 175 smk's and thats what I hope to get to.

 

[Jumper]

Re: SMK's and Varget in a AR 10 T

You never mentioned your OAL so I don't know if this will help you or not but I have the same rifle and I get better accuracy with all bullets if I stay about .010" less than max length.

 

[notquiteright]

Re: SMK's and Varget in a AR 10 T

In my DPMS using 45 grains of varget just seems to cycle the weapon a tad bit cleaner. 44 worked well enough on most days but after a long day it could baulk. No such problems using 45 but I doubt I shoot that much per day again.

 

[BCP]

Re: SMK's and Varget in a AR 10 T

Try 44 in thick brass, 45 in thin, loaded to 2.8.

Also next time you buy bullets consider going with 175s they just seemed to fly better at least for me. Could never get a 168 load I was happy with.

 

[Guest]

Re: SMK's and Varget in a AR 10 T

The max charges that Sierra provides are always very light. Your load is more than a full grain less than what I load 175s with for gas guns. I seat the bullets to an average coal of 2.815", never to exceed 2.820". This allows function in AR-10 magazines. If you safely work up your loads to the 44-44.5 grain area, you groups should shrink.

Mike

 

[okiefired]

Re: SMK's and Varget in a AR 10 T

I've never understood the infatuation with 168's in a 308, never found a role for them. For my AR10T.... 178 Amax's, FGMM brass, 210m's or BR2's lighten off 44.6gr Varget. A little warm but thats what it likes.

Whenever you're heatin things up, just watch for pressure signs. Most rifles respond a little differently. When advice comes in blanket statements, take'em with a grain of salt. Do your own "safe" testing. Try OCW or ladder tests.


okie

 

[scifri44]

Re: SMK's and Varget in a AR 10 T

Ok, I have a M1A scout 18in barrel 1-11 twist . Im loading 45.5gr of varget with 168gr SMK . BR-2 primers LC brass and getting a little less than 1/2 MOA at 100yrds. But not quiet 1/4 MOA , so Im thinking 3/8 MOA . And C.O.A.L set to magazine length . I post actual OAL length tomorrow . A few days ago , I shot it though my chrono and shot a five round string. Rounds go as followed:

1) 2733 FPS
2) 2734 FPS
3) 2734 FPS
4) 2744 FPS
5) 2726 FPS

So, its up to you if you want to try it out. And as a reloader , im sure you know the dangers that come with it . Good luck bud.

 

[bowslngr]

Re: SMK's and Varget in a AR 10 T

On the OPs original question, with a 11.25 twist you will not have trouble stabilizing the 168 SMK with any reasonable load.

 

[littlerascal56]

Re: SMK's and Varget in a AR 10 T

My Armalite AR-10T shot 1 MOA with 44.0 Varget under Hornady 168BTHP Match bullets...in WW brass...exactly as Armalite promised. Never got it to do much better by increasing the charge. I stock lots of Varget for my bolt guns, so I really wanted to get a decent load for that AR.

Tried some Benchmark loads and the groups jumped to 1.5" MOA. The Benchmark loads didn't require weighing, as they were dropping +/-.1 grain from my BR-3 measure. Not a bad load for a progressive loader or someone who shoot lots of ammo out of an AR-10.

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jumper</div><div class="ubbcode-body">You never mentioned your OAL so I don't know if this will help you or not but I have the same rifle and I get better accuracy with all bullets if I stay about .010" less than max length. </div></div>

The magazine has my OAL limited. I am running around 2.84 to insure they dont hang in the mag.

 

[ClayDirt]

Re: SMK's and Varget in a AR 10 T

Straight from Armalite

ACCURACY GUARANTEE: ArmaLite AR-10(T) rifles are guaranteed to meet the
same targeting requirements (the center of impact of the rifle) as the M16A2 rifle as
spelled out in milspec MIL-R-63997. In addition, they produce 5 shot groups of less than
two inches extreme spread at 200 yards, measured between the centers of the extreme
shots, when using Federal Gold Medal (GM308M) ammunition or better.

 

[fusiachi]

43.6 gr. Varget under 168 SMKs is lights out in my 18" DPMS. Velocity isn't great at about 2500 fps but it's a rock solid 600 yard rifle.

 

[GhostFace]

If for some reason you can’t get Varget to shoot in your Armalite I suggest you buy a pound of 4064 and try again. I’m on my second T barrel and it exactly like yours, I just finished with my first load development. This time I went with a ball powder because I’ve grown tired of weighing each charge. My first T barrel was a 24 inch LW 1/10 twist that I gradually cut down to 18 inches. It did not like RL15 at all and I didn’t play with Varget too much because at the time it was sporadic to get. It absolutely loved 4895 and 4064.

ETA I didn’t realize this was brought back from the dead....