Does Varget Often Puke M1As?

[Grump]

I'm taking a second stab at developing a Varget load for an M1A, this time using 178-gr A-Max bullets.

Things are strange and usually accuracy outright sucks. Like 2-3 MOA sucks, out of a rifle that performs right at 1 MOA or better.

Ran some 3-round tests and the lowest charge weight chrono'd 100+ FPS faster than the ones 1.1 gr and 2.2 gr heavier. A follow-up 5 round group at about halfway between the middle and high ones averaged 2725 fps, with an ES of 134.6. New battery, and the chrono gave normal/expected values with another rifle during the same session. No pressure signs, either.

And accuracy was once again like really bad milsurp ammo.

So, Varget + M1A + 178 A-Max or 175 SMK (& clones) = you're lucky or you're not??

My 4064 loads with both bullets continue to work just fine.

 

[sinister]

Re: Does Varget Often Puke M1As?

If you can't get ANY .308 Winchester caliber rifle to shoot well using 4064, 4895, or Varget something's wrong with your rifle or scope.

 

[Jerry m]

Re: Does Varget Often Puke M1As?

When I was shooting an M1A I could never get the desired accuracy with Varget. IMR4895 and H4895 always shot much better. I understand that if you have a bin full of gas pistons, you can swap them out and 'tune' to the load. I didn't and switched to a quicker powder.

Good luck

Jerry

 

[bunsen27]

Re: Does Varget Often Puke M1As?

http://www.m14.ca/reloading/14_loading.pdf

See pg 10 under the section <span style="font-weight: bold"><span style="font-style: italic">Powder and Port Pressure</span></span>

4064 or 4895 are a better choice than Varget for M1A's

 

[lennyo3034]

Re: Does Varget Often Puke M1As?

178 gr bullet at 2725 fps? That seems rather hot for an M1a. I'd be concerned about damaging the op rod in the long term.

 

[BCP]

Re: Does Varget Often Puke M1As?

Varget burn rate is about identical to 4064 (I've heard from a couple different people that varget is actually a short-cut version of 4064 but I don't know if that's true or not).

What charge weights were you using?

 

[Graham]

Re: Does Varget Often Puke M1As?

I would try 4895. Varget might be just a bit slow for a gas gun.

 

[Boomholzer]

Re: Does Varget Often Puke M1As?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bunsen</div><div class="ubbcode-body">http://www.m14.ca/reloading/14_loading.pdf

See pg 10 under the section <span style="font-weight: bold"><span style="font-style: italic">Powder and Port Pressure</span></span>

4064 or 4895 are a better choice than Varget for M1A's </div></div>

Interesting read, thanks.

 

[Grump]

Re: Does Varget Often Puke M1As?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bunsen</div><div class="ubbcode-body">http://www.m14.ca/reloading/14_loading.pdf

See pg 10 under the section <span style="font-weight: bold"><span style="font-style: italic">Powder and Port Pressure</span></span>

4064 or 4895 are a better choice than Varget for M1A's </div></div>
BTDT years ago, and my ejection pattern and QuickLOAD both disagree. At least at the velocities I want--2625 and less.

Other powders like RL-15 predict, with QuickLOAD AND from firsthand reports here on the hide, an ability to get much faster than 2600 with 175s and safe chamber pressures, but the port pressures above that speed go where beyond the specs for the M14 gas system.

All this is with the 22-inch barre.

 

[marduk185]

Re: Does Varget Often Puke M1As?

use 4064 or h4895 and less is more on bullet weight for m1a.

 

[Grump]

Re: Does Varget Often Puke M1As?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mar2012</div><div class="ubbcode-body">use 4064 or h4895 and less is more on bullet weight for m1a. </div></div>
Well, a few NM-tuned M14s won a few 1,000-yard matches at Camp Perry over the years, first using the original Sierra 180-gr MatchKing that was a FMJBT, later with some possibly-unwise loads pushing the newer HPBT design in the 190-gr.

When they were making the ammo right, the M118 with the 173-174 gr bullet shot okay out of those 1:12 twist barrels. That load was designed for the M14.

The latest: 43.2 gr of Varget brought 2701 fps, 2.5 MOA, and no "pressure signs" like flatter primers despite modeling at a chamber pressure up there where no one should go. One source says that much should be making the brass start to flow. But port pressure is within spec at 15,556 PSI piezo.

The barrel time for that says 1.041 ms, which is pretty close to the 22-inch OBT node at 1.013. However, something a bit odd in observed results makes me wonder if the flash suppressor makes the thing the equivalent of a 25-inch barrel, vibration-wise. If that's the case, then the 1.041 travel time matches well with the 25-inch barrel OBT value of 1.064 ms.

Trying 40.5 next. That predicts to

My SMK loads shot 0.74 inch that day, velocity unknown because the chrono was not set up for that target.

 

[wtopace]

Re: Does Varget Often Puke M1As?

I have shot Varget behind a 180gr Nosler BT in an M1A Super Match without any problems.

 

[Pabs]

Re: Does Varget Often Puke M1As?

I was getting 3/4 moa 10 shot groups using varget behind 168 mk with cci mag primers. That was with a M1A super match as well.