.308 Varget/GameKing load NEED HELP

DP425

I’d rather be sleeping
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Minuteman
Feb 28, 2009
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Hoping to get some help here. Loading some 165gr Sierra GameKing for a buddy of mine- first batch of 60rds I loaded up to the Sierra manual stated max of 43gr for ten rounds with .5gr steps down, 10rds each. Well, here is the velocity average I came up with shot over a chrono at about 50 degree temps with a drizzle:
41.5gr - 2313
42.0gr - 2374
42.5gr - 2395
43.0gr - 2423
We didn't gather data on anything under 41.5gr since the velocity was so low- brought back the left-overs and tore them down.

Sierra says 2700fps with 43.0gr of Varget loaded under 165gr SIE GameKing seated to 2.75 OAL and 24" test barrel. We ran ours at 2.8" OAL in a DPMS LR308 w/18" barrel. That is nearly 300fps difference, which seems to be excessive. Enter-in Hodgdon's load data:

Hodgdon states 2773fps with 46.0gr of Varget under 165gr Hornady SP at 2.75" OAL and 2731fps with 46.0gr of Varget under 168gr SIE MatchKing at 2.80" OAL.

So, loaded up 165gr SIE GameKing at 2.80" OAL, 10rds each from 44.0gr to 46.0gr in 0.5gr steps. Results are below (fired under same conditions as before, as best can be judged without instruments):
44.0gr - 2493
44.5gr - 2529
45.0gr - 2572
45.5gr - 2602
46.0gr - 2629

So, don't really notice any primer flatening or any other tell-tail signs of massive over-pressure. My concern is, we're getting just over 70fps less velocity out of this 18" barrel than the stated velocity out of a 24" barrel and it can be assumed we're testing in lower temps. Seems a bit strange to me. Can anyone verify the load data against something you've loaded before, or a third party data source? I've got over 400rds to load which will become the standard load for him to shoot- need to make sure we're not running too hot and the conflicting info is a bit of an issue. Thanks!
 
Re: .308 Varget/GameKing load

Also, if anyone is interested, he's JUST getting into rifle shooting; read pretty good reviews on the DPMS rifle out of the box and the price was right so I sort of steered him toward it. I'd like to share this initial grouping results. For the first test group, he fired all rounds in groups of 5, we then averaged the two groups for a 10 round average for each loading. Second test group I fired the second 5 round group for each load. He's not all that consistent yet and I'm working with him on shooting as much as possible while working loads and recording data. Anyway, I think the results will be surprising.
TEST GROUP 1
41.5gr - 1.358moa (only one 5rd group recorded)
42.0gr - 1.495moa
42.5gr - 1.072moa
43.0gr - 1.078moa
TEST GROUP 2
44.0gr - 0.538moa (only one 5rd group recorded)
44.5gr - 1.188moa
45.0gr - 1.585moa
45.5gr - 0.959moa
46.0gr - 0.543moa

That's a 1.090 MOA average with hunting loads while doing load development. I'd call that pretty impressive for an DPMS rifle. Of course, averages are just that- I wouldn't sit here and call it a 1MOA gun, because as of yet it has not shown to be able to give those results EVERY time, but I would call it a 1 MOA average. Shooter also had some effect on these numbers. Some of the larger groups were strung vertically. The gun is capable of better than what was printed, but even at that, I'm pretty impressed for what it is.

The gun is running a Giessele DMR trigger, PRS stock, Vortex Crossfire scope in Larue mount and harris bipod.

Anyhow, all of that aside, I hope to hear some input on the loads.
 
Re: .308 Varget/GameKing load

I have not worked up a 308 gas load. Check out the load section (sub-forum at the top of the reloading forum)for LOTs of 308/Varget recipies. Not many for gamekings, but should get you in the ballpark. I dont know anyone that uses Sierra data, they seem to be extremely conservative or else we are all very aggressive!
 
Re: .308 Varget/GameKing load

KY, that's what I was kind of hoping to hear- Hodgdon's data being a full 3 grains heavier for max load with the same velocity tells me something isn't adding up. I'm inclined to listen to hodgdon over sierra since they make the powder
 
Re: .308 Varget/GameKing load NEED HELP

Couple of points.

A) 0.5gr is a good enough step for find where pressure gets out of hand, but way too big a step to find the accuracy node. Most nodes are smaller than 0.3 gr in width. With 0.5 steps you won't find more than half of the nodes.

B) an 18" barrel (comapred to a 24" barrel) might be as low as 100 fps slow or as little as 25 fps slow depending on the burn characteristics (pressure curve) of the load.
 
Re: .308 Varget/GameKing load NEED HELP

Thanks for the input guys! I'll dive in a bit further...

I'm using a Lyman 1200 DPS3 powder dispenser, which I've tried weighing the charges on a Dillon digital scale and shown a weigh variance of up to .3gr from the charges the DPS was throwing and showing to be all identical. The velocity variance in shot strings would some what indicate to me that the Dillon was reading accurately, but the DPS was not (we're talking some extreme spreads of up to 75fps in a 5-shot group).

So, given we needed to get some ammo put together ASAP so he can get trigger time, and I don't have any other powder drops, we just rolled with what we've got. That is a factor to why we're not doing steps any smaller than .5gr at this time. Looking to pick up a beam scale for additional weight verification and RCBS digital powder drop (hope to have better luck with the RCBS) before we reload this brass (its all brand new brass).

We had a very fluke group at 46gr that came out to about 0.18 MOA- that skewed the results a bit since the other group for 46gr was around 0.98MOA. In reality, 45.5gr ended up being the smallest when removing the highly abnormal first 5-shot string. We're looking for consistency here, not totally unrepeatable results.

Hopefully this thread won't die out before all of the bugs get shook out, I'll keep it updated as the new equipment comes in and new loads are developed. Didn't have much luck finding data on here for hunting. Ccoker, I'd be VERY interested in your velocity numbers.
 
Re: .308 Varget/GameKing load NEED HELP

Im running this for my hunting load:

165 Sierra GK BTHP
45 gr Varget (went up to 46 but 45 was my rifles sweet spot)
Fed210M
Lapua Brass

Having no pressure issues at all. I have not chronoed this load so I have no Velocity data.

Im shooting this load in a Savage Tactical with 20" Barrel
 
Re: .308 Varget/GameKing load NEED HELP

that is with a Remington LTR, 20" barrel

I had a Tikka a few years ago that did one ragged hole with my same load data but at 45.5g of Varget, the stainless lite, my buds Varmint model shot the same load, one ragged hole again.

with the LTR groups opened up at 45.5
 
Re: .308 Varget/GameKing load NEED HELP

UPDATE:

This load seems to be holding .5-.75 MOA 5-shot groups consistently when the shooter does his job. Don't recall what the COAL was- my buddy has all the info.
 
Re: .308 Varget/GameKing load NEED HELP

DP425 if you can move the target out to 300 yards and start the load development again, but once your mate feels like he has gotten the hang of shooting.

Shooting out to 300 yards in a ladder type test will show you which loads have the least amount of vertical spread... ideally this is the information your after and will equate to usually, one ragged hole groups at 100 yards considering the shooter does his part.

Also, to comment on the lower velocities you have obtained. The barrel length is significantly lower than that tested in the manual and this would account for some of the velocity loss. A ballpark figure is close to about 20fps per inch of barrel.

You have a 275 FPS difference using 43.0gr Varget when compared to the Sierra manual loads. Thats about 120FPS difference due to the barrel alone... who knows what other conditions existed.

THe Hodgon data you provided seems consistent with your barrel length.

If you could perform a ladder test out to 300, and work up a load like that, i think regardless of the velocity you should have a very accurate load for your rifle out to longer distances.

smile.gif
my 0.02
 
Re: .308 Varget/GameKing load NEED HELP

Thanks VMAN! When he's ready to reload this batch of 500 (I think he's down to around 300 remaining), he should be doing pretty well on the basic mechanics of prone firing- which should allow for more precise development... and the method you mentioned seems like the best route to go.

Actually heard from him later today- went to the range today and he couldn't do better than 1.25 MOA. I wasn't there to coach his shooting, and I don't know the conditions... but it's a hell of a break from what he was shooing a couple weeks ago with the same stuff. He said it was bright and sunny... high heat. Might have had a little mirage to contend with, in addition to not being experienced with environmental influences. I'd say it's likely most of the difference was in shooter, not ammo. But, I'd like to wring the most out of this load for him... so we'll plan on a bit further testing once he's got more trigger time!

Again, thanks for the helpful advise!
 
Re: .308 Varget/GameKing load NEED HELP

YEh nothing beats trigger time... nothing

To further add to the ladder testing... you just dont get reliable results at 100m that also confirm what is a good load.

You can take multiple varying loads and as long as they are consistent with each other and the shooter knows what he/shes doing they can usually make good groups at 100 regardless. Its after 100 that you really start to see what happens when the projectile leaves the barrel at a harmonic that doesnt offer accuracy.

Think of it like a sine wave, up down up down in a smooth pattern. What the ladder test does, is help to define the region on that sine wave that is equivalent to a peak or a trough in the wave... its at those stages in barrel harmonics that when the projectile is leaving the barrel you experience the least amount of vertical spread due to slight muzzle velocity variations... may sound techincal but really its not too crazy. Different loads have your bullet leaving the barrel at different stages in the sine wave. Bench rest shooters would all have their loads worked up to this level, and regardless of them knowing the science behind it or not, highly accurate bullet/rifle combos all have their ammo customized to shoot at the tops of bottoms of these sine waves.

The results are evident at long ranges. Once you take the vertical variation out of the equation, it comes down to the shooter and the wind. We are just trying to remove another variable

sine.gif
 
Re: .308 Varget/GameKing load NEED HELP

Quickload predicts 76 kpsi 2966 fps with Sierra 165 #2145 bullet, with 49.4 gr Varget and a 24" barrel and 2.8".

That would probably be around the threshold of short brass life.

If one backed off 6% powder charge for safety margin, ala Vernon Speer 1956, that would be 46.6 gr, which Quickload thinks is 62,737 psi, 2810 fps

With an 18" barrel and 46 gr, Quickload thinks it will be 2611 fps, which is close to your 2629 fps measured.
 
Re: .308 Varget/GameKing load NEED HELP

Clark, Thanks for running that through quickload for me! I suspected the 46gr was more along the lines of max load than the 44gr stated by sierra.

VMAN, thanks yet again! I'll be looking for those highs or lows once he's done with this batch... Also need to get the RCBS drop and a quality beam scale. The DPS-3 has a TON of potential, but it seems like they missed the mark a bit. When I have a variance of .3gr when measured on my dillon digital scale and the DPS is telling me each charge is identical in weight... we have a problem. Advertised at .1gr +/- accuracy... not a +/- .15gr avg or up to +/-.2gr. Of course, the dillon is also +/- .1gr.... so could it be just the variance in the two scales? Maybe... This is why I want another scale- measure 20 or 30 dispensed charges between the three scales and work out averages. In theory, with scales measuring +/- .1 grain, no matter the number of scales, the same powder charge SHOULD not vary more than .2 grains (if powder dispensed for DPS measures 46, it should not weigh more than 46.2 or less than 45.8 when weighed on two test scales having a variance of +/- .1 grain. With three scales I can run the numbers and determine which scale isn't within tolerance, or verify which ones are.
 
I suggest if you use upper levels of Varget like 45.5 with 165/168 you use WW brass or Norma Brass for its extra powder capacity.
I have great results with 45.0 / 45.5 / 46.0 with 165gr. My best group was with 45.5 of Varget with CCI BR2 primers and 165gr in WW Brass.
 
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