View Full Version : Varget powder Lot change.
After nearly a year or so of NOT being able to find VARGET powder for our .308 175 smk bolt gun load, Pappabear bought a bunch of recent production 8 pounders. I'd read that Varget lot changes could result in noteworthy velocity changes... So we chrono'd the old lot against the newer stuff. :(
Old Varget:
2589 avg velocity with an SD of 11.
New Varget:
2520 avg velocity with an SD of 8.
69 FPS slower with all else being equal... Same 20 inch barrel, same primer, same brass, same charge of 43.8 grains loaded on the same chargemaster on the same day. Bummer. I shot these on the 1075 yard gong back to back, and the New lot of powder was a 1/2 mil lower POI.
SeriousStudent
02-28-16, 19:16
Very interesting. I'm going to make a mental note to run chrono tests again after changing lot numbers.
I just snagged a spare laptop for the reloading room, I'm going to add some columns to the spreadsheets I am working up.
Dont know if its going on right now, but I think it was 2-3 years ago word was(I have nothing but word of mouth to back this up) that Varget was not being dried the same due to them attempting to pump out production. Instead of 2 or 3 drying cycles it was getting 1 and getting bottled leading to variances from "normal" production. Again, not sure if this is true or not, and I dont know enough about powders to know if a powder that didnt have all the chemicals baked off of it(or whatever the drying process does) would have different velocities.
But as they always say "check your load when changing lots".
Yeah. The only reason I chrono'd this was because I'd read about this happening over on accurateshooter.com. I'm a little bummed. Now I need to redevelop, and will probably be getting into a slightly compressed load.
that sucks. i have been looking for varget. maybe i should try something else
i've also been wondering why my rifle is shooting so much slower than others' so this may be the culprit
I'm going to bump the load up to 44.3 and see what happens. IMR 4064 is a great option. RE-15 is popular, but way too temp sensitive for me.
Different lots of the same powder often perform differently, so your results come as no surprise. A person employed in the firearm ammunition industry once told me that different lots of powder have different "octane" and each lot is tested to determine the optimum charge weight for a particular cartridge. That is why you may find a different charge weight if you disassemble match cartridges from different lot numbers and weigh each component.
The gentlemen offered me the information 25 + years ago and my own testing confirms what he told me.
I'm going to bump the load up to 44.3 and see what happens. IMR 4064 is a great option. RE-15 is popular, but way too temp sensitive for me.
44.3grs is what I use in my 5r and it performs great. The bigger thing I've noticed is that the smk can be a little finicky on the jump. If my seating was off it affected accuracy more than lot changes in varget
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30 cal slut
03-01-16, 12:39
ah crap. i have a mix of old and new varget on the shelf.
The bigger thing I've noticed is that the smk can be a little finicky on the jump.
My .308 Tactical, factory barrel had a huge leade when it was new. I probably have 3500 plus rounds through it... It's been a year since I measured the lead, but fortunately, I've not noticed the huge jump to be problematic yet.
ah crap. i have a mix of old and new varget on the shelf.
I taped the lid on the new lot shut with a note that said "chrono new lot" on top. I didn't expect such a dramatic difference.
Hey Mark, how many rounds fired from the barrel since you tested the old lot until the new. I'm wondering if part of it is barrel wear?
Never mind--just read it again, oops.:o
I always kept a decent amount of the same lot squirreled away for my bolt gun and would do the same when running out. This was factory FGMM though.
Hey Mark, how many rounds fired from the barrel since you tested the old lot until the new. I'm wondering if part of it is barrel wear?
I always kept a decent amount of the same lot squirreled away for my bolt gun and would do the same when running out. This was factory FGMM though.
I shot them the same day. Loaded 7 rounds of old and new lot. Then I literally went back and forth at 1075 yards and watched the new lot's bullet drop low into the dirt.
Copy, changed my post, after reading yours again. I've always liked the IMR4064, very consistent and accurate through time.
Copy, changed my post, after reading yours again. I've always liked the IMR4064, very consistent and accurate through time.
4064 is the most pretty powder ever. I keep it on hand just because it's good looking. ;)
I've always blended different lots within powders & haven't ever noticed any significant difference in zero; however, I'm not doing any uber accurate shooting.
Curious if a 50/50 mix would result in half change or doesn't it work that way?
I've historically just poured the last part of a jug into the next, and never gave it a second thought. But Varget had a rep for lot to lot variability. Not sure what a blend of the two might do. Probably yield some velocity swings.
44.3 gr of the new lot showed 2573 fps with and SD of 9. I think I'll stick with that load.
44.3 gr of the new lot showed 2573 fps with and SD of 9. I think I'll stick with that load.
What was the velocity & powder charge difference from the old lot?
We were in the 2590 range on warm days. This morning was fairly cool.
Bumping this one to add that nearly the same thing has happened with our 300 Win Mag powder of choice. H1000. Got into a newer lot of H1000 and lost 40 FPS on 225 ELD bullets.
I'm going to blend all of our remaining H1000 today. I plan to do the same with all of the Varget I have too. Long range shooting is hard enough without this nonsense.
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