New lot of H4350 is much hotter

[Edwin Gideons]

I was at the range yesterday confirming dope before the Fall Scramble while also testing a new lot of H4350 since I'm at the end of my first 8lbs. After solid confirmation from 600-1030 everything was tracking 100%. I dropped in a few rounds loaded with the new lot of powder and the rounds were impacting quite a bit higher. I had to come down .2 mil from 600-900 and .3 at 1030. I put the rifle on the labradar today, first confirming my former load at the expected 2850. The new lot of powder averaged 2920 for 5 rounds and luckily still shot .25", about .75" higher than the old load. So, I am fortunate that the rifle still likes the load and will only have to make a small adjustment on my zero but I'm scratching my head at such a speed up with a different jug of the same powder. Both jugs were bought at the same time but are different lot numbers. I'm also fortunate that I still don't have pressure issues even though the load is over max. I just wanted to get opinions or experiences with this powder or any other that may have done this before. Is there anything else I should look out for or expect. All my specs are below:

Tikka T3 .260 w/ 26" Proof Sendero profile w/ Silencerco Omega
Lapua brass, 43.5gr H4350, 140 ELD-M, 2.850, GM210M

This original load was a carryover from my M70 in .260 and it shot exactly the same in that rifle prior to building the Tikka.

 

[USMCDOC]

I was at the range yesterday confirming dope before the Fall Scramble while also testing a new lot of H4350 since I'm at the end of my first 8lbs. After solid confirmation from 600-1030 everything was tracking 100%. I dropped in a few rounds loaded with the new lot of powder and the rounds were impacting quite a bit higher. I had to come down .2 mil from 600-900 and .3 at 1030. I put the rifle on the labradar today, first confirming my former load at the expected 2850. The new lot of powder averaged 2920 for 5 rounds and luckily still shot .25", about .75" higher than the old load. So, I am fortunate that the rifle still likes the load and will only have to make a small adjustment on my zero but I'm scratching my head at such a speed up with a different jug of the same powder. Both jugs were bought at the same time but are different lot numbers. I'm also fortunate that I still don't have pressure issues even though the load is over max. I just wanted to get opinions or experiences with this powder or any other that may have done this before. Is there anything else I should look out for or expect. All my specs are below:

Tikka T3 .260 w/ 26" Proof Sendero profile w/ Silencerco Omega
Lapua brass, 43.5gr H4350, 140 ELD-M, 2.850, GM210M

This original load was a carryover from my M70 in .260 and it shot exactly the same in that rifle prior to building the Tikka.

Sounds like your barrel has a wide tune to it

 

[dskogman]

That's a healthy charge in a straight 260. I'd say your previous lot was slower than average. I have not seen that big of change from lot to lot in H4350 but have in others.

 

[Berger.Fan222]

If you just opened the jug, leave it open in a place with ambient humidity of 40-60% and temps close to room temp, and it will slow down a bit as it comes to equilibrium with the moisture in the air. There will still be some lot to lot variations, but you will eliminate the "dry powder" effect that seems to speed things up when a new jug is opened.

 

[ShootDots]

Hodgdon's Varget, H4350 and H4831/(SC) ALL have "issues" with Lot-to-Lot consistency. I have seen each of them as much as a grain of powder charge difference, either + or -, to get back to your intended velocity. Now it is not always a full grain, however, there is almost always at least some variations..