New lot of H4350 powder...hot!!!

[Tangodown911]

I snatched up a 1lb container of h4350 to do some load development on the new .260. I was getting avg. 2820 fps with the hammer load of 43.5g on a 24" barrel. I ordered an 8lb. container from powder valley of same stuff... H4350. Now same load was getting me an average of 2909!!! Wow! I understand that lot to lot may vary but I'm thinking that was a bit much. Several other loads with several bullets were all approx. 80fps hotter with the new powder. How typical is this?

Now I got to figure how much to dail down to get back into that accuracy node. As accuracy was not what I was expecting with the new faster power.

 

[Shady_Jay]

Re: New lot of H4350 powder...hot!!!

H4350 has been one of the most inconsistent for me from lot to lot. My .260 loads have changed from 41.0 to 42.5 to 41.9 on each 8lb jug. However, the powder itself within the lot is pretty consistent.

 

[95LTZ]

Re: New lot of H4350 powder...hot!!!

My 6XC loads changed .6 grs. when I changed 8# jugs of H4350. I had loaded up some with a new 8 pounder only to find shiny ejector marks. My other components were 115 DTAC's BN coated & Wolf primers. I am thinking of dumping all three 8 pounders together and then having a large batch to work with.
Semper Fi

 

[LR338nut]

Re: New lot of H4350 powder...hot!!!

What lot number is it?

 

[ChadTRG42]

Re: New lot of H4350 powder...hot!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LR338nut</div><div class="ubbcode-body">What lot number is it? </div></div>
Yes, what lot # do you have? I'll post my lot # later when I get there.
I switched lots recently, and gained 50 fps (2820 to 2870) with the exact same powder charge. I have no complaints, since it's shooting bug holes and moving faster. I always try to order my personal powder with at least 2 kegs of the same lot #. This will last about 2500 rounds, or one barrel worth before you set it back.

 

[Lazuris]

Re: New lot of H4350 powder...hot!!!

Stupid question??

Can I mix lots together. I have 10 1# 3 different lots. My current lot is producing 2835fps w/ 43g 4350 139 lapua 260.

 

[9H_Cracka]

Re: New lot of H4350 powder...hot!!!

Powder burn rate can vary +/- 5% and still be in spec.

You saw a 3% change in velocity from lot to lot.

Comparing these two numbers in a vacuum does not take into account where you are on the pressure curve with your specific rifle and load combination. If on the steep part of the curve then minor powder variance can result in a major velocity change, whereas if you are on the flat part major powder difference can result in a minor velocity difference.

I don't go post my surprise when changing powder lots on the Internet; I chrono test the new lot and adjust the load to meet my velocity spec for the rifle/ammo combination.

It's just a fact of life when reloading. Expect it. Get used to it. Plan for it.

 

[19Scout77]

Re: New lot of H4350 powder...hot!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lazuris</div><div class="ubbcode-body">Stupid question??

Can I mix lots together. I have 10 1# 3 different lots. My current lot is producing 2835fps w/ 43g 4350 139 lapua 260. </div></div>

yes

 

[9H_Cracka]

Re: New lot of H4350 powder...hot!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 19Scout77</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lazuris</div><div class="ubbcode-body">Stupid question??

Can I mix lots together. I have 10 1# 3 different lots. My current lot is producing 2835fps w/ 43g 4350 139 lapua 260. </div></div>

yes </div></div>

Yep - I do it often. The resultant mix takes on its burn characteristics based on the percentage from each lot. Since you'll usually be mixing a small amount from an old lot with a larger amount of a new lot, it is still important that you figure out the resultant velocity of the new lot as outlined above for safety and velocity/ES/accuracy reasons.