Just like MagnumManiac I blend as I go and it's surprising the consistency over time. I don't recall a time when I was taken by surprise. Mild tweaks and I'm off and running. The wife isn't always happy with my raids on the glass salad bowls though.
Powder lot to lot variation
- Thread starter Gregg C
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I'm curious about your experiences with blending powders of different lots. I have always been cautious about doing this. If lot A had an average velocity with a given load of 3000FPS and lot B had an average velocity of 3020FPS, with each lot producing comparable .5MOA accuracy and an ES of 10FPS, I would think the blend of 2 equal parts of A and B might result in an ES of 20FPS instead of the 10 FPS of each of the original lots. What has been your experience in this respect?
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With the old lot heavy bolt lift was at 106.4grs . I backed off to 105.0 and loaded 25 rounds at different CBTO lengths and fired them all. No problems, but that eas the last of that bottle. Cracked open another bottle, loaded up another 25 for additional tuning at the same load. I thought that 1.5grs off max would be ok. About 1.5 per cent, but I didn't think of it like that. Flattened primers and hard bolt lift convinced me to stop. Pulled the bullets, resized (FL this time ) and put back 104. Shot them today, went beautifully. Similar velocities. And settled on my seating depth. Buutt....
Buutt...I cracked open my 8lb bottle and loaded up another pressure test. This time at 103.5 and up. Yup. I only let one go. 103.5grs. Chronograph said 3715. Primer flattened. Don't believe that velocity. 300gr bullet. NOW what ? Pulling bullets AGAIN !!!
Doninidaho
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I like the idea of mixing all of my 8lb jugs....any idea how I might best mix 80 lbs of H1000?
Powder by federal regulations is supposed to be within 10% of performance to carry the same identification on a lot to lot basis. But if you are using 80gr that could be 8gr and be within specs. So it is best to go to starting loads and work up.
Ed
Ed
So, after that mixture is completely gone, how do you absolutely find the identical mixture with new powder?
Your previous load may not work.
I chrono everything I shoot so I have a good idea of what vel I need therefore when I start loading from a new lot I load to my accuracy load as determined by vel. I use a LabRadar and try to only by powde in 5/8 lb containers.
MagnumManiac
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I rarely run out of an 8lb jug and I blend the last few lbs into the new one.
A tweak here or there is needed throughout the season as barrel wear increases and I know my velocity 'sweet spot', so I tweak as needed.
The only powder I ever had an issue with were the batches of AR2208 (Varget) in your neck of the woods, that were drastically different to previous lots. Bad enough that gun damage occurred in a few instances here and overseas.
In my case, a blown primer was the result in my 22-250AI comp rifle, a ring of gas cutting and an eroded firing pin nose.
We think that the batch of Varget we got was mislabelled H4895, but it was never revealed.
Even after that incident, I feel confident enough to still blend old into new.
Cheers.
SealT5
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I would imagine it would be very inconsistent trying to equally mix multiple jugs. Just my $0.02
DUSTY NOGGIN
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yes you have to at least do a few, just up to velocity you had before , 5 to 10 rounds should get
if youre shooting magnums , an 8 pounder will get you about 600-800 shots , if you had to buy a one pounder that might get you between 65 and 110 shot , you know 10 of them shots will be used to check the bottle
if youre shooting smaller rifle cartriges in the 40 range , a 1 pound container can be between 150 and 250 shots, it may make a little more sense to go that route
in earlier post someone said earlier that retumbo had good lot to lot , i have to say they have been lucky so far as that is the one i have seen the most extreme variations in , and the reason i will work up again at every new powder change
if youre shooting magnums , an 8 pounder will get you about 600-800 shots , if you had to buy a one pounder that might get you between 65 and 110 shot , you know 10 of them shots will be used to check the bottle
if youre shooting smaller rifle cartriges in the 40 range , a 1 pound container can be between 150 and 250 shots, it may make a little more sense to go that route
in earlier post someone said earlier that retumbo had good lot to lot , i have to say they have been lucky so far as that is the one i have seen the most extreme variations in , and the reason i will work up again at every new powder change
Exactly what I'm using. Retumbo.
Buy powder at least 8 lbs at a time. Drop 10% from your current load and Chrono three, match them to the 10% less load, same grain weight, from the old batch of powder. I record all of these test loads. It is pretty easy to tell if the new batch is faster, slower or the same. Only a few times have I found a difference bigger than 20 fps on loads over 45 grains. Once I know the relative comparable velocities it is easy to match the new powder to the old without having to go through a big load redevelopment.
