So i have been shooting my new 6xc with H4350 (40.0) [MENTION=14289]303[/MENTION]0 fps with 105 berger hybrid with great accuracy. During load development when i settled on this load i fired 2 five shot groups at .373 and .216 to confirm no flukes. Just confirmed my velocity at 800 on Monday and accuracy was excellent at 5 3 shot groups falling under 3 inches and 1 3 shot group of 1.67" so this thing can shoot. Well, after that i loaded my 100 brass again with a new pound of powder bought at a different time still H4350 though and i started shooting to find i cant keep anything under .75-1.5 MOA at 100 and farther is worse. I decided to chrono the load again and over 20 shots i am getting about 3175, with a ES of 30 and SD of 13. I confirmed these numbers with dialing to 600 which use to be 10.25 is now ~9.25-9.5 and i shot my glock through the chrono which i did the same time during load development for the 6xc just to see if it is reading the same as it did before and it was, so its not the chrono. Has anybody else seen this kind of swing with H4350? By the way i am using an RCBS chargemaster and i also confirmed my seating depth has not changed.
- Thread starter STI_1911_Guy
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Different lots of powder can have different characteristics. I heard that it can be as much as 10%. I've experienced it personally with Varget, and to a lesser extent with H4350.
This would equate to about 5% so that wouldn't be unrealistic then i guess. I guess i should check a few before loading a bunch next time....
Yeah, I kinda learned that way too. I'm in the process of switching to a different brand of primers due to availability. I'm going to load a few with the new primers, see where the velocity/accuracy is at, and adjust powder amount from there.
always buy 8 pounders..................
Yeap, have found the same thing with H4350 recently on a load I've been running for quite some time. Just adjust your load to the same velocity you had good luck with before and you'll be back in business. This is why I always try to buy a single pound for testing purposes, and then once I settle on a powder, I buy either 8lb jugs or a large qty of the same lot if only 1lb bottles are available.
In my testing Im getting 27fps difference, no biggie really, ES & SDs are same, ES-35 & SD-13.
I have heard of guys taking Hornady 6.5 Creedmoor loads apart and finding the load on the box is not what they find in the case but the different factory loads shoot the same . I think Hornady does and energy test on powder batches and loads from that spec .
I bought 12 lbs of H4350 a few months ago, all in 1 lb containers from various stores. I avoid this problem by mixing all the lots together, creating ONE custom lot. I have been doing this quite a bit over the last three years or so.
^This^
Also, while I have not seen any detailed testing, I think much of this has more to do with how much water the powder has absorbed... rather than lot to lot difference. But at any rate, once I started blending new stock with old I stopped having this problem.
PS...
I am using 39 grains under a 105 hybrid for 2968fps in the 6xc, with a 21" benchmark. Curious what your barrel make and length is.
I just started shooting the XC a few months ago and I am amazed at the accuracy, while I am sure luck was a part of it I shot a 5 shot group a few weeks ago that was half MOA at 1k with 4 of those 5 landing inside three inches. I see more XC barrels in my future...
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A few years back Varget had a couple of wild lots, guys were getting big velocity swings. I'd imagine all powders do and with the popularity of H-4350 a lot of it is being shipped. That's why the manuals all recommend dropping back and working up when changing lots.
David Tubb would test each new 8# jug and write the load for that lot right on the jug. That became his reference for that lot. I changed every time. You could say it's in your XC's blood.
In my experience as the barrel wears the velocity will drop, due to throat wear is the theory. I usually bump the charge to keep velocities consistent. This usually occurs about every 3-4 lbs. It works out.
David Tubb would test each new 8# jug and write the load for that lot right on the jug. That became his reference for that lot. I changed every time. You could say it's in your XC's blood.
In my experience as the barrel wears the velocity will drop, due to throat wear is the theory. I usually bump the charge to keep velocities consistent. This usually occurs about every 3-4 lbs. It works out.
I am running a criterion 26" heavy varmint on a remage build. I am also very pleased with the accuracy and ease of load development was a plus to.
Yeah, my wife goes to the Tufte seminars on presenting data.
Edward Tufte - Wikipedia, the free encyclopedia
1 - (3175 - 3030) = 0.048 = 5%
The OP went on and on blah blah, but you really cleared it up.
Whoops! You WERE the OP.
My jug of H4350 is 4% slower than the Quickload library H4350.
I just got a new jug. I am looking forward to testings.
