Warm lot of H-4350

[Drop Port]

For those of you using H-4350, I just got a hot lot. I noticed the same charge weight filled the case a lot more. I backed off a half grain and still gained 40 FPS in my 6.5x47L.

Lot# 1032014
5283

 

[whysman]

Do you have a lot number from your prior load?

 

[savagedasher]

The case fill is not good .I understand the speed difference . Try putting some in a pan and let it air out. Larry

 

[Keith Glasscock]

I have a newer lot too. I was surprised by how warm it is. I only run 51 grains in my 284 (32") and get 2820 with 180 hybrids.

To make QL match up, I have to run the Ba up excessively. That said, The rifle just showed me a couple of weeks ago that I have the right powder.

 

[Syncrowave]

Thanks for the head's up.

 

[savagedasher]

I have some bench rest friend they always dump a new can in a pan and air it out. What I suggested is a easy try..I would like to hear back.
Larry

 

[BoydAllen]

A test that I read demonstrated that drying out powder increased velocity to a significant degree, so you may want to reconsider that option. The test involved no change in the actual number of particles of powder per charge. The weight varied by moisture content. The article was in Precision Shooting magazine.

 

[Syncrowave]

A test that I read demonstrated that drying out powder increased velocity to a significant degree, so you may want to reconsider that option. The test involved no change in the actual number of particles of powder per charge. The weight varied by moisture content. The article was in Precision Shooting magazine.

Interesting. Glen Zediker in his book "Handloading for Competition" suggested that charging cases by volume might yield equally if not more consistent results than charging by weight, due to powder picking up or giving up the weight of moisture. He said that he'd weighed charges thrown by benchresters' powder measures and found that identical volumes varied in their weights, but gave consistent velocities. Reading between the lines, he theorized that the weight differences were due to changes in moisture that didn't affect pressures/velocities, if I understood him right.

 

[BoydAllen]

The test that I read was very through. Weighed, sized and primed cases were charged with powder that was from a freshly opened cannister. The charge weights were recorded (total weight minus weight of each primed case), and some were chronographed. The open cases of powder were racked in a closed container with a significant amount of desiccant below and left that way for some time, until their weights were as low as thy would go, then the cases of powder were weighed, and some were chronographed. Then the remaining cases were racked in a closed container with water below them and left till their weight stabilized, and some were chronographed. The difference in charge weight from dry to wet was 2%, and the difference in velocity from dry (highest) to fully humidified was I believe 320 fps. I believe that this sort of test trumps theory and supposition every time.

Another example comes from Jim Borden, who loaded a number of batches of ammunition for a large match, over a period of a couple of weeks (or more, I forget) in which the weather varied considerably. There were wide variations from session to session, in the heat and humidity. At the start of each session he adjusted his load so that it produced the desired velocity, because he views tune as velocity specific. By the time he had, I think 300 rounds loaded, the extreme spread, batch to batch of charge weights required to produce the same velocity was 1 1/2 grains. His shooting buddy, told him that he had made a mistake in his approach that would surely lead to accuracy problems at the match, so some rounds were pulled from each batch, and groups shot with mixed ammunition. The groups were pleasingly small. It has been a while since I was told the story, but I am pretty sure about all of the important details, especially the grain and a half, and the accuracy obtained when testing.

 

[greenwood]

New 8# keg H4350 running ~100+ fps faster in 6XC. Spilled the remaining powder from 1# bottle after working up a powder node. The increase speed and pressure found when using new keg to find seating depth. Perhaps the old 1# was slow, but getting to near 3000 fps took more powder than most 6XC reports. No lot number found on keg.

greenwood

 

[OldManTA]

Boyd,
My recollection from reading on the Lapua site backs up your information on moisture content. I have discussed load development with a friend in Phoenix specifically for the 6XC using H4831sc. I would have had to use about 2 grains more powder to get the same results he was getting out of a similar barrel and chamber.
Tom Alves

PS: That's another reason for using CAUTION when using a load you got off the Internet!!!