H-4198 Temp sensitive?

[wtkaiser]

I haven't been on in many months, so you might have hit this topic. But with all the threads still looking familiar, I have to ask. Does anybody have some experience to tell me if H-4198 is temperature sensitive or not? I had a couple experiences just today (cool, overcast day right after a rain) at the range that makes me think it is. I had a .45-70 and a .356 Winchester bullet stick in rifles of the appropriate caliber. Both bullets are lead, so should present no problem. But right before they stuck, both ammos also hangfired a couple rounds. Then came the awful silence, the withdrawn, uncapped case and the unburned powder flowing all over the place. To have that happen twice in one day was most inconvenient.

[XxWoodsHunterxX]

How many grains? Bullet grains? Oal?

[wtkaiser]

The details are almost unimportant, but it was cal .30-06. charge ranged from 42-47.5. Bullet was the 150 palma BT (got 'em on sale from Midway). Standard primers (and this is what would have needed to be changed if I knew ahead of time it was temp sensitive).

WHOOPS! Just looked at powder. Forget the h-4198. change that to IMR 3031. but the question stands.

[crowbar]

IMR would be more temperature sensitive than one of Hodgdon's "Extreme" powders like H4198, H322, Benchmark, H4895, Varget, H4831, etc.

IMR 3031 is about midway on burning rate chart between the faster H4198 and the slower H4895.

Visit www.hodgdon.com for more info.

[wtkaiser]

Whoever reads this thread, I apologize. I read .30-06 data and implied it was for the other two. My .30-06 did NOT fail this morning. My .45-70 did and my .356 did. They were both using a light charge of 4198s. H-4198 for the .45-70 and IMR 4198 for the 356, because they were both loaded with lead bullets. I am certain it was because of the weather, and I should have paid attention to the hangfires that preceded the FTFs that eventually came. It was cold for southern CA today.

Put this thread to bed, and me with it! LOL

[Enfield47]

I wouldn't think that 60 degree weather would have much effect on a powder (even if its temp sensitive). If you were in really cold or hot weather for an extended period it could have an effect.

[mark501w]

What was the .45/70 load?

[JagerDog]

I wouldn't think that 60 degree weather would have much effect on a powder (even if its temp sensitive). If you were in really cold or hot weather for an extended period it could have an effect.

^^^^this. Something else is your problem.

[wtkaiser]

It may have been somewhat cooler, but nothing too nasty. It was well above freezing. I wouldn't have thought it was that temp sensitive, either, but that's the only explanation I can come up with. The gun was fine, then a hangfire or two, and then it stopped completely. The case ejected, the bullets didn't and powder all over the place.

[wtkaiser]

The .45-70 load was 34-35 grains of H4198 behind a 305 grain lead bullet. It was a really light load taken from an old Lyman manual in loadbooks. Primers were standard rifle.

[wtkaiser]

Hodgdon quote a similar load for 300 grain lead bullets in the trap door. The Sharps replica can shoot much heavier loads than that, but I wanted a trapdoor load out of curiosity

[mark501w]

What primer? I'am using a 405gr bullet & 37gr of imr4198 in .45/90 right now with a mag win primer. Probably has something to do with the primer lighting off that volume of powder in a large case. You could try a different primer or make up some wads out of heavy paper to hold the powder against the primer. Cut a disc that fits in the case snugly & push it over your powder charge & seat your bullet.

[wtkaiser]

Primers were win LRP. And you make a good point. I have never used a wad before, as NRA says not to - it could ring the barrel. But others say go ahead.

[mark501w]

.Don 't pack the case with your wad build a disc to set in the case. There's Dacron that's used for light loads & large cases. I have used wonder wads,a felt wad black powder guys use get the .45 cal ones. Or up your load a few grains.

[CSACANNONEER]

I wouldn't think that 60 degree weather would have much effect on a powder (even if its temp sensitive). If you were in really cold or hot weather for an extended period it could have an effect.

Temp does play a part in the way all powders preform. Some more than others. I have a lot of friends who preheat their match ammo to over 100 degrees and don't remove it from the heater until they are going to chamber and shoot it. I know one guy who won't even let it set in his chamber for more than 30 seconds without loading a newly heated round and reheating the one that sat in the chamber too long. Of course, that is for consistency and probably not the OP's problem.