Originally Posted by Mule Deer
A couple comments:

Shrapnel almost always jumps into these threads, saying he's used H335 for many years in his .223s and never had any problems.

But one thing he doesn't mention is that he HATES hot weather. I have shot PDs and "gophers" (Richardson's ground squirrels) with him many times over the years, and cannot remember ever doing so on a day over about 80 degrees.

Might also mention that I have tested a bunch of powders at temperatures from zero F. to around 100 degrees--and by that I mean in actual temperatures including the rifle, not just chilling or heating the ammo, which only rarely produces similar results. The velocities of the best temp-resistant powders don't change much at all from 70 down to zero, and even somewhat below zero. But they ALL result in faster velocities (and hence higher pressures) at temperatures above 70, usually becoming more obvious around 80.

The more temp-resistant powders, however, do tend to gain less velocity/pressure at over 80 than "standard" powders. Also, even the most temperature-sensitive powders (among which I'd list H335) don't vary much in velocity from temperatures in the 20s to around 80. Or at least none of the presently produced rifle powders I've tested have.

All of this is why I prefer the term temperature-resistant, rather than temperature-insensitive. None of 'em are totally immune to temperature, especially heat.


I have shot prairie dogs with H335 in weather above 90 degrees and still had no pressure issues. I am talking about real life experience and not surmised or hearsay. Mule Deer has a selective memory and likes to bring up instances where he looks as good as possible, he does have an image he needs to keep up.

Yes, John and I have shot a lot together and he would be amiss if he didn’t admit that I do have good guns and hit more than I miss with 223’s loaded with H335. John also is the one that made the sarcastic statement about how all the trucks driving around Montana with cracked windshields was due to cartridges loaded with H335 and cracked those windshields from cooking off in the heat.

John will also remark how I sight guns in on rocks and not always paper targets. He is also right about that, but it produces the same results that bsahunter does with all his targets.

Nobody else but John and HawkI have any ability to comment on what or how I shoot.

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