|
|
Joined: Sep 2006
Posts: 23,647 Likes: 1
Campfire Ranger
|
Campfire Ranger
Joined: Sep 2006
Posts: 23,647 Likes: 1 |
John,
Very interesting........thanks for the comments.
MM
|
|
|
|
|
Joined: Jul 2001
Posts: 60,168 Likes: 16
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,168 Likes: 16 |
You're welcome. There's going to be an article on powder and temperature in an upcoming issue of HANDLOADER, but probably not until fall, because I have to do some more hot-weather testing first.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
|
|
|
|
|
Joined: Oct 2008
Posts: 8,748
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Oct 2008
Posts: 8,748 |
Appreciate all the inputs and look forward to your article. I did get a few data points from a ball powder both before and after it was modified by flattening (and whatever else they did). It lost a little velocity and did not demonstrate to be any more temperature resistant. 70 to 15deg. Kind of disappointed as it offers great velocity and accuracy. But, I can always carry a few in my pocket and keep them warm if it really bothers me!
|
|
|
|
|
Joined: Mar 2007
Posts: 9,212 Likes: 3
Campfire Outfitter
|
|
OP
Campfire Outfitter
Joined: Mar 2007
Posts: 9,212 Likes: 3 |
Anyone have any way to validate the claim that magpro increases "lubricity "as told to me by nosler.
I would not buy something that runs on any kind of primer given the possibility of primer shortages and even regulations. In fact, why not buy a flintlock? Really. Rocks aren't going away anytime soon.
|
|
|
|
|
Joined: Oct 2008
Posts: 1,187
Campfire Regular
|
|
Campfire Regular
Joined: Oct 2008
Posts: 1,187 |
Anyone have any way to validate the claim that magpro increases "lubricity "as told to me by nosler. Well, being a General Dynamics spherical, it has a fair amount of graphite. Does that count? 
|
|
|
|
|
Joined: Feb 2007
Posts: 7,442 Likes: 1
Campfire Tracker
|
|
Campfire Tracker
Joined: Feb 2007
Posts: 7,442 Likes: 1 |
My RL22 loads were equally accurate at any temperature but not equal in velocity. Mine too...
You only live once, but...if you do it right, once is enough.
|
|
|
|
|
Joined: May 2005
Posts: 7,094 Likes: 2
Campfire Tracker
|
|
Campfire Tracker
Joined: May 2005
Posts: 7,094 Likes: 2 |
I've done 25 years worth of load building and accuracy chasing, I understand powder temperature sensitivity and barrel harmonics.
My studies have never attempted to quantify this;
If a given combo was to shoot .5 moa at a known node at 25*f, does the velocity difference at say....75*f bring the load out of the node? I'm using 3% as a temp sensitivity number for argument sake and assuming that we loaded and chronographed @ 25*. If we had 3000fps @25* and gained 3% at our top temperature that's a gain of 90fps.
Aside from the potential pressure issue does the rifle fall out of the node? Does the temp of the rifle itself come to play to equalize this? Should we load for "X" velocity by adjusting the powder charge? Yes, to many of your questions. Rifle temperature can influence burning rate especially in hot climates. Most Americans never hunt in those extremes as the majority of hunting seasons are in cooler to cold temperatures. Double based powders have demonstrated this more than single based powders which is why there is so much interest in the newer powders that are demonstrating a relative insensitivity to temperature shifts. I have hunted in hot temperatures where the hunt is cancelled because of the increase in snake activity which like powders, increased as does temperature. During those hotter temperatures, loads worked up in cooler temperatures are more easily noted as changing pressures and and accuracy. John
When truth is ignored, it does not change an untruth from remaining a lie.
|
|
|
|
|
Joined: Feb 2009
Posts: 133
Campfire Member
|
|
Campfire Member
Joined: Feb 2009
Posts: 133 |
I had an interesting experience one summer.(Probable temp., high 80s or low 90s.) I had worked up an accurate load in my 257 Roberts, using a below-max charge of H4831, and a 120 gr bullet. No pressure signs whatsoever. I loaded a round, then paused for a few minutes. I returned, and fired the loaded round. I noticed the bolt was a bit "sticky" upon opening, the primer was flattened more than others of the same batch, and the case had expanded slightly into the ejector(?) opening, leaving a bright mark.  I figure the heated barrel and chamber heated the round enough to increase pressure in what before had been a consistent load.
What's the worst thing that can happen? O.K., what's the next worst thing?
|
|
|
|
|
Joined: May 2007
Posts: 2,225
Campfire Regular
|
|
Campfire Regular
Joined: May 2007
Posts: 2,225 |
Around here all the LRP bunch gobble up every lb of H4350 within a 100 miles, while there are shelves flowing over with IMR 4350. They tell me it is a temp sensitive issue.
|
|
|
|
|
677 members (160user, 204guy, 219 Wasp, 1lessdog, 12344mag, 1beaver_shooter, 63 invisible),
2,266
guests, and
1,212
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums81
Topics1,192,840
Posts18,496,815
Members73,979
| |
Most Online11,491
Jul 7th, 2023
|
|
|
|
