Let me relate a little experiment that I did. We were at the range one day last spring while doing some load developement for my 30-338. I was wondering "well this group is fine at 78 degfrees f. I wonder what the difference will be if it is around freezing" We had a ice chest with our cold drinks & sandwiches in it. I took a zip lock bag from one of the sandwiches & put five 30-338 rounds in it & put that into the ice chest. After 45 minutes of laying on top of the ice the ammo felt about as cold as the cold drinks. I shot this cold ammo at the same target I had already used. The group was very close to the same size (.875) but the group had dropped verticaly be 4 3/4" at 100 yards. Chamber pressure drop due to temperature. The sandwich did not go to waste.
------------------ NRA Life member
[This message has been edited by Bear Claw (edited 11-22-2001).]
Posts: 8346 | Location: Jennings Louisiana, Arkansas by way of Alabama by way of South Carloina by way of County Antrim Irland by way of Lanarkshire Scotland. | Registered: 02 November 2001
I may be asking a silly question here, but maybe you could humor a country boy a little bit- What is a 30-338 and how is it different from a 300 Win mag?
TIA
Posts: 7763 | Location: Between 2 rivers, Middle USA | Registered: 19 August 2000
As I recall the 338 came out first (1958?), and the 300 Win Mag a couple years later (1962?). During the interim the 30/338 wildcat came out and developed a following with some long range shooters. It was assumed that Winchester would follow suit but instead they produced the .300 WinMag, in which they moved the shoulder forward to gain a bit of room for more powder capacity and subsequent velocity gain. Of course, the neck on the 300 WinMag ended up being rather short in order to keep the cartridge length within the confines of a standard length action.
A 30/338 is very similar to the .308 Norma Magnum cartridge. Differences between he three is actually rather small.
Posts: 3276 | Location: Western Slope Colorado, USA | Registered: 17 August 2001
uh, uh, bear claw what you loaded at high temp. then you went to low temp. also created humidity in the shell, then you shot it. not conclusive unless you could have measured by some miracle the humidity inside the shell, when you reduced the temp? Ain't reloadin a bitch luck hotdog
The 30/338 is nothing more than the 338 Win. Mag necked down to .30 caliber. My hunting load is a 165 grain Barnes X bullet on top of 71.0 grains of IMR 4350 Fed. 215 primers WW cases (this is over MAX. according to the manual but i worked up to it very slowly)I'm not recomending this load to anyone, just answering questions. Across the Chrony this load goes 3173 fps (five shot average) 25" Lothar Walter barrel, 1300 contour CM with a 1 in 10 twist, FN Supreme action Timney trigger, McMillan stock. I was suprised that it dropped so much. This wasn't a controlled test but then i'm not a Scientest. Would a cold gun have made the group drop even more? If so should we let our guns reach the temperature that (in our best guess) we will be hunting at? Hmm? More testing is needed! Back to the lab Egore!
------------------ NRA Life member
[This message has been edited by Bear Claw (edited 11-22-2001).]
[This message has been edited by Bear Claw (edited 11-22-2001).]
Posts: 8346 | Location: Jennings Louisiana, Arkansas by way of Alabama by way of South Carloina by way of County Antrim Irland by way of Lanarkshire Scotland. | Registered: 02 November 2001
Bear Claw, I like the 30/338 also. In most bullet wieghts the difference in it and the 300mag is so small it don't matter and in some it's faster. I'm curious about the new short mag from Win and Rem.I kinda like the case design of the Rem, wondering about the shoulder though, kinda tapered ain't it...
Dropping the temperature of a monometal bullet by 30 degrees will make it contract about 15 micron. If the rifle is hot, it may be enough to lose the gas seal between bullet and bore, if it was marginal, thereby reducing speed. Jacketed lead bullets will not conract by the same amount and will also shorten in length under pressure and expand diametrically to fill the bore and seal well.
How will your rifle, ammo, zero, react in november on a mountain in NYS in a snow storm? or out in the west in down right blizard in say Wyoming or South Dakota? The climate alone can take your zero a fling it into the 4th dimension. I read a good article on this mess in I believe an issue of Rifle magazine, although it could have been Handloader, I'm not sure. I'll dig through the ever growing and swirling pile of gun, hunting, and ammo magazines and catalogues that are in the corner of my room and I'll tell you what magazine, the date and the issue.
------------------ When in doubt, do a nuclear strike.
Posts: 1723 | Location: wyo | Registered: 03 March 2001
