338 Winmag/R19 Temp opinions

[preacher]

As I have posted many times before, I had a big time problem with the older 185XLC and R19 back in 20001. I had worked up a load in the Fall with all I could get behind that slick-as-snot 185XLC ( I didn't have a LEE FCD back then and don't think they were even made then) I don't remember the charge now ( slept since then and those notes went with the rifle when I gave it to my Pastor down in Texas) But it was a very compressed load so as to get any real speed (around 3100 if I remember right) behind that slick XLC ( hardly any real bullet pull with those!) I had a late season cow elk tag for the end of December and about 10days before we got a real good cold snow. it was right at 10 deg here in the SLC valley even. I thought I would check my zero again as ( being the Military Trained FDC Artillery Reliability Freak I am) I had a bad hunch about the cold. I allowed both rifle and the loads to get to outside temps, set up my chrono and began. OMG! Instead of the less than 1" group I had in October, I had 4-5" and speed had dropped a tad over 200fps! I came home and pulled the bullets. The R19 had made a solid cake, had to scrape it all out with a screwdriver, I mean all of it! I was using a Fed 215M primer too. I jumped on H4350 and below Barnes' Book Max at the time ( I do remember that, just not the exact charge) and got it zeroed again. I got my cow at 250yds, no problems. However, it spooked me to high heaven on R19! I've only trusted it again in the 240W ( the best in every 240W I tried it in) and tested it in the cold. So....
Could it have been the heavily compressed charge (though I have always used compressed loads in a lot of rounds, safely though with slow powders, just not R19) was it a bad Lot? Was it a combination of heavy compression/amount of charge as opposed to the '06 size of the 240W? I see you guys use R19 in the 338WM and I literally "cringe"! ha. What is your secret and how cold have you used your loads in and "hit" what you were aiming at? Bumfuzzled in Utah.... :evil: :twisted: :shock:

 

[truck driver]

Bumfuzzled in Utah I have tried it under several different Nosler & Hornady bullets. The batch I have is slow and has to be adjusted in QL to get the pressure up so I can get some speed out of it so I switched to R17 and it works a lot better in the 338Wm for me and you don't have to compress it like R19.
Been wanting to try some R26 in it since it seems to work well in other mag calibers along with R23.
But I don't have the experience with the 338Wm like some of the other guys here , I'm just getting started with it.

 

[preacher]

Thanks uncle Rodg!

 

[SJB358]

I’ve used RL19 in some wicked cold temps and still managed to put solid shots on elk out to 400 yards. That was using the 210 Partition and 250 Partition. I’m sure that RL19 drops some speed if loads are developed in 70 degree weather then used at 10-20 degrees but I’ve did my load work in the 50-60 degree range and haven’t had a problem with drastic speed diffs at 20-30 degrees. I like the stuff in the 338. It has always worked for me. I use 17 quite a bit now but if you have doubts sticking with RL16, H4350 and other known temp stable powders probably isn’t a bad way to roll.

 

[preacher]

Thanks Scotty. I figured it was probably just the issue of being compressed into a solid cake. That was the problem with the old XLC bullets, you just couldn't get enough powder in many sized cases for some of their bullets to get any real speed, ergo, accuracy as they loved to go fast. I was just so used to working up a load in the summer/mild Fall to insure no heat related problems. I learned this back in Texas as a beginning reloader and rabid reader. I don't ever remember reading of an issue like I had later in the cold. My Afrikaner friend who did culling in South Africa ran into similar though. He was using some kind of Somchem powder, using his .308 and the Speer 180 Mag Tip on eland. He went from mild temps in Joberg into subzero temps in the Drakensburg (sp?) mountains. His bullets barely got through the skin! He finally got one into the base of the skull on the poor thing and went to military fmj to finish his shoot. So it pays to doublecheck. I would never had known that about my R19 load if I hadn't got to thinking about what I had learned from FDC/powder temps, ha. Admittedly, that's a big "spread" between an 8 inch Howitzer and a 338 winMag ( well...maybe not "that" much! ha)

 

[Nimrod84]

Preacher,

I can't comment on loss of speed or accuracy of RL19 in cold weather. But I think your initial post show a few possibilities for the caked powder. I've heard (hearsay and rumor here) about a police office that would routinely hose his revolver down with WD40 with ammo in the cylinder - supposedly his ammo wouldn't fire and when the bullets were pulled the powder was a sludge. Poor neck tension and or unsealed primers allowed a solvent to liquefy the gunpowder.

You noted that the XLC's had poor neck tension, conceivably a significant amount of moisture or some solvent could have contaminated the powder and the destabilized powder froze in the 10 degree weather. Conceivably loading in high humidity could allow condensation inside the case during the temp swings and produce the same caking. A highly compressed charge could elaborate the caking if my suggested scenario(s) are correct. There is a reason military ammo has tar around the bullets and sealant on the primers...

FYI - I'm not trying to scare you or anyone about water and gunpowder. I don't seal my bullets or primers and I don't think most people need to. I do know a few hunters that have been to the Artic and Rainforests and they seem to seal their ammo up as tight as they can.

Edited to add - gunpowder has moisture in it already, more moisture slows the burn rate down and less speeds up the burn rate. Which could account for your 200 fps loss of velocity - excess water and cold temps slowing the burn rate and solidifying the powder. The Norma manual (newest?) has a good article on water and gunpowder and I think accurateshooter has some excerpts of the article on their website.

Just a shot in the dark, but I hope it help ease your bumfuzzled mind.

 

[preacher]

Could be, but at room temp it was still a solid cake! I have never sealed any handloads either, but sure have shot a lot of military stuff through the years ( seemed like a gazillion rounds when "I" was in the military, ha) I may have to wait until I get to Heaven to find out exactly what happened!