Is BLC-2 temperature sensitive?

[Dand]

I have worked up some loads with BLC-2 in my .223 Ruger #1 that are max by some load manuals and slightly over max by other manuals - but one shoots very well for me.

I've done the firing at 25- 35 degrees but plan to head to Montana and shoot them when it is likley to be 50 to 70+ degrees.

I'm wondering if that temperature range would be a concern for max loads?

I have sent this same question to Hodgdon but their website suggests they might not get back to me any time soon so thought I'd ask for folks' experiences here.

Thanks

[Questor]

Yes, it's temperature sensitive. The load data is typically developed at about 70 degrees F. If in doubt, keep the load a few tenths of a grain less than max.  In any case, you'll need to re-zero your rifle when you get to Montana.

[quickdtoo]

Here's a discussion on that topic with some input from Hodgdon by Mac on BL-C2.

Tim

http://www.gboreloaded.com/forums/index.php/topic,97719.msg1098248402.html#msg1098248402

[Catfish]

ALL POWDERS, run higher pressures with warmer temperatures. For that reason it is always best to work-up loads at the hottest temperature the round will be used at.

[Graybeard]

Not true. The Hodgdon Extreme line and most of the ball powders offered by Western Powder Co. are not temperature sensitive. Still it is true that most powders are to one extent or another but more are being developed regularly that are not.

[Siskiyou]

You guys got me thinking and it hurts my head.  I use Ball Powder in some of my loads, WW785, WMR, H414, H870, and AA8700.  At this time I have not experienced a problem.  I have tested on paper and game WW785 the most without issues.

My question is what defines extreme.  Is it +100° down to -20°?  Most of my deer hunting falls between 70° and  +20°F. 

I go out and do some shooting in 90° in the summer, and some in 40° weather in the spring.  According to my records most of my time shooting over the Chrony has been in the 40° range, and in the upper 70’s.  On targets I am not seeing a difference in load performance.  But I am not shooting at long range.

I can compute my bullet path with a 100 fps difference and see that if my rifle is sighted in at 225 yards the difference is starting to show at 300 yards but still within Point Blank range; the maximum Point Blank range is still 305 yards for both loads.

Two stick powders I load a fair amount is H4831 and IMR4064. 

I load 160 and 175-grain bullets in the 7MM Mag. using H870, AA8700, and H4831.  Within the temperature range described, am I better off using H4831?

What caught my attention was Bill’s statement that Western Powder ball powders are not temperature sensitive.  It makes sense to me because a lot of 7.62 ammunition is loaded with ball powder and is used worldwide.  But what the military does regarding ammunition does not always work; the M16 jamming problem in Vietnam after the switch from stick to ball powder is an example.

[Sweetwater]

A few years ago, I moved from SW Wyoming into Southern Cal. I remember some sticky cases while shooting my Wyoming ammo in that California sun. I switched over to H4895Extreme for some of my loads and was pleased to see consistent results on the Chrony in the early morning 35 degrees or the noon 100 degrees or more. We were shooting in Jacumba out on I-8 East of San Diego, and that kind of temperature change that far south was a bit of an eye-opener for me. So were the sticky cases, as I'd never had any previously with any rifle powders. The H4895Extreme was pleasant to work with and removed the temperature sensitivity.
In Wyoming, as well as Maine, we just didn't shoot in the heat. Mostly we shot in cool weather...not always, but mostly, same here in North Idaho. But, in Southern Cal, you either shoot in a certain amount of heat, or you don't shoot much. And time marches on..

Regards,
Sweetwater

[Catfish]

G.B. and Sweet Water,
  Ok, you guys have me wandering now. All the powders I ever checked have been hotter in warmer tepmitures, so now I`ll have to crono some loads at different temps and see what I get with the powders I use. I`ll get back with you about my test results.

[Graybeard]

Yup Catfish most are temperature sensitive but several years back Hodgdon came out with the first of their Extreme line that is not temperature sensitive and that is one of the things Western touts about their line of ball powders as well. Now that they own Accurate powder I'm hoping they do the same with it as I really like the various Accurate powders.

For sure Winchester 760 is VERY temperature sensitive. I long ago had a Remington Model Seven SS with the black plastic stock. A pretty much max charge of W760 shot sub half inch in that rifle at 100 yards so I loaded up a bunch of them. This was in cool weather and I hunted with those loads that season with no problem. Next summer I was shooting some of the same lot of ammo and wow what a difference. It locked up the bolt handle and pierced a primer or two. Needless to say I broke the rest of them down so I'd not accidentally shoot anymore in warm weather with them. They shot beautifully in cool weather but clearly were dangerously hot in hot weather. Since then I've tended not to use W760 in anything near max loads.

[Dand]

thanks for the comments and information.  Looking closer at my test targets it looks like I wasn't gaining that much by going to the max. So I've dropped down .5 to 1 grain and will stick with that.  No need to push the limits of my rifle in the middle of a long planned trip. I too have seen some loads developed at 20-30 degrees seem pretty warm at 70+ degrees  but it wasn't BLC-2.  And checking temps in Montana I could be seeing above 80 some days so being careful is the smart way to go.

Quick D thanks for the link - it was most helpful.

Sure appreciate the top notch discussions on GB - quality from quality folks.

Dan