Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Reply

R-25 temperature variation

 
LinkBack Thread Tools Display Modes
  #8  
Old 01-02-2012, 11:27 PM
Bronze Member
 
Join Date: Dec 2007
Posts: 57
Re: R-25 temperature variation

Well in my stw 120 fps difference results in 5.5 inches difference at 550 yards. The problem is what happens if your shells end up on the dash of the truck and are at 100f? I will try some different powders and post the results. I picked up some ramshot today, and will get some retumbo (they were all out till next week).
I have shot Rl 22 and 25 for years. For the most part it is accurate and always seems to be faster than most other ones. I guess I never tryed across the chronograph in the colder weather.
Reply With Quote
  #9  
Old 01-04-2012, 02:11 PM
Platinum Member
 
Join Date: Jan 2003
Location: The rifle range, or archery range or behind the computer in Alaska
Posts: 3,592
Re: R-25 temperature variation

I read all the time about this and it baffles me. I have never seen this at all. In fact I have seen the opposite. I dont know if there are factors that we are not aware of that come into play such as load density, or high/low pressure loads, etc....but I have tested RL15, RL19 and RL25 in several different guns/calibers from 0 degrees to 80 degrees side by side leaving loads outside all night and regulating others in my house and warm vehicle and have always seen very consistent numbers (within 25-40 FPS) and in one comparison, the velocity increased a bit with the cold cartridges (????). I know of other that have performed similar comparisons with similar results.

On the other hand I found VVN540 to be fairly sensitive. I documented the spreads from -2 degrees, 55 degrees and 80 degrees incorporated this factor into my ballistic calculator. I set it up for a baseline. When I enter the current air temp, it adjusts my velocity accordingly (the beauty of developing your own software). The groups and suprisingly, my 300 yard zero did not change (the beauty of harmonics).

Regardless, I hear lot of comments about RL powders and they always seem to contradict.
__________________
__________________
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.
Reply With Quote
  #10  
Old 01-08-2012, 11:48 AM
Silver Member
 
Join Date: May 2008
Location: Ohio
Posts: 248
Re: R-25 temperature variation

Mike,
I'm gonna agree with you on this, always hear this stuff and it doesnt really figure to me.. I've used Reloader and Hodgdon extreme powders in both hot humid and extremely cold conditions and I dont see a huge desparity( i get good results with both al yr round). At least not enough to change my entire loading.. and If so, I would make a summer load and a winter load with the same bullet.. But so far I have not been so inclined to do that.
Different chrono's have diff operating temps and , when you go from hot humid to extreme cold, the aire is drier, it seems I can group better during the winter, I don't worry about the velocity for the most part.. further, if I was in a match in 5 F degree weather..I wouldnt be, if ya know what I mean...
Anyways thats my 2cents on it..
Reply With Quote
  #11  
Old 01-08-2012, 02:37 PM
Platinum Member
 
Join Date: Jan 2008
Location: Northeast
Posts: 2,441
Re: R-25 temperature variation

I have had good success with the Hodgdon extreme powders, namely, h4831 a n Retmbo. I have used them from 0-80 degrees. I have had some issues with temperature with the Reloader powders.
__________________

"Let us speak courteously, deal fairly, and keep ourselves armed and ready"-T. Roosevelt
Reply With Quote
  #12  
Old 01-08-2012, 09:34 PM
Bronze Member
 
Join Date: Dec 2007
Posts: 57
Re: R-25 temperature variation

Well I tried this today. There may not be as much of a difference as I first thought there was. Here is what I tried today.
I loaded 6 bullets with 3 different powders Ramshot, H-1000, and RL-25, I used 79 grains of each kind of powder with a 100 grain bullet. I took 3 of each load and put them in the freezer overnight. The other ones when I went out to shoot I left them in my inside jacket pocket. The temp today was just below freezing. The average for 3 shots are as follows.

Ramshot 3581 warm and 3574 cold. I did notice that the ramshot had a couple of hangfires.

RL-25 3741 warm and 3724 cold

H-1000 3686 warm and 3724 cold, the only problem was I had a little chrono error and it only recorded 1 shot, so the cold was not really an average.

I will try this with some retumbo as soon as I can find some.
Reply With Quote
  #13  
Old 01-14-2012, 08:44 AM
Bronze Member
 
Join Date: Dec 2009
Posts: 61
Re: R-25 temperature variation

I believe all powders are temperature sensitive.

Instead of introducing potential errors by using a chrono repeat your temperature experiment but shoot at 500 yards and check the difference in drop. Shoot one cold and one hot and see what kind of spread you got.

I live in a cold place and if you don't account for temperature you won't hit where your aiming.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: R-25 temperature variation
Thread Thread Starter Forum Replies Last Post
Velocity variation with my 6.5-284 Greyfox Reloading 5 10-06-2011 12:53 PM
Bullet Variation mtang45 Reloading 1 01-17-2011 11:50 AM
Measured headspace variation Stevanda Reloading 5 07-26-2010 04:22 PM
How much variation is there between powder lots? tlk Reloading 3 02-26-2010 09:37 AM
temperature to velocity variation input scott Rifles, Bullets, Barrels & Ballistics 7 07-05-2006 06:00 PM


All times are GMT -5. The time now is 06:39 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC