Temperature Sensitivity/Insensitivity

[300winnie]

Is this more marketing hype than truth?

From what I can read, a lot of people are saying that RL22 is one of the most temperature sensitive powders there is, yet I did a poll on the a/r site to see what the favorite powder is for the .300 Winchester Magnum and as of the time I am writing this post 61% of the voters preferred RL22. The other 39% was spread out over 3 other popular powders (H1000, H4831/H4831SC, and IMR 4350) in pretty equal distribution. It is not a large sample, but it mirrors what I have read on these sites for a long time.

So, if RL22 is so sensitive, why is it so popular in comparison to the so-called temperature insensitive powders such as H1000 and H4831?

I am tempted to buy a jug of RL22 to try, but want to sort through some of the mumbo jumbo first.

Thanks.

 

[goodgrouper]

I have been shooting RL22 in my 300 win mag for about 10 years now and it has been the most accurate powder in my rifle for the entire time. I have shot probably 8 or 9 different lots of RL22 through it and have used the gun to kill everything from prairie dogs in the middle of July to elk in January.

From this, I can tell you that even the slower lots of RL22 that behaved more like RL25 still preferred the same charge as the faster lots which is 75.5 grains with 180 grain bullet. These slow lots sometimes were 150 feet per second slower but still shot same p.o.i. and accuracy was identical. All I had to do was adjust my drop charts.

So, I always loaded the same charge, but in cold weather my charts had to be adjusted slightly and same for hot weather.

I kept detailed notes of weather when I was chronographing it and compared them in similiar temps from year to year.

When I have a hunt coming up, I will go out a few days before the hunt and chrono it while shooting at 1k yards to make sure I have good info to plug into my ballistics program.

Temperature does change how fast it pushes the bullet to some degree ( all powders do to some extent) but more importantly, temperatures and elevations change how the bullet flies after the powder is burned.

Bottom line:
ambient temperatures change how ALL powders burn and alter the exterior ballistics of ALL bullets. So buy a chronograph and use it often and take good notes while shooting. /ubbthreads/images/graemlins/wink.gif

 

[scott]

Have to ask, what are your temp variations? say at 20 and 70 deg etc?

scott

 

[300winnie]

I could be hunting as low as -20F or as high as 90F.

 

[Buckmaster]

300Winnie, have you tried H-1000? I have used it in other rounds and found it to be very accurate. I also found IMR 4350 to be super accurate as well, but it is also temp sensitive.

If you can get H-1000 or any of the Hodgdon Extreme powders to shoot well then don't worry about what 61% of people are shooting.

I would try the H-1000 to start. I'd be surprised if you don't have good accuracy with it.


Good Luck!

 

[jwp475]

[ QUOTE ]
Is this more marketing hype than truth?

From what I can read, a lot of people are saying that RL22 is one of the most temperature sensitive powders there is, yet I did a poll on the a/r site to see what the favorite powder is for the .300 Winchester Magnum and as of the time I am writing this post 61% of the voters preferred RL22. The other 39% was spread out over 3 other popular powders (H1000, H4831/H4831SC, and IMR 4350) in pretty equal distribution. It is not a large sample, but it mirrors what I have read on these sites for a long time.

So, if RL22 is so sensitive, why is it so popular in comparison to the so-called temperature insensitive powders such as H1000 and H4831?

I am tempted to buy a jug of RL22 to try, but want to sort through some of the mumbo jumbo first.

Thanks.

[/ QUOTE ]

What googrouper said sums it up pretty good........

I use H-1000 not because it was the fastest out of my gun (it was not), but it was the most consistant ( 5fps extreme spread)

 

[RuffHewn]

Do a search on the DoD development of the A191 ctg, basically a .300WM firing a SMK190 about 3000 fps. There is good info on RL22 and several other powders. At the conclusion of the tests RL22 was the powder selected.

I use 68.5 gr RL22 with my molyed SMK190 load in my .300WSM and was completely satisfied with temp stability till temps were above 100-105 deg. From 25 to near 90 deg RL22 compares very well with the H4350 I use for the Hornady 178gr moly A-Max.

VVN 560 is another powder that is likely to be suggested and I found it to be very good from late fall to early spring but as temps rise above 60 - 70 deg I began to like it less and less.