R19 cold temps issues anyone?

[highdrum]

It was a temp stability chart.

Trusting someone else data is just that, a reference. I don't buy it. Maybe if he was loaded at 85% case fill. You always want to select a powder that has 95% or better fill. Keeps ES down and in my experience offers cleaner more consistent burn. RL33 is know for horrible temp swing, however loaded compressed and 1gr below max, it burns clean and from 30-80° I only observer 30'ps gain.

 

[Mram10us]

Trusting someone else data is just that, a reference.

True. What variations have you seen with r19 and r17 in different temps that shows r17 superior to r19 ?

 

[highdrum]

True. What variations have you seen with r19 and r17 in different temps that shows r17 superior to r19 ?

I don't have personal experience as I run RL16 and RL26. But I've read a lot of people showing very low temp shift. Alliant advertises rl17 as temp stable, rl19 it does not.

 

[Capt RB]

One thing about temp sensitivity is the fact that case volume case fill % and application can have a dramatic effect on how stable a powder is beyond the coatings applied to the powder. It is far better to test wht you can buy vs lust for stuff you cannot

 

[Vol1975]

Im gonna do a test maybe this weekend with reloader 19 & 26. I will Test 60 degree and somewhere in the teens. I will record and post the difference.

here is my test so take it for what it's worth
rl 19 in 7mm with 168gr accubond
Test temp 65degree and 20degree +\-

65 degree string 3 shot strings
2993,2985,2968 1/2 group. This is my sight in load I worked up back of this with know FPS for this load.
2bd string. 2987, 3005

65-70 degree with bullets sitting in the sun for 1 hr
3012, 3024,3021,3022 1/2 group. Little faster impact same point

20 degree with frost on bullet cold
2957,2937,2966,2956
Not sure on this because bullet has frost on it with condensation. Bullets were keep in cooler with ice and rock salt. Temp gun sayin basically 20 degrees

thing I noticed was cold temperature point of aim shift 1 inch low at 100 yards and was not as accurate 1 inch group but I shot sorta fast so it could have been me.

Rl 26 same test
Different 7 mm
175 grain accubond
Point of aim no difference at 100 yards
65 degree 2806, 2805,2787. 3/4 group

15 degree
2741,2795,2785
3/4 group

So far h1000 for me has been really good for temp swings. This is a big deal for me because I hunt from 75 degree to -20.
cheers. I hope this help.

cheers