I appologize if this has been covered before, but I haven't been able to find it. How does Alliant's RL-17 stack up as to temp sensitivity? I have some but here in SE Ga., we experience temp swings according to season from 100 degrees (sometimes +) to near to slightly below zero - a pretty wide swing. Here in the swamps, the humidity makes these temp swings even more remarkable. Nothing contains or saps heat more than water, so if I work up loads in the hot summer and then shoot them in the colder winter months, this CAN be a significant factor in whether the load works across the board when the seasons change so drastically. Thanks for any info you can provide.
None of the Reloder powders are temp. stable. Supposedly, they are coming out with a new line of temp. stable powders......supposedly. Last time I was on their website there was zero information on them. They are certainly not available anywhere I have seen.
Um, not exactly.
Temperature resistance is relative. There isn't a powder made that produces the same velocity from zero to 100 degrees Fahrenheit, though some do a very good job from zero to 70. Some of it also depends on the specific application.
Reloder 15 is pretty good--or became pretty good when it was reformulated about 2000, to meet some military specs. Before that it kinda sucked. But 15 still isn't as temp-resistant as the Hodgdon Extremes. In my experience RL-17 is about the same as 15.
As I noted, it depends. RL-17 isn't as temp-resistant as several other powders, but more so than many.
Which is why I use the term temperature-resistant, rather than temperature stable.
John,
I was responding to Reloder28. Didn't see you posted until just now.
I sure wish Rick would fix the quote settings.
As John said, "resistence" is the correct adjective here. I've shot R17 for several years now in a 284 where it has provided both top velocity and accuracy in my rifle with Barnes TTSX 140-gr and 150-gr bullets.
I worked out my loads under Iowa summer suns and humidity. Temps from 80 to 90 degrees and then hunt with those loads in the fall and winter. My one anecdotal example of an extreme test came about three years ago in the Sandhills of Nebraska where opening day and a blizzard converged precisely with mid-morning temps at a frisky -20. So, we might say a hundred degree spread.
My shot came right at 500 yds at a frenetic, rutting ten-pointer who halted his mission just long enough for a steady shot over a pack. Range and hold were spot on as during very warm, summer practice sessions.
That's all I've got.
In my .260 I use Reloder 17 with 130 gr. bullets. I produces excellent velocity and excellent accuracy. It has also proved very stable to drops at distance, in a varying degree of weather. From summer heat(100) down to normal comfortable shooting temps (30s). In my application I have never seen differences in drops or pressure experiences.
In my 7x57 it has not proved as accurate or stable as other powders tried.
If I remember right Sam Olson posted some of his results of hot/cold weather performance with RL17 a couple of years ago.
TX, I did do test a couple winters ago but can't remember the exact findings.
Pretty sure I did load work up in 50-70F and then shot at -20F.
If I remember correctly R17 lost about 100-200fps at -20F.
I concluded that it isn't going to make much difference on shots under say, 300 yards.
Scenarshooter had issues but he shoots a lot farther and more often in cold weather than I do.
H4831sc is the best I've tested, H4350 is okay and I would think R17 is fine for anything over 0F and 400 yard shots.
Basically I wouldn't worry about it but then again I don't do load work up in hot temps either.
It's sort of a hard subject to really pin down.
Although not in the extreme temps SamO did, I sort of performed/confirmed/whatever you want to call it with RL22 and one of my 7mags this past November. I generally do my load workup in the early Spring here, before it starts getting too hot, normally in the 50-65* range. Last November it was unseasonably freezing asss in the TX Panhandle, temps in mid-teens. I saw zero POI problems out to 900 yards with RL22/160AB loads. I'm probably way wrong, but I think this temp stability thing is way overblown in most instances.
I sure wish Rick would fix the quote settings.
I was not aware of a problem, and maybe Rick isn't either. miles
JG,
It's only way overblown until it matters, and the only way to tell for YOUR hunting is to do exactly what you did.
It usually doesn't matter much with ANY powder from 50-65 down to the mid-teens, with any powder, which is probably the temperature range for a bunch of American hunters.
As Sam mentioned, it also usually doesn't matter if you don't shoot over 200 yards, though a couple of times I have seen rifles that were sighted-in at 70 degrees shift point of impact 3" at 100 yards at zero. That amounts to 6" at 200 and 9" at 300 yards, which would make a difference.
But usually the difference in POI at 100 between 70 and zero is nothing to an inch or so, which the average deer hunter will never notice.
Different rifles and load combination also react differently. If the powder is particularly well-suited to the case and bullet (which is true of the 7RM and 160's) then there won't as much variation.
Rifles with thinner barrels typically show more POI difference between particular charges of powder when working up loads, and will usually change POI more readily with a significant temperature change. Rifles with heavier barrels typically show less POI change with different charges of powder when working up loads, and also typically show less change of POI at different temperatures.
Since in a typical year I can hunt in temperatures from below zero to over 100, I test my rifles to see if a certain powder/load reacts to those temperatures. If not great, but I want to know beforehand, instead of assuming it's no big deal.
Although not in the extreme temps SamO did, I sort of performed/confirmed/whatever you want to call it with RL22 and one of my 7mags this past November. I generally do my load workup in the early Spring here, before it starts getting too hot, normally in the 50-65* range. Last November it was unseasonably freezing asss in the TX Panhandle, temps in mid-teens. I saw zero POI problems out to 900 yards with RL22/160AB loads. I'm probably way wrong, but I think this temp stability thing is way overblown in most instances.
I agree. I talked to the guys at Alliant one time and they said that there is not a powder made that does not have some temp issues. It depends on what you load and how much difference it makes.
I use Re22 with 139-140-grain bullets in my 7mag and have not noticed anything that would allow me to blame it for missing a shot!
In my experience rl 17 sucks. It produced speed differnces of 125 fps or more in my 243 ai. It would also shoot a .75 200 yard group. The same group turned into 0ver 5 inches of vertical at 550 yards. I have since found a load with 4831sc that holds 1/3 moa of vertical to 1000 yards with the same gun. 4831sc is soooo much more stable I am surprised jb puts it in the same sentence
There is often a "sweet spot" for many cartridge-powder-bullet-rifle combinations. I've found that with my 9.3 X 62 and RL-17 behind the 286 NP. 1-grain less and it falls apart.
The same was true for a 350 Rem Mag - RL-15 and the 250gr Speer GS.
Either of those rifles would shoot those loads sub-moa faithfully regardless of temps. A magnum primer was/is always used (WLRM).
Bob
www.bigbores.ca