RL26 vs. RETUMBO. . .your experiences please.

[STEEL SLINGER]

I'm shooting several cartridges at the present time with RL26 and can't say enough good things about it. . .BUT. . .lately I'm reading a lot about temp swings from .5 to 2 fps per degree of temperature change and this is something that concerns me being I live/shoot in Florida. I pretty much hunt the South East, but I do venture out west, so there is a temp issue there. And yes, it does get pretty **** cold in Florida from time to time. I haven't played around much in various temp swings with the RL26, so I can not comment on it's stability. What I would like to know is if you guys can give me some real world experiences using these two powers. The one rifle/cartridge I'm working with now is a 280AI shooting 168 grain bullets, so lets use this as a base. From what I'm reading Retumbo may be the better alternative ? ? ? What are you thoughts. Thank you.

 

[billigoat]

Tag

 

[STEEL SLINGER]

Someone has to have some experience with these two powders in various temperatures! ! !

 

[Engineering101]

steel slinger

I talked to the Alliant technical rep today for about an hour. The reason I called was to ask him if Alliant had any plans to fix RL-22/RL-25 to be more temp stable. I told him that they were good performers but really sucked temp stability wise. He said they have no plans to change those powders seeing that they also have temp stable powders and he named their three powders designed to be temp stable which are AR/COMP, RL-16 and RL-23. He said there is a forth powder that has shown good stability but they can't claim that because it isn't the same chemistry as the other three and wasn't designed to be temp stable - but from what they have seen it is pretty good. I was surprised when he said that the powder was RL-26. Good to know. I'm going to take him at his word and use the stuff because it is pretty unbeatable from a performance standpoint. I'm also going to do the freeze test to see just how stable it is in my rifles. When we get a good 90 degree day I'll take some to the range in a cooler that has been sitting in my freezer overnight and compare it to the 90 degree ammo. I've done this in the past with Magnum (which Barnes bullets tested and showed was very stable) and sure enough, it was very stable. Bottom line, use it but test it in your equipment so you know its limits.

 

[Dosh]

SS, can't comment on RL26, but here in Az I live a 1000' and hunt at 5-7000'. The temp differences can be near 90 degrees. I use Retumbo in three rifles and after adjusting for altitude it is temp stable as I've found. The new IMR Enduron powders are listed as temp stable also. You can only try Retumbo and see if the groups are acceptable. Good luck

 

[Triple BB]

Seems like there have been a number of threads about RL 26 and temp stability. I was thinking of ways to keep shells temp consistent. Easiest one might be to sight the rifle in with shells that have been kept in a shirt pocket under a jacket. Then when a guy is hunting, keep the shells you intend to shoot at longer ranges in your shirt pocket. You could still keep a shell in the chamber and magazine for closer shots as small changes in velocity with this powder wouldn't be an issue out to 400 yards or more. I'm impressed with the groups I'm getting with RL26 in one of my 300 RUMS.

 

[reeldawg]

I live in NE Florida. I have tried RL26 in a 7WSM, 6.5 Sherman and a 280 AI. From what I have experienced it appears that loads near the upper end are tempremental. I developed a load in my 6.5 Sherman in August. I shot the same load a month later, it was actually a little cooler, it blew primers. I was doing load development for my 7 WSM. I found a good load that was near the max load, with no pressure signs. Shot the same load the next week, it had stiff bolt lift. The temrature was in the 50s both days. The velocity increase is amazing with RL26. I had a pretty similar experience with a 280 AI. In all the rifles I had been using H-1000 and Retumbo.

Jay

 

[jgal72]

Same here in 280 AI. worked up load with no pressure signs. Two months later in colder weather I started getting stiff bolt lift.

 

[Engineering101]

Saw this on another thread about stiff bolt lift in colder weather and I'll mention the same thing I said there. When it gets cold you fire up your house heating system which drops humidity in your house. That seeps into your powder - even loaded rounds = and dries it out and the burn rate goes up. I've seen it with RL-26 and Retumbo.

 

[reeldawg]

My heater has hardly been on so far this winter. My AC has been running most of our winter.

Jay

 

[Engineering101]

AC will also DROP humidity. I mention this just in case it is the problem. Could be something else. Just check it off the list of possible causes.

 

[Engineering101]

Here is a better explanation.

TECH TIP: Humidity Can Change Powder Burn Rates « Daily Bulletin

 

[reeldawg]

That's interesting. I don't see the swings with H1000 or Retumbo as I do the RL-26. I do get some amazing velocities with it. I am working with a load for my 7WSM that's below Alliants max that's sending 180 VLDs @ 3040 fps. The other load was with 168s was around 3250. This was near the max load. The first time I shot it it,no presssure signs. A week later, pretty much same weather, stiff bolt and cratered primers. I didn't believe the speeds, checked it with another magnetospeed.

Jay

 

[Engineering101]

reeldawg

The obvious conclusion is the burn rate of your powder changed. Doesn't mean that is the case but it is the simple answer as in KISS. So then you gotta ask "How could that happen?" What changed? Maybe you mixed up two different powder lots. Maybe it was warmer. Or maybe the moisture content in the powder changed. Up to you to figure that out. Another possibility is your load was right at the edge of doing what it did this week last week and a very small change in something pushed it over the edge like you were firing the rounds faster so the chamber was warmer. Sound like whatever the cause you are going to have to back down on the load.