RL15 vs Varget weight charge differences

[FTRinTexas]

Have you found that RL15 and Varget powders are exact interchangeable? Therefore, if using Lapua brass with 45.4g of RL15 and 155 Scenar, to keep same velocity of 2900fps, would the charge at 45.4g of Varget do it?

Have been told by several shooters recently that they are interchangeable, but will test it after the holidays with a chrony to verify in my rifle. Looking for real life same day comparisons. Thanks.

 

[Heavies]

Have you found that RL15 and Varget powders are exact interchangeable? Therefore, if using Lapua brass with 45.4g of RL15 and 155 Scenar, to keep same velocity of 2900fps, would the charge at 45.4g of Varget do it?

Have been told by several shooters recently that they are interchangeable, but will test it after the holidays with a chrony to verify in my rifle. Looking for real life same day comparisons. Thanks.

No, I dont think so. Maybe with the lot to lot swings of Varget, they may have had some that mimicked RL15. I found RL-15 to create less pressure than Varget, thus able to reach higher velocities.
If you shove the amount of Varget in the case to get RL-15 speeds bad things may happen.

I would never interchange different powder recipes.

Start low and work up, for safeties sake, don't take short cuts... IMHO

 

[Mudcat]

I would never just use powders interchangably....and, I dont think these match up, btw. Good way to blow you gun up, and maybe you.

 

[Preacher]

No one should even think about trying that idea, it's just not worth the risk you'll be taking..
Drop down low and work up like its supposed to be..

 

[Redhighpower]

In my .223 I found that R-15 is hotter than Varget. I use 24 gr of R-15 on all my across the course bullets or .25 gr of Varget on all my across the course bullets. My across bullets are 69s,77s, and 80grain SMKs. In both cases my velocities are about equall.

 

[alf]

In my .223 I found that R-15 is hotter than Varget. I use 24 gr of R-15 on all my across the course bullets or .25 gr of Varget on all my across the course bullets. In both cases my velocities are about equal.

I found the same thing in my lots of R-15 vs Varget in my 6 Dashers.

My 15 is about a grain hotter than my Varget.

I do new load work ups with a new lots of the same powder. To try and substitute the same charge of a different powder violates all reloading procedures.

 

[shooter63]

i use 32.5gr of rl15 versus 33.2grof varget with same bullet & primer this is the difference in my brx & difference in powder i have but always start low like everyone says & work up each gun being different also powder lots and a world of other stuff regards shooter63.

 

[Laurie]

In 223 with heavy bullets (80gn and up) and in .308W, I've always found Re15 to be slightly slower burning - in .223 I'd normally end up using 0.4 or 0.5gn higher charges on weights between 24 and 25gn.

As others have said, you simply MUST NOT assume any interchangeability between powders, and relative burning rates can change according to the cartridge's case capacity / charge size v bore and bullet weight. That's one reason why powder manufacturers always stress never to use burning rate charts as a guide to charge weights through load substitution or interpolation.

Since you're currently using the marginally slower burning of the pair, you'll have to drop down to a lower level - at least 1.0gn lower - than your original Re15 starting (not current) load and work up from there with VarGet. As others have noted, both powders can vary noticeably between lots and that makes any attempted substitution even more risky