Reloader 15 vs Reloader 15.5

[SkullKeeper]

Has anyone (yet) used 15.5 in place of 15 in heavy rifles ? I’m looking at possibly using it in 450#2, 458 African, and 404J. RL15 seems impossible for me to locate.
Thank you in advance for any input.

 

[Ruraldoc]

I used it a in 470 double. Pretty much a substitute for RL15 with more temperature stability.

Since it is slightly slower burning than RL15, you should be fine with RL15 starting loads as starting loads for your own data development.

An Alliant spokesman confirmed this with Rifle Shooter Magazine saying you can use Reloader 15 starting load data for RL 15.5.

 

[Ruraldoc]

@Rare Breed has used it in 470,I believe he has used it in 404 as well. I would contact him.

 

[SkullKeeper]

@Rare Breed has used it in 470,I believe he has used it in 404 as well. I would contact him.

Ok very good to know about your 470 loading. Thank you sir.

 

[HACT07]

I have some but have not done any work with it yet.

It is indeed too bulky for ar grendel loads.

Now in my cz bolt grendel with the longer mag length I can use it should prove to be useful. My money load for a 120 gold dot is with varget, will be interesting when I run the 15.5 with the gold dot to see what it does.

 

[SkullKeeper]

I used it a in 470 double. Pretty much a substitute for RL15 with more temperature stability.

Since it is slightly slower burning than RL15, you should be fine with RL15 starting loads as starting loads for your own data development.

An Alliant spokesman confirmed this with Rifle Shooter Magazine saying you can use Reloader 15 starting load data for RL 15.5.

That confirmation is very good news, I just hope I can locate more RL15 at some point but in the meantime I will try the 15.5
I’m curious - what is your load data for your 470 ?

 

[Ruraldoc]

My load data comes from @Rare Breed, to prevent mistakes I would contact him directly.

He has a couple of threads here where he provides his load data as well that you can search for.

 

[SkullKeeper]

My load data comes from @Rare Breed, to prevent mistakes I would contact him directly.

He has a couple of threads here where he provides his load data as well that you can search for.

Ok gotcha - thanks again !

 

[Rare Breed]

Has anyone (yet) used 15.5 in place of 15 in heavy rifles ? I’m looking at possibly using it in 450#2, 458 African, and 404J. RL15 seems impossible for me to locate.
Thank you in advance for any input.

I do for my 470 NE with fabulous results. I load 84 grains, use a Trader Keith #2 filler and get 0.6 inch regulation at 50 yards. It took both my elephant and cape buffalo this past April

 

[SkullKeeper]

I do for my 470 NE with fabulous results. I load 84 grains, use a Trader Keith #2 filler and get 0.6 inch regulation at 50 yards. It took both my elephant and cape buffalo this past April

Excellent and good to know! Curious as to how much variation in powder charge you were using with RL15 and the 84 gr of RL15.5 ?

 

[Rare Breed]

Excellent and good to know! Curious as to how much variation in powder charge you were using with RL15 and the 84 gr of RL15.5 ?

None. They are too close to matter in my experience. I can tell you that 15.5 is now my favorite powder for my 470

 

[Wahoo]

What velocity are you getting out of that load?

 

[Rare Breed]

2175 FPS

 

[Rare Breed]

I have a 24 inch barrel on my 470 BE Rigby

 

[Wahoo]

Interesting. I was getting 2040 with 84gr Rl 15. Dacron filler and 500gr A-frame crimped. 24” barrel Heym. Measured w Garmin.

Anecdotally- (not Rl 15 but using a diff powder)- When all other things (powder charge, bullet, brass, primer, COAL, crimp ) were equal and only variable was Dacron vs Kynoch wads the kynoch wads gave 25 fps increase in velocity. No clue what it means just providing very limited data observation.

 

[Wahoo]

Apologies @SkullKeeper. I did not mean to derail your topic.

I have only some experience with Rl 15 in .470. Zero experience with Rl 15.5 which was your original inquiry

 

[SkullKeeper]

2175 FPS

That’s excellent

 

[SkullKeeper]

Apologies @SkullKeeper. I did not mean to derail your topic.

I have only some experience with Rl 15 in .470. Zero experience with Rl 15.5 which was your original inquiry

@Wahoo no worries whatsoever! You are perfectly fine giving side observations and details. You just never know what information will be shared that we all can use sir!
And a big thanks to @Rare Breed for the testing and vital information shared about this new powder !

 

[ALbowhunter]

Varget could also be a replacement for RL-15. I was having trouble locating RL-15 for a 9.3 B&M, so I referenced a few loading tables for somewhat similar cartridges that had data for Varget and RL-15. I found the data showed equal charge weights produced similar velocity, pressure, and load density. In my testing, it took 72.7 grains of Varget to produce the same velocity as 72.5 grains of RL-15. I never made it any further in load development with the Varget, as I was able to locate RL-15 soon after.

 

[SkullKeeper]

I recently substituted RL15.5 for RL15 grain for grain and did chronograph testing. I came out with the same velocity average. The group was a bit to the right of what I expected but it could’ve been my shooting setup as it was definitely not ideal for target testing. More shooting needed to confirm POI but for now it seems RL15.5 will work.