Reloader 15.5

[Burt Gummer]

Hey Folks,

    I don’t recall seeing any of this powder around yet since our betters over there in D.C. want supply shortages and non stop inflation to be the way we Build Back Better but I’m hoping someday I’ll have the privilege of finding some. Anyone work up a load with this yet? What velocities are you seeing and is it as temperature stable as they claim? Thanks for reading.

[Lemonaid]

JRB has a vid where he tests out RL 15.5 and 6 arc.
https://www.youtube.com/watch?v=-p6_Aqe0WdE

[grayfox]

Folks in DC, hmmm. O yeah! you mean the build back broke-r!!

[Burt Gummer]

Visited my local reloading shop today and what do you know? RL 15.5 IN STOCK! I picked up one pound of it to give it a try. I’d really appreciate opinions from anyone that has an educated guess on where to start with this powder using 108 gr and up bullets. I’ll be starting 2-3 grains lower than the 6.5 grendel load data shows if I can’t get any opinions on here and will post my findings as soon as I get a chance to head to the range. Have a Happy Turkey Day!

[Newmexican]

Eager to read your report, Burt. Wonder just how much slower burning 15.5 is compared to 15.

[trianglevelvet]

I'm interested in this powder for ARC as well. I've got some.
JRB's one test seemed to indicate that RL15.5 is too fast burning for most arc loads.
I'm hoping maybe his result was a fluke.
It seems like it SHOULD be in the correct burn rate area for ARC.
So far I've been sitting on my RL15.5 since it's too bulky for 556 loads in 77gr.
The web site natoreloading seems to think it's a great powder for another cartridge that starts with a V.

I'm trying to find a good powder to get decent velocity with 107gr SMKs and 103 ELDXs that's temp stable.
I'm wondering if StaBall might be the ticket.

Any test data anyone has for temp stable powders in the heavier ARC loads would be valuable.
Please post if you've done tests.

[Burt Gummer]

Okay folks. I will assume at this point I’m not going to get any recommendations on charge weights. Most likely because I couldn’t wait any longer and couldn’t stop my press from turning out 60 rounds. I couldn’t resist going to the range tomorrow with 57 degree temperatures. That’s a good day right now in MO.

   I put together two separate batches with the following recipes:

1. Hornday Fired and F/l sized brass, various 26.6-28.2gr powder weights, BR-4 primer, and Barnes 112 gr Matchburner.

2. Starline 6.5 Grendel re-sized with F/L die to 6ARC previously fired, various 26.6-28.2gr powder weights, Winchester #41 primers, and Barnes 112 gr Matchburners. 

   Just going to see where the pressure signed start showing and get velocity data tomorrow. I will be calculating off of three shots for each different powder weight. I’ll report back soon.

[Burt Gummer]

I should’ve mentioned as well that I am doing my best to take a somewhat safe educated guess at this. I watched the video in the above link to get a feel for what worked for Johnny. I combed the web and also found some QuickLoad data and used some common sense as to whatever “falls between RL15 and RL16” on the burn rate chart according Alliant means from their advertisement. Judging by Johnny’s results I think he put it best as it probably more like a RL 15.2. My theory is that it’s going to burn closer to Varget and Winchester 748 which is hardly the middle ground between RL15 and 16 and where Leverolution is found. This however is why I’m interested. For me Win 748 is thus far the most preferred powder for my Criterion barrel. The rumored outstanding temperature stability is maybe even a bigger reason to try it out. That’s one area the W748 is falling short. To be clear this is an 18” gas gun doing the work. I believe the high 27 and especially the 28.2 gr loads to be way over pressure but just want to confirm for myself since each rifle is slightly different.

[Burt Gummer]

It was a good day at the range yesterday. All testing was completed and I still had time to ring some steal and print a 5 shot group at 600 yards with my normal loads using 112 gr Matchburners over 27.1 gr of Win748 powder. The results were strong enough for RL15.5 that it will definitely warrant more thorough testing to see how accurate I can make it in my rifle. Anyways, I’ll get to the good part, the data! To save typing I’m just going to provide the best performers as follows based on three shot groups at a mild 52 degrees:

Hornady 6ARC brass/BR4 Primers
27.1 gr = Avg 2445 fps, ES = 11, SD = 3.5
27.4 gr =        2469 fps,        19,          5
27.6 gr =        2496 fps,        19,          5.5
27.8 gr =        2505 fps,        16,          5
28    gr =        2522 fps,        18,          5
28.2 gr =        2544 fps,        13,          4

Starline 6.5 Grend. brass resized and Winchester 41 primers
27.1 gr = Avg 2460 fps, ES = 18, SD = 5
27.2 gr =       2475 fps,         22,          6
27.8 gr =       2518 fps,         13,          3
28    gr =       2537 fps,         16,          4
28.2 gr =       2555 fps,         17,          4.5

The groups were shot at 300 yards and seemed to back up the numbers above. My best group was with the Starline brass and 27.8 grains. It hammered out a .24 MOA group at 300 yards. It seems like it likes the 27.8-28.2 range and all of those groups were around .5-.75 MOA. This should be a very useful powder if more testing keeps backing up this data.

 The next range trip will be doing 5 shot groups as well as putting Win 748 head to head with it. It’s not unusual for me to get .5 MOA accuracy using 27.1 grains and the Barnes bullets. I’m really excited for the potential of RL15.5 seeing that it appears to be offering some accurate loads that are also about 50 fps faster than W748 and did I mention TEMPERATURE STABLE! At this point it’s all coming down to ES and SD’s and I think I’ll be settling down on one of these two powders. 

In the prior post of mine above I stated that the 28.2 gr would most definitely be at or over max. I’m going to walk that back slightly. With no official load data for 15.5 yet it’s really anybodies guess as to where the max truly is but here’s what changed my mind. Based off of the load data at the bottom of the page in this link https://www.handloadermagazine.com/6mm-arc where it has a max charge for Reloader 15 of 27.5 with 110 gr A Tips as well as published Lyman data that I was provided at my local reloading store saying max charge for RL15 is 28.2 using 107 gr bullets. Surely if you can use 27.5-28.2 of RL15 than the slower burning 15.5 should be safe in those ranges as well. 

I should mention that when working up the reported loads I wanted to see how much 15.5 would simply fit in the case. It’s a very bulky stick powder which is it’s downside for this tiny cartridge. I couldn’t get much more than 29 gr in before it topped off the opening. I’m going to push a load up to 28.4-.6 and see what happens. They’ll be getting heavily compressed at that point but NONE of the rounds tested so far have shown high pressure signs.

[StoneHendge]

OP, how long is your barrel?

[Burt Gummer]

OP, how long is your barrel?

Compass Lake Engineering 18” Criterion with JP Enhanced Bolt

[StoneHendge]

OP, how long is your barrel?

Compass Lake Engineering 18” Criterion with JP Enhanced Bolt

Thanks! That's quite a bit better than what I was getting with Varget (105s at 2450 out of a 16: Lilja near max). 

Have you tried using a drop tube to put powder in the case? It makes a significant volume difference for me for putting both Varget and Shooters World Precision in Grendel and ARC cases.

[Burt Gummer]

OP, how long is your barrel?

Compass Lake Engineering 18” Criterion with JP Enhanced Bolt

Thanks! That's quite a bit better than what I was getting with Varget (105s at 2450 out of a 16: Lilja near max). 

Have you tried using a drop tube to put powder in the case? It makes a significant volume difference for me for putting both Varget and Shooters World Precision in Grendel and ARC cases.

Interesting. That’s better velocity out of Varget than I would’ve guessed. With my barrel being two inches longer you would think 2500 fps is achievable with it.

Anyways, I’m happy with the results and potential so far with RL15.5 and just the loads I’ve made but will still see what you can get with up 28.6 gr. I won’t push it more unless load data gets published for it and allows for it. For what I’m using it for anywhere in the 2500’s with temperature stability will do the job just fine. Mainly a steel plinker for long range. 

I am curious about the drop tubes however. I didn’t know they were used for that. I’ve been using the Frankford Arsenal metal funnels with sized necks for each caliber that then rest on the shoulder of the case as you drop it in. Do the drop tubes do a better job at filling the case than this method?

[StoneHendge]

Burt, a drop tube does drop denser charges. For whatever reason, when the kernels fall down the tube, they land and stack more compactly. I have a 5" tube I paid under 10 bucks for. I just taped it to a universal funnel and then it has a universal end to meet the case mouth. I'd take a picture, but I don't currently have access to it. I'll dare say that using it also gave me a slight velocity increase and slightly better sd's (Shooters World Precision in 6.5 G with 123s and Varget in ARC). Not nearly large enough of a statistical sample to say its true, but it makes sense with a more consistent packing and hence burning of powder through the case.

Someone does sell a funnel / tube combo with this use in mind. I think its Frankford, but my Google Fu is weak tonight.

[Newmexican]

Burt, you are doing some wonderful work. Appreciate you sharing your results.

[Old Bob]

Frankford Arsenal has a funnel set with 8 different nozzles for different cartridges but they don't have drop tubes for them.

https://www.frankfordarsenal.com/reloadi...and-tools/

Area 419 also has a funnel set with 6 different nozzles & they do have drop tube sections you can buy to make a drop tube any length you want. They aren't cheap though. Brownells has them ...

https://www.brownells.com/reloading/powd...xTimeEvent

I first used a drop tube when I was loading 1F blackpowder in my 45-70 cases. Makes big difference when loading coarse grained powders.

[Burt Gummer]

Burt, a drop tube does drop denser charges. For whatever reason, when the kernels fall down the tube, they land and stack more compactly.  I have a 5" tube I paid under 10 bucks for.  I just taped it to a universal funnel and then it has a universal end to meet the case mouth. I'd take a picture, but I don't currently have access to it. I'll dare say that using it also gave me a slight velocity increase and slightly better sd's (Shooters World Precision in 6.5 G with 123s and Varget in ARC). Not nearly large enough of a statistical sample to say its true, but it makes sense with a more consistent packing and hence burning of powder through the case.

Someone does sell a funnel / tube combo with this use in mind. I think its Frankford, but my Google Fu is weak tonight.

My reloading knowledge is expanding. I’m new to it and on top of it have only worked with the LEVR and CFE223 disc shaped powders until now. Thanks for explaining the theory for extruded powders. I’m open to trying one out. We’ll see what cheap option I can come up with at the hardware store. Thinking 1/4” acrylic pipe with a funnel and duct tape just to give it a whirl and see. Does it need to be any certain height to work properly?

[Burt Gummer]

Burt, you are doing some wonderful work. Appreciate you sharing your results.

My pleasure sir! No one ever has to thank me for taking time to head to a gun range! I was hoping I would be dialing in one or two different powders like Win748 and LVR so that I had a hot and cold weather load but with the new discovery of 15.5 it seemed silly not to rule it out before going through all the other work. I should be able to really run it through the ringer now as well since I picked up another pound of it today. If only one powder worked in my rifle I hope it’s this one. I’ll be posting plenty of range results.

---

Frankford Arsenal has a funnel set with 8 different nozzles for different cartridges but they don't have drop tubes for them.

https://www.frankfordarsenal.com/reloadi...and-tools/

Area 419 also has a funnel set with 6 different nozzles & they do have drop tube sections you can buy to make a drop tube any length you want. They aren't cheap though. Brownells has them ...

https://www.brownells.com/reloading/powd...xTimeEvent

I first used a drop tube when I was loading 1F blackpowder in my 45-70 cases.  Makes big difference when loading coarse grained powders.

Thanks for the links and your experience using them. I actually have the funnel kit shown on the Frankford Arsenal page. I’ll admit they’re only about 1-1.5” in height so probably don’t get the drop tube effect from them. I’ll put a cheap test together before investing any substantial money in it.

[Old Bob]

Burt, a drop tube does drop denser charges. For whatever reason, when the kernels fall down the tube, they land and stack more compactly.  I have a 5" tube I paid under 10 bucks for.  I just taped it to a universal funnel and then it has a universal end to meet the case mouth. I'd take a picture, but I don't currently have access to it. I'll dare say that using it also gave me a slight velocity increase and slightly better sd's (Shooters World Precision in 6.5 G with 123s and Varget in ARC). Not nearly large enough of a statistical sample to say its true, but it makes sense with a more consistent packing and hence burning of powder through the case.

Someone does sell a funnel / tube combo with this use in mind. I think its Frankford, but my Google Fu is weak tonight.

My reloading knowledge is expanding. I’m new to it and on top of it have only worked with the LEVR and CFE223 disc shaped powders until now. Thanks for explaining the theory for extruded powders. I’m open to trying one out. We’ll see what cheap option I can come up with at the hardware store. Thinking 1/4” acrylic pipe with a funnel and duct tape just to give it a whirl and see. Does it need to be any certain height to work properly?

Since I was dealing with black powder, I needed to stay away from anything that might generate static electricity, so my drop tubes are made from brass tubing I got at a hobby shop. Acrylic piping should be OK with smokeless powder. Powder measure reservoirs are acrylic ... I think. The tube I use for black powder is 15". Another tube I use for large kernel smokeless powder is 12".  I tried a 20" tube but found it didn't compress the powder column any more than the 15" tube. The brass tubes are 3/8" dia.

[StoneHendge]

Burt, this is the 5" tube I'm using: https://www.brunoshooters.com/mm5/mercha...Code=15507

It doesn't give any details but was made for a benchtop powder dispenser they no longer offer. I stuck the top end in a universal RCBS funnel and taped it; the bottom has a slanted interior like a universal funnel, although not up to 50 cal. I bought it locally and have no idea what shipping would be.