Powder characteristics question for you gurus

[XLR308]

I have had a question floating around in my noggin for a few days that I can't seem to answer on my own. I have been reloading since the early 90's so not a total newbie.
The primary powder in question is H100V but others with the same double formulation I would assume would be relevant.
I am curious if this powder will have less of a sensitivity to temp changes if used in cases that allow a 100% case fill with no air gap in the powder colum and obviously not be running on the ragged edge of pressure but on the slower end of the spectrum for the case and bullet I am experimenting with.

 

[spife7980]

While I cant for certain answer it I see the temp as a chemical effect and the case fill as a physical so no, I dont think that physically being fuller would help with it chemically being less energetic due to temp. Two independent variables.

 

[shoot4fun]

I looked on Hodgdon's reloading website. H100V burn speed doesn't lend itself to just any cartridge case size but I did see one that might be a good test mule for your theory. Look at the new 6GT.
In my mind, even if you found the perfect correlation between case volume and H100V temp sensitivity it would be so narrow as to not have much value.
Especially considering there are powders out there that can do what you want in a broad spectrum of use.

 

[XLR308]

That's pretty much where I am at considering the property of the powders double base formulation is just more prone to velocity swings due to temp changes.
I worked up a ladder with three different powders yesterday that generally aren't listed in load data for the 6.5x47 because i have to much slack time on my hands and am bored and curious and H100V is one of them since i have a bunch of it.
Guess I will just have to let the experiment run its course and see if my temp sensitivity test for it are consistent with what others have noted in calibers it's generally listed for.
I also have ladders worked up for velocity and pressure tests with AA4064 and AR-COMP in the little Lapua case.

 

[Steel head]

Yea I played with H100V for a bit.
It can get spooky fast!
For mild plinker loads it’s not a bad powder.

 

[shoot4fun]

That's pretty much where I am at considering the property of the powders double base formulation is just more prone to velocity swings due to temp changes.
I worked up a ladder with three different powders yesterday that generally aren't listed in load data for the 6.5x47 because i have to much slack time on my hands and am bored and curious and H100V is one of them since i have a bunch of it.
Guess I will just have to let the experiment run its course and see if my temp sensitivity test for it are consistent with what others have noted in calibers it's generally listed for.
I also have ladders worked up for velocity and pressure tests with AA4064 and AR-COMP in the little Lapua case.

I found it a little odd that Hodgdon has data for H100V with the 6-47L but not the 6.5-47L. Then seeing the data for 6GT raised another flag so to speak. The volume for the -47L is same for 6 or 6.5 and only slightly less IIRC than for the 6GT.

 

[XLR308]

I looked on Hodgdon's reloading website. H100V burn speed doesn't lend itself to just any cartridge case size but I did see one that might be a good test mule for your theory. Look at the new 6GT.
In my mind, even if you found the perfect correlation between case volume and H100V temp sensitivity it would be so narrow as to not have much value.
Especially considering there are powders out there that can do what you want in a broad spectrum of use.

The lot I have seems to be a good bit faster than were it is located on the burn rate chart and seems to be much closer to H4350 burn rate. When it was introduced i bought two 8# bottles of it so it's some of the earlier lots of powder.

 

[shoot4fun]

Yea I played with H100V for a bit.
It can get spooky fast!
For mild plinker loads it’s not a bad powder.

True.
I found this phenomenon is a few powders over the years. The latest one that comes to mind is IMR8208XBRin some applications. I used it in 6BR with 107SMK way over the max recommendation and never had any issue. I tried it later in 7MM08, starting with below the max recommendation and moving above it by a little bit. None of the loads showed any signs of over pressure we tend to look for but most all that Lapua Brass was ruined.

 

[shoot4fun]

The lot I have seems to be a good bit faster than were it is located on the burn rate chart and seems to be much closer to H4350 burn rate. When it was introduced i bought two 8# bottles of it so it's some of the earlier lots of powder.

I remember during the great H4350 shortage of a few years back that several tried it as a H4350 replacement. I also, at least for the majority, it did not work out well.

 

[Steel head]

I remember during the great H4350 shortage of a few years back that several tried it as a H4350 replacement. I also, at least for the majority, it did not work out well.

Lol
I was one of those.

 

[XLR308]

True.
I found this phenomenon is a few powders over the years. The latest one that comes to mind is IMR8208XBRin some applications. I used it in 6BR with 107SMK way over the max recommendation and never had any issue. I tried it later in 7MM08, starting with below the max recommendation and moving above it by a little bit. None of the loads showed any signs of over pressure we tend to look for but most all that Lapua Brass was ruined.

I know that it has a reputation for going from mild to wild with pretty small changes in charge weight. My theory is that when used in the small 6.5x47 case and being a bit on the slow side it may behave a bit more predictable but I've had some of my theories go to hell in a hand basket before. When I test it I will have a Magneeto speed attached so if I see velocities to high for my liking at the lower charge weights will most likely stop and pull down the rest of the rounds.

 

[XLR308]

Either way good, bad or ugly I will list my results for the three powders in the 6.5x47 load data thread.
If H100V shows signs of promise I will do more testing for temp sensitivity in the x47.
I have 75 cases set aside that i use for experimenting so I'm not trashing any of the 100 count lots i normally use.

 

[ken4570tc in WY]

The 'mild to wild' characteristic is common with double based powders. At controlled pressures it performs as advertised but the nitroglycerin content will turn loose the wild side when pushed to the critical pressure level. That level is very temperature sensitive, way more than the nitrocellulose by itself. It's not safe to experiment with double base powder. I have personally seen it go from no pressure signs to explosive. Fortunately, for me it didn't blow the gun apart. It did cause the chronograph velocity to jump from 3600 fps to over 4000 fps and flash 'EEEE', since it was out the range of the instrument. Bolt lift was hard and the primer was no where to be found until I dismantled the Howa at home. I had only increased the powder charge by 0.1 grains. This was with fire formed cases and new powder that had been stored inside the house and not subjected to high heat/cold conditions.

 

[XLR308]

The 'mild to wild' characteristic is common with double based powders. At controlled pressures it performs as advertised but the nitroglycerin content will turn loose the wild side when pushed to the critical pressure level. That level is very temperature sensitive, way more than the nitrocellulose by itself. It's not safe to experiment with double base powder. I have personally seen it go from no pressure signs to explosive. Fortunately, for me it didn't blow the gun apart. It did cause the chronograph velocity to jump from 3600 fps to over 4000 fps and flash 'EEEE', since it was out the range of the instrument. Bolt lift was hard and the primer was no where to be found until I dismantled the Howa at home. I had only increased the powder charge by 0.1 grains. This was with fire formed cases and new powder that had been stored inside the house and not subjected to high heat/cold conditions.

I understand the characteristics of double base powders and have used quite a few of the finicky ones over the years to include W748, RL15, BLC-2 and RL22 to name a few.
I have just read more about H100V being more temperamental although I haven't experienced any issues using it in 243win, 270win and 300wm but I haven't ever pushed it beyond what I considered its accuracy node in those calibers so never really pushed it to the top end like I would with say H1000 in those I listed.

 

[shoot4fun]

I understand the characteristics of double base powders and have used quite a few of the finicky ones over the years to include W748, RL15, BLC-2 and RL22 to name a few.
I have just read more about H100V being more temperamental although I haven't experienced any issues using it in 243win, 270win and 300wm but I haven't ever pushed it beyond what I considered its accuracy node in those calibers so never really pushed it to the top end like I would with say H1000 in those I listed.

I remember someone on here musing that Hornady had switched their 6.5 Creedmoor Match loads to H100V during the H4350 crisis and that the move was very detrimental to accuracy of that ammo. True or false? IDNK

 

[XLR308]

I remember someone on here musing that Hornady had switched their 6.5 Creedmoor Match loads to H100V during the H4350 crisis and that the move was very detrimental to accuracy of that ammo. True or false? IDNK

I also recall reading that as well but it was long before I had a 65CM, it's still a fairly new round for me.
My hopes are that it will behave a bit more predictably in the 6.5x47 giving it's smaller capacity and being a little slower burn rate similar to the way 1200R behaves in the 223 rem as opposed to the slightly larger 68spc.
It's a good powder in both but with a small increase in the 68spc case it can start trashing cases very quickly.

 

[Steel head]

I understand the characteristics of double base powders and have used quite a few of the finicky ones over the years to include W748, RL15, BLC-2 and RL22 to name a few.
I have just read more about H100V being more temperamental although I haven't experienced any issues using it in 243win, 270win and 300wm but I haven't ever pushed it beyond what I considered its accuracy node in those calibers so never really pushed it to the top end like I would with say H1000 in those I listed.

I love W748 but you have to show it some respect or it will bite you.

 

[XLR308]

I love W748 but you have to show it some respect or it will bite you.

Yes it will right in the ass when you least expect it.
I have on hand and use probably more ball powders than most around here.
They are just so damn easy to work with from a metering stand point if loading bulk ammo for plinking.

 

[Doom]

Actually, air in the cartridge is a diluent and tends to lower temperature and peak pressure, for a given charge weight, assuming that the ignition remains uniform.

Having been bitten by H335 and ruining some Lapua 223 brass when I first started reloading I tend to stay with single base less temperature sensitive powders.

 

[XLR308]

Actually, air in the cartridge is a diluent and tends to lower temperature and peak pressure, for a given charge weight, assuming that the ignition remains uniform.

Having been bitten by H335 and ruining some Lapua 223 brass when I first started reloading I tend to stay with single base less temperature sensitive powders.

This is more along the lines of conversation I was looking for considering fill % for the powder I am working with but H335 is not a slow powder for the 223rem and using it in the context of my original question isn't a good comparison.
After trying H1000 in the 6.5 Creedmoor with 147eldm which I know is to slow but it produced excellent accuracy even with a ladder that spanned several grains I have been curious to try H100V in the 6.5x47.
It is very close in burn rate to several powders that are normally listed but I can't find any info of anyone that has tried it.
I guess I just need to load everything up and head to the range this morning and give it a go.

 

[XLR308]

I went and shot part of the ladder I I had loaded up with H100V and 123CC unfortunately my battery on the MS died and the new spare I had was totally dead.
But up until that point all was looking good and the speeds were pretty decent.
No signs of pressure for the 7 rounds I shot but will have to go back out with a fresh battery and finish the string.
Rifle specs are as follows.
Kelblys Atlas Tac action
TT Special trigger set at 1.25#
Schnieder medium Palma 1-8" P5 finished at 24" With Hellfire brake
XLR Carbon chassis

New weight sorted Lapua brass
CCI-450
Nosler 123 CC
CBTO 2.103" (.020" JUMP )
H100V
1) 38.8 2749fps
2) 39.1. 2812
3) 39.4. 2808
4) 39.7. 2850
5) 40.0. 2860
6) 40.3. 2915
7) 40.6. Battery died
8) 40.9. 2952
9) 41.2 2968
10) 41.5 3012 (Zero pressure signs no restistence on opening bolt)

I also ran a ladder with AA4064 that tracked pretty close to the H100V ladder before the battery died. The velocity was pretty good atleast in my opinion and seemed to show a nice low and high node for what this barrel consistently has shown with Varget being low node at 2850fps range and high node in the 2950fps range with the 123CC.
Powder AA4064
1) 36.9 2777fps
2) 37.2 2833
3) 37.5 2855
4) 37.8 2874
5) 38.1 2907
6) 38.4 2929
7) 38.7 2957
8) 39.0 2963
9) 39.3 3007
10) 39.6 3035 ( bolt lift the same but showing slight cratering on primer )

9) 39.3 3007fps

10) 39.6 3035fps

I got out and finished with the last ladder I had today with a new battery in the MS.
It appears that AR-COMP is the powder I have been looking for to use with the 123CC.
It showed the least amount of vertical speed through the charge range even though it was the fastest burn rate but had acceptable accuracy so will give this one more attention.
New weight sorted Lapua brass
CCI-450
Nosler 123CC
AR-COMP
1) 34.7 2879fps
2) 34.9 2891
3) 35.1. 2899
4) 35.3. 2916
5) 35.5. 2932
6) 35.7 2954
7) 35.9 2955
8) 36.1 2964
9) 36.3 2968
10) 36.5 2997

 

[ken4570tc in WY]

For your AA4064 loads, I'd recommend stepping back to the 39.3. It'll give you some wiggle room when the temps get hot and your brass life will be better.

 

[XLR308]

For your AA4064 loads, I'd recommend stepping back to the 39.3. It'll give you some wiggle room when the temps get hot and your brass life will be better.

That's what I'm working on now but am going to do an OCW with the 38.7- 39.0 range in .1gr increments.
This barrel seems to like that 2950fps range and there was a nice flat spot there.

 

[XLR308]

For your AA4064 loads, I'd recommend stepping back to the 39.3. It'll give you some wiggle room when the temps get hot and your brass life will be better.

I think you might have been on the money with your assessment as the range I tried was in a scatter node regardless of velocity I just didn't want to run at the top of pressure level with a powder that isn't temp stable enough for a good cushion.
I will explore AR-COMP more and determine if that is a more viable option given its stability with temperature variation.