H4350 vs RL16- Some Charts on Temp Stability

spife7980

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So I went out and did a little temperature testing this past Memorial Day. I was shooting a 24" Criterion 6XC with 105 RDFs .020" off the lands in 4x fired Norma brass. My H4350 load is 39.4 gr and my RL 16 load is 39.8 gr. The H4350 has a grain or so of wiggle room before any pressure signs, the RL16 loads are only a couple tenths off of heavy bolt lift. Both make nice little clusters though.



Anyways, I used a magneato speed v3 and little small infrared pocket thermometer for the temps, its not nasa quality but if can detect the relative difference in ice and fire.
I put 5 rounds of each powder in a ziploc and buried them in an ice chest before I went out. Then once out at the bench I left my ammo box in the shade and I put 5 rounds of both powders on the metal bumper in the sun to get them hot. Measured the temps were 35, 86 & 120.

With the MSv3 strapped on I ran a few sighters to warm up the barrel and put me on the 500 yard plate so I wasnt just putting them into the dirt. I shot slow and ran a chamber chiller between series to try and keep barrel heat out of the equation. It is starting to get hot enough here in TX that barrels get hot quick and stay there.

I started with the ambient temp rounds and actually shot 6 of each instead of 5 like the other temps just because I was sitting there and felt like it. Then I shot the cold rounds, then I shot the hot rounds so as to allow them to get as warm as they could get, took a couple hours all together.

Anyways, heres the charts
1527778350877.png

1527778362167.png

1527779052631.png



Soooo it looks like the RL16 really is more temp stable, at least in my situation.
 
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spife7980

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Great test, but dang you got some ugly SD's!
Ehh, not really. It could be because they have set there for awhile and maybe a neck weld issue? But Im going to guess that my carbon ring is coming back. Take 1 out of each series and they come back much nicer and that 1 is always a higher jump, presumably because the ring is pushing pressures.
But I dont really care as its good enough for my steel at 1k so I could honestly care less what the statistic numbers say. Im not missing over or under so I trust the target more.
 
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lash

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That's a nice little test. As you said, it's at least indicative of how those powders will act for that rifle and load. It also gives me the idea that RL16 might be worth a try. Thanks.
 
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rduckwor

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Interesting that the RL16 SD decreased steadily with increasing ammo temp.

Thanks for the info.

RMD
 

spife7980

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Interesting that the RL16 SD decreased steadily with increasing ammo temp.

Thanks for the info.

RMD
Yes but if you remove the one shot that spiked to 3102 in the RL16 35 degree the SD comes back down to 6.4. Dont put too much emphasis on these small sample size numbers, just the general trend.
 
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shoot4fun

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Maybe even more importantly than the relatively small difference in temp sensitivity between H4350 and RL16 is that I find (one the 6.5 & ^ Creedmoor tests I did) that RL16 showed a much wider accuracy node when fired on a 300 yard ladder test. It was especially true with the 6 Creedmoor.
 
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Gilly

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Cool test, thank you.

Really the only thing left to answer about R16 is lot to lot consistency. I have large quantities of h4350 and R16 and based on my testing, 16 is just a better powder for creedmoor and .260.
Have been wondering about RL-16 in my 260 with 130 OTM if it would be better suited than H4350? Care to share velocity comparison? Was worried I’d run out of case capacity with rl16. I’m at 2910 with 45 grains 4350 in a 21” Barrel lapua brass.
 

Supersubes

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Have been wondering about RL-16 in my 260 with 130 OTM if it would be better suited than H4350? Care to share velocity comparison? Was worried I’d run out of case capacity with rl16. I’m at 2910 with 45 grains 4350 in a 21” Barrel lapua brass.
I shoot 140 and 147 in mine. It does have worse bulk density than h4350, but I think it’s more compressible as well. The kernel shape is irregular. They're cut to length at an angle, and many have a burr on them. Really ugly powder actually LOL. I guess looks aren’t everything...

In my experience you’ll match your current velocity with .5-.7 more 16, with a tick less pressure. I can’t recall a single reference here to someone going slower with it. Most seem to be reporting r17 like increases. It seems to play nice with H4350 as well. During my testing I was switching back and forth between powders, without cleaning, and I couldn’t detect any difference on target or the Labradar. Not hugely important, but one less thing to worry about.
 

JOE62

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I have to agree with the wider node statement. I’ve been developing a load for one of my rifles with RX 16 and it has worked great so far. I’m waiting for delivery of some Berger 140 Hybrids to do my OCW with. I loaded 41.0 grns with Sierra 142 SMK and it shot very well. I wanted to try some more but I ran out of bullets. Very good information on the temp stability. Thanks
 

Culpeper

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Spice, do you need another set if calculations with a baseline, weighted averages, and then percentages to show temp sensitivity? It averages out to .5% H4350 and .8% RL16 for ballistic app purposes. They are in the same burn rate band and I bet you will get different results each time you try your experiment but the differences will be immaterial. I normally cut the burn rate in half for app purposes. Just one of those things that don't add up to dry shit like wind calcs vs actual dope.
 
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Rockhurr

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So heres is a dumb ass question... if powders have same burn rate, they produce same pressure and pressure is what produces speed? So then how can one powder with less pressure produce the same or more speed or Does it?
 
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Supersubes

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So heres is a dumb ass question... if powders have same burn rate, they produce same pressure and pressure is what produces speed? So then how can one powder with less pressure produce the same or more speed or Does it?

Think of the differences in the average pressure between the two. Then consider how stuff burns, and what’s happening to the the combustion chamber (it’s growing quickly).

The one with the highest average pressure will produce more velocity, even if they peak the same. In a perfect world, we’d have a powder that would spike straight to 55k psi, and hold that pressure till the bullet left the barrel. Reality is way different. The lions share of the work is done early, including the peak pressure, which then trails off quickly.


Random pressure trace pulled off the net. This isn’t comparing powders, just showing how short the peak durations are.

3CD0BD23-B289-4D40-9893-079C1F63DC7D.gif
 
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shoot4fun

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So heres is a dumb ass question... if powders have same burn rate, they produce same pressure and pressure is what produces speed? So then how can one powder with less pressure produce the same or more speed or Does it?
This is why finding a published burn rate chart is getting more difficult. "Same" burn rate is a serious misnomer. Powders may be in the same burn rate but do not burn the same. Alliant 2000-MR, H4350 and RL16 are all in the "same" burn rate but all have different (some very different) pressure curves. I found a simple switch from H4350 to RL16 (same charges) gave me a much wider accuracy node and smaller SD. That is a win-win. I am not a Chemist nor a Physicist and can't answer to the "how did they do that" question but talk to one of the guys at Hodgdon or Alliant and they will dazzle you.
 

918v

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Because pressure dies not produce speed. Kinetic Energy produces speed. The release of energy through combustion propels the bullet. Some powders produce more energy at the same pressure level.
 
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918v

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Question:

One load is maxed out. The other is not. Is it possible that H4350 can be temp insensitive at a higher pressure. Can RE16 be temp sensitive at a lower pressure simply by virtue of change in efficiency?
 

Rockhurr

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Think of the differences in the average pressure between the two. Then consider how stuff burns, and what’s happening to the the combustion chamber (it’s growing quickly).

The one with the highest average pressure will produce more velocity, even if they peak the same. In a perfect world, we’d have a powder that would spike straight to 55k psi, and hold that pressure till the bullet left the barrel. Reality is way different. The lions share of the work is done early, including the peak pressure, which then trails off quickly.
Thanks! But is what you just
Because pressure dies not produce speed. Kinetic Energy produces speed. The release of energy through combustion propels the bullet. Some powders produce more energy at the same pressure level.

Why do powder manufacturers only show pressure curves and not energy curve? And why relate burn rate between powder and not energy rate?
 

DDRH65CM

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Is it possible that the Alliant powders create speed based on heat? Seems like it's less pressure but the barrel gets hotter than say H4350 (when using RL16)
 

spife7980

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"Heat" isnt really a factor, more of a by product of the chemical make up of the particular powder and the conditions it experiences when burning.

Alliant Reloader powders are double based which means it has a bit of nitroglycerin in them in addition to nitrocellulose vs the single based which only have the nitrocellulose. That nitroglycerin gives them a bit more (as well as different) energy when burned.
Its why I could get the same speeds as H4350 with half a grain or so less RL16 even though they are basically the same on the "burn rate" scale.

There is a variable scale where the different chemicals burn in different ways and at different times, different factors effect how those variables lay together. To create a burn chart properly you would need more than a 2 axis graph to properly display it which I figure is why the powder companies dont bother doing it anymore.
 
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Rockhurr

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Is it possible that the Alliant powders create speed based on heat? Seems like it's less pressure but the barrel gets hotter than say H4350 (when using RL16)
I also noticed that R16 kicks a bit harder too. Anyone noticed that?
 

918v

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Thanks! But is what you just



Why do powder manufacturers only show pressure curves and not energy curve? And why relate burn rate between powder and not energy rate?
Look around. Do you think an average hand loader would benefit? Have you seen the parameters you can manipulate in QL? You want manufacturers to print all that shit?
 
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Rockhurr

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I would, next to pressure..i mean if energy release is what drives a bullet I would see every benefit to show it. Pressure is just for safety purpose in this case.
 

pitdog85

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I switched from H4350 to RL 16 in my 6.5x47L a while back. I also believe its is superior overall SD, ES, velocity and case fill. It does seem to heat the barrel up a fair bit though. I ran a string through 47 shots in the summer sun and the barrel was still hot 45 mins later after driving home.
 

MangoFett

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Have been wondering about RL-16 in my 260 with 130 OTM if it would be better suited than H4350? Care to share velocity comparison? Was worried I’d run out of case capacity with rl16. I’m at 2910 with 45 grains 4350 in a 21” Barrel lapua brass.
I shot rl16 and 130's in a 260 for two years, pm me if you want graph comparisons or info
 

akh223

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It's interesting that the best SD's are at the highest temp. Do you think that is due to a more complete combustion at the higher temp?

If you had a load that was much lower in pressure, do you think the same test would show the best SD at the highest temp again?
 

Cascade Hemi

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What I noticed is that the high temp strings have closely clustered velocities. I wonder if there was heat soaking in the two lower temp strings that unevenly heated the cartridges due to shooting cold ammo below, or close to, ambient air temperature?
 

Milo 2.5

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What I noticed is that the high temp strings have closely clustered velocities. I wonder if there was heat soaking in the two lower temp strings that unevenly heated the cartridges due to shooting cold ammo below, or close to, ambient air temperature?
I would usually give the nod to spife conducting a test, and not saying he didn't. But if you plan on testing RL 16 over a series of temps, your barrel had better be in the same condition each time. Like clean, fire 5 foulers, then test. 16 lays down a layer of hard carbon in the first 5-6" of a barrel like no other.
If you test one temp 40 rds after a cleaning, then another with 250rds down the tube, your numbers are not realistic.
 

Cascade Hemi

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I would usually give the nod to spife conducting a test, and not saying he didn't. But if you plan on testing RL 16 over a series of temps, your barrel had better be in the same condition each time. Like clean, fire 5 foulers, then test. 16 lays down a layer of hard carbon in the first 5-6" of a barrel like no other.
If you test one temp 40 rds after a cleaning, then another with 250rds down the tube, your numbers are not realistic.
I appreciate the work. I suspect the lower temperature velocities are actually a little lower if you remove the high outliers. The original post is probably still indicative of the actual change someone would see.
 

Milo 2.5

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I appreciate the work. I suspect the lower temperature velocities are actually a little lower if you remove the high outliers. The original post is probably still indicative of the actual change someone would see.
I agree to some extent. I had some issues with my first Dasher, shooting RL 16, I switched to varget to up my pressure. It did not solve the problem, shot great, so returning to 16 with a diff lot of powder, my speeds were 2910 with a 110. I cleaned the barrel and it dropped to 2890, still tight numbers and accuracy.
My point was, there are things that skew test results.
 

flyright

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RL 16 is the only powder I've used that formed a thick carbon ring in less than 50 rounds in one of my 6.5 CM's. I cleaned it and went back to H4350 and no problems with a carbon ring in 300 rounds. I've got about 3lbs of the remaining RL 16 and I'm hesitant to try it again.

I used the RL17 back when H4350 was hard to get and got great velocity and accuracy with no carbon issues. I also never had any huge velocity swings when using it in 30-90 degree temps. Just FYI.
 

abn31c

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I've burned lots of 16, love the stuff but I use h4350 now (again) because of the carbon issue.
 

tcamel4

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I know this is old, but wanted to ask if you 16 shooters are just cleaning more often to avoid the carbon? I have absolutely loved 16 in my 6.5 creedmoor and I run a suppressor. I run some wet patches through every couple hundred rounds and haven't had any trouble....

carbon causing problems for others?
 

Rockhurr

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Few of you guys mentioned carbon ring forming using R16. Is that the carbon buildup on the case neck you guys are talking about? If so, i have that same problem with h4350 too. A friend told me that if you trim your case neck too short you create a bigger gap for blowback into the neck causing the buildup... is that also a cause?
 

spife7980

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Few of you guys mentioned carbon ring forming using R16. Is that the carbon buildup on the case neck you guys are talking about? If so, i have that same problem with h4350 too. A friend told me that if you trim your case neck too short you create a bigger gap for blowback into the neck causing the buildup... is that also a cause?
No, a carbon ring is build up ahead of the case neck in the throat of the rifle where it will intrude into what should be the bullets space.

Stole this from google
1571413876450.png
 
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Milo 2.5

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Few of you guys mentioned carbon ring forming using R16. Is that the carbon buildup on the case neck you guys are talking about? If so, i have that same problem with h4350 too. A friend told me that if you trim your case neck too short you create a bigger gap for blowback into the neck causing the buildup... is that also a cause?
I am not going to re-read, but I think hard carbon being laid down in the first 6" of the barrel is more of an issue than carbon ring with RL 16.
I have a Hawkeye borescope, never have I seen a ring in the bore, see buildup where neck ends in the chamber, which is what I call a carbon ring. Carbon rings are amplified by incomplete burns of powder.
 
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Rockhurr

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Wow... thanks guys. But sounds more like the ring is basically just carbon build up in the barrel.
 

Rockhurr

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Aside from this carbon buildup... Everytime i clean my barrel i use Montana Extreme bore solvent first to clean the barrel. Is this stuff supposed to clean out the carbon or what do you guys recommend for carbon cleanup? Then once the patches cone out clean, i use Montana Extreme Copper Killer to rid the copper buildup... However, everytime I pass a new soaked patch with this stuff on it it comes out black. It doesnt matter how many times i clean it it comes out black....what the heck is this stuff ad why it never stops coming out black? I even removed my MB before cleaning and it still does that. Need help!
 

abn31c

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Aside from this carbon buildup... Everytime i clean my barrel i use Montana Extreme bore solvent first to clean the barrel. Is this stuff supposed to clean out the carbon or what do you guys recommend for carbon cleanup? Then once the patches cone out clean, i use Montana Extreme Copper Killer to rid the copper buildup... However, everytime I pass a new soaked patch with this stuff on it it comes out black. It doesnt matter how many times i clean it it comes out black....what the heck is this stuff ad why it never stops coming out black? I even removed my MB before cleaning and it still does that. Need help!
Keep cleaning. 16 is great stuff, but lays hard carbon like no other. I use it for my hunting load, not for match use for me.
 
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Supersubes

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Aside from this carbon buildup... Everytime i clean my barrel i use Montana Extreme bore solvent first to clean the barrel. Is this stuff supposed to clean out the carbon or what do you guys recommend for carbon cleanup? Then once the patches cone out clean, i use Montana Extreme Copper Killer to rid the copper buildup... However, everytime I pass a new soaked patch with this stuff on it it comes out black. It doesnt matter how many times i clean it it comes out black....what the heck is this stuff ad why it never stops coming out black? I even removed my MB before cleaning and it still does that. Need help!
Use a brush first, let it soak for a minute, then patch out. I use bore tech eliminator for everything.
 
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Steel head

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I know this is old, but wanted to ask if you 16 shooters are just cleaning more often to avoid the carbon? I have absolutely loved 16 in my 6.5 creedmoor and I run a suppressor. I run some wet patches through every couple hundred rounds and haven't had any trouble....

carbon causing problems for others?
So far I’m cleaning it about the same as I did for H4350 or IMR4451.
Right now it’s been about 325 rounds since last cleaning.
I haven’t had any issues.
I’m thoroughly a fan of R16 for my 260.
Easy speed with less powder.
Excellent accuracy and SD.
Good temp stability and lots of headroom if I wanted to go faster.
 
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Milo 2.5

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Aside from this carbon buildup... Everytime i clean my barrel i use Montana Extreme bore solvent first to clean the barrel. Is this stuff supposed to clean out the carbon or what do you guys recommend for carbon cleanup? Then once the patches cone out clean, i use Montana Extreme Copper Killer to rid the copper buildup... However, everytime I pass a new soaked patch with this stuff on it it comes out black. It doesnt matter how many times i clean it it comes out black....what the heck is this stuff ad why it never stops coming out black? I even removed my MB before cleaning and it still does that. Need help!
Get some boretech C4 or gunslick foam, need a brush with foam though.
The more range trips you make and not clean 16 from barrel, harder it gets to get out.