IMR-4064 Powder Temp Sensitive or Not ?

[D-4297]

I keep hearing from some shooters that IMR 4064 is Temp sensitive , and reading both older , and newer articles that it has been re-formulated , to improve this issue . Can't seem to get hold of any of the proper knowledgeable people to get this answered , so I would appreciate getting information on this issue .

 

[rijndael]

IME with hot summer temps, Yes.
How recently was it reformulated?

 

[D-4297]

According to the different articles I've read , published in the 80's , 90's , and after 2010 , this powder has "evolved" with three "re-formulations" since the mid to late 1950's . The last change being about 10 years ago . I understand it is still being used by the U.S. military because it was highly useable with no negative effects in various climates . So maybe "useable" to the military , with no temp issues , isn't the same as useable to precision shooters ?

 

[rijndael]

My experience with it was around the 2010 timeframe, so I don't know if it was pre or post 2010 reformulation.

 

[46and2]

I keep hearing from some shooters that IMR 4064 is Temp sensitive , and reading both older , and newer articles that it has been re-formulated , to improve this issue . Can't seem to get hold of any of the proper knowledgeable people to get this answered , so I would appreciate getting information on this issue .

While it's still cold out, shoot some cold then shoot some that has been sitting under the truck heater in the floorboard on the way to the range.
Chrono both and let us know.

 

[Mark W]

I have some hunting loads that shoot really well with IMR 4064, but I’ve never tried them in the warmer months.

 

[r bose]

IMR 4064 has always been a favorite of mine for 308 loads. Must be a reason why Federal uses it in their Gold Medal Match 168g matchking loads knowing the rounds could be shot in any conditions, anywhere.

RL-15 gets a bad rap for being temp sensitive. If it is, why would LC use it in the M118 LR 308, 175g matchking sniper round knowing the ammo could be used anywhere on the earth and has to perform well?

Temp sensitivity gets way too much attention in my opinion. Develop a safe load when the temp outside is warm. Deal with (adjust sights up) the slight velocity loss when it gets cold. IF you choose to do this backwards and start popping primers when it warms up 20 degrees outside, you're asking too much out of the case/caliber your using in the first place. A 308 isn't a 300 Win Mag

 

[K22]

Used IMR 4064 for years in the 22 250, 243, and 308 and never found it to be any more "temperature" sensitive than other "stick" powders.

The only powder that I encountered that was truly temperature sensitive meaning pressure surges in hot weather was H380 in the 22 250. I had to scale back the powder charge about 1 grain.

In my experience no matter which powder I use, some point of impact changes will occur from winter to summer. This I suspect is due to changes in air density, cooler air being more dense than hot air. The changes I experienced are about 1/2 to 3/4 inches which is insignificant for a big game hunter but can be significant for a varmint and predator hunter. I always recheck my sight in when changing seasons since I hunt all year around, varmints in the spring / summer - predators in the fall / winter.

 

[Ranger007]

According to the different articles I've read , published in the 80's , 90's , and after 2010 , this powder has "evolved" with three "re-formulations" since the mid to late 1950's . The last change being about 10 years ago . I understand it is still being used by the U.S. military because it was highly useable with no negative effects in various climates . So maybe "useable" to the military , with no temp issues , isn't the same as useable to precision shooters ?

D can I please ask what your source is for the info?

 

[Evan]

I've found IMR 4064 and 4350 to only be slightly more sensitive than "stable" powders like Varget and H4350. Across a 30 degree swing, I only come down a tenth or two of a grain to stay in tune with my 22BR - 29gns to 28.8gns to correct a 70degree load for 100 degrees.

They're much closer to stable than H380 or AA2200 which swing massively!

 

[Joseph Jones ctsr]

On the temp stability chart Varget is the best at .19fps per deg, imr4064 is .52fps per deb which is very good. In comparison rl22 is 1.54fps per deb. I use 4064 in my 308 loads, I get better velocity than Varget and don't notice much difference in stability.

 

[D-4297]

D can I please ask what your source is for the info?

If my failing memory serves , it was a article covering 4064 , it's development by Dupont originally , and the change when it was sold off to someone else , and then sold again to IMR . It was mentioned in some military data books I was reading out of boredom while at Parachute Rigger School at Ft. Lee ,Va. in early "69" . A Tech manual listing lots of Data for the Military rounds used in the M-14 . Hmmm . Which books and magazine articles did I read some 15 to 50 years ago . But if the powder hadn't been mentioned frequently , it wouldn't have stuck in my mind . Best answer I can give you .

 

[Ranger007]

If my failing memory serves , it was a article covering 4064 , it's development by Dupont originally , and the change when it was sold off to someone else , and then sold again to IMR . It was mentioned in some military data books I was reading out of boredom while at Parachute Rigger School at Ft. Lee ,Va. in early "69" . A Tech manual listing lots of Data for the Military rounds used in the M-14 . Hmmm . Which books and magazine articles did I read some 15 to 50 years ago . But if the powder hadn't been mentioned frequently , it wouldn't have stuck in my mind . Best answer I can give you .

Ah thank you sir. I asked because I thought you may have gotten some data from Propellant Profiles. I have been contemplating purchasing for awhile now because I am very curious to learn a bit more about powders.

https://www.wolfeoutdoorsports.com/propellant-profiles-6th-edition/

 

[D-4297]

Welcome . Unfortunately , I'm cursed with a near photographic memory , and can remember stuff I read decades ago , but can't remember where I read it . Including lots of technical data details . It would drive ya to drink .....Forgot , it already did . If you're shooting a .308 , 4064 is a viable powder if you can get it in your area . Varget , H-4895 , N-150 , N-140 are other options that will work . Find what your rifle likes , and feed it that powder .

 

[D-4297]

While it's still cold out, shoot some cold then shoot some that has been sitting under the truck heater in the floorboard on the way to the range.
Chrono both and let us know.

I was more concerned about the temp shifts here in Zona . It was 36 degrees this morning when the first rounds went down-range at B-A this morning , and by end of April , first week in May , it could be 110 . I do understand that all powders have a certain amount of temp sensitivity , and my question was , "Can anyone tell me if they had improved the 4064 , above what it used to be . Seventy-five degrees is a pretty good swing , after all .

 

[rijndael]

It was 36 degrees this morning when the first rounds went down-range at B-A this morning , and by end of April , first week in May , it could be 110

We also see large temp swings. 45-50F in the morning and 95-100F in the late afternoon.

 

[Evan]

I was more concerned about the temp shifts here in Zona . It was 36 degrees this morning when the first rounds went down-range at B-A this morning , and by end of April , first week in May , it could be 110 . I do understand that all powders have a certain amount of temp sensitivity , and my question was , "Can anyone tell me if they had improved the 4064 , above what it used to be . Seventy-five degrees is a pretty good swing , after all .

My last can from '92 and my bottle from '08 behave the same.

Just picking a nit, but I wouldn't expect any load with any powder, even the almighty Varget, to shoot across all seasons from winter to summer. Heck, the same load doesn't shoot across a single day, if you're really chasing the best it can do.

 

[Mike402]

Just one data point, but this is real world results for me. My hunting load in my 30/06 is 47.9gr of 4064 in Lapua Brass, Hornady 178 ELD-X, loaded to a COAL of 3.334 inches. Velocities measured from a Magnetospeed V3. These are 10 shots each, same load fired in 2 different temperatures. Just a note - I try to keep the temp of the cases in line with the ambient temperature so I don't skew the results (i.e. don't let them bake in the sun and warm up)

At 95 degrees, I'm at an avg of 2781 w/ ES of 11, SD of 5.7.
At 65 degrees, I'm at an avg of 2741 w/ ES of 17, SD of 7.6

So for me the MV variation is 1.33. That's what I use in my ballistic solver. Just like anything else you can't rely on the numbers floating around such as those posted on the temp stability chart above. You have to actually get out and test w/ your equipment and components. I wasn't aware of the reformulation, but all my powder is less than 10 years old.

As a comparison, I came up with 1.00 MV variation from H3450 in my .243 load. .83 MV variation from Varget in my 6 Dasher load.

From what I understand, all loads are temp sensitive as you get towards the hot end of the spectrum (of course some more than others). Where the extreme powders really shine is going from hot to cold.

 

[PRR1957]

I found this last year as an Internet search. I don’t know who compiled or published it. Also. I’m not sure if the temperatures are in Fahrenheit or Celsius. I still need to contact Hodgdon or Alliant to verify these numbers.

 

[D-4297]

Just one data point, but this is real world results for me. My hunting load in my 30/06 is 47.9gr of 4064 in Lapua Brass, Hornady 178 ELD-X, loaded to a COAL of 3.334 inches. Velocities measured from a Magnetospeed V3. These are 10 shots each, same load fired in 2 different temperatures. Just a note - I try to keep the temp of the cases in line with the ambient temperature so I don't skew the results (i.e. don't let them bake in the sun and warm up)

At 95 degrees, I'm at an avg of 2781 w/ ES of 11, SD of 5.7.
At 65 degrees, I'm at an avg of 2741 w/ ES of 17, SD of 7.6

So for me the MV variation is 1.33. That's what I use in my ballistic solver. Just like anything else you can't rely on the numbers floating around such as those posted on the temp stability chart above. You have to actually get out and test w/ your equipment and components. I wasn't aware of the reformulation, but all my powder is less than 10 years old.

As a comparison, I came up with 1.00 MV variation from H3450 in my .243 load. .83 MV variation from Varget in my 6 Dasher load.

From what I understand, all loads are temp sensitive as you get towards the hot end of the spectrum (of course some more than others). Where the extreme powders really shine is going from hot to cold.

Thanks @Mike402 . That is kind of the current "real world" info I was looking to get from someone . It gives me a workable yardstick . Much appreciated that everyone contributed on this .