H4350 velocities @ temp..... data....

[Sniper260]

In a post a few weeks ago a few of us posted what reloader 15 gave us velocity wise at certain given ambient air temps and it was somewhat conclusive that reloader 15 varies 1fps per tempature degree.... it was kind of interesting that a few of us all had the same data conclusions....

so for what its worth i wanted to know yalls velocities with H4350 from the 30 degrees mark up to 110 or so.... any verified data works... just see if there is any correlation out there with how much ambient air temp changes the velocity with H4350...

share your data!

30 degrees - ? Fps
40 degrees - ?fps
50 degrees - ? Fps
60 70 80 90 100.....


caliber dont matter... but you can add it in if youd like..

 

[Wannashootit]

H4350 is sold and marketed as being insensitive to temp changes, and I have never encountered any in practical experience (which has been limited to basically 50-90+ degree temps here in FL).

Others I'm sure will argue otherwise.

Due to H being about as scarce as hen's teeth I just bought a jug of IMR 4350 and am anticipating velocity/pressure differences that I don't have with Hodgdon.

I suspect, that the overwhelming popularity (and thus lack of availability) of the Hodgdon is due to it's consistency.

 

[hondo1312]

I'm not going to argue with you about the temp (in)sensitivity of H4350, but I recently participated in a thread on this concerning Varget. I posted a link to the Hodgdon data claiming 8 fps variation from 0-125 deg F, and another member responded that he had verified he was getting 1 fps per degree variation from -20 to 115 deg F.

I'll be in a class this weekend and try go run some rounds over my magnetospeed from 40-80 deg F to see what I come up with.

 

[6brshooter]

No powder is temp insensitive. I found that alot of change occurs below 30*. -20-115, sure there's probably130 degree variation, but i bet in the 30-90* range it is not 1*/1fps constant. Hodgdon extreme powders show less variation in that range then most other powders, at least in my experience. 243 data with h4350, 3068@30*&3090@90*; 22 fps loss over 60*. Same rifle with imr4350, 3000@40*&3079@80; 79fps loss in 40*. These numbers are in the middle of what most people shoot in, temp wise, not extreme conditions that really change velocity. I personally don't care to shoot alot once it's below -5* or much over 110 heat index. My results with h4350 across several different rifles and calibers all echo what i have posted here. Alot of people talk down varget and h4350 in favor of other powders, but during this scarce i had no problem finding r15,r17,imr 4064, imr4350, and imr4895, as opposed to that "junk" varget, h4350,and h4895. Lol

 

[bkw1911]

I've shot in cold to high high heat without any issues or changes. However below 30 there was definitely some change and velocity loss. Not sure on velocity but it was about .2-.3 mils at 1k. It was 8-14 degrees for that match.

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[Aimsmall55]

I've shot in cold to high high heat without any issues or changes. However below 30 there was definitely some change and velocity loss. Not sure on velocity but it was about .2-.3 mils at 1k. It was 8-14 degrees for that match.

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Yep, there seems to be a "tipping point" , at which h4350 takes a drastic fall in terms of velocity. It's not anything you can say" ok it's .75 fps per degree" because its really stable mild climates but as soon as its FRIGID outside that's when it SLOWS WAY DOWN. 30 degrees was what I noticed also in being the tipping point so to speak.

 

[TRAAV]

I agree below 30 it starts to drop off

 

[Das Capitolin]

No powder is temp insensitive.

THIS. I've recorded Hodgdon's H4350 to move approximately 8-12 FPS per 10F in temperature, between 24F and 104F. My typical summertime 260 Remington load uses a Hornady 140gn BTHP Match bullet shot through 26" barrel with 42.0 gn or H4350 for approximately 2740 FPS. In the winter I've found that same load to drop as low as 2670 FPS. I've recently measured at various temperature in-between, and it seems like the 1*F=1FPS theory holds true.

 

[J-ROD]

Just curious, are you guys using dope to back calculate fps?
Since I have been using a magnetospeed chrono, I see practically no difference in a 308 using varget and H4350 from 30F to 90F. If anything, I think varget increases pressure a little when it's really cold out. PP 2000mr and a couple imr powders on the other hand seem to be .7-1fps/degF.

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[Das Capitolin]

Just curious, are you guys using dope to back calculate fps?
Since I have been using a magnetospeed chrono, I see practically no difference in a 308 using varget and H4350 from 30F to 90F. If anything, I think varget increases pressure a little when it's really cold out. PP 2000mr and a couple imr powders on the other hand seem to be .7-1fps/degF.

I can't speak for others, but my chrono matches ballistics. There's a significant difference in my cold/warm/hot bullet drop, at least with H4350.

 

[Sniper260]

Interesting.... I am still working on load development with my 260, I havent shot it over a chrony yet though. 42 gr under a 140 berger is looking like my load. Thats interesting though, gives me an idea on what to kind of expect. Interesting how several of yall agree on the 30 degree mark it slows down a lot.

 

[bkw1911]

Overall it's still more stable than anything else I've shot. The only time I've adjusted my data was under 30deg. Other than that I don't mess with it and I still hit everything. We get up to 110+ in the summer and even on longer strings it stays pretty consistent. I don't plan on shooting under 30deg again, it was miserable for an AZ boy. 2 pairs of gloves with hand warmers and still feeling like I was getting frost bite is not the kind of shooting I enjoy.

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