Rick Jensen Temp-Tests New IMR 4451
Rick Jensen, Captain of the U.S. F-Open Rifle Team, recently tested some of the new IMR 4451 powder. Rick and other team members were looking for a good powder that could replace Hodgdon 4350 which is difficult to obtain currently. The makers of IMR 4451 claim that it is not sensitive to temperature and that it delivers competitive accuracy. So far, Rick’s tests, done with a .284 Winchester and 180gr Berger Hybrids, appear to confirm those claims. Rick posts:
“I did a little informal powder comparison of H4350 versus the new IMR 4451. Rifle used was a Kelbly Panda with a 30″, 1:8.75″ twist 5R Bartlein barrel [chambered in .284 Win]. All charge weights were 50.0 grains using CCI BR2 primers. I was very impressed with this new powder and I believe it to be equal to H4350 as far as temperature sensitivity.
I did not test for accuracy but I will tell you my groups were pretty much equal between the two and all were in the .2-.3 MOA range. I will defiantly be shooting more of this powder in the weeks to come, assuming the supply chain will allow. It looks very encouraging to finally have a alternative to H4350 that we might actually be able to buy.”
Chronograph Results with Temps from 23° F to 101°
Here are chronograph results of a comparison test between IMR 4451 and H4350. Rick’s rifle was cleaned and allowed to cool between each test. Five fouling shots were fired before each test. Important: Note that for both Test #1 and Test #2, the powder order is reversed in the mid-temp fields (IMR 4451 first, then H4350). For the low and high temp entries, H4350 is listed first.
Here are the IMR 4451 fired cases, displayed Left to right, coldest to the hottest (in terms of case temp when fired). All charge weights were the same: 50.0 grains.
Similar Posts:
- Powder Comparison Test: H4350 vs. IMR 4451
- Rick Jensen Named Captain of U.S. F-Class Open Team
- Smarter Shooter: Keep Your Ammo Cool on Hot Summer Days
- Beat the Heat: Keep Your Ammo Cool in Summer
- Don’t Roast Your Ammo — Watch Temps in Hot Summer Months
Tags: Chronograph, F-Class, F-Open, Hodgdon, IMR 4451, Powder, Propellant, Temp Sensativity
Interesting results always like more options.
can you confirm if the 4451 took more or less powder then h4350?
thank you
Thanks for posting!
Would like to know how the ammunition was “conditioned” to each temperature.
What about how clean it burns. Did they make any progress there? I believe they were claiming that it would burn cleaner.
The variation on test two at low temperature seems out of line. Does the 12 degrees lower temp make that much difference?
Here is what I did to condition the ammo. All were done overnight except for the 23 degree ammo. The cold ammo was simply left outside for the night. The room temperature or middle temp was kept in my reloading room. The hot ammo was put in a small ice-chest that contained a heating pad. Temperatures were checked with a calibrated infrared laser thermometer. The 23 degree ammo in the second test was put in a freezer for a couple of hours while I shot the first test. The velocity loss was real whatever the cause. Some have shared with me that they think the primers act crazy when subjected to more extreme cold. I honestly don’t know.
Other notes:
All charge weights were 50.0 grains.
CCI BR2s were used in both test.
Velocity was recorded using an Oehler 35.
Nice test. Great to have a alternative. The IMR powders seem to be the most available as well. I used IMR 4064 as a varget substitute last summer for Palma.
How different is H4350 from IMR4350? I am currently testing IMR4350 as a replacement for Varget. At least on the burn rate rankings the IMR4350 is very close to H4350.
Where the rounds shot in a round-robin fashion (cold, room, hot, cold, room , hot…) to distribute the effects of barrel fouling and heating?
IMR 4350 and H4350 are close, Varget is much faster.
No Kris they were not. I shot slow enough and it was cold enough out side that day that I don’t believe barrel heat played any roll in the effects. All I was trying to accomplish with this was a true head to head comparison of IMR4451 to H4350
Off topic but Interesting that Nosler found that RL 15 was the most accurate powder in .284 with both a 160 and 175 grain bullets.
Most 284 reloading data you find in books comes from the hunting days. The Berger manual is about the only ones that has any modern relative match bullet data in that I know of.
I just acquired the IMR4451 and IMR4166 .
I will do my testing with a 260 rem and a 1-8″ – 22-250 Rem .
Your test/article is great and much appreciated . Thank you .
Murray, what were your results with the 4451 in 260rem?
Been using 4451 (45gr) in .243win w/ Sierra 85gr HPBT WLR primer, PPU case 22″ Savage 10, and getting 3440 fps, with no sign of excessive pressure….and fantastic accuracy (.65) will work up a load with 85gr Nosler partitions, and hope for similar results, although nosler data indicates a max load of 41.5 gr, so will start at a lesser charge, than with the other bullets ….
Thanks for this article!