IMR-4350 vs. AA-4350 vs. H-4350

[big6x6]

Ever look at reloading data or burn-rate charts and get confused? :? When it comes to the Big Threes 4350s, I get nothing BUT confused. For YEARS I always thought that any powder with an "H" in front generally meant it was slower than its like-named counterpart. I also have for years taken for granted that basically AA-4350 and IMR-4350 data was interchangeable and have used data as such. But if you REALLY look at reloading data and burn-rate charts, no one agrees with powder burn rates and this includes the 4350s. Here are where the authorities place the 4350s:

Hodgdon

82. IMR4350
83. H4350
84. AA4350

Western Powders(Accurate Arms)

122. AA4350
123. IMR4350
124. H4350

Hornady

103. AA4350
106. IMR4350
107. H4350

Vihtavuori-Lapua

H4350 approx equal to AA4350
IMR4350 slower than either

Sierra

AA4350
IMR4350
H4350

IMR Powders

81. IMR4350
82. H4350
83. AA4350

Lyman

77. IMR4350
78. H4350
79. AA4350


So no one agrees. I find this extremely strange. And seeing how the 4350s are probably the most popular medium to large capacity powders, it looks like this would be something shooters need to know. I used IMR4350 when I first started reloading and started using AA4350 about 8 or 9 years ago. Lately I purchased some H4350 to use in my 22-250 Ackley. So now I have all THREE of the 4350s. This got me to thinking....

The Test

So I came up with this idea. Take three popular cartridges that are compatible with the 4350 series of powders and load each with the same powder charge and same bullet. So that's exactly what I did. I took my 22-250, 30-06, and .300 Winchester Mag and loaded them up. Getting data for each was a problem because most manuals only list one 4350 under each bullet weight. I picked powder charges somewhat on the conservative side to err on the side of caution. I had never used any of the loads before and had no idea of the results. I loaded 5 of each load for velocity readings and shot a 3-shot group with the first three shots of each load just for fun. Here are the loads:

22-250
75gr A-Max
35gr 4350

30-06
150gr Hornady SP
58gr 4350

.300 Winchester Mag
165gr Speer SP
69.5gr 4350

My thinking is that the powder with the highest velocity will be the fastest burning powder while the slowest velocity will be given by the slowest burning powder.


The Results

Not what I expected. I expected AA4350 to be faster than IMR4350 to be faster than H4350. I got it completely reversed.

22-250 Remington
IMR4350
Ave velocity- 3042
Group- .82

AA4350
Ave velocity- 3020
Group- .59

H4350
Ave velocity- 3145
Group- .64

30-06
IMR4350
Ave velocity- 2743
Group- 1.05

AA4350
Ave velocity- 2719
Group- 1.56

H4350
Ave velocity- 2830
Group- 1.35

.300 Winchester Mag
IMR4350
Ave velocity- 2983
Group 1.19

AA4350
Ave velocity- 2900
Group- .35

H4350
Ave velocity- 3045fps
Group- 1.33

So what does this prove? In my mind this proves 100% that H4350 is the FASTEST burning of the 4350 powders. It gave the highest velocity in EVERY cartridge, sometimes over 100fps faster. That's quite a difference when you're talking about a 165gr bullet. There is also no doubt in my mind that AA4350 is the SLOWEST buring of the three. It gave the lowest velocity in EVERY cartridge. IMR4350 was really on the heels of of AA4350 sometimes within 22fps of the slower AA powder. You can also see why these are such popular powders. Every load was plenty accurate enough to be a good hunting load with no load shooting larger than 1.56 inches and one load shooting exceptionally well with a .35 inch group. Of course I wasn't even trying for best accuracy.

30-06 and .300 Winchester groups

Ruger M77 30-06

Remington Sendero SF .300 Winchester Magnum

 

[tooldog]

Excellent information! That was a lot of effort to figure that out! After reading the post, I looked at the old chart I had and found the same issue:

136. 4350 Accurate
137. 4350 IMR
140. H4350

You think some one would have noticed that before now.

tooldog.

 

[Harry1]

Great report Chuck! That took a lot of effort. So many times in this sport information is proven to be true only after you have tried it!

 

[RogerDailey]

...So what does this prove? In my mind this proves 100% that H4350 is the FASTEST burning of the 4350 powders. ..

Lots of good effort. Thanks for sharing the results. Please remember that changing lot numbers of a powder can change the results.

Some quick arithemtic says your velocity variation was on the order of 3-5%. I have seen that much variation between different lot numbers of the same brand and same number designation powder.

 

[richdeerht]

In .30-06, I use 59 gr of IMR-4350 with a 150 gr Accubond on deer and got good results.

Hodgdon data for a .30-06 with a 150 gr bullet goes up to 62 gr of H4350! That must be a smokin' hot load.

 

[Doohan]

Great report Chuck..

That Sendero @ .35 makes my berries tingle! LOVE IT! :shock:

 

[bronko220002]

Excellent. Ty for the effort and info

 

[longcruise]

Since hodgedon owns all three and have load data for all three on their site it should be pretty easy to figure it all out. Your results certainly show a difference but at least for me not enough to make it a factor. I've used all three over the years in 270 and I've decided that my favorite is the one priced the best.

 

[ElDiablo]

Holy ancient thread…..

 

[Shorty]

Hodgdon’s latest powder burn rate chart.

 

[Shorty]