Diff. between H4350 and IMR4350

sharp shooter

sharp shooter

CGN frequent flyer
Rating - 100%
83   0   0
Location
Essex county (Ontario)
I bought a pound of H4350 for loading but noticed that most guys on here tend to prefer IMR4350 in their .30-06 load data. What is the main difference between the two?

Also, my brother bought me some 165 grain SST for Christmas. What are your thoughts on them for moose. I don't think that they are tough enough for a long range quarter shot or are they? Maybe partitions are my best bet for long range shots right? I haven't shot a moose with either.

Steve
 
Last edited:
According to the Sierra manual, the IMR will generate about 100 FPS more with 165 and 180 grain bullets. The 165 SST is probably better suited to deer; 180's for moose in 30-06.
 
H4350 is a bit slower powder; closer to RL-22, whereas IMR-4350 is closer to RL-19.

Both are excellent, but depending on your load you may have trouble getting enough H4350 into your cases. IMR-4350 results in pretty close to a full case with 180 gr. bullets, and a slightly greater volume of H4350 is required.

The biggest mistake many make is to assume that they are interchangeable because of the similar numbers - they are most assuredly NOT. Using the faster powder in place of the slower powder, grain for grain, can be dangerous.

Handloading isn't (or at least shouldn't be) an attempt to wring the highest possible velocity out of your rifle. If you want more velocity, get a bigger rifle. Handloading should be about consistency, quality and accuracy. Don't worry about "getting another 100 ft/sec." with some other powder. All you'll do is beat up your rifle, shorten your barrel life, and throw your brass away after two firings.....and maybe enjoy a face full of shrapnel, if you insist on pushing things. A .30-06 isn't a .300 Win Mag, but they do sell .300 Win Mags for those who absolutely need another 100 ft./sec.

Just try to load the most consistent, most accurate ammo you can...and I guarantee, eventually you'll end up with a whole cupboard full of different powders.

One rule of thumb that's always worked for me is to use the slowest powder available that will result in a full case, or even in a slightly compressed load. That's usually where the best accuracy will start to show itself. That's why the -4350s work so well in the .30-06, as do RL-19, RL-22 and others in that range.

You might want to dig up a chart of comparative 'speeds' of powders, just to gain some insight. Google will find you several to choose from.

And last but not least READ YOUR MANUAL....or even two or three of them! Especially that seemingly boring first part, before the part where they start listing loads. You'll be surprised how much information there is hidden in there! Fine tuning that perfect load is somewhat trial and error, but the basics principles of handloading should NOT be. And never forget; free advice given by Joe Dink on some internet message board is worth exactly what you paid for it - and it just could get your head blown off, so treat it accordingly.
 
Did you use a crony at those temperatures?

Jordan Smith said:
Maybe, but I haven't had a problem with IMR4350 in the .25-06, .280, 7RM, .308, .22-250, or 7-08 when using it in 30*C weather, all the way down to -32*C. The biggest change I've seen is about an 80fps loss.
Click to expand...

Did you use a crony at those temperatures?
+ 30 to - 32 and only on 80 fps difference???
 
Yessir. I use my Chrony almost every time I fire my rifles. I use it in the heat of summer and in the deep freeze of winter. Only ~80fps loss at most. You will note that the velocity loss and temp senstivity of different powders varies with different cartridges, bullets, and applications. IMR4350 may lose very little or no velocity shooting one bullet in one cartridge, but loses a moderate amount in another cartridge shooting a different bullet. These have just been my experiences...
 
"...Diff. between H4350 and IMR4350..." The burn rate. Very close but not the same. With .30-06 165's, H4350's starting load(53.0 2678 fps)) is 3 grains more. As is its max load(59.0 2938 fps). The max load is not a compressed load, whereas the IMR's max load of 60.0 is compresssed. Four whole fps difference at max loads.
The compressed/not compressed thing just means the IMR powder granules are bigger. Compressed loads are nothing to worry about.
If you have an IMR4350 load worked up, you'll have to work up the load with H4350. Accuracy won't be much different, but the groups might be.
After all that, you'll find IMR4064 gives more consistent accuracy than either 4350 powder.
 
sunray said:
".After all that, you'll find IMR4064 gives more consistent accuracy than either 4350 powder.
Click to expand...

Pretty dogmatic statement from someone who obviosly knows little in a practical way about powders. 4064 may give better accuracy in a few rifles, while one of the 4350s may well be better in others. Since in a 30-06, 4064 never fills the case, it is far more likely to give variances in velocity than the 4350's, which come very close to filling the case. Eagleye.
 
H4350 is supposed to be more temperature insensitive than the IMR counterpart. I personally prefer H4350 and 180 grain bullets in my .30-06 handloads. I found very consistent velocities and great accuracy.
 
IMR Powder is made in Canada. Hodgdon extruded powder is made in Australia by ADI. The ADI extruded powders, which Hodgdon markets as Extreme are very temperature insensitive. This is a very useful feature of a powder in a country like Canada with temperature extremes. For that reason I always choose the H version over the IMR version. Seems kind of ironic as a Canadian to chose an Australian powder, marketed by an American company, that also owns IMR the Canadian company.
 
You must log in or register to reply here.
Back
Top Bottom