Home Forums Reloading Big Game Rifles 270 win, and H4350 vs IMR4350

How much difference between these two powders? My wife's 270 is shooting nice groups with H4350 and 110 TTSX. Trouble is I am almost out of H4350. I have a couple pounds of IMR 4350. Can't find any of the former in the area. I see they are very close on the burn rate chart. I would of course work up with a different powder. How different do you folks think it might act?
Thanks.

wsmnut

They are very similar to burn rate as you mentioned, and the have many overlapping qualities. Lots of times if one will work the other will work as well. The biggest thing to me in the difference between the two powders is that the H variety is not temp sensitive while IMR is.

Heavy have you personally actually tested this yourself and or is it something you read? And if you actually did it how did you perform your tests?

Only reason I ask is that I did some cold weather b4 and after testing this winter and found some interesting things. Poing being I feel....that there's a tish bit of marketing hyhpe to the temp stuff.

Thx

Dober

For eons I ran IMR 4350 in my 270 year round and I never once had any reason to doubt it. Now I have not tested to two side by side to see exactly how they both perform in cold and hot weather but in all honesty I don't worry about that much.

My thoughts are if it'll shoot well with one it'll shoot well with the other. I'd get after it and not worry one bit.

Dober

We did the testing ourselfs (we as in myself and the guys I hunt with) we ran a lot of powders though different temps. IMR was not as bad as some but still lost around 150fps from 60 to 0 degrees. While H4350 only lost about 40fps.

I do agree that the temp stability stuff still loses some but in general it has been a lot more consistant for me.

The other thing to keep in mind when testing in hot and cold temps there is more to the equation than just the powder. I have not read anything about this and have no way of telling if it is in fact true but it does seem to me that the primer in cold temps may be the culprit for these temp stabil powders loosing some velocity.

I agree that there's more to the equation than meets the eye. several of the people I know who've tried to do this kind of work when I spoke with them I found out that they weren't using the same cases and the same lot of powder and the same clock etc..

IMO for this kind of work one has to be very anal, otherwise some weirdo and wonky #'s come up. Plus I feel that the tests should ideally be done on a couple of different days just to be sure one isn't getting a wonky reading.

When you saw the 150 fps loss was it with same cases, same lot of primer and powder and such? That's a lot more loss than I'd ever spect to see.

And obviously it with the exact same gun right?

Not trying to interogate you, but I like to be very careful about this.

Thx
Dober

Same rifle, cases, lot of primers ect. when we did the test we put the rounds in the frezzer over night so that they would all be consistant. We have a range at out house so they went right from the frezzer to the rifle. We don't get a lot of 0 degree days over here in western washington to do testing so we have to improvise.

I also think that a lot of times when these test are done they are done in a way that when the rounds are shot it might be 0 degrees outside but the rounds were in the house all night and then rode in the warm truck to the range. Lots of the tests are done at the outside temp and do not take into account the actuall temp of the powder/components so the results do not show that much of a loss.

I believe it was BobinNH that also found the same velocity loss with IMR4350 as we did. It was in the RL 22 thread a month ago or so.

The rifle should be cold too.

H

I recently asked Mule Deer about the two and he mentioned that in the last couple of years that H4350 is now formulated to closely match IMR grain for grain. It used to be that H was slightly slower and would require just a slightly higher charge to match the velocity of IMR. Acording to JB and the latest Hodgon data the powders are now about equal in velocity for a given charge weight.

This is pure speculation on my part but from my reading and more reading it seems that in the past that IMR had a slight edge in accuracy more often than H having an edge. In the Nosler reloading guide IMR 4350 is one powder that is often the most accurate powder in many different cartridges/loads. I wonder if Hodgon knew this and reformulated, ever so slighty, H4350 to match the burn rate of IMR 4350 to equal the very slight edge in accuracy of IMR4350.

Again, it's speculation on my part and certainly debatable.

fish head

For what it's worth, I tried some of thest tests on H4831/H4831SC when they came out. With the same loads in my 25/06 the velosity average was the same but SC meters so much better.
As for the temperature extremes, I tested from the mid-70's to the mid-20's.(It just doesn't get as cold here in PA. as it does out West there.)
And with the same lots of bullets/cases/primmers and powder my average velosity dropped 33fps due to the cold.

While charges have varied a bit between the two powders in question, I have found if you have a good load using one then you should be able to find a good load using the other. I'll state again that the charges may vary a bit but in my limited experience so far I've been able to use both powders with equal results in a given cartridge.

I shoot 54 grains of IMR4350 with 130 grain SP's. They shoot excellant out of a Remington Model 700 BDL.

Shot a lot of 4350 over the years. But now I like the H4350 because its and extreme powder.

Thanks for the intelligent discussion folks. I am headed out tomorrow morning to test out the IMR 4350.

wsmnut

Based on my experience (which may not be as much as others), the velocity of the two in the .270 was too close to worry about in the field. I just went on accuracy. For some reason H4350 seemed to be a tad more accurate in 140s and 150s. For the Nosler 160gr bullet though, I'll take IMR's version.

I have tested both powders in hot ie over 80degrees F and cold -25 degreesF.in both 270 and 3006. I couldnt chronograph as ,my chronograph doesnt register at the low temperatures. What I have noticed is that in order to maintain point of impact and group size with IMR 4350 I have to add a grain (or so) of powder to restore point of impact and to get group sizes back to what they were in warmer
temperatures. I have not noticed this with H4350, or at least not to the same degree. Same guns, same cases bullets and primers. Incidentally I read many years ago from Ed Matunus who worked for both Remington and Winchester as a ballistican over his career, that the chemical composition of Federal primers made them somewhat more sensitive to temparatures than Winchester or Remington. Im not sure this information is still current although it may be. I still use a lot of federal in certain cases and adjust the load between summer and hunting season.

Good topic. I have used H4831SC because of JOC. If it had not worked out, H4350 would have been on deck.

Better get you a pound of each. I've found acrost the board with like numbered powders, ie IMR4350, H4350; Imr4895, H4895, etc, one or the other will be more accurate in your rifle by a noticable amount.

True for me. Nuts. Three pounds of H4350 on the way from Powder Valley.
Groups opened up no matter what I tried. Live and learn!
Thanks again for the discussion.

wsmnut