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H4895 vs. IMR 4895
uni82
Member Posts: 416 ✭✭
Is there much of a difference between the two? I went to their websites and the description are almost exactly the same, verbatim. Are they a merged company? Are the powders almost the same? I was also comparing loads on different websites and they all have pretty much the same powder charges. Just need someone to clarify this hopefully. Thanks!
-Joe
-Joe
Comments
Same with ACCUR 4895. That IS its own company but it is a similar powder. Still consult a good reloading manual.
-JD
175 gr. Sierra HPBT match over 44 gr. of H4895----2550 fps
Same bullet over 45 gr. of IMR4895--2486 fps
Both loads shot very well and group sizes were virtually identical.
The original formula for H4895 and IMR 4895 were almost the same. That was back when they were straight powders and size was the determining factor in burn speed.
Today IMR 4895 retains the original properties while H4895X is almost a completely new powder. All one need do is look at the kernel sizes. What Hodgdon did with it's extreme powders is cut them down to the size of the fastest powder in it's class, i.e. small rifle like 4227and mid-rifle like 4895, then coat the kernels externally with a burn retardant spray so that the burn rate is slower and resembles that of the older powder. FWIW, H4895X kernels are half the size as the old H4895 and IMR 4895. The idea of keeping the same number is due to branding. No sense in calling it a new powder if everyone still wants to use the old H4895. It's like saying new and improved (but not saying...) when changing the composition up entirely but not having to go back to the old product.
Bottom line: IMR 4895 is still to my knowledge the same as it was and H4895X is literally a new powder. Both have nearly equal burn speeds and relative pressures.
Around 1962, I bought a used model 70 heavy barrel varmint rifle in the reletively new .243 Winchester cartridge. The first load I tried in it was a 75 gr Sierra HP with 40 gr. of what became H4895. It shot so well that it became my standard load.
As time went on Hodgdon started packaging his powder in cannisters and DuPont, to get on the bandwagon, brought out their own newly manufactured version and called it IMR4895. I don't know this for a fact, but I believe they made theirs, delibertly, a little slower burning than the origional to be on the safe side. Of course, surplus stocks evetually ran out, and Hodgdon contracted out to get new stocks of H4895.
I mentioned an example, earlier, of an experiment between the two 4895's fired in an M1 rifle. My notes show that I did an experiment 22 years ago with the .243 rifle and load mentioned above. With identical components except for powder and fired on the same day: 75 Sierra HP and 40 gr. of H4895 resulted in 3350 fps. With 40 gr. of IMR4895--3263 fps.
So, as far as the origional H4895 and IMR4895 being almost the same: There was only one and it was made by DuPont (IMR) and sold by Hodgdon (H). From the introduction of IMR4895 powder, they have not been the same and are not the same now even though they are marketed by the same company (Hodgdon). I believe they are made by different manufacturers.
As far as grain size of H4895 being smaller; it always was quite small compared to IMR3031 or IMR4064, etc. and measured well. The kernels I measured today check .034 dia. and .058 long for the IMR and .029 dia. and .060 long for the H--not much difference.
Long story short: The 4895's are not the same nor are other powders with similiar names/numbers the same. You will, for example, get in a lot of trouble substituting IMR4831 for H4831 in top loads.
That's my story!
I believe your story. That's why I said almost the same. I ran the same experiments you did with my dads .243 back in the 70's and showed very little difference in the velocities. That was measured on a 200 yd. (about) range I set up. Both grouped extremely well. It was too close to call as to which one had the most drop. When I first chronoed the loads it was the early 90's. There was less than 50 fps difference in average. H4895 was the faster. Also, it was clear into the '70's that Hodgdon was using surplus powder. And, as a side note to that my uncle worked at the Hawthorne, NV ammo depot in the 50's. When they decided to destroy all the bins of pulldown 4895 He brought a bunch home in paper grocery bags. Good thing it's really dry in Nevada. We used a lot of that up killing gophers. When it was gone we had to go into town and buy it. Just like you, it was a bring your own can. You could pay a buck more for the cans instead of bulk, though.
Most of the '60's and '70's data that I used didn't show a difference between them. Fortunately, we had some dedicated reloaders in my hometown who explained there was a difference. Incidentally, that is where a lot of them started going over the published guides with IMR because they purposely made it slow. So, we then resorted to checking pressure signs for knowing when to back off.
Incidentally I don't agree that pressure signs start to occur at 70k psi. It varies from cartridge to cartridge. And case brand. I know for a fact military lots of 5.56 are loaded to 62K psi. Most show primer flattening. GP-11 7.5 Swiss (Ruag) shows primer flattening, and I know they aren't over 60k. They aren't recommended in anything prior to the 1911. (which I don't get, 1911's are rebuilt)
Now, if you look at the IMR 4895 of yesteryear and H4895X of today you will see a noticeable size difference. And, 3031 is finer than the old 4895 because that's how they made it faster. But not as fine as the current H4895X. You wouldn't be thinking of AA3100? That has some sizeable kernels. More like chunks of coal. Hodgdon did the same thing with H4831SSC, and now IMR7828SSC as H4895X. Reduce kernel size and slow the speed down using a retardant.
My bottom line is find where the rifle shoots the best. If where that is causes erosion or pressure signs find the next accuracy node down. Finding a powder that mostly fills the case isn't always the answer. You made need to change up drastically. Always, Always, Always, find a safe load to start with. Working up safely and going over a published load is a lot safer than starting out blind above where you should be. I've done that. It's not a good feeling.
I believe we've answered uni62's question or maybe got him more confused.
sandwarrior: Another interesting story. And no, I didn't mean AA3100. The kernels are quite long in IMR3031 and IMR4064 and do not measure very consistently while the 4895's are much better in that regard. And the results from the 1987 .243 test I ran showed results like yours with very little difference in group size.
I believe we've answered uni62's question or maybe got him more confused.
We no doubt sound like two old F@r^& at the reloading store about to get told to shut up so the proprietor of the shop can get some business done![:0][B)]....[:D]
So, yes they're close. No, they are not the same. Reloading manuals have differentiated them since the late 70's and early 80's. Different enough that you should NOT mix the data.
Edit:
Perry,
I'm still jealous from the last time you told us that. If I'd have only known I wouldn't have wasted so much on those gophers...[^]
=JD