Surplus IMR4895-bigger granules than Commercial???

[sobrbiker883]

I just got an 8lb jug of surplus IMR4895 from a guy today. He called and said someone else that bought some noticed the powder is different than his regular IMR4895.
I just compared and the stuff I bought (marked "IMR4895, Military Surplus Gunpowder, Lot #A131").
It smells like IMR4895, same color granules, but they are almost twice the size of the recent purchase IMR4895 I have on the shelf.

Anyone have any experience like this and is it completely different powder?

 

[Clark]

Re: Surplus IMR4895-bigger granules than Commercial???

From a post in 1994 by Ed's Red:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">COMPOSITION OF IMR-TYPE POWDERS..
The basic composition of DuPont IMR-type powders is 100% NC of 13.15% N content, to which are added 0.6%DPA and 1% K2SO4. The only exceptions are IMR4831, to which the DPA is 1.1% and IMR4895 which is 0.7% DPA.
IMR8208M contains an ethylene dimethacrylate EDM deterrent. All IMR-type powders differ essentially only in their deterrent coating and granulation.
The length and outside diameter are not sufficient for
identification of the powder type. The extrusion pin for cal.
.30 powders is .015" and inside shrinkage is approximately 55%.
The granulation of a single perforated, extruded rifle powder is
expressed:
.049 x .015 x 1/11

in which the first group of figures represents the outside diameter of the grain, the second group the diameter of the perforation, and the third the length of the cut or the number of grains per inch, when all dimensions are expressed in inches. The web thickness of a single-perforated grain is equal to 1/2 of the difference between the outside diameter and the diameter of the perforation. A 1.0% decrease in web or 0.1% increase in total volatile content (TV) will increase burning rate by 1%. A change in TV has ten times as much effect upon burning rate as a corresponding change in web thickness.
...</div></div>

What does it all mean?
IMR4895 will be .033" diameter and .058" long.

 

[sobrbiker883]

Re: Surplus IMR4895-bigger granules than Commercial???

Thank you sir, the grains I have are .052" diameter and .082" long, +/- .005-.010"

At least the guy I bought it from called me and is willing to take it back.

 

[cav has been]

Re: Surplus IMR4895-bigger granules than Commercial???

The knowledge shared on this site just blows me away sometimes! Thanks Clark!

 

[Victor N TN]

Re: Surplus IMR4895-bigger granules than Commercial???

I would have no problem shooting pull down powder. I have 4, 8# jugs of it now.

The difference in appearance is probably because it's several years old. They haven't started cutting the kernal sizes until the last few years. That does make it easier to meter. But it shouldn't cause any difference in the way it shoots. I would start off maybe 2 grains light of my regular load and work it back up. Just keep an eye open for high pressure signs.

Good luck.

 

[sobrbiker883]

Re: Surplus IMR4895-bigger granules than Commercial???

That's what I was originally thinking Victor, but it is still much larger than th measurements in Clark's post with info from 1994.

I remember I4895 being a bit larger than current stuuf but this stuff I got is large!
If I had ordered it from a supplier, I'd be apt to agree and shoot it, but I bought it from an individual, and have no idea who he got it from. I'm thinking I'd rather have three pounds of current production than eight pounds of an unknown for the same money.

 

[Victor N TN]

Re: Surplus IMR4895-bigger granules than Commercial???

You may be right.

 

[sobrbiker883]

Re: Surplus IMR4895-bigger granules than Commercial???

Victor-can you measure a granule or two from yours (diameter and length)?
If its the same size as what you've got I'd be happy as a clam to keep it and shoot it.

Like I said, this stuff smells just like IMR4895-everything about it but the size is what I'd expect.

 

[Victor N TN]

Re: Surplus IMR4895-bigger granules than Commercial???

I'm not at the shop right now. I don't keep anything here at the house. If nobody chimes in I'll try to do it for you the end of the week when I get back.

Sorry I can't help out right now.

 

[sobrbiker883]

Re: Surplus IMR4895-bigger granules than Commercial???

Thanks Victor-based on the 1994 info, I'll probably return it to the guy and get my money back tomorrow.

(unless anyone else has pulldown handy they can measure)

 

[81STFACP]

Re: Surplus IMR4895-bigger granules than Commercial???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">Thanks Victor-based on the 1994 info, I'll probably return it to the guy and get my money back tomorrow.

(unless anyone else has pulldown handy they can measure)

</div></div>

sobrbiker883,

Here are some pictures for you. I bought 2 eight pound jugs that sat in the cabinet for a few years till I started shooting this particular M1A. I tried every powder I have, but the rifle appears to like this powder and the 155s. Of course it is only for short range ammo.

BTW, when I did projects for Motorola/Freescale I bought a house in Gilbert/Higley area and flew back and forth to Texas every other weekend.

 

[sobrbiker883]

Re: Surplus IMR4895-bigger granules than Commercial???

Thanks!
I do know that before they used coatings to control speed they did it all by size.
Maybe I just got some big stuff.