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I was looking at the Hogdon 2009 Annual Manual for Winchester Polyformed hulls, and they are listed this way in 16 gauge:

2 3/4 Winchester polyformed plastic game shells (plastic base wad) IMR

and the other is listed as:

2 3/4 Winchester polyformed plastic game shells (plastic base wad)

What is the difference?

Joined: 15 Jan 2009 Posts: 728

I believe IMR refers to the IMR line of smokeless powders that Hodgdon acquired sdome time ago.

Joined: 06 Aug 2009 Posts: 960

IMR - Improved Military Rifle - The line of powders was originally started by Dupont, It has changed hands 2 or 3 times and is now owned by Hodgdon. There is a short history on IMR's website.

On the Hodgdon site if you see "(IMR Data)" or "(IMR)" after the 16 gauge Winchester hulls , that data is for Winchester Compression Formed hulls. It is older data that IMR actually tested(Personally, I think the IMR data is good stuff).

The rest of the data is for the newer polyformed hulls, and Hodgdon does not care where the hull was made(US, Italy or Australia), they consider them all the same.

I hope this helps.

Member Joined: 09 Aug 2004 Posts: 401 Location: Tennessee

rerundogchaser37,
I've loaded rifle cartridges for 40 years and never gave a moment's thought to the meaning of IMR, I just figured that it was part of the brand name. Guess I could have Google-searched it, but never thought to. Thanks for that little bit of info!
See? You CAN teach an old dog new tricks.
Bill

Joined: 06 Aug 2009 Posts: 960

Roadkill,

I have always used and still use IMR powders, they are my favorites, especially PB, SR7625 and 800-X.

The old tin Dupont cans might have had IMR spelled out on them in fine print, but I can't remember. Stray bits of trivia float through my noggin sometimes, and I do mean STRAY!!! Laughing

Joined: 06 Mar 2008 Posts: 596 Location: 17603

Gents,
On the subject of those old tins, I scored 8 cans of PB yesterday, old stock that a gunshop was clearing out, as well as a can of AL8 and AL5. Along with a case of 5000 Fiochi 616's, $200 out the door, I'm pleased Smile

.
R*2

Joined: 06 Mar 2008 Posts: 596 Location: 17603

Tony,
I think "SR" is Sporting Rifle.
R*2

DC and R*2 are both correct!

Here's a 1959 photo of both cans with IMR and SR spelled out.

Good prices!

Anyone besides me remember what a pain those little bitty caps were? It might take ten minutes to get the 4064 back into the can when you were through weighing out your loads!

Slidehammer

Joined: 06 Aug 2009 Posts: 960

Tony,

I don't know the exact history from Dupont owning the line of powders and the Hodgdon purchase, but IMR was the company name for a bit. That is why Hodgdon refers to the data as IMR Data.

I have data manuals dated from August, 1989 to May 2001, with the name:

IMR Powder Company, Plattsburgh, NY12901

Hello All

According to the "Complete Guide to Handloading" by Phil B Sharpe 1937 and more

DuPont IMR #15 Introduced in 1914 -- This powder, the first of the so-called "Improved Military Rifle" series or progressive burning powder, ---

Before this time DuPont made MR (Military Rifle) powders.

Hope this helps

Mike

Phil Sharpe was one of the best versed arms historians and reloading experts to ever come along. He was instumental in the developement of the 7MM magnums and other similar rounds. The 7MM Sharp & Hart was one of them. The Remington 7MM magnum is based on his work. I read quite a bit of his works along with the works of many others. I never missed an issue of the once great gun mags like Guns and Ammo and Shooting Times before the Federal Govenrment, liability laws, tort lawyers, and Madison Avenue types ruined it all for us. I also ordered quite a few great gun and reloading books out of these mags as well. Some of these books probably would not be considered publishable today. The legal staff would be screaming bloody murder Smile

.

Dupont developed the IMR powder series under contract to the US military just prior to our entering WWI. Longer range, higher velocity cased light artillary ammo and small arms rifle and machine gun rounds with spitzer type bullets like the S type 8MM Mauser round were being developed by the German arms industry along with newer, more progressive burning smokeless propellants to help push the projectiles to higher velocities. The US and the rest of the European powers had had some serious catching up to do for over a decade and were hard at it. The 30-06 was one of the better developements out of those efforts along with the high velocity .30 cal. spitzer ball round for it.

Dupont developed canister and bulk grades of extruded single based propellents like IMR 4198, 4895, 4350, and 4831. These and others were some of the propellants developed and used in US MilSpec cased ammo from 1917 through Korea.(Shortly after 1950, Olin developed the ball powders now commonly used in milspec and commercial ammo as well as by reloaders.)

Bruce Hodgdon got his start by buying up tons of surplus 4831 propellant after WWII, and marketing it out via mail order to the shooting public in quantities suitable for shipping by common carrier. It proved very useful in many of the 25 through 30 cal '06 based commercial and wildcat rounds being developed as well as for the newer belted magnum rounds like the 7MM Remington and 264 WW. Jack O'conner loved the stuff for some of his pet 270 rounds. You could say Hodgedon was one of the fathers of modern post WWII reloading.

Dupont expanded its canister grade production line to keep things going after the war as well as producing bulk grades for Remington and some other ammo companies. Remington ammo still uses bulk grades of these propellents in its commercial rifle ammo.

Quite a bit of what we still know and use came out of the post WWII surplus military stocks of arms and munitions. Hodgdon and a handful of others were smart enough to capitalize on it. We are the benificiaries of their efforts.... or would be if the Feds and the lawyers would leave us alone long enough to enjoy ourselves. Rolling Eyes