Has IMR-3031 Changed?

[JDinFbg]

I've been trying to find something that shoots well in my 30-30 94 Win. with 26" octagon barrel. I started with W-748 using Hornady 160gr. FTX bullets with not much success. I then tried IMR-3031 with the FTX and two different 150gr. bullets. Supposedly, IMR-3031 is one of the 'go-to' powders for the 30-30, but my results were not good. I got to looking at suggested load data from current-day sources versus what was listed in some late 1960's vintage manuals I have. I listed these findings in the attached PDF file. Current-day sources list max loads comparable to what the old manuals listed as starting loads. So my questions: Has the characteristics of IMR-3031 changed over the years? Have newer data sources become more conservative in their suggested loads (due to lawyers getting involved)? From my tests so far, it appears my results were getting better with powder charges closer to the current-day published max loads. So, I'm wondering if I can safely push the bullets a little harder using the IMR-3031 powder that is in current-day production?

 

[Ru4real]

Yes, 3031 has changed some, I think. My gramps handloaded 170gr jacketed flat points over 30 grains of IMR-3031 from the 1950’s through the 1980’s for the M94 Winchester’s in 20 inch barrels.

I loaded IMR-3031 bought in the 1990’s to use with Speer 70gr bullets in the 223 for 3000fps at the 24” muzzle, good for years. I made more, same recipe, with IMR-3031 bought in 2017. In groups of 10 spent cases, about 5 of the 10 have holes through the primer. Maybe lot to lot powder variation, but maybe not. Maybe CCI primers are weaker these days, LOL!

I’ve had great success, both in accuracy and performance with IMR-3031 and 160gr FTX in the 30-30. Here is a photo. You can see a hole through a 3” black ash sapling, with my son’s dead deer in the background. Still had enough oomph to break its spine in the deer’s neck. Two guns are leaning up against the tree. My BLR in 358, and my son’s 30-30. Yup, that same 30-30 my gramps loaded for.



View attachment 946152

 

[Ru4real]

My gramps always had a spitzer bullet loaded first in the chamber of that 94.

 

[Charlie98]

Load testing methods have changed over the years, most notably the change from CUP to PSI. I'm sure IMR3031 has been changed, too, even beyond the differences from lot to lot.

I found my brother's Marlin 336 very picky about bullets. I always used Speer bullets, but switched once to Winchester component bullets that I got and the accuracy doubled. It was also quite picky about bullet weight... it did not like 150's. As far as powders... I used H322 for a while, then switched to IMR3031... but I couldn't really tell a difference there, go figure.

Maybe try a different manufacturer's bullet and see what you wind up with.

 

[243winxb]

No, IMR 3031 has not changed.
1st Speer #8 manual is known for hot over pressure loads. Its 1 of the manuals i started loading with.
2nd 30-30 bullet diameter was .307" in some brands of bullets*, this produced less pressure.
3. Change bullet brand, pressure goes up or down depending on bearing surface & jacket thickness. Lead core alloys can be different. Some harder then others.
4. *POWDER*- There can be a 10% difference from lot to lot. From slowes to fastest. (IMR4831 testing))

My M94 gets lighter loads then my 10" T/C Contender did using IMR4895 with 150 gr at almost 2000 fps.

 

[Project355]

Well.... who knows the lot-to-lot variation, as nearly all powders are blended.

That's why we start low, and work up. Always!

 

[WestKentucky]

There definitely is change over time, whether that be actual change in powder produced or degradation of powder over time. I got some 3031 in a bench buy a few years back and loved it. It worked out well for a few calibers. It was 7.99 according to the sticker on the can so I’m guessing 80s production. The 2015 production didn’t do as well in 223, but it still does fine in 30-30 based cartridges. I assume I saw degradation, but it also fits what some others have described using powder of more recent production.

 

[George P]

How many times has IMR changed hands and manufacturers?

 

[JDinFbg]

I’ve had great success, both in accuracy and performance with IMR-3031 and 160gr FTX in the 30-30.

What charge of IMR-3031 do you use with the 160 gr. FTX? What length barrel does your 30-30 have? Is it regular rifling or micro groove?

 

[JDinFbg]

Speer #8 manual is known for hot over pressure loads. Its 1 of the manuals i started loading with.

I started loading with the Speer No. 7 manual, but the data for the 30-30 is the same as given in the No. 8 manual. Of the old data sources I noted, Speer did list the highest max, but only 0.2 grains more than the Hornady 1st Edition, and 0.5 grains more than the Lyman 44th Edition. For current data sources, Nosler listed the highest max at 31.0 grains. I only tested up to 30.0 grains with the two 150 gr. bullets I tried (Hornady round nose, and Speer flat nose), so it would appear I could go up 1 grain more and still not exceed the max for current data sources. At the highest loads I've tested so far, I did not have any high pressure signs or difficult case extraction.

 

[243winxb]

3. Change bullet brand, pressure goes up or down depending on bearing surface & jacket thickness. Lead core alloys can be different. Some harder then others.

Each bullet will have its own maximum & pressure.

No pressure signs, go up on the powder charge, if you wish.

 

[Ru4real]

What charge of IMR-3031 do you use with the 160 gr. FTX? What length barrel does your 30-30 have? Is it regular rifling or micro groove?

The velocity written is out of a 20” Winchester Model 94 with regular rifling. The table in the post above by 243winxb shows my load is above max. But pressure indicators have always been good in my guns.

View attachment 946250

 

[JDinFbg]

The velocity written is out of a 20” Winchester Model 94 with regular rifling. The table in the post above by 243winxb shows my load is above max. But pressure indicators have always been good in my guns.

Thanks. This is very helpful information. I only tested 3 loads of IMR-3031 with the 160 gr. FTX - 27.0, 27.5, 28.0. At the 28.0 gr. load, it looked like the group was starting to come together. So, maybe working up toward your 32.0 gr load, watching for adverse pressure signs, I can find a load that shoot well in my rifle. This also gives me confidence that the max loads for IMR-3031 listed in the three, late 1960's vintage reloading manuals I have may not be unreasonable for testing the 150 gr. flat nose bullet I have.

 

[jmorris]

I have a really old 20lb keg of IMR 3031 and the extrusions are longer, the new stuff is much less likely to bridge on small case mouths.

Some other powders, like W231 have gotten cleaner. Using the same data and components, with the same gun some of my old metal can loads are noticeably dirtier than the later plastic jug versions.

 

[TRX]

> Current-day sources list max loads comparable to what the old manuals listed as starting loads

I have 50-odd years' worth of printed loading data in books and those little folding hand-outs. For the same powders, I see trends of charge weights going up and down, along with ballistics.

My theory is that the marketing guys push for the highest velocities possible for more sales mojo, and the lawyers are pushing for "safe" loads to reduce liability exposure. Certainly load data for .44 and .357 Magnum yo-yos up and down for no obvious reason...

Also note that few of the loads in the old tables were pressure checked, which was a tedious and expensive process in the days before strain gauges. And a lot of the data in the newer tables is generated via software. Reading all the boring material in the introductory pages and the stuff in the back past the last tables will usually reveal where the data came from. It's not that they're hiding it, it's that the vast majority of people using the tables don't care.

 

[243winxb]

Load testing methods have changed over the years, most notably the change from CUP to PSI.

This^^ Better testing of PSI.

 

[tmd16556]

I’m curious about this too. I have old loading notes for the 250 savage from my great grandfather when 3031 came out in the 1930s. It replaced du Pont 17 1/2. I was planning on re-working his hawk hunting load (60 gr bullets for the 25-20 over 37 gr) but didn’t get around to picking up any 3031 before the great panic began, so that adventure got delayed.

I was going to work up to “the load” from a reasonable starting load anyway, but I’m curious how much the powder changed since it’s introduction almost 90 years ago. The only samples of old 3031 I had corroded brass cases over the years and got burned up in the fire pit after pulling the bullets. Turns out it’s not good to store for 80 years, particularly in the Deep South with no air conditioning for the first 40 of those years.

 

[horsemen61]

Have newer data sources become more conservative in their suggested loads (due to lawyers getting involved)?

You answered your own question right there

 

[JDinFbg]

Since I started this thread, I have done some more testing with IMR-3031 in my 30-30. Based on Ru4real's posting that he was shooting 32.0 gr. of IMR-3031 with the Hornady 160 gr. FTX bullet, I loaded up a series of test rounds with 150 gr. Speer flat nose bullets going up to the max of 34.0 gr. as shown in my old Speer No. 8 reloading manual, the data from which I summarized in my initial post. At 34.0 gr. of IMR-3031 launching the 150 gr. bullet, I observed NO issues with difficult case extraction NOR any excessive pressure signs based on looking at the fired primer. The primer definitely had been pushed hard against the bolt face, but the primer was intact with no punctures or cratering around the firing pin (FYI, I'm using CCI large rifle primers). From my tests, I conclude that a) 34.0 gr. of IMR-3031 is likely the max anyone would want to try in the 30-30 with the 150 gr. bullet, b) IMR-3031 has not changed appreciably over the years, and c) today's published loading data for the 30-30 is very conservative. Unfortunately, I have yet to find any load that shoots well in my 94 Winchester with a 26" barrel. Either I have something fundamentally wrong with my rifle, or just haven't found the right bullet and powder combination.