Imr 7828?

[FAsmus]

Gentlemen;

Here at my place the only powder that has shown up recently is 7828.

Have any members used this stuff for cast bullet shooting? ~ If so, what caliber and what have your results been?

Good morning,
Forrest

[Threepersons]

7828 works great in my 25-06 AI

[MtGun44]

It's a very slow magnum powder. Not sure how well it will burn at lower pressures,
that would seem to be the primary issue.

Bill

[williamwaco]

I wouldn't do it!

I know it hurts but I think you should wait for a suitable powder.

[Lloyd Smale]

works in full power loads for me in everything from the 6mm rem to the 8mm mag. It is especially good in mag rifle rounds and is proably my favorite powder for that purpose.

[FAsmus]

Lloyd;

Really!

What cast bullets are you loading for?

Good morning,
Forrest

[FAsmus]

William;

I'm going to have to work on it I think. ~ It is either figure something out or quit shooting..

Forrest

[FAsmus]

Gentlemen;

I have made up loads and checked performance with three of my 30'06 rifles and my 7x57 Mauser as an initial trial of IMR 7828 in 30 caliber and 7mm.

After checking data I loaded what I estimated would be around 1900 - 2000 ft/sec. For the M1903, shooting 311284 I loaded 43 grains 7828. For the 2-groove M1917 and the modern M70, both shooting RCBS 30-180-SP, I loaded 45 grains 7828.

All loads proved to be on the low side of pressure (expected) and all left some "sunburned" ash in the bores (also expected). Accuracy in all three rifles was quite good for an initial test, the 2-groove M1917 doing the best of all. No sign of leading was seen and the patch passed through the barrels was smooth and only showed the very light ash mentioned above.

I also loaded my M1908 Brazilian Maser in 7x57 with this powder. I loaded RCBS 7mm-168-SP with 40 grains 7828 ~ and this one really did wonderfully well: No sunburned grains and decent working pressures. The load runs clean, hard and very accurate.

I believe I will load to 7mm as standard with 7828 as tested and work on the 30s a little more ~ they seem to need a bit more powder ..

Good afternoon,
Forrest

[FAsmus]

Gentlemen;

Since the last test I have loaded the two-groove M1917 with the HT RCBS 30-180-SP and 46 grains 7828. I upped the charge from the starting load of 45 grains to see if this little increase would eliminate the 'sunburned' grains of ash left in the bore as was the result of the first test. This part of the test was perfectly successful - the load shot hard and clean for all rounds.

I loaded 70 rounds, not only for the sake of seeing if the ash would go away, but to test the long range accuracy of the load.

On the firing line the rifle instantly proved that the load was much faster than my previous combination of 32.5 grains IMR 4895 ~ the receiver sight had to be lowered 5 minutes lower than the 4895 in order to print center on the first 350 yard target. Once centered I had no trouble keeping the next shots 'in the white'.

It was a hot day so I allowed the rifle to cool every 20 rounds or so. The skinny issue barrel on the M1917 got hot fast, but didn't take too long to cool off either. This was also part of the test I was conducting - finding out how much heat the 'BAC' lube would handle at speed with accuracy. It did get plenty hot even after only 20 shots and the lube worked perfectly.

I found that the load has one difficulty - that being its considerable power rocked me back enough off the cross-stick rest that I had trouble seeing dust from misses - which is essential when you're trying to figure new elevations for a new loading combination.

I played around with the closer targets for awhile, then moved on out, writing down the new elevations as I went. Mid-point in the distances I had to add my sight extension to the Redfield sight since even with the faster load I thought I might run out of sight-staff before I reached the 834 yard target.

I had to skip the 587 yard "Chicken' because there is soft bullet-swallowing dirt as its backstop: No dust at all; misses were invisible.

The 670 yard 'Round' was next and I got on it with my second shot - centered in the white. The next four also landed very close to the first hit. To those of you who know, groups like that are seldom seen in cast bullet shooting.

The 834 yard target is where the small-bore 30 calibers run out of steam. I knew my load had to be in excess of 2000 ft/sec and most probably supersonic at 800 yards but it really starts to drift around out there too. Knowing this I was mainly trying to see how it did so far as consistent velocity was concerned.

Now, even at the good velocity I was getting I had enough time after each shot was fired to move to the spotting scope and see the bullet arrive on target. This permitted me to see if shots landed either high or low from an established elevation even if I blew the condition and landed to one side or the other of the steel. ~ A poor man's chronograph you might say.

It took a few shots to 'find' the 'center' of the wind but then things went very well. All shots, even misses to the left or right of hits were right-on for elevation.

I left the range a happy shooter.

Now, my only problem is that I've fired off all the old 7828 I had on hand and am looking at new production 7828. during the loading procedure for the last 70 rounds I had realized this and, before I changed the powder measure's setting of 46 grans for the old stuff I emptied out the last few grains of the old and threw charges of the new 7828 with it. The new powder weighed exactly one grain more than the old for the same volume. ~ My 46 grain load may have to be a 47 grain load if I can bring myself to believe that volume is more important than consistent data from the manufacturer.

In any case, if 7828 is the only powder on your shooting store shelf, don't give up! It is good stuff, just a bit more expensive to shoot.

Good afternon,
Forrest

[jonp]

Good information and the type of stuff that is good to know not just internet hearsay.

[Echo]

Good job, Forrest.

[Lloyd Smale]

sorry i was refering to jacketed bullets.
Lloyd;

Really!

What cast bullets are you loading for?

Good morning,
Forrest

[FAsmus]

Gentlemen;

Thanks fellows. I hope this little bit of testing might make it possible for some of us to go shooting in spite of the powder shortage.

By the way; all bullets fired in this test were heat-treated.

Good afternoon,
Forrest

[FAsmus]

Gentlemen;

In my last post I told how things had gone at the long range facility we have here. All shooting was done with the original old 7828 - old enough to be in metal cans instead of the current plastic canisters. This shooting turned out to be the last of the old Lot of 7828 that I had.

I alluded to the difference in weight of powder charges between the old and new powders thrown without moving the powder measure in a previous post, finding that the new stuff weighed more than the old did at the same setting by one grain. ~ I've seen this before when I encountered some old powder that was still usable but 'dry'. I decided to load and shoot some of the new powder using the measure setting found to be successful with the old Lot.

I headed to the range with 70 rounds loaded as planned. Once up there it was soon evident that the rifle was shooting harder with the new Lot: Sight elevations were lower right-off and recoil was more noticeable.

It was hard to tell if the new Lot was more or less accurate than the old stuff was - I could and did get reliable hits on the silhouettes but there is hardly any way to see what you can see when shooting off the bench up close.

I kept on shooting, winding up a full 8 minutes lower elevation setting for hits at the 834-yard distance with the new Lot as compared to old Lot and it was starting to seem that it was a little less accurate too ~ but that could have been me and recoil. No problems arose concerning leading/fouling even at this increased speed.

I thought about all this and have concluded that this new Lot of 7828 should be tested pretty much as if I were experimenting with a totally 'new' type of powder. ~ I have loaded a box for this purpose and will test them tomorrow.

Good afternoon,
Forrest

[FAsmus]

Gentlemen;

The testing has been done by now and the new 7828 is certainly a different animal than the old.

I dropped the loads back considerable, beginning at 40 grains and working up to the 46.5 grain load that worried me last post.

The 40 grains load was best - it left some powder ash in the bore, but gave acceptable accuracy. Loading to 42 grains opened things up noticeably, 44 grains saw shots stringing up and down the target like beads. 46.5 grains provided no real group at all ~ only a big pattern appeared down range.

The only gratification I feel is that I only bought 2 pounds of this new stuff. It'll be used up 40 grains at a time until gone.

~ Then, not to be defeated I also tried out some IMR 7828 "SSC" or "Super Short Cut". This is a short grain version of the 7828 and since it is in smaller granules it burns faster. I loaded 38 grains of this and moved up to 40. The 38 grain level provided groups in the neighborhood of 5x1.200 and 5x1.125! Very nice shooting for this iron sighted rifle and my eyes.

So, I moved on to the 40 grain level and was amazed at the wide patterns it provided! Just 2 grains difference and disaster. The problem for me is that if the powder is this touchy the threshold of poor accuracy could come along at any time, such as a change in temperature. The prospect is discouraging.

All for now, good day,
Forrest

[leadman]

You said your boolits were heat treated but not what the BHN is. It is possible that the new powder is causing you to be at the point where the alloy is overpressured.
I ran into this when testing the Hi-Tek coating in my 30-06 and 223 Rem. I was using 50-50 COWW/Lino heat treated to 28BHN (IIRC). and at 2,400 fps in the 30-06 the accuracy started to go away, by 2,550fps it was throwing patterns. I changed to heat treated linotype and the accuracy while not where I want it yet is improved.

The second edition of Richard Lee's manual has some good info on alloy strength and BHN.

[FAsmus]

Leadman;

I do not have a hardness testing devise. I quench from the mold into cold water in my unheated shed when the OAT is running around 20 - 30 degrees.

I did not mention that all loads in this latest test were chronographed. The speeds were not all that extreme at all and there was no evidence of alloy failure.

Velocities for the loads on this test were:

40 gr 7828 1790 ft/sec
42 gr 1885 ft/sec
44 gr 1972 ft/sec
46.5 gr 2095 ft/sec

For the "SSC" 7828 here is what happened ~ and I do not understand why the speeds came out the same.

38 gr SSC 7828 1853 ft/sec
40 gr 1853 ft/sec

Thanks for your post - any other ideas?

Good morning,
Forrest

[FAsmus]

Gentlemen;

Just some words here about the latest shooting with the new lot of 7828 in the 2-groove M1917 Enfield.

I'd moved on, nearly forgetting the 7828 since I last loaded it back in August 2013 ~ that was about the time 4895 and some Varget appeared back on the shelves..

Since then my son has returned home from 5 years in the USAF. He'll be here over the summer, which gives us some good time for shooting together. ~ Elsewhere in this forum I have mentioned us shooting his marginal M48 Yugoslavian Mauser and my Type 38 JAP carbine together.

Anyway, this new circumstance got me looking over the M1917 load book one day where I found my old shooting records sitting there unfinished. I decided to get it done this summer.

Since this thread was started I have used up the last of the Argentinean Mag-Tech primers that I stocked up on during the primer shortage and gone back to Winchester regular and magnum primers.

I loaded 40 grains standard 7828 - 15 rounds each with WLR and WLRM the only difference in the loads. I also loaded 38 grains "SSC" 7828 15 each with the same split in primers for a total of 60 test rounds.

At the range the 40 grs of 7828 worked reasonably well - with very little difference between the two primers' performance. I did note the version with WLRM primers showed a bit of bullet yaw when I looked closely at the prints while the WLR load did not.

It was warm there on the line and the 7828 heated the rifle up quickly, slowing my rate of fire considerable. The 2-groove armory replacement machine-gun barrel is kind of a skinny thing for sure!

I was happy with this shooting, the standard primer version showed accuracy sufficient to use up my two pounds up on the hill-top long range silhouette range later on, going 1.66 for the average of three five-shot groups. (iron sights) ~ The WLRM group average turned out exactly the same for its three groups but I don't like seeing yaw when I know the bullets are going 1800+ in the first place.

The "SSC" testing was useful since it made a clear distinction between primer preference. The load with WLRM primers was good enough for long range use until the "SSC" is gone, giving as it did an average of 1.65 but the loads with WLR blew up to over three inches.

This should be the end of cast bullet 7828 shooting once the powder is used up. I would mention in passing that I use White Label "BAC" lube these days and when I ran the wet patch through the barrel after all the shooting was complete it passed through smoothly and showed only the typical smoke - no powder "ash" on the patch and certainly no trace of alloy fouling.

Good morning, Forrest

[MT Chambers]

It was used for years by Remington for factory 7mm Mag. loads and was not avail. to reloaders for a long time, it is only good for near max. loads in the magnums esp. the Weatherbys, etc.

[DLCTEX]

My 257 Wby. loves 7828SSC with jacketed 100 gr. bullets.

[Blackwater]

I don 't know where ol' Jump Trap is now, but he used to post here a lot, and he was a big fan of using the ultra slow burning milsurp powders for cast, and said he could get really great accuracy with them, along with really good velocities. He said he thought the very slow burners started the bullets out more congenially, and let them align with the exact bore center better, and really became a big fan of the ultra slow burners with cast. In some cases, and I don't recall the caliber but it MAY have been .30/30, one of his favorites, I think I recollect that he used a very small "priming charge" of a faster burning powder to get the pressure up high enough to provide a much improved powder burn, and thus, real accuracy with the smaller cases with higher expansion ratios. I miss ol' Jump. He was an inveterate experimenter, and even went so far as to do blow up tests on all manner of old and milsurp rifles. Very interesting what all he dealt with. FWIW?

[leadman]

As a note I use an old metal can of long grain 7828 in my Encore 7mm Rem Mag.with 150gr Nosler Ballistic tips at 3,300 fps.
The listed load had CCI 200 and that is what I used for a long time, then for some reason I switched to WLRM. Starting flattening primers and cracking cases. back to the CCI 200s and all was well again.
So play with primers until you have a good load.

[FAsmus]

Leadman;

Roger the old metal can 7828 ~ that was the kind of 7828 that got me started. I liked it but there was only that one container. The new 7828 in plastic didn't work the same at all so I had to re-do the load work-up.

The end results are good again but it sure acted differently at the change over. I think mostly because the older lot was pretty dry.

Primers are all the difference in the "SSC" version. I'm glad I didn't but any except that one experimental pound.

Forrest

[Budzilla 19]

The only powder for 7 STW in my opinion only ! Load it up and don't be scared!!! However, having said that, I will definitely take another look at 7828 for cast in 30/06 for sure! (I just stumbled up on this post while just browsing around the site!)sure am glad I found it, thanks guys. Options, I love them.