Warning on older Alliant Steel Powder Shotgun reloading data!

derbyacresbob

Well-known member
Not to long ago I found out that many of my 12 ga coyote and goose loads that I reloaded using BPI's Handloading Hevi-Shot Fourth Edition manual have way to high of pressures.

I sent off some 12 ga 2-3/4" 1-3/8 oz loads to have tested. I based these loads off of BPI and RSI's Hevi-Shot and Heavyweight shot reloading data for 12 ga 2-3/4" 1-1/4 oz loads. I lowered the powder charge 4.0 grains and raised the shot charge 1/8 of an ounce. The results were 15,808 psi average or 4,308 psi over Max allowable pressure.

That pressure pretty much had me shocked when I saw it.

So I sent off some of the 12 ga 3" Fiocchi 1-1/2 oz loads with 35.0 gr of Steel Powder that the BPI manual shows to have 10,800 psi. I have at least 400 of these shells loaded. These loads averaged 14,918 psi or 3,418 psi over Max allowable pressure.

I have shot hundreds of these loads without any problems.

So now I am in the process of taking hundreds of Steel Powder reloads apart to lower the shot charge weights or lower the powder charges to get the pressures under Max.

Yesterday I sent off some more Alliant Steel Powder loads to be tested at Precision Reloading. I will post the results on this thread when I get the test sheets back in 10 to 14 days.

It looks like quite a few of the guys on Duck Hunting Chat Forums load at least 10% lower than what the data calls for on many of the older data Alliant Steel Powder loads.
 
What did the base of your hull look like at 14,918 pressure?

Did those high pressure loads pattern well?

Hard to believe it did not blow the gas seal with those kinds of pressures.
 
They are mostly Rem HD BB and Hevi-Shot loads and a bunch of HW13 #2, #4 and #6 shot loads. I don't know if the pressures are that high on all of them or not. I don't know what the hull and wad looked like because I wasn't there when Precision Reloading tested them.

The 2-3/4" Federal Gold Medal load with 1-3/8 oz of Hevi-Shot and 32.0 gr of Steel Powder having pressures over 15,000 psi just shocked me.

I have a 2-3/4" Fiocchi load with 1-1/4 oz of HW13 #6 shot and a 3" Fiocchi with 1-1/2 oz of REM HD BB shot with 31.00 gr of Steel Powder going back to be tested so hopefully these loads will be much lower. These loads are with a newer lot of Steel Powder.

Every load I have ever made with Steel Powder I have weighed each powder charge and shot charge on my scales.
 
I do believe the max PSI on a 3 1/2 Shotgun is 14,000 and in the UK they use 15,000 as the top end .
I'm thinking I'd use up the shells and adjust on the next go round . Just thinking out loud
 
Originally Posted By: jetman I do believe the max PSI on a 3 1/2 Shotgun is 14,000 and in the UK they use 15,000 as the top end .
I'm thinking I'd use up the shells and adjust on the next go round . Just thinking out loud

I don't have a 3-1/2" shotgun.
 
Couple of things come to mind.

I have been in a pressure lab, some of the stuff they use shocked me.

Their shotgun may have a different bore dia, forcing cone, etc which would radically effect the pressure.
 
Interesting topic guys with some "real" numbers for debate. Just met a fella that's working with people on the TSS shot, and they've been sending shells away to get tested too - just to be sure. Keith adds a good point on nothing ever being the same in things that go boom, but almost 50% over pressure is definitely considerable. Interested to see where this one goes.
 
This is a problem that is just starting to show up this Wild fowling off season.
Alliant steel has been impossible to get for a couple of years until late last year when it returned.
This latest Steel is hotter than the powder that was on sale prior to this.
In 10ga i used to load In a Federal case with Federal 209A primer 45 to 47 grains with one load 1530 to 1600 fps approx and 11500psi max with the newer steel its 41 to 42 max and will make max of 1500FPs and 43 is over 12000psi So it is Different.
Steel as always been the same right from the start used to load 50 grain similar loads to the federal had more velocity 1650fps the norm. Now by the time you have reduced the loads to be safe its scrubbed off a lot of speed or you reduce your shot charge to compensate for this latest steel powder.
I can see Aliant loosing ground here with steel shot home loading, Steel as been popular partialy due to the huge amount of data over the years the RSI manuals status of steel Lightening steel, These type of publications were drawn up on earlier Steel powder and the Data with the new Steel is not performing the same.
 
I've got a few dozen shells loaded with that exact 3" 1-1/2 oz. load Bob. Not sure if I'll just use them up or pull them down, but for sure the next time I load 1-1/2 oz Hevi-shot BB I'm backing off the powder!

- DAA
 
Has Alliant addressed this in a bulletin? Any creditable information on date codes when Alliant Steel burn rates changed?

Alliant Steel, Alliant Bluedot, and Hodgdon Longshot, have been the common choices in magnum shotshells, and max load pistol cartridge SD loads. I have a few canisters of Steel, that were probably purchased before and after "late last year". It sure would be nice to know what the manufacturer says about this, and when the change occurred.

Squeeze
 
I have never seen any bulletins from Alliant regarding A steel, But i am convinced there is difference.
I know most loading Tens with the New powder are in the 40 grain to a max of 43 grain for lighter 38 gram loads where historically 42 gram loads tended to be in the 45 grain even a little more with no issues showing up in prof house tests or in longer term use.
This is 10s in federal cases RSI or TPS wads and normal crimp closure without any After crimp RTO to potentially put pressures outside expected.
Curent Aliant data is showing loads late 30s to mid 40s on one ten load at least, those who have tried the 45 loads have been stripping them down after the first shot its significant enough to concern them.

 
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Precision Reloading got three different test loads that I sent them yesterday. One of those loads ia a 3" Fiocchi 12 ga hull, Fio 616 primer, 1-1/2 oz load of Rem HD BB shot with a BPI TPS wad with 31.0 gr of Steel Powder.

This 3" load with 31.0 gr of Steel Powder is 4.0 gr lower than the BPI load that had 35.0 gr of Steel Powder. So hopefully the 31.0 gr load will be usable.

Many of the guys on Duck Hunting Chat Forums have reduced their Steel Powder loads 10% or more for quite a while now. The newer lots of Steel Powder are much hotter than the first lots of Steel Powder were.

Below is the reply I got back from BPI about their "Handloading Hevi-Shot Fourth Edition Manual".

There are several factors that can be occurring. The 4th ed. of the Hevi-shot manual is almost 15 years old and was discontinued from print years ago. It is definitely not up to date with new components and manufacturing changes.

· A few years ago Fiocchi made changes to the basewad of their hulls. The material composition, shape and thickness of the interior basewad changed. This in and of itself is sufficient to change the pressures in old load recipes.

· Hevi-shot has also seen changes over the years. The material composition varies, which in turn effects the density. Density variations in shot will effect pressure, which is the number 1 reason why differing shot types can never be interchanged in a load recipe.

· Current lots of Steel powder are not the same as older lots. There has been significant performance changes in lots of this propellant over time.

· Current Piezoelectric testing equipment and transducers are much more accurate than they were 15 years ago. We use the most current models in our test facilities. I cannot verify what equipment is used at the facility you had your loads tested.



 
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Definitely appreciate you going to the trouble and expense of actual pressure testing and sharing it with us Bob. Big time!

Be very interested in the results. My HS BB load will change accordingly!

- DAA
 
It wants Hogdon st marks to come out with a steel powder alternative that works like the first ever lot of A steel did, over here at around 45GBP for just 1lb of A steel and given the variations in the latter lots i for one am loosing patience with it.
 
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Originally Posted By: DAADefinitely appreciate you going to the trouble and expense of actual pressure testing and sharing it with us Bob. Big time!

Be very interested in the results. My HS BB load will change accordingly!

- DAA

I have at least 600 of the 3" 1-1/2 oz loads with Remington HD BB, Federal Heavyweight #2, Hevi-Shot #1,B, BB and HW13 #2 and #4 shot that need to be changed.

On quite a few of the #4 shot and #6 shot loads I just dropped the shot charges down from 1-1/2 oz to 1-1/4 oz and added some cork or felt spacer wads and then re-crimped them. I don't want to do that with my coyote loads because it will drop the pellet count down lower than what I want them to be.
 
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I just got a newer lot of Steel Powder from Powder Valley and loaded up some Fiocchi 3" 12 ga 1-1/2 oz loads of Rem HD BB shot with 31.0 gr of Steel powder. I sent them to Precision for testing. These loads averaged 1317 fps at 12,563 psi. So going from 35.0 gr down to 31.0 gr was not enough. This Steel Powder lot is 039 X052416.

The original load from BPI's Handloading Hevi-Shot manual, load # HS030233 showed 35.0 gr of Steel powder with the Fio 616 primer and TPS 1275 wad with 1-1/2 oz of Hevi-Shot was 1375 fps at 10,800 psi. The same BPI manual showed the same load but with 3.0 gr more of Steel powder, 38.0 gr of Steel Powder at 1355 fps at 10,800 psi. It sure seems to me like 3.0 gr more powder would make the pressure be higher than the same load with 3.0 gr less in it.

I also had a 2-3/4" Fiocchi 1-1/4 oz load tested that was based off of BPI's "Tough Duck" #HS030246 load. The "Tough Duck" load was 35.0 gr of Steel with a 1275 TPS wad at 1330 fps at 10,000 psi. I had the same 1-1/4 oz load tested but with 3.5 gr less Steel Powder. My 31.5 gr load averaged 1345 fps at 9545 psi.

I was hoping that I wasn't going to need to test anymore 1-1/2 oz 3" loads but it looks like I need to send some loads off for testing at least one more time.
 
Wow, that's a really big variation. Ten percent is pretty big, normally you'd have to get unlucky hitting both ends of a +/- to approach 10%. But that is more than 10%!

Reminds me a bit of RL-22 back in the day. I was using it in a fast twist .22-250AI with 80 gr. bullets and saw some BIG lot to lot fluctuation. Rifle shot best with a particularly hot lot that most guys didn't like so I stocked up on it and wore out two barrels using that one lot #. Probably still have a couple pounds of it in the back of the powder locker.

Looks like I really ought to just go ahead and pull those loads apart and redo them. Not a huge deal for me, I only have 30 or 40 or so of them loaded.

Thanks again Bob!

- DAA
 
At some point you have to decide where to draw the line, based on those figures if you back loads off any more its looking bleak.
I think i would be moving on from A steel and those loads.
What about longshot are there any loads with that suitable. ?
 
The only 3" Longshot Hevi-Shot loads listed by Hodgdon are 1-1/4 oz loads at 1200 fps in Federal hulls and the pressure is fairly high on them.

I am going to load up some more 1-1/2 oz Steel Powder loads with less powder and have them tested, to see if I can get the pressure under 11,500 psi. If the speed is around 1200 fps that will be good enough.
 
Longshot makes highish pressure but steel is not exactly living up to expectations in these later lot nos.
If you reduce those loads by much more they are going to be quite pedestrian certainly wont be what they were originally.
What about Blue Dot ? Never touched old steel, but just how behind is it now, and data out there for Blue dot, just a thought.
Im just trying to come up with a few ideas might work for you.
 
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