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Update: Promo ¾ oz. 20g loads

13K views 31 replies 17 participants last post by  DanAKAL 
#1 ·
Just got pressure data:
Rem. 20g Gun Club hull
STS 209 primer
12.2 gr. Alliant Promo
OEM WAA20 wad
¾ oz. #9 shot

30" test barrel, cyl choke, .616 bore
5 shots, 41 Deg. F

FPS:
1197
1188
1179
1180
1181

PSI:
9200
8800
7900
8800
8700

Ave. PSI: 8680
 
#3 ·
Doesn't surprise me at all, but it's certainly comforting to know.

Now I can shoot those things in my fragile tubes with total peace of mind. And the pressure would be even less using my 11/16 oz. shot weights.

I'm telling ya, that is a beautiful 20 gauge Skeet load -- and leaves the barrel incredibly clean.

In my view, we've invented something of great value here that not only is an excellent Skeet load but allows the use of Promo for both 12 and 20.

I guarantee you'll never see that load in an Alliant cookbook.
 
#4 ·
You guys should get a "sticky" thread going with your unpublished recipes that have been pressure tested. Include all the details including where the recipes were pressure tested. This will separate the "winging it" loads from the ones that have actually been pressure tested. Include a disclaimer to cover your and Shotgun Worlds butt....

Scott
 
#5 ·
Actualy, I'm looking at a 1996 edition of the Alliant reloading guide and it indeed shows 3/4 oz loads in both Remington RXP and AA hulls using Red Dot. Depending on hull and wad either 12 to 12-1/2 gr gets the 1200 fps at pressures as listed of 11,300 to 11,400 with 12-1/2 gr in the Remington hull and 10,800 psi with 12-1/2 gr of Red Dot and the RXP20 wad in the AA hull. That too is the lowest pressure listed of 10,800 psi. Considering what I've read and heard, any, and I mean ANY listed Red Dot load IS safe with Promo, grain for grain! This ought to put to bed the legitimacy factor of the Promo load. Alliant themselves published this identical load some 10 years ago!

Case, what was that guarantee again?? :wink:

What do I win??? :roll:

BP
 
#6 ·
I was expecting somewhat higher pressures than those obtained, however, I'm using the newer style WAA20 wad without any card filler wads as per the old data. I feel these card wads raise pressures somewhat because they don't compress very well. My crimps were also fairly shallow, which tends to keep pressures low, and I suspect when hercules developed these older red dot loads, they used fairly deep crimps, just to assume a worst case scenario.
My .02
 
#7 ·
Well, assumptions may be incorrect and indeed the pressures listed in the loading booklets are Approximate, whatever that relates to? I doubt the cards make much if any difference in pressure especially considering the dia. of the overpowder cup vs. the size of the AA and especially the RP hull just above where the wad sits in the hull. I assume it doesn't make any real difference. I don't even think the crimp depths incolved here make any particularly signifficant difference in pressure, but..... :roll:

BP
 
#8 ·
The card wad assumption is just that; IMO when you add a non-compressible entity to a shotshell, you're effectively reducing the internal volume of the hull, and henceforth, peak pressures will be higher. The thought that deeper crimps raise pressure is not my assumption, I actually read an article where this was established via pressure testing. I think this was in the reloading column in a somewhat recent Skeet Shooting Review, but don't quote me on that.
 
#11 ·
Burnt Powder said:
Case, what was that guarantee again?? :wink:

What do I win??? :roll:
Nice exercise in extrapolation there, BP, which makes sense to me.

You win this month's Golden Chucky Cheese Award for excellence in packratting and hoarding ancient load guides.

And probably never throwing out anything.

I'll bet your shop and house would make Fibber McGee's closet look like a paragon of neatness and organization.

And don't try to claim you're too young ever to have heard of Fibber McGee (and his wife Molly).

That dog won't hunt.
 
#13 ·
Burnt Powder said:
Actualy, I'm looking at a 1996 edition of the Alliant reloading guide and it indeed shows 3/4 oz loads in both Remington RXP and AA hulls using Red Dot. Depending on hull and wad either 12 to 12-1/2 gr gets the 1200 fps at pressures as listed of 11,300 to 11,400 with 12-1/2 gr in the Remington hull and 10,800 psi with 12-1/2 gr of Red Dot and the RXP20 wad in the AA hull. That too is the lowest pressure listed of 10,800 psi. Considering what I've read and heard, any, and I mean ANY listed Red Dot load IS safe with Promo, grain for grain! This ought to put to bed the legitimacy factor of the Promo load. Alliant themselves published this identical load some 10 years ago!

Case, what was that guarantee again?? :wink:

What do I win??? :roll:

BP
I have the 1981 Hercules reloading guide and it gives the same loads with red dot. That means the published these loads for at least 20 years. Must be safe. Wonder why they quit publishing the red dot loads for 20ga. Wanted people to buy another powder for 20ga? I wonder.
 
#16 ·
Thats good stuff to find out. When this first all got started I had mentioned about using this load for my 9 yr old. I just got him another 4lb jug of Green Dot. When thats finsihed it will surely be promo. I just dont think I'll tell him and see if he notices.

Thanks guys
Tim
 
#17 ·
pumpgun said:
Thanks to all who responded. There was an earlier thread on using clays in 20g loads. With this promo data it would seem entirely possible. If enough people are interested, perhaps we could all pitch in and submit a load for testing.
Thanks as well for the info on the Promo loads. Wrote it down an will have to give it a try.

I'm interested in the Clays load for the 20 ga. I think I was the one that posted about trying it in the 20 ga.
 
#18 ·
Case;

Yup, Jack Benny and Rodchester, Pa and Ma Kettle, Dragnet, and a couple very hip songs, The "Green Door" and "How Much is that Doggie in the Window?" Even remember the "Shadow"! Wooooo! :roll: Geeze, I can remember when Moby Dick was still just a minnow! :wink:

Yes, Case o'l buddy, I do have quite a few old load data booklets. The one I recall quite vividly and can't seem to find now after some 45 years is my old original Norma powder loading guide. That chapps my ham! :x

BP
 
#20 ·
I believe 70 deg. is pretty standard. Unlikely there'd be any significant difference. Now if the testing was done at -20 then I'm not so sure :? Some powders are more temp. sensitive than others, esp. certain rifle powders, and to some extent, the slow burning shotshell powders, ie. blue dot. I've chrono'd shotshells year round, and really haven't seen any major differences in velocities with the faster powders used in 12 and 20g target loads.
 
#22 ·
SShooterZ said:
How much of a pressure increase do you think you would see by going to 7/8oz payloads?
My guess is another eighth of an ounce couldn't push it up more than 1,000 psi, which would still be under SAAMI service limits.

But that's just a rank guess -- could be less, could be a lot more.

With a powder that fast, even an eighth of an ounce might jack up the inertia enough to put the pressure over the top.

If it did, it wouldn't be enough to matter in a 20 gauge barrel, but it might crack the chamber of one of those thin 20 gauge tubes.
 
#24 ·
Pump gun , Case
Just wanted to throw in my thanks for the work on the Promo loads. Is the cost of the pressure equipment prohibitive? If it's not too bad maybe a couple of interested people could throw in some money to offset the cost. I geuss a big part is in the barrels for each gauge. Just a thought.
 
#25 ·
360 said:
Is the cost of the pressure equipment prohibitive? If it's not too bad maybe a couple of interested people could throw in some money to offset the cost. I geuss a big part is in the barrels for each gauge. Just a thought.
I have the $279 RSI PressureTrace system and NEF 28 gauge and .410 bore single-shots for dedicated test guns. I plan on ordering additional barrels for 20 and 12 gauge.

Installing the strain gauges on the receivers is a tricky process and I just haven't found a day yet when I can devote my undivided attention to it.

But I will right soon.

It's probably not quite the equal of a $1,200 Oehler Model 43 Ballistic Lab, but it should be accurate enough to keep one from blowing up a gun.
 
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