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Matthew

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Discussion starter · #1 ·
I’ve got a buddy that wants to use this powder for 20 gauge loads. I can find plenty of data for 12 gauge, but none for the 20. Is anybody aware of any load data? I looked at a Hodgen load data book and isn’t see anything.
 
I’ve got a buddy that wants to use this powder for 20 gauge loads. I can find plenty of data for 12 gauge, but none for the 20. Is anybody aware of any load data? I looked at a Hodgen load data book and isn’t see anything.
Call them and ask them. Their phone number is (913) 362-9455 (you'll have better luck calling than sending an email.)

If they've tested it, they'll tell you.

But if it's not in their data, they probably haven't tested it.

Perfect Pattern is pretty "fast" for sub gauge loads.

And it's Hodgdon.
 
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Thank you so much Tim. Much appreciated. Right now he’s recoil sensitive due to a surgery. I told him to just load a super light 12 rather than trying the 20.
Perfect Pattern is a good choice for a soft 12 gauge load.

Not sure what hull or primer you'd be using but they have some one ounce loads in the load data for Perfect Pattern down around 1000 fps (Remington Hulls, Winchester Primers). That would be pretty doggone soft.
 
Discussion starter · #7 ·
Perfect Pattern is a good choice for a soft 12 gauge load.

Not sure what hull or primer you'd be using but they have some one ounce loads in the load data for Perfect Pattern down around 1000 fps (Remington Hulls, Winchester Primers). That would be pretty doggone soft.
Again thanks Tim. I’ll tell him.
 
This is an interesting one to me. So, if there is a 7/8 load for 12ga. Would it not work to have a 7/8 load for 20 gauge? More of a discussion topic. The payload is the same so the physics are the same right?. Before someone calls me dangerous, I don’t condone loading outside of a known recipe but genuinely curious what would be the dangerous part of trying a 7/8 12 ga load in a 20 ga. Shell?
 
The payload is the same so the physics are the same right?
No, the problem is the volume. Fast burning powder in a smaller volume results in high pressure.
 
The volume of the powder? The shot? Or the whole thing? I can agree that the volume of a 20ga is smaller than a 12ga but I guess I envision the wad being there to solve volume issues. The length of the wad column is what increases /decreases the overall space in the shell and the shot cup size is set to hold a certain volume of shot. 7/8 loads already exists for 20ga so I guess I’m still trying to make it make sense. Tim, I certainly am not questioning you as I have seen your numerous works but I’m still failing to understand how this problem can’t be solved by a different wad. Or maybe it can and this wad just doesn’t exist yet. I am only a 12ga reloaded so my 20ga knowledge is not there. I’m also a Perfect Pattern fan in 12ga.
 
Funny this exact topic came up at the range a few months ago. Guy I was shooting with was complaining about no 20ga PP recipes. I said, “interesting, if it’s possible in 12 then it should be possible in 20.” But maybe not
 
You're basically putting a 12g recipe into a 20g chamber and that would result in an increase of pressure to an unknown amount as it hasn't been tested. That's my take. I figure if Hodgdon didn't publish it there's a reason for it.
DG
 
Funny this exact topic came up at the range a few months ago. Guy I was shooting with was complaining about no 20ga PP recipes. I said, “interesting, if it’s possible in 12 then it should be possible in 20.” But maybe not
I have to admit, you're getting out of my sphere of knowledge here, so I am only going by what I have heard from others more knowledgeable than me. So this answer is a little of that, and a little of my own speculation. In other words, I'm pulling this right out of my back-side...

Unfortunately, my go-to guy at Hodgdon that I used to call with these questions, Ron Reiber, has retired and I really don't know any of the new guys. I still have a few sources, so I will see what I can find out.

Generally speaking, the powders that CAN be used for both 12 gauge and 20 gauge fall into the "slow-burning" category. For example, Hodgdon Universal Clays and Hodgdon Longshot.

Perfect Pattern is a pretty fast burning powder so it's suitability for sub-gauge is unlikely.

If you look at the burn rate chart on Hodgdon's web site, you will see that Perfect Pattern is number 5, Universal Clays is number 35, and Longshot is number 54 on a list of fastest to slowest.

As far as volume, it's the physical inside diameter in the chamber we're talking about. That's the key, but I really can't answer your question with 100% certainty.

If you look at a pressure trace for a typical burn (below) you'll see that the peak pressure occurs really fast (less than 1/1000th of a second.)

So fast that at the peak pressure, the stuff in the cartridge has barely moved. Almost all of the powder is burned before the crimp opens.

So when powder burns, it turns to gas. If a unit of gas is confined into a smaller volume, the pressure has to be higher.

I know "empirically" that if you try to use a fast-burning powder in a sub gauge cartridge, and you put enough powder in the cartridge to get a reasonable muzzle velocity, you end up with an unsafe pressure; and if you put in an amount of powder to get a safe pressure, you get a very low muzzle velocity.

I know this didn't really give you the "why" Perfect Pattern can't be used in a 7/8 ounce 20 gauge cartridge, so I will call on some of my resources and see if I can get you a better answer.

Image
 
The ratio of the surface area of the base of the wad to the payload is quite different. With the same powder, the 20 gauge will build pressure more quickly because the payload won't accelerate as quickly at the same pressure. Like Tim said, you'll be trying to pen up the expanding gas in a smaller space.

A slower powder gives the payload more time to get moving while it's building pressure.

Larry
 
Ok! Actually both Tim and FWF provided a lot of stuff that I wasn’t thinking. Especially the surface area of the base wad being smaller comment. That makes complete sense. Also that you can do it but to do it under acceptable pressure would mean a velocity that isn’t to a useful level. I appreciate it gents! Bubbasdad92, thanks for your helpful comment too 😉.
 
I’ve got a buddy that wants to use this powder for 20 gauge loads. I can find plenty of data for 12 gauge, but none for the 20. Is anybody aware of any load data? I looked at a Hodgen load data book and isn’t see anything.
Perfect Pattern will not drive 7/8 Oz. of lead shot to 1,150-1,200 FPS at a safe (on average, as in being on average at or below the SAAMI's 20 Gauge 12,000 PSI MAP) peak chamber pressure. In a world in which most if not all double base shotshell powders reside within a 'relatively' narrow range of rather similar 'total energy' contents for a given weight, Perfect Pattern is designed to release this energy content much too rapidly to remain within deemed to be safe peak chamber pressure constraints for this use.

As an example, the fastest 'relative burn rate' powder that Alliant lists for 7/8 Oz. payloads in 20 Gauge in conjunction with AA and STS hulls within their published 2023 Reloaders Guide is their '20/28' powder. 20/28 sits at position #30 within Hodgdon's July 2024 dated 'Relative Burn Rate' chart. And Perfect Pattern sits at relative burn rate position #6 within the same chart. Hodgdon's Perfect Pattern releases it's inherent energy way too fast for 20 Gauge use.

With powders total energy contents being 'relatively' (as in 'ballpark') similar overall, suitability to safely accomplishing a given task is in large measure about the energy release rate designed into the powder.
 
Discussion starter · #18 ·
Well, I shot my first batch of this powder this afternoon. I must say, I was very much impressed with its performance. I tend to let the birds get out there a bit and it smoked them with authority. The kick wasn’t quite as bad as my 1 1/8 with 700-X. Lastly I got a very good deal on it and my supplier has a lot of it at least for now. I’m pretty well fixed up.
 
HS6 is set for a 20 and Universal has a load or 2. I loaded a Universal load and shot it out of my AL 48 Black Magic. Man it about knocked me over ! Too much light load in heavy gun. It will make a good load though.
 
This is an interesting one to me. So, if there is a 7/8 load for 12ga. Would it not work to have a 7/8 load for 20 gauge? More of a discussion topic. The payload is the same so the physics are the same right?. Before someone calls me dangerous, I don’t condone loading outside of a known recipe but genuinely curious what would be the dangerous part of trying a 7/8 12 ga load in a 20 ga. Shell?
It is a great 12 gauge 7/8oz. powder. Very low recoil. Obviously the barrel diameter of a 20vs12 is significantly different thus the pressures are significantly different.

You should call Hodgdon but I think they will say not to load 20gauage with PP.
Remember the recoil of a 20 can be greater than a 12 depending on the load.
 
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