Would anyone have a good low pressure load for Cheddite/RST 2.5" hull? I'd like a 7/8 oz load. Recently closed a deal on a very nice English box lock. Tried it out using RST 7/8 oz at 1125 fps and it performed quite well.
Suggest that you look at some of the published loads using 800X & Windjammer wads.
800X is a tricky powder. It meters much better in single stage loaders than it does in progressive loaders with the exception of Spolar. It is a large flake that does not flow as well as smaller flake powders. I also find humidity changes seem to make a big difference so check your powder drops when you get started.
On a 600jr it will work flawlessly because the handle goes up and down multiple times more than the bar goes back and forth. So over multiple stations use, the powder gets repeatedly vibrated down, the same way over and over again so the powder drops are very equal. on a 650 , grabber or later loader powder gets dropped every time the handle gets lowered and then raised. And if you don’t do it with the exact same speed and exact same clunk at the bottom and top of the cycle the powder can be slightly different in drops.
When you go on the powder makers web site look at Federal hulls. Some decent loads there. Do figure out what pressure level you are after. A 20 will run a bit higher than a 12 so you won’t find many 5-6,000 psi but you can find some 7-8,000 psi. Figure what your gun was proofed at and look for a 60-80% service load. I try to keep my loads at 8,000 or less. A lot of options at that level on both Alliant and Hodgdon.
Relative to bore capacity a 7/8 oz load in a 20 gauge is approximately proportionate to a 1¼ oz load in a 12 gauge. You won't find many super low-pressure loads in 12 gauge either for 1¼ oz loads. For true low-pressure loads in a 20 one needs to drop to no more than 3/4 oz of shot which is equivalent to the 12 loads of 1 1/16 oz.
I’m not at home but there are several decent loads using, 572, 20/28, unique and even herco.
Do be aware Remington 20’s often measure 2 9/16” not the full 2 3/4”. I trim them down to 2 1/2” with an exacting knife and a homemade chamber adapter that I just stick the hull into and trim off what sticks out above the top. I can still fold crimp them so super easy. I load them on a Spolar reloaded and it takes about five minutes to get my crimp fully adjusted.
Rem hull trimmed 2 1/2”, unique 16.5, rem 209p primer, orange duster wad, 1155 FPS, 7.7kpsi. My shot bushing drops about five to seven pellets light with 7 1/2 shot so I’m slightly under 7/8 ounce. With 9’s it’s spot on. You could vary the load down to 15.5 grains for Summertime use and a bit lower pressures. When in doubt load up six and send them out for pressure testing.
Find a load close to what you want and modify to suit your needs. Then load six and get them tested. After that you have an nearly endless supply of safe reload, if you pick commonly available components. Known, verified pressures with decent velocity.
Definitely try 20/28. It meters extremely well and is a dense powder.
Winchester AA hulls are a good choice. I prefer a brass base for older guns. The hulls measure in at around 2 5/8 so little to no trimming.
These 3 are out of the Lyman Shotshell Reloading Handbook, 5th Ed.
They are listed for 2 3/4" Cheddite hulls. I use the first one myself in 2 1/2" Cheddites. I use either used RSTs or I once found some paper 2 3/4" Cheddite hulls and just cut them down to 2 1/2". You have to roll crimp it for the shorter case. The Blue Dot loads perform well, but they are a little loud and very dirty.
20ga Cheddite Hull
Ched 209 Primer
RXP20 Wad
24 Grains Blue Dot
7/8oz Shot
1259 FPS
7300 PSI
20ga Cheddite Hull
Ched 209 Primer
WAA20 Wad
16 Grains Unique
7/8oz Shot
1186 FPS
7200 PSI
20ga Cheddite Hull
Rem 209P Primer
RXP20 Wad
17 Grains 800X
7/8oz Shot
1200 FPS
6600 PSI
Thank's all. Gives me a place to start my investigations. Matt, the 16 grain Unique load look's promising. How do you find the WAA20 wad for a fit in the Cheddite hull? Have you done any loads using 3/4 oz. shot? 3/4 oz. in a 16 or 12 break clays nicely and should perform well in a 20 as well. 7/8's was chosen for a field load and a target load. 3/4 may make a better target load. My RST flats just came in and I'll have the winter to set up for reloads.
Eric, the only one I've actually used the Blue Dot load as I have plenty of components for it. All of those were intended to be fold-crimped in a 2 3/4" case, so I would be prepared to roll crimp any of them.
I recently shot some 3/4oz RSTs and I was surprised how hard they hit clays. Good luck!