quacker--
As the RSI manual used HeviShot, if you have a denser material, the RSI data should be conservative. That is, the denser shot should produce less pressure, making it safe to load with that data. The key word there is "should be"... only you can decide what reloading substitution risks you want to accept.
This product announcement from Remington indicates the density is 12.0 g/cc.
https://www.remington.com/news/2006/rem ... ammunition

This is nominally the same density as HeviShot, as well as the same hardness relatively (tungsten based hard stuff). If this is accurate then 1oz of #6 pellets should be sufficient. That's 206 pellets. I would use RSI #26 or 27 for 1oz recipes. However, those are 1500 and 1575 fps, which is totally not needed for HD #6 shot... I might drop the powder a bit myself.
At 1500 fps you'd get 60 yds for 1.5" gel penetration, and 36yds for 2.25" gel penetration. You decide for yourself what the relationship between gel penetration and duck/goose lethality is, these are the numbers I think are reasonable.

 

Lot of the problem I've been finding with the lighter weight HS/HW loads is STEEL powder just seems to be to slow burning for many of them, from what I've been seeing from Pressure Trace results because of increased density HW shot produces a lot less pressure than steel shot loads do, sometimes upwards of 15-20% less than steel loads of equal weight.
Haven't worked on to many lighter weight 12 gauge loads yet but I'm thinking I may try Blue Dot in some of the lightweight RSI recipes that call for STEEL powder.

 

I'm leaning towards RSI #21 which is a 1-1/8 oz load in an Win AA hull @ 1500 fps. The recipe calls for37gr of ASTEEL. How much can I drop that charge and still be safe? I would like to get the velocity into the 1350-1400 fps range if possible.

 

Unique in 1oz load 1250fps, 10;500 psi.

 

Does the more sense shot create less pressure because there is less volume, therefore less surface area contacting the bore?

 

Does the more sense shot create less pressure because there is less volume, therefore less surface area contacting the bore?

yes. So long as you keep the same weight payload.

 

I'm leaning towards RSI #21 which is a 1-1/8 oz load in an Win AA hull @ 1500 fps. The recipe calls for37gr of ASTEEL. How much can I drop that charge and still be safe? I would like to get the velocity into the 1350-1400 fps range if possible.

you can drop it to zero and be safe... less powder in a recipe is always "safe"-- so long as you don't get so low, maybe below 5000 psi, that ignition/burn becomes unreliable. But there are tons of folks and guns that shoot all their loads at 5-6000psi. Just dirty usually. I'd try 33 or 34 gr asteel and see what speed you get.

 

Does the more sense shot create less pressure because there is less volume, therefore less surface area contacting the bore?

Maybe not the best analogy to explain it, the old pound of feathers and pound of rocks comes to mind. They both weigh the same but if you wanted to toss the pound of rocks 50 feet it takes a lot less force than to toss the pound of feathers just because of the lighter weight and volume of the feathers.

 

Does the more sense shot create less pressure because there is less volume, therefore less surface area contacting the bore?

Maybe not the best analogy to explain it, the old pound of feathers and pound of rocks comes to mind. They both weigh the same but if you wanted to toss the pound of rocks 50 feet it takes a lot less force than to toss the pound of feathers just because of the lighter weight and volume of the feathers.

No, actually I would say thats a pretty good analogy. Makes sense

 

I had a 1 oz TSS load tested in a 2-3/4" Federal Gold Medal hull, with Steel powder a 35 mm TPS wad with a BPGS under the TPS wad. If you want to see this data sheet send me your e-mail address in a PM.

It has good speed over 1400 fps and uses around 7.0 gr less Steel powder per shell than some of the RSI 1 oz loads.

 

I had a 1 oz TSS load tested in a 2-3/4" Federal Gold Medal hull, with Steel powder a 35 mm TPS wad with a BPGS under the TPS wad. If you want to see this data sheet send me your e-mail address in a PM.

It has good speed over 1400 fps and uses around 7.0 gr less Steel powder per shell than some of the RSI 1 oz loads.

Thanks, but I only have enough shot for maybe 40 rounds so I'm going to stick with RSI because I already have all the components needed. After this shot is gone, I'm sticking to all steel loads.