10 gauge loading question

[George Lang]

I am currently loading 1 1/4 oz Nice Shot 10 ga. loads in both Remington and Federal cases using Sherman Bells loads for 1 1/4 oz. Bismuth in these cases. According to his info they develop 5900 and 5800 psi respectively with roll crimps. My questions are what would happen to pressures if I used the 6 point crimp instead of the roll crimp and is there a difference in pressure between Nice Shot and Bismuth? Also what is pressure difference between lead, Bismuth and Nice Shot? Thanks for your input.

[Pete Lester]

I am all for experimenting within reason but there is no comparing Nice Shot to Bismuth and by substituting Nice Shot for Bismuth in a published Bismuth load means you have no idea what the pressure is. There is only one published load for Nice Shot in the Short Ten and it is a 1 3/8 ounce load. Nice Shot can be substituted for lead in any published load but you must add 1500 psi to that load when using Nice Shot. Bismuth being lighter requires a taller shot column than an equal weight of lead. That means more surface area against the bore and more pressure. I would not feel good substituting Nice Shot for Bismuth but I would be fine using it in a lead load with low pressures. From what I understand all things being equal a roll crimp reduces pressure 600-800 psi over a folded crimp all else being equal.

[charlie cleveland]

pete i thought a roll crimp had less pressure than a 6 point or 8 point crimp..charlie

[Frank Cronin]

Follow the lead recipe for 1 1/4 oz and take account with additional PSI increase like Pete said. I would not shoot the loads you have that have bismuth since the pressures are unknown.

I have used Long Shot with 1 3/8 oz of Nice Shot #2 for ducks and geese and I believe Pete has it in his 10 gauge spreadsheet. I put a 16 ga. felt wad in the shot cup under the shot for better crimps for this load. Devastating load to feather'ed critters....

http://www.randywakeman.com/Nice_Shot_Reloading_Data_10_Gauge.htm

[Steve Havener]

The only way you are going to know for sure is to carefully load at least 3 shells preferably 5 and send them to Tom Armbrust for pressure testing.

[Frank Srebro]

That means more surface area against the bore and more pressure.

I understand that bismuth would have more surface area against the bore as compared with lead (with the same weight/diameter of shot), but why would that result in more pressure? Can you please elaborate? Thank you.

[Paul Harm]

I too thought a roll crimp had less pressure than a fold crimp. The depth of a crimp effects pressure whether a fold or roll, so maybe a deep roll crimp would have more pressure than a normal fold crimp. If you're loading at low pressure with normal depth crimps I don't believe it makes much difference which crimp you choose. JMHO

[Pete Lester]

Charlie and Paul, what part of my last sentence is/was not clear?

"From what I understand all things being equal a roll crimp reduces pressure 600-800 psi over a folded crimp all else being equal."

[charlie cleveland]

i reread this thing 4 times..i dont know where i got this in my head that you said roll crimp was more pressure than 6 point or 8 point crimp..pete plainly states 600 to 800 lbs less pressure with roll crimp...my mistake...charlie

[Pete Lester]

I understand that bismuth would have more surface area against the bore as compared with lead (with the same weight/diameter of shot), but why would that result in more pressure? Can you please elaborate? Thank you.

Frank, chamber pressure is created by the resistance of the ejecta against being moved forward. Resistance is either + or - by changes in the weight of the ejecta and by changes in the amount of resistance/friction of the ejecta against the barrel wall. An equal weight of Bismuth, say 1 1/4 ounce has a much longer shot column compared to 1 1/4 ounce of lead. (1 1/4 ounce of Bismuth has a little more surface area against the bore than a 1 3/8 of lead.) The larger surface area of the shot column creates more resistance through friction and increases pressure. That is why Bismuth can not be loaded using lead recipes for the same weight with an expectation of similar pressures.

[Frank Srebro]

Pete, thanks for the detailed writup. It's good advice not to use lead recipes for the same weight (mass) of bismuth shot.

[George Lang]

Pete my question is what the effect on pressure would be if I substituted Nice Shot for Bismuth using Sherman Bells info. The loads listed for BISMUTH are:
1- Rem hull, 1 1/4 oz. Bismuth, 29grns 7625, SP10 wad, 24 grns PSB(or not), roll crimp--1083fps/5900psi.
2-Fed hull, exactly the same components except 30 grns 7625 for 1084fps/5800psi.

What would the effect on pressure be substituting Nice Shot for Bismuth???

Thanks, George

[Pete Lester]

Pete my question is what the effect on pressure would be if I substituted Nice Shot for Bismuth using Sherman Bells info. The loads listed for BISMUTH are:
1- Rem hull, 1 1/4 oz. Bismuth, 29grns 7625, SP10 wad, 24 grns PSB(or not), roll crimp--1083fps/5900psi.
2-Fed hull, exactly the same components except 30 grns 7625 for 1084fps/5800psi.

What would the effect on pressure be substituting Nice Shot for Bismuth???

Thanks, George

I don't know, substituition of Nice Shot for Bismuth does not make sense to me when the folks at Nice Shot tell us it can be substituted for lead in any published lead recipe BUT you must add an additional 1500 psi to that lead recipe when using Nice Shot.

Given that, why would you not choose one of the Sherman Bell recipes for lead using a Rem hull and SR7625 powder? I see some on the 10ga spreadsheet that would be about 8000 psi using Nice Shot (and that is with a folded crimp).

[George Lang]

Pete I do currently load Nice Shot using lead recipes. I was just wondering would the relationship, pressure wise, would be between Nice and Bismuth. I reread my original post and it should have read; I am currently "LOOKING "to load----. It would seem that the switch, in the above loads, should be equal or less pressure when using nice shot??? I know this is all speculation and we won't know until some actual pressure tests are performed. George

[Pete Lester]

Pete I do currently load Nice Shot using lead recipes. I was just wondering would the relationship, pressure wise, would be between Nice and Bismuth. I reread my original post and it should have read; I am currently "LOOKING "to load----. It would seem that the switch, in the above loads, should be equal or less pressure when using nice shot??? I know this is all speculation and we won't know until some actual pressure tests are performed. George

I am curious, since there are published lead loads with known pressures using the components you listed why would you like to substitute the Nice Shot in a Bismuth load for? What are you trying to achieve, lower pressures?

[George Lang]

I have both Nice and Bismuth on hand and curiosity took hold of me, and pressure was a consideration especially if a 6 pt crimp was used. I would like to keep psi under 7000 and was looking at possible ways to achieve that using Bells data swapping out combos of shot and crimps.

[Pete Lester]

I don't know that you can achieve that goal of 7000 psi. I see a 1 1/4 ounce load of lead using 29gr of 7625 and folded crimp in the Rem Blkltr hull, it develops 5900 psi. 1 1/4 ounce of Bismuth in that hull with 29gr of 7625 develops 5900 but uses a roll crimp. My guess, and it's just a guess is you would be around 8000 psi with 29gr of 7625 and Nice Shot, probably lower if you use a roll crimp. You would have to send it out for testing to confirm it.

[George Lang]

Pete are you saying that Nice Shot would have higher psi than Bismuth? It would appear that 5900psi minus approx 600psi for roll crimp plus 1500psi for nice shot should be about 6800/7000psi, or am I missing something? I've only recently started to load for shotshells(0nly 10 ga so far) and I'm sure that there must be more variables then I'm familiar with at present. That's why I'm asking I need to be educated and enlightened. Thanks.

[Pete Lester]

The difference betwen equal weights of Lead vs Bismuth is the height of the shot column and amount of surface area in contact with the bore. 29gr of 7625 is 29gr of 7625. With the lead load you generating 5900 PSI. Nice shot has the same size shot column as lead, but because it's harder than lead it generates more pressure as it has a harder time squeezing down through the forcing cone. This puts you up around 7400 psi with a fold crimp. Using a roll crimp will drop pressure, maybe 600, maybe 800 maybe even a 1000. Only testing will tell for sure. I would stay with the low pressure lead load and add 1500 psi. I can't imagine a sound Parker 10ga having an issue with an 8000 psi load. If you go too low you risk bloopers, especially in cold weather.

[Pete Lester]

Duplicate Deleted.

[Paul Harm]

My mistake- maybe a brain fart.

[George Lang]

Does anyone have contact info for Tom Armbrust? I assume he is the person that pressure tests shotgun loads.

[Steve Havener]

Tom Armbrust
Ballistic Research
1108 W May Avenue
McHenry. IL 60050-8918

Ph 815-385-0037