pressure differences in different length hulls with slugs

[jason f]

When using gas seals and nitro cards to adjust column height for a fold or roll crimp. I have read from different post on here to use longer hull. Why? If using same powder charge in different length hulls is there a pressure difference?

[Bullshop Junior]

I would imagine that there would be. Probably not a whole lot, but some.

[turbo1889]

According to my pressure trace records, when you put a load for a shorter shell in a longer hull and just add nitro cards to make up the difference in wad-column height the pressure goes down slightly. If you do things the other way around and take out cards to fit a load for a longer hull in a shorter one pressure goes up, sometimes just a little, sometimes a lot, sometimes way too much to be safe depending on the load.

I have yet to see a case where putting a load for a shorter hull in a longer one and adding cards to make up the difference created a problem. I have seen a few loads where putting a load that was fine in a longer hull into a shorter one did create a potential problem with a load that was over pressure, but not always.

[Bullshop Junior]

According to my pressure trace records, when you put a load for a shorter shell in a longer hull and just add nitro cards to make up the difference in wad-column height the pressure goes down slightly. If you do things the other way around and take out cards to fit a load for a longer hull in a shorter one pressure goes up, sometimes just a little, sometimes a lot, sometimes way too much to be safe depending on the load.

I have yet to see a case where putting a load for a shorter hull in a longer one and adding cards to make up the difference created a problem. I have seen a few loads where putting a load that was fine in a longer hull into a shorter one did create a potential problem with a load that was over pressure, but not always.

Thats kind of what i was thinking. Its kind if like shooting 38 loads in 357 cases.