Reloading a shorter 12g shell

[Chasingpink]

I am looking for some input on this
I would like to reload shorter 12g shells. I am unable to find much info on this.
First does the space between the powder and shot make difference in chamber pressures?
Could one compress a wad a little to fit the cut down shell with out raising the pressures to much?
Could one take the load data from 2 3/4" shells and not have them blow up in ones face?
Is there any good books or web pages forums for this?

Thanks

 

[Rookie{OMC}]

I use this wad, http://www.ballisticproducts.com/Short-Shell-Wad-12ga-250_bag/productinfo/072SSW/

I get them from, h ttp://www.bilozir.net/ballistic_products.htm he's just south of Calgary a bit.