dp,

I have the same gun in .45 and shoot 60 grains of 3f goex with either a prbor a 285 grain hollow point/hollw base conical from buffal bullet company. I use a wad with both and at 50 yards both shoot really well. I haven't put the gun through a serious range session yet, but the shooting I have done I am happy with.

Mine also does not have "cabela's" anywhere on it and you are correct that it is produced by Investarm. They are solid guns and you should be happy with it, especially for that price, you practically stole the gun.

Here's a link to the manual:

http://www.investarm.it/media/pdf/manuale_avancarica_uk.pdf

It seems pretty vague, but it does list max loads.

Good luck with the new ML'er.