The advice from loading manuals says do not substitute components. I don't and I wouldn't recommend anyone to substitute.
Yup....and I have been willing to make some exchanges to low pressure target loads....typically under 8,500 PSI but when I start making hunting loads at roughly the 12,000 PSI level I get real squeamish about substituting.
I was once told by a man on Browning's trap team that primers are primers.....load any you have on hand......well. I'm not buying that for a second. However the dealer that substituted hulls based solely on similar internal volume still has me wondering.....
Because I roll crimp all my hunting loads, I can get away with a fair amount of volume difference and still get a good crimp.....I've even put thin felt wads inside the shot cup to take up room when the shot didn't fill enough.
I think the above post by Saskfox is sage advice.....Let's hear others on this subject.