I have had 3 inertia pullers, broke all 3 fairly quickly. Moved onto the RCBS Collet Puller, it handles all but 1 of my calibres with ease. The 50 cal collet for 505 Gibbs kept breaking trying to pull heavily crimped 600g bullets, they are too thin and easily break, have broken a collet on a 500 Nitro too, but I think it was already cracked from use on the 505 Gibbs. Each collet isn't cheap, but rarely poses a problem, other than the thin 50 cal, the 45 cal has never broken. I have every cal but 24…no need, I'll never own a 6mm anyway.
Cheers.