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One of the best tests of crimped vs no-crimped bullets was conducted by an arsenal making 30 caliber match ammo for M1's and M1903 .30-06 match grade rifles. Several hundred rounds of ammo using the same lot of bullets (with cut cannelures for crimping case mouths into them), cases, primers, powder & charge weight and assembly tools and dies were made with each type. Accuracy with the non-crimped bullets was 20 to 30 percent better than the crimped ones.
A few lots of non-cannelured bullets were made and loaded the same way but without crimping. These produced better accuracy than non-crimped cannelured bullets. So the arsenals quit crimping and canneluring those 172-gr. FMJBT match bullets.
It's easy to see how much crimping non-cannelured bullets get deformed and unbalanced. Crimp some bullets into sized cases without powder or primer. Use an impact bullet puller (with a rubber pad in its nose for the bullets to bounce off of so they're not deformed) to get the bullet out of the cases. Roll the bullets on a flat steel plate with a bright light shining on their far side then look at the gap between the plate and bullet. You may need a magnifying glass to see how the bullet's waist at the crimp point varies its gap to the plate. That gap's typically not uniform; evidence the bullet's been unbalanced.
If you want to shoot unbalanced bullets, do so. But they won't shoot very accurate.
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