Thread: 228 Speer projectiles in 223.

Still a stupid idea. Where would you get data from? Regardless of shape the extra dia will push pressure up. How much? Who knows? The target shooters used to use undersize barrels to help the crappy NATO projectile shoot better but that was a projectile with hardly any full dia body in a much larger bore. Sounds like someone may be trying to unload something. Get the right projectile.
GPM.