freebore 358 norma magnum
Hi all, I've been researching my 358 Norma Magnum for reloading info with the supplies I can obtain in my local area, It's like looking for parts for some old car where not much is in stock, and with the primer and case availability, its a challenge...Other than I am still looking for an item or two I was interested if the 358 Norma uses freebore to attain better accuracy as some particular guns do....It could be that most don't mess with freebore and load the listed tables from bullet or powder manufacturers......and do just fine....any idea's?? thanks for your time.....Gene
Most factory 358Ns are freebored to reduce pressure so that more powder can be loaded for higher velocities. This usually does not help accuracy and may reduce accuracy because of the long bullet jump. 358N cases can easily be made from 300WM by sizing with the 358 dies and trimming to length. It helps to prevent case loss if you go up in smaller sizes such as 8mm or 338 first although I have made them in one pass. They can be made from 338 cases but they should be fire formed and they still end up with a short neck which when combined with a long throat can make for accuracy problems. If you have a gunsmith cut chamber it may or may not be freebored and you should check before using loads for the freebored chamber as it can elevate pressures if not. It is a very good Alaskan caliber but only for those that reload as loaded ammo is very scarce and very expensive. Mine is shooting a 250gr at 2880 without pressure signs. I would really like to see American gun makers chamber for this one.