Thread: So this happened at the range.

So dealing with the 303 first, either (a) make a chamber cast or option (b) get a case, fill it with a harder lead say 4mm from the top, let it set (always helps!) then get a projectile at least a few thou over bore diameter……..and here’s why, ive had a good number of 303’s with a massive difference in actual bore size, remember that the tooling dies wore over time and there were variations, big variations, back to option (b) place that fatter projectile into the neck of the case, place it lovingly into the breach and close the bolts, here’s the trick, if it requires some extra love to get her home that’s all good, to really finish the job, get the cleaning rod, take the end jag of and put the rod down the barrel against the projectile, keep the bolt closed and tap the rod, you are trying to squash the projectile so it fills out against the groove and lands, open the bolt and push the projectile out…

Here’s the fun, measure the diameter, now aim for say 2 thou over for THAT rifle as your sizing, now repeat with out ramming the rod down the bore, this will give you the ability to understand seating depth, also keep the round as you can do the same for other 303’s

You want the projectile to engrave rifling……but also with the ability to cycle the bolt and have the round eject…..with projectile! I always kept a cleaning rod with me for the whoopsy moment.

The next aspect will be playing with the most gentle approach to applying neck tension, also I can’t recommend getting a case neck flaring die to help in the process…..