barefooter56
Well-Known Member
- Joined
- Nov 10, 2014
- Messages
- 913
climb-101,I did some quick measuring tonight on the cases. the neck measurement according to the Sierra book is .372,
my fired cases measure .372 outside and .340 inside and the SMK is .337
loaded cases measure .367
I also measured the neck thickness and its .014 thick.
so what I'm seeing from the numbers the case is expanding at the neck .003 to let go of the bullet. I am assuming that this is plenty of expansion and that the chamber isn't too tight. any body have any other thoughs on these numbers, possable measurements of there own to compare them too
Looks like you have plenty of clearance for adequate release of the bullet and your gunsmith gave the rifle his OK. You may want to make a dummy round to the lands using a once fired, neck sized case from that rifle that still chambers smoothly. After you have the dummy round made . Polish the tarnish off the bullet with some 0000 steel wool , chamber the round and check for lands marks on the bullet. If there are lands marks of any length. Begin to seat the bullet lower in stages until the lands marks are about the same thickness as the mark of the point of a really sharp #2 pencil point makes on paper. Be sure to polish the lands marks off the bullet each time before you re-chamber it after seating the bullet lower. Now measure this round with a set of calipers and a bullet comparator of your choice and a magazine length dummy round loaded in a fired case. Lets see how close to the lands your mag length ammo is to see if may be an issue. Process = eliminate one thing at a time , test and note result as you go along.