Everyone breathe...
Jeepster 11,
I reviewed a few of your previous posts, so I am basing my assumptions off of what you have written in the past.
From your first post in this thread, I understand that you have loaded both Speer and Hornady bullets in a .308 Winchester case. Thus far, the cartridge with the Speer Bullet would not chamber, but the cartridges loaded with Hornady bullets would.
I have concluded that from your posts on other threads that you load straight wall cartridges (.500S&W .460S&W and 45-70govt). There are significant differences in loading bottle necked cartridges and straight walled cartridges. What loading manual are you using? Both Speer and Hornady manuals cover the topic pretty well.
To cover the reason that some would chamber and others would not, we will need some information.
1) What is the specific bullet you are using? The manufacturer's number will be on the box and in the loading manual for both Hornady and Speer.
2) What is the overall length you are loading both the Speer and Hornady bullets to?
3) Where did you get your brass from? If it is once fired military, it could be oversized from a too generous chamber.
4) Are you full length sizing your brass? if so, do you know how to adjust the die? Remember, this where straight wall and bottle neck reloading differs.
5) What overall length are you loading the rounds to?
6) What length are you trimming your brass to?
7) Where the heck did you get your load data from? a quick check at
www.hodgdon.com has you WELL UNDER the starting load! If you have not consulted a manual, PLEASE DO SO! This becomes less a matter of accuracy and more a matter of SAFETY.
8) I am not aware of a "Italian mauser", except that one might mistake an Italian Carcano chambered in 7.35x51mm Carcano with a worn chamber for a .308. OR, your associate has a sporterized Mauser, whuch might have an improperly cut (read: too deep) chamber.
Loader9 is correct that improper loading could cause great harm or even death. Please provide as much info as you can so we can help and maybe keep you safe.
VR
Matt