Size of case mouth for rifle

[CBP]

I purchased an RCBS 2 die set for my 6mm Rem. I set the dies in my Lee Turret press the other night and ran a test case through the full length resizing die. Next, I trimmed the case to length and chamfered the inside and outside of the mouth. Since this was a test round, I didn't add the primer or powder. Next step was to seat the bullet to the proper depth so i could get the correct adjustment for the die. I could not get the bullet started in the mouth of the case. T he bullets are 100 gr. Core-Lok. Since I have been re-loading pistol for about 1.5 years, I was used to the case mouth being belled with the powder charging die so I could start the bullet. Should I be able to start the bullet in the case mouth or not? I did seat the bullet by aligning it with the case mouth and holding it into place as I raised the case into the die, but the bullet fell against the side of the die. Seating the bullet seemed "hard".

I measured the diameter of the expanding plug on the decapping pin. It measures 0.2415, which is 0.0015 inch less than the bullet diameter. According to the Lee manual, the neck should be 0.001" less than the bullet. Am I wrong to think that the bullet should be able to be started in the case mouth of a rifle cartridge? No way for that to happen if the case is to be smaller than the bullet. It just seemed strange to have the bullet fall against the inside of the die. Maybe just one of the nuances that makes reloading pistol different from rifle. I thought maybe the expanding plug was too small, but possibly everything is correct.

 

[ranger335v]

Lee is correct so far as "ideal" neck inside sizing (expanding actually) for best run-out. Most die sets leave the necks significantly smaller than is best and many people (incorrecdtly) think the extra "bullet tension" means a tighter bullet grip. That's really not true, it just makes the bullet be the expander, actual bullet grip will never be more than 1-1.5 thou because the brass simply stretches after that much.

Part two, it's difficult, sorta, to stop the bullets from tilting as they are raised in the seater and it really doesn't much matter, so you are wrong to expect the bullets to start before seating begins. But with conventional seaters, the bullets are pushed into the tighter upper section of the die and held there fairly straight before seating begins.
(A Lyman "M" die's expander plug does allow bullet heels to enter the case mouth - I love that die for that reason, have one for every cartridge I load for - and can make seating slightly more straight.)

 

[ole farmerbuck]

Lee is correct so far as "ideal" neck inside sizing (expanding actually) for best run-out. Most die sets leave the necks significantly smaller than is best and many people (incorrecdtly) think the extra "bullet tension" means a tighter bullet grip. That's really not true, it just makes the bullet be the expander, actual bullet grip will never be more than 1-1.5 thou because the brass simply stretches after that much.


I have to disagree with that. (bullet tension part) I have 2 Lee neck size dies i use for .223. One for the AR's which is turned down to leave the case mouth at .219. The other is for the bolt guns and it leaves the case mouths at .222 .5. Trust me, when i pull a bullet from each, i can tell which die they were resized with.