i was just loading up some 6mm cr, with some hornady 100 gr that i have been using for my 243. i set overall length to match a factory cartidge and there is lot of space between case mouth and cannelure.

i have 2 questions
1-does this make a difference in accuracy
2- would i be safe in seating bullet all the way down to the cannelure

thanks for all the help

Are you measuring to the tip of the bullet? Or to the Ogive to duplicate the factory cartridge?

the tip

Most bullets don't have the cannelure, so it doesn't affect accuracy much if at all just by being there. If you use it to crimp the bullet, it can change things. Namely neck tension and concentricity. Since that bullet was designed primarily for the .243 and 6mm Rem, where they placed the cannelure on it reflects where it should be placed based on the OAL of those rounds.

Seating the bullet down that far in the 6 Creedmore will only increase the jump, and it will effectively create more freebore which lowers chamber pressures. If your chamber is concentric with the bore, and your rounds are very concentric, it can shoot very well with lots of freebore especially if your cases are neck turned.

thanks for clarifying

You need to measure your magazine as to how long you can seat a bullet out and try it in your chamber, then adjust the depth to match the magazine, so it will feed..normal is .050 off the lands for accuracy but that a bunch of hooey..You have to play with that as to where it shoots best..This is not as hard to do as it sounds..Once you get it figured out to where it feeds and chambers properly, it will in most cases group just fine..That jump that folks talk about is much over rated, all that counts is at the target..

Dear OP,

#1- Yes it does make a difference. Most of my rifle shoot best between 25 thousandths jump and 5 thousandths jam (be careful with jam for a hunting rifle). Barnes shoot best 35-50 thousandths off the lands.

#2- Yes, it's safe but why would you do that and create all that obnoxious free bore or jump while reducing case capacity?

Get the right tools to measure the base to ogive "BTO" with each specific bullet and go from there. No sense guessing nowadays.

...or just throw them together and hope for the best. You might be happy enough anyway!

Zeke

quote:

Originally posted by ZekeShikar:
Dear OP,

#1- Yes it does make a difference. Most of my rifle shoot best between 25 thousandths jump and 5 thousandths jam (be careful with jam for a hunting rifle). Barnes shoot best 35-50 thousandths off the lands.

#2- Yes, it's safe but why would you do that and create all that obnoxious free bore or jump while reducing case capacity?

Get the right tools to measure the base to ogive "BTO" with each specific bullet and go from there. No sense guessing nowadays.

...or just throw them together and hope for the best. You might be happy enough anyway!

Zeke

What Zeke said, but, like he said, don’t jam bullets in the rifleing for hunting. I like to just kiss the lands, if it comes to that, but never jam. If you really want to jump down the accuracy game rabbit hole, check out the Sinclair International catalogue. They have all of the tools for target shooters and accuracy nuts.

I think people are falsely paying too much attention to this for hunting.

For bench rest match shooting you can play with it as much as you like.

For hunting rifles I load the ammo to the maximum over all length for that cartridge - if the bullet and the magazine would allow it.

Lighter bullets are too short for this, so I seat them one caliber in.

That is it.

Been working for us so far, and I don’t listen to too much bullshit on the Internet!