Thread: Projectile Bearing Surface vs neck contact vs jump to lans

Got some of the new 120 gn speer gold dots to try as a hunting round in the 6.5 creedmoor
Playing with seating depths today and I can drop a projectile in then chamber a case with only about 0.01 Bearing surface in the neck so Obviously going to have a massive jump to the lans

But just how much bering surface needs to be in the neck
To make a good Reliable load a mate told be he always has at least a projectile diameter of bering surface in the neck
But in this case that would be a .264” jump to lans
Which is massive

What’s your options

In your case with a hunting rifle / load, you should limit your COL to whatever is max so it still fits in the magazine to get a quick follow up shot on it's way.

No worries there @JaSa the mag has been modified to hold 2.930 so plenty of mag space
Generally I would just load to mag length in a hunting rifle though

Your mate is right, especially for hunting. With rounds in a magazine the bullet can move back under recoil. You can of course get away with less but only advisable in a controlled single load target situation. You could also try seating the bullet to .250 and see how it shoots. I normally increase the neck tension via a smaller sized bushing for cases that have minimal length of grip on a bullet.

I have found a couple of mm of bearing surface being held in the neck to be fine in a hunting rifle but only a 308 so light recoiling.

Originally Posted by rambo-6mmrem

Got some of the new 120 gn speer gold dots to try as a hunting round in the 6.5 creedmoor
Playing with seating depths today and I can drop a projectile in then chamber a case with only about 0.01 Bearing surface in the neck so Obviously going to have a massive jump to the lans

But just how much bering surface needs to be in the neck
To make a good Reliable load a mate told be he always has at least a projectile diameter of bering surface in the neck
But in this case that would be a .264” jump to lans
Which is massive

What’s your options

if it wasnt me that told you thats what i do and its worked so far for me

I would seat at least bullet diameter into the neck. Some of my rifles have over 200 thou jump and shoot very well. I also find 20-45 thou jump is fine,even with secant ogive bullets. Neck sized fireformed cases work just fine this way.

Its more a doughnut reducing move the whole 'put it back one diameter length' things isnt it? I recently read an artlcle where some bench rest guy cut his necks back 99% and they still performed with precision.... i'll find it and stick it on here. Ugliest bullets on the planet and damn them for shooting well!

Wildcat with Almost No Neck — Stan Ware’s Wicked Wolfpup « Daily Bulletin there it is. Witchcraft