7MM Remington Mag neck tension

[Kuyong_Chuin]

My brother finally got everything I need to load up some 7MM Remington Magnum rounds for him at least till the time comes when I have to trim the brass. So I was laying here messing around with one of the new cases that he bought as well as some of the once fired cases and got curious on how much of the bullet is actually in the case. So I am holding the bullet to the side of the neck and move the bullet to the point to where it would be at the min OAL so I could mark and measure the bullet. While holding it up, the hole in the neck looked too big to me so I took the bullet and started to push the bullet in the neck of the brass by hand. Sure enough I can push the bullet all the way to seating depth and back out with my fingers. For a round that everyone and his neighbor is telling me it doesn't have to be crimped because it is in a bolt action rifle this scares the heck out of me that the bullet is that loose in both new and unsized once fired brass. Up till now I have loaded pistol rounds only and the bullets are never so loose that I can more than just start it in an expanded case. If the bullet is that loose in this round and you don't crimp it what is supposed to hold the bullet in place? Because unless the seating die resizes the neck tension to me this is a dangerous situation and I want the round to be safe as well as accurate for my brother.

 

[jwrowland77]

Resize the case and the bullet should hold just fine.

I reload for my 7mm RM and I never crimp the bullet in place. I never crimp any rifle round.

 

[beeenbag]

Resizing the case also resizes the neck back DOWN. Run a case through the resizing die, then try that again, I bet it will not go by hand.

 

[rcmodel]

No way should a bullet be that loose in a brand new unfired case.
They are already sized the right size when they make them.

First thing you need to do is measure the bullets and see if they are actually 7mm (.284"), or something else.

Sounds like you got hold of some .270 (.277") bullets to me.

If they are in fact .284" bullets, then resize the new cases and try it again.
But you shouldn't need too.

Rc

 

[gamestalker]

Is this condition happening with the new brass, or the one that has been fired? Either or, just resize it, problem solved.

GS

 

[Kuyong_Chuin]

No way should a bullet be that loose in a brand new unfired case.
They are already sized the right size when they make them.

First thing you need to do is measure the bullets and see if they are actually 7mm (.284"), or something else.

Sounds like you got hold of some .270 (.277") bullets to me.

If they are in fact .284" bullets, then resize the new cases and try it again.
But you shouldn't need too.

Rc

I measured the samples from both boxes of bullets and they are .284 rounds. I can push the bullets in with my fingers on both the new brass and the unsized once fired cases. Some of the once fired cases are looser than others but I have yet to find one that I couldn't put in or out with just my fingers. I'll run one through the sizing die to see if it tightens the neck up.

 

[rcmodel]

Fired brass is supposed to be loose.

Brand New brass isn't supposed to be loose.

rc

 

[BYJO4]

You need to size the case whether it's new or not. That should eliminate your problem. Neck tension should hold the bullet and require you to use your press to seat the bullet.

 

[jwrowland77]

You need to size the case whether it's new or not. That should eliminate your problem. Neck tension should hold the bullet and require you to use your press to seat the bullet.

I generally never have to resize new brass but I may start.

I just went through 500 .308 win Winchester headstamp new cases and didn't need to resize at all. All I needed to do was run the case mouth up into the die just enough to make sure it was a circle.

Sounds like though, resizing regardless new or old might be the fix.