Neck Tension Test On a Hard Surface

[General RE LEE]

Loading my 7mm STW out of curiosity I've pushed the bullet hard into the bench and the bullet seated deeper into the case. Is this an indication of poor neck tension or is this a bad test?

 

[cape cove]

Just an opinion here, but I would think that the neck tension would be on the weak side. If it is magazine loaded then most likely the OAL would change under recoil.

 

[Mikecr]

Not for sure tension, but possibly low friction.
Unless an obviously weak hold, I wouldn't be concerned with it.

Is this new necks, fired necks, preps?

 

[xsn10s]

Loading my 7mm STW out of curiosity I've pushed the bullet hard into the bench and the bullet seated deeper into the case. Is this an indication of poor neck tension or is this a bad test?

It's hard to judge that unless we're actually doing the push test. You could shoot a magazine full and check each one with calipers to see if any get seated deeper after each shot.

 

[243winxb]

I've pushed the bullet hard into the bench

Just shows how strong you are. 35 pounds is military minimum standard for the 5.56.

Make a dummy round. Place on accurate digital bathroom scale. Make a leverage arrangement with a piece of wood. Slowly push bullet into case, slowly. Watch scale readout.

I have put over 100 pounds on a 45 acp dummy round, with NO bullet movement. Neck tension .005"

The 223 gets 35 lbs with .002"

https://www.handloadersbench.com/fo...load-data/27215-neck-tension-experiment/page2

 

[243winxb]

From link above. PSI is different then pounds, but shows what different NTs produce.

 

[Varmint Hunter]

Do you lube necks before sizing? That could be an issue too.

My buddy used a 375 in Africa. He was shooting factory ammo with moly coated bullets. He told me that the bullets would move in the necks.

 

[General RE LEE]

Thank you all these are once fired Hornady 7mm STW cases that have been full length resized with Hornady New Dimension die and tumbled before seating.

 

[xsn10s]

Well my guess is either not enough neck tension or a tapered bullet.

 

[Varmint Hunter]

The expander ball can be reduced in diameter using some emery cloth, oil and a drill/driver. Just a thought.

 

[MagnumManiac]

First thing I would do is mic the expander with a .0001" accurate micrometer, the tenths are important, and see what it reads.
If less than .002", this MAY be too little neck tension, but not necessarily.
I run .0015"-.001" in numerous cartridges with lubed necks and it is very difficult to get a bullet to move in the neck unless it is freshly annealed. Have had them pull out after seating just from the way they fit the seating stem after annealing. Spring back was lost.

Cheers.

 

[bullet man]

get a lee factory crimp die a use a crimp, military always uses one.

 

[Mikecr]

It's a bad idea to set high seating interference for higher friction.
Instead, if you need higher friction then just cause that. Clean neck IDs. Clean bullets. Do so after annealing if you want extreme friction.
Also understand that friction and tension are different animals. Nothing to do with each other.

 

[General RE LEE]

For the record rounds shot great yesterday and no moving in magazine. I guess if you push on a table hard enough a perfectly fine bullet can seat into the case.