More neck tension questions, sorry

[mike a]

Neck tension right at the neck / shoulder junction. So I've seen this mentioned a little but not really discussed. It's been called the ( force vector, neck/ shoulder abuttment, and that tight spot!) Now I'm taking about 30 degree shoulders. Specifically 6.5 creedmoor in my situation. I've loaded 308 and 243 (20 degree shoulder) and not run into this tight spot. Note I'm not talking donuts. I do enough 243 to know a donut when I see one. So I'm using lapua brass and have a lite neck turn on it. Redding f/l bush die, Wilson chamber type seater with arbor. No force gauge. I have two sinarios. With and w/o annealing. I'll just cover not annealed and say that annealing makes things worse. I'm currently using a .298 bushing and the bullet seats easy and smooth right until the junction like .002 n/t should feel like. ( you all know what it feels like right?) Then at the junction WAY to tight. I tried a .290 bush but get zero n/t until the junction and then just enough to hold the bullet finger tight. The more fired/ work hardened the less problems. ( more spring back I guess) note I don't use the expander ball as it kills my runout. I've thought about an .002 expander but don't see the spring back at the (force vector/abutment/tight spot thingy) changing. Sorry for rambling. 30 degree shoulders have me screwed up. Thanx Mike A.

 

[fgregorio]

Hey mike a, out of many different solutions possible for that issue, I'll give you a cheap solution and an expensive solution FROM MY OWN EXPERIENCE (others might not agree, but I kept my records to make science):
Cheap solution- float shell holder by removing the spring clip and replacing said for an o-ring. Keep the shell holder and the point of contact of the ram and shell holder surgically clean. Buy a Lee collet die and check this forum on how to maximize its use: cost $20, average runout 1.5 thou I.e.
Expensive solution- involves annealing machine, 21st century hydro seater, Wilson neck sizer, hornady one shot case lube, another 21st century arbor press, Lee universal case expander for case mouth, Forster case inspector. Cost ~$1000. Can monitor and adjust neck tension to 5 psi or less and shoot the bullets in order of seating pressure. Av runout for neck turned cases: close to 0.0.
Unless if you shoot benchrest I'd suggest the cheap option. You have a lot more to gain if you weight batch primers with a milligram scale. And chamfer and flare the flasholes from the inside and then ream the flashholes with a no go gauge just over bore.
1- I would perfect the ignition and get the Lee collet die. And Lee universal case expander to replace case mouth chamfering. (Groups should halve from this chapter)
2- Barrel tuner+ barrel tap test+ vibration damping+ setting for each distance for positive compensation. (Groups should halve again)
3- weight batching of projectiles and cases (small reduction in group size)
4- powder weighing using a beam scale and webcam. Learning all from this forum on how to maximize. (Small reduction in group size)
5-annealing and all the expensive steps. (Small reduction in group size)

 

[243winxb]

Neck tension right at the neck / shoulder junction.

Size only 1/2 of the neck. The neck shoulder junction should expand to the chamber diameter. No contact with the base of the bullet.

Unless i am missing something, not loading for the 6.5?

 

[Willie]

FWIW, I load for 30* and 40* shoulders and have not seen this. I turn into the shoulder, sizing neck a bit tight, run a .002" under K&M expander, and confirm with a pin gage. I also anneal ever firing, prior to FL sizing. Using Redding and Whidden bushing dies. Works for me, your mileage may.....................

 

[mike a]

Hey mike a, out of many different solutions possible for that issue, I'll give you a cheap solution and an expensive solution FROM MY OWN EXPERIENCE (others might not agree, but I kept my records to make science):
Cheap solution- float shell holder by removing the spring clip and replacing said for an o-ring. Keep the shell holder and the point of contact of the ram and shell holder surgically clean. Buy a Lee collet die and check this forum on how to maximize its use: cost $20, average runout 1.5 thou I.e.
Expensive solution- involves annealing machine, 21st century hydro seater, Wilson neck sizer, hornady one shot case lube, another 21st century arbor press, Lee universal case expander for case mouth, Forster case inspector. Cost ~$1000. Can monitor and adjust neck tension to 5 psi or less and shoot the bullets in order of seating pressure. Av runout for neck turned cases: close to 0.0.
Unless if you shoot benchrest I'd suggest the cheap option. You have a lot more to gain if you weight batch primers with a milligram scale. And chamfer and flare the flasholes from the inside and then ream the flashholes with a no go gauge just over bore.
1- I would perfect the ignition and get the Lee collet die. And Lee universal case expander to replace case mouth chamfering. (Groups should halve from this chapter)
2- Barrel tuner+ barrel tap test+ vibration damping+ setting for each distance for positive compensation. (Groups should halve again)
3- weight batching of projectiles and cases (small reduction in group size)
4- powder weighing using a beam scale and webcam. Learning all from this forum on how to maximize. (Small reduction in group size)
5-annealing and all the expensive steps. (Small reduction in group size)

Barrel tap test?, postitive compenwhat? I choose door #1

 

[mike a]

Size only 1/2 of the neck. The neck shoulder junction should expand to the chamber diameter. No contact with the base of the bullet.

Unless i am missing something, not loading for the 6.5?

Yep. I'm gona try that. But 2/3. Than Mike A

 

[mike a]

FWIW, I load for 30* and 40* shoulders and have not seen this. I turn into the shoulder, sizing neck a bit tight, run a .002" under K&M expander, and confirm with a pin gage. I also anneal ever firing, prior to FL sizing. Using Redding and Whidden bushing dies. Works for me, your mileage may.....................

Hi Willie, I do turn into the shoulders on 243 to reduce donuts but haven't tried it on the 6.5. So that's an option for me. I like the expander idea also. Good info. Thanx Mike A

 

[ballisticdaddy]

It almost sounds like the brass is not being fire formed back to the chamber completely? Especially if after multiple firings this gets less noticeable. Are you running a very light charge? Have you tried different seating depths, like one that keeps the boat tail just above the neck/shoulder junction?

 

[mike a]

It almost sounds like the brass is not being fire formed back to the chamber completely? Especially if after multiple firings this gets less noticeable. Are you running a very light charge? Have you tried different seating depths, like one that keeps the boat tail just above the neck/shoulder junction?

Hey fello commy, I'm in emperial county. No the charge is plenty stiff. A bullet drops right in on fired brass. I'm trying the 2/3 neck size right now. I'll keep you posted. I wish I could seat long but must go mag length. Thanx Mike A

 

[Sniper338]

The way I understood the post it sounds like a donut inside the neck at the bottom.

If thats the case I use an expander die expand it, then slightly neck turn the bottom of the neck again, if it trims then you know you pushed that donut out...

Kinda lost reading the op tho.

 

[Richard Coody]

The way I understood the post it sounds like a donut inside the neck at the bottom.

If thats the case I use an expander die expand it, then slightly neck turn the bottom of the neck again, if it trims then you know you pushed that donut out...

Kinda lost reading the op tho.

I go with this one. Use an expandrel mandrel, push the donut to the outside and neck turn into the shoulder.

Or get an inside neck reamer. If it hits your tight spot then it will ream it out.

 

[wholman]

Sounds like base of bullet is crunching powder.

 

[Sniper338]

Sounds like base of bullet is crunching powder.

Crunching powder doesnt give a hard feel to seating. And you can hear it sometimes. Has no effect on seating force you can really feel

 

[BoydAllen]

Another approach is to have your chamber throated out a bit so that your bullet's shanks do not come into the problem zone. Of course there may be magazine length issues that preclude this approach.