neck tension

[shoots_5]

Hmmm....had something strange occur today as I was attempting to make up some test loads with my 260 using IMR 4451 and 140 Berger Hybrids. I use Wilson neck sizing dies and seating dies. I went ahead and trimmed my cases as they were starting to get a bit long, then chamfurred and deburred. I also annealed them and ran them through the Wilson neck sizing die that I've always used. Anyway, primed and charged some cases and started seating bullets and went to measure the base to ogive length and noticed that just the force of the caliper was pushing the bullet farther into the case....in fact I can move them around with my fingers! Now obviously I have a neck tension issue with the size of bushing I'm using, but my question is why? I have not had this problem prior. Is it because I trimmed the cases? Is that an indicator that the brass is becoming too thin? Using RP cases, .288 bushing. Thinking maybe I need to go down to a .287 or .286 after the brass has been fired a few times and trimmed?

Just measured a loaded round from the same lot of brass that hasn't been fired yet and it measured .289. The brass that won't hold the bullet now also measures .289 so I suppose logically it must have thinned out due to case stretch I suppose?

 

[Guy Miner]

I dunno... And I too use the Wilson dies & trimmer... Hmmm.... Might have to thunk a little on this one.

 

[shoots_5]

This is the first time I've annealed these cases....could I have made the brass too soft so that .001 neck tension isn't enough now?

 

[MAinAR]

This is the first time I've annealed these cases....could I have made the brass too soft so that .001 neck tension isn't enough now?

I see it real common to step down 1 or 2 more thou after several firings and annealing......can't tell you why, maybe the group here can. Now if you go smaller bushing and you can still push in or turn by hand, you may have brass/annealing problem.

 

[jimbires]

here is a link to redding reloading that has bushing size info . I think you will find your answer here . I always buy a few bushings so I can try to get the tension I want . on my bushing dies , I turn my necks and I do not use the expander button . I anneal every other time .I measure my neck diameter with a blade mic . Jim


http://www.redding-reloading.com/compon ... -selection

 

[baltz526]

Some brass is springy after a few firings. I just tossed some 7mm Rem Mag brass because of this. It just would not hold bullets.

 

[shoots_5]

Ya, I understand how to figure out what size bushing. Where I'm confused is why the one I have used for 3 loadings suddenly won't hold a bullet on the 4th reload. Is it thinning of the brass? Just trying to understand the why of what's going on. I've already ordered another bushing to see if I can continue to use this brass.

 

[jimbires]

Ya, I understand how to figure out what size bushing. Where I'm confused is why the one I have used for 3 loadings suddenly won't hold a bullet on the 4th reload. Is it thinning of the brass? Just trying to understand the why of what's going on. I've already ordered another bushing to see if I can continue to use this brass.

do you have a ball micrometer to be able to measure the neck wall thickness ? if you do you could measure these that are not holding the bullet and compare this measurement to a case that will hold a bullet . if these two measurements are the same then I'd say you need to anneal your brass . brass is an elastic it does move and will spring back . I'm guessing the brass after 4 firings is starting to get work hardened , causing it to act differently when being sized .

I'm betting it's the brass needs annealed . Jim

 

[shoots_5]

I don't have a ball micrometer. But I did anneal the brass this time around. First annealing for this lot of brass. I usually try to do it after 3-4 firings. Maybe I didn't heat the brass enough when I annealed it? Hell, I don't know....right now I'm just annoyed that I have a pound of the new whiz bang powder and I can't go test it until I get my dies/brass issue sorted out!

 

[IdahoCTD]

Annealing the brass doesn't make it thinner so you were only loading with .001" of neck tension before too. After several firings the brass will have less spring back and when run through a die will try to stay larger. I hope that makes sense. I would go to the next tighter bushing but you can seat your bullets long and let the throat push them in to fit when you chamber them so you can shoot it.

 

[Vince]

Annealing the brass doesn't make it thinner so you were only loading with .001" of neck tension before too. After several firings the brass will have less spring back and when run through a die will try to stay larger. I hope that makes sense. I would go to the next tighter bushing but you can seat your bullets long and let the throat push them in to fit when you chamber them so you can shoot it.

Makes sense.

Sent from my SGH-M919 using Tapatalk

 

[jimbires]

when setting up my annealer I use junk brass . to check your annealing temp you would want to paint the inside of the case neck with tempalac . I use 750* for this . if your not getting the brass up to temp you are not annealing it . it takes the proper time and temp to anneal . the burn color on your annealed brass is no proof of how well they were annealed .

I usually have .002 or .003 under bushings in my dies . I'm a hunter and my ammo will end up in my pocket or back pack . I just don't think (trust ) .001 is going to hold my bullet well enough for rough carry . now if you had enough tension before with a .001 under bushing, I think annealing the brass will allow that bushing to properly size to that spec again . or you can buy a smaller bushing now and get by for a few more reloads . then the brass will harden more and you'll probably be back to this place again . Jim

 

[30-338]

I don't have a ball micrometer. But I did anneal the brass this time around. First annealing for this lot of brass. I usually try to do it after 3-4 firings. Maybe I didn't heat the brass enough when I annealed it? Hell, I don't know....right now I'm just annoyed that I have a pound of the new whiz bang powder and I can't go test it until I get my dies/brass issue sorted out!

The Wilson neck die only sizes 3/16" of the neck from case mouth. If you did anneal first and that's only change you made then it your annealing. Depending on how much your sizing neck down on a fired case you may be able to extend annealing to 5/6 firing.

I'm big fan of the Wilson neck dies and below is older picture on some that I use

viewtopic.php?f=4&t=11613

 

[Guy Miner]

Puts my grand total of three Wilson dies to shame...

All I have is .204 Ruger, .25-06 & .308 Win...

 

[30-338]

Puts my grand total of three Wilson dies to shame...

All I have is .204 Ruger, .25-06 & .308 Win...

You think that bad here is some of my Wilson seating die

viewtopic.php?f=4&t=11614

 

[Guy Miner]

Since I live just about 10 miles from Wilson's shop in Cashmere, WA... The whole area appreciates your patronage!

 

[shoots_5]

That's an impressive collection of Wilson dies and seaters!

 

[30-338]

Since I live just about 10 miles from Wilson's shop in Cashmere, WA... The whole area appreciates your patronage!

I've been supporting them over 30yrs now and I still have some of their FL Sizer.

 

[257 Ackley]

when setting up my annealer I use junk brass . to check your annealing temp you would want to paint the inside of the case neck with tempalac . I use 750* for this . if your not getting the brass up to temp you are not annealing it . it takes the proper time and temp to anneal . the burn color on your annealed brass is no proof of how well they were annealed Jim

Agree....the brass needs to be brought back to it's original flexibility if you are going to be able to continue using it. The only way to set up dwell time that is consistent is with Templaq. Once you know the dwell time, it doesn't need to be checked every time. Every different brand of brass and caliber will have different dwell times.

I have Lapua brass used for matches with over 20 firings that still has the same bushing used as new brass. I anneal after every firing though.

Even match loads that are fired one round at a time shoots better with more than .001 neck tension, so you may want to test a smaller bushing.