Always trimming dasher brass

[K redden]

My dasher brass grows 2K every time I size it . It's brown box lapua sized on whidden full length dies. I bump the necks back 2K . The brass fire formed at 1.550 or longer after the second firing. Now I have to trimm constantly. I've always just neck sized every thing and had no problems. Even my swift didn't grow like this. Is it the full sizing. And should I keep full sizing. Or should I quit bumping the necks back until needed. I switched to full sizing because that seemed to be the consensus for good uniform loads.

Thanks for any help K Redden

 

[jaybray]

I have the same set up as yourself. Brown box brass and whidden full length die. I must have fired my 20 cases 10 times each and have never trimmed them. My cases measure 1.538 give or take a few thou.

 

[K redden]

I should also state that I had brass 1.560 long after the third firing. They where only neck sized on a Redding bushing die. If i measure a round at 1.550 before I full size, then size it will come out at 1.552 a 1.554.

 

[noload]

Do you anneal every time?

My dasher brass grows 2K every time I size it . It's brown box lapua sized on whidden full length dies. I bump the necks back 2K . The brass fire formed at 1.550 or longer after the second firing. Now I have to trimm constantly. I've always just neck sized every thing and had no problems. Even my swift didn't grow like this. Is it the full sizing. And should I keep full sizing. Or should I quit bumping the necks back until needed. I switched to full sizing because that seemed to be the consensus for good uniform loads.

Thanks for any help K Redden

 

[savageshooter86]

What neck is your chamber and what are you sizing your brass down to? Is your die the bushing die or std die?

Reason I ask(could be way off) is in my 308 FTR rifle when I FL size(using expander ball), my case stretches a good bit. BUT when I used a bushing to size only 1.5 thous under loaded round, it didn't grow much. So in my FTR going from a fired neck of 343 down to 326 IIRC in my Whidden FL die, then the expander opening mouth back to 334, caused a good bit of growth.

 

[fourpower]

set your dies up for zero headspace. I use forster dies on my laupa 6.5x47 and have 30 reloads on brass and have not had two trim yet!

 

[K redden]

I only bring my neck down 2K, no expander ball. Am going to proceeded with the die backed off just a bit and go from there . If the shoulders need bumped ill do so when needed . Will see how this goes and repost. Thanks for the info. K Redden

 

[jrm850]

Reply when you figure it out. I would love to be able to get my brass to that length.

 

[boltfluter]

I think you have a mismatch between dies and chamber up by the shoulder body junction. Measure before sizing and after. You may be surprised. Good luck.

Regards, Paul

www.boltfluting.com

 

[mikecr]

+1 for mismatch between die and chamber

 

[Patch700]

Have to agree with paul and the above on this one... You wont see a more pronounced rate of growth more than you do with excessive body sizing.

I would bet you a cold beverage that if you set your die up to not bump the shoulder at all and started working BACK from there that you will see your base to shoulder measurement grow and grow until you've reached a point where you are only sizing half the body of the case.

Keep in mind if you are trimming alot every firing the brass has to come from somewhere , knowing brass flows forward we know the base or web area will eventually become quite thin. That equals case head seperation.

If you have access to other manufacturers dies in that caliber that would be beneficial to try first before having a die custom matched to your chamber.

Good luck

 

[K redden]

You guys are right. I backed the dies off 2 full turns. Doesn't even come close to bumping the necks back, and growth starts happening there. Bring the dies to one full turn backed off and get 2-3K growth. Bring the dies down from there and no more growth. Maybe whidden can ream my dies for me. Chamber was reamed with a Kiff reamer for gold box brass. I wouldn't think this chamber would be way oversized but you never know.

 

[expiper]

OP,,,if your chamber was cut ""properly"" with a Kiff reamer most likely a Redding type S full length die will work perfectly,,,,I would try one before giving anyone else any more of your ca$h,,,,Roger

 

[ridgeway]

You guys are right. I backed the dies off 2 full turns. Doesn't even come close to bumping the necks back, and growth starts happening there. Bring the dies to one full turn backed off and get 2-3K growth. Bring the dies down from there and no more growth. Maybe whidden can ream my dies for me. Chamber was reamed with a Kiff reamer for gold box brass. I wouldn't think this chamber would be way oversized but you never know.

Your moving 1-2 revolutions of the die? Thats moving way too much. You only want to bump the shoulder back .0015-.002". Moving a full turn...wow. Fire a case and set your die off of that...its not a guessing game screwing the die in and out a few turns.

 

[savageshooter86]

I would bet the die isn't set up properly. Your Whidden dies should have instructions in there how to set them up. Also gives you a tool to measure how much you are setting your shoulder back during sizing

 

[dmoran]

A typical die is 7/8" diameter and has 14-threads per Inch. Which equals the fallowing when adjusting:
0.071" = 1 Full Turn of the die
0.036" = Half turn
0.018" = 1/4 turn
0.009" = 1/8 turn
To adjust a die 0.002" one way or the other, is less then 1/32 of a turn.
Donovan

 

[K redden]

I'm not trying to set my die buy turning it 1-2 turns by feel. It was set with the bump guage and an average of 5 fired brass . Set the die up to set shoulders back 2-k. just to double check this ( and not used for an accurate measurement ) I pulled my firing pin and set a sized brass in the chamber. Bolt closed with no resistance , then one layer of scotch tape and slight resistance.
As far as two turns out ,( yes I know this is a lot) but that is where I start to see the case start to grow. I think most dies are sizing by this point, just not getting growth at this point.
This one is stumping me for sure. Thanks for the help K Redden

 

[K redden]

Just talked to whidden, for less than two minutes. Tried to explain the situation. Told them every thing I've told you guys. The said when you size brass it grows. I said it sounds extreme for a dasher. They said no . I said I have to trim dasher brass every two firings . They said sounds about right. ][URL][/URL] so frustrated right now. Pretty much said they couldn't help me. None of my other whidden dies do this. Not even on my 338 edge. 8 firings and no need to trim.

 

[dmoran]

Since it no doubt is a sizing issue, I would like to know both the before and after sizing specifications of the fallowing:
- Web diameters below expansion line
- Web diameters above expansion line
- Shoulder diameters
- Lengths to shoulder datum
- OAL's
By accessing these measurements, should pin-point where the issue to be coming from.

Also, could color a case or two with a Sharpie, size it, and look to the wear for heavy contact area's.
Also make sure the die is thoroughly clean, and not a lube or brass build up.

My 2-Cents
Donovan

 

[K redden]

Since it no doubt is a sizing issue, I would like to know both the before and after sizing specifications of the fallowing:
- Web diameters below expansion line
- Web diameters above expansion line
- Shoulder diameters
- Lengths to shoulder datum
- OAL's
By accessing these measurements, should pin-point where the issue to be coming from.

Also, could color a case or two with a Sharpie, size it, and look to the wear for heavy contact area's.
Also make sure the die is thoroughly clean, and not a lube or brass build up.

My 2-Cents
Donovan

Hate to see these forums go unfinished so here's more info
Web dia on fired and sized brass is .471 . Just above that where the die quits sizing measures .470 fired and sized. Fired shoulder measures .4595. Sized shoulder measures .455. Don't know how to measure length to shoulder datum but I'd call it 1.195 on both. Oal 1.550. Hope this helps. With the spring back in the brass I'd say my dies are sizing about 6k at the shoulder