Dasher brass fire formed to 1.55

[K redden]

Just ff a bunch of dasher brass. The blue box blew out to 1.550 on the first firing. 1.555 on the second. Just thought I’d share as it was really nice they didn’t end up short.
Loads were 30g varget with a amax
Jammed .040. Fed 205 primers. These bullets seat just above the neck shoulder junction
29.5 blew very close to the same. with a very dry chamber. Just not quite as crisp of a shoulder.

 

[senderoll]

That’s awesome!! Mine always come out 1.543-1.545

 

[6bra1k]

i am a no bullet false shoulder pistol powder guy with a small wad of tissue
my trim length is 1.545...
way waste good brass

 

[K redden]

i am a no bullet false shoulder pistol powder guy with a small wad of tissue
my trim length is 1.545...
way waste good brass

Just curious. But why trim that much shorter than your chamber length. I’d assume the chamber length is longer than original brass length of 1.555
And me and the kids have fun shooting the ff loads We were getting 20 shot groups under .7 in the old fireform barrel.

 

[6bra1k]

Just curious. But why trim that much shorter than your chamber length. I’d assume the chamber length is longer than original brass length of 1.555
And me and the kids have fun shooting the ff loads We were getting 20 shot groups under .7 in the old fireform barrel.

mine is 1.550

 

[NorCalMikie]

Know your "measured" chamber length and use that as a rule.
Most chamber reamers cut about .020 "longer than max trim length" so you'll know when and if you may need trimming.

 

[6bra1k]

Know your "measured" chamber length and use that as a rule.
Most chamber reamers cut about .020 "longer than max trim length" so you'll know when and if you may need trimming.

NOT EXACTLY TRUE.
production guns yes, custom no..its what you ask for with your reamer.
mine are typically 5-7 thou

 

[bulaman]

Just ff a bunch of dasher brass. The blue box blew out to 1.550 on the first firing. 1.555 on the second. Just thought I’d share as it was really nice they didn’t end up short.
Loads were 30g varget with a amax
Jammed .040. Fed 205 primers. These bullets seat just above the neck shoulder junction
29.5 blew very close to the same. with a very dry chamber. Just not quite as crisp of a shoulder.

Did you build a false should or just jam and shoot?

 

[K redden]

Just jam and shoot

 

[DJSBRS]

Where on the case do you think everyone of them stretched to meet that 1.550? Do you think everyone stretched at the same location and now have the exact same case volume?

DJ
DJ's Brass Service

 

[NorCalMikie]

NOT EXACTLY TRUE.
production guns yes, custom no..its what you ask for with your reamer.
mine are typically 5-7 thou

All of MY "custom cut chambers" are at least .020 over Max trim length and I didn't ask for anything different. Best to measure, know what you've got, write it down and use that measurement when sizing.

 

[6bra1k]

All of MY "custom cut chambers" are at least .020 over Max trim length and I didn't ask for anything different. Best to measure, know what you've got, write it down and use that measurement when sizing.

long neck space is the home of carbon rings.
while i do clean well, shot neck space means nowhere for carbon ring to form.
i would not consider a .020 custom..that is saami spec.

 

[K redden]

Where on the case do you think everyone of them stretched to meet that 1.550? Do you think everyone stretched at the same location and now have the exact same case volume?

DJ
DJ's Brass Service

I’d say since they started out at 1.55 and blew to 1.55 And I didn’t trim any brass off of them . That yes , they should have the same volume . Reguardless of where they stretched. Whether or not this was the proper way to fire form brass is probably better left to the pros. Just worked good for me. If there is a better way please let me know and I’d love to try it

 

[dbduff]

Where on the case do you think everyone of them stretched to meet that 1.550? Do you think everyone stretched at the same location and now have the exact same case volume?

DJ
DJ's Brass Service

Are you back to work? Missed you!

 

[Radar]

I’d say since they started out at 1.55 and blew to 1.55 And I didn’t trim any brass off of them . That yes , they should have the same volume . Reguardless of where they stretched. Whether or not this was the proper way to fire form brass is probably better left to the pros. Just worked good for me. If there is a better way please let me know and I’d love to try it

When you are blowing the shoulder out and forward and ending up with the same case length I'd be a little worried about where that extra brass came from. If it came from the web you will know soon enough and that won't be a pleasant lesson.

 

[K redden]

When you are blowing the shoulder out and forward and ending up with the same case length I'd be a little worried about where that extra brass came from. If it came from the web you will know soon enough and that won't be a pleasant lesson.

I’ll look into that. Hope it didn’t. I just thought it was good to have a full length case. Always heard the old brown Box brass would form full length. Just thought this was good for the blue. also. Not seeing any sighns it came from the web. But will keep an eye on it

 

[Alex Wheeler]

Long brass means stretch in the case somewhere. I hydro formed my dasher brass it came out 1.539 or so because the neck was pulled down into the shoulder, exactly how I wanted it. And I like the room at the end of the neck in the chamber too. I spec my reamers for more room at the end of the neck than most saami rounds. Did the short chamber thing in the dasher days and learned my lesson. If your brass oal length is varying more after fire forming than before your not making good brass. Long should not be the goal, consistent should be.

 

[K redden]

Where on the case do you think everyone of them stretched to meet that 1.550? Do you think everyone stretched at the same location and now have the exact same case volume?

DJ
DJ's Brass Service

Where on the case do you think everyone of them stretched to meet that 1.550? Do you think everyone stretched at the same location and now have the exact same case volume?

DJ
DJ's Brass Service

I’m worried now that I’m getting some negative feedback about my brass . I know you do this for a living as I’ve sent brass into you and had excellent results with it . Is there a target length I should be going for . Where should it be stretching from . Neck - shoulder only , or entire length of case. I was under the impression that the old brass would blow to these lengths , but the blue box was hard to get this long. I’m all about learning.
I don’t want to toss this brass , but if I messed it up I’ll start over. Attached a pic that shows the old case shoulder line. Hope it shows up. Thanks for any info.

 

[DJSBRS]

I don't think you should toss them as you got what you asked for.

I have never seen 6 BR brass Dasher brass remain the same length 1.550 after fireforming to to Dasher. Fireforming is pushing the brass out and forward. Hydroforming is pushing the brass back and then to the outside walls. By hydroforming, I believe it is not stretching the brass at all. However, it is expanding sideways to contact the the die walls to form by hydraulically driving the pressure down in to the cartridge instead of firing out the barrel. Thus the brass length retracts on forming because it is pushing the insides out at over 50,000 PSI.

Now with that being said, my proprietary method is a one time hit of pressure. I believe if I had to bang ( hit the piston on fluid used on the brass several times with a blunt hammer ) they all would not be the same formed.

The key is consistent brass. Personally, I think weighing sorting is not as important as to finding the pieces with the same volume and after firing, they all go into the x ring or group. The X ring, group cases are the best you can make and I would keep those separate for record rounds.

They make chocolate and vanilla for a reason . You choose what you like.

Just my .02¢ worth.

DJ
DJ's Brass Service

 

[6bra1k]

I don't think you should toss them as you got what you asked for.

I have never seen 6 BR brass Dasher brass remain the same length 1.550 after fireforming to to Dasher. Fireforming is pushing the brass out and forward. Hydroforming is pushing the brass back and then to the outside walls. By hydroforming, I believe it is not stretching the brass at all. However, it is expanding sideways to contact the the die walls to form by hydraulically driving the pressure down in to the cartridge instead of firing out the barrel. Thus the brass length retracts on forming because it is pushing the insides out at over 50,000 PSI.

Now with that being said, my proprietary method is a one time hit of pressure. I believe if I had to bang ( hit the piston on fluid used on the brass several times with a blunt hammer ) they all would not be the same formed.

The key is consistent brass. Personally, I think weighing sorting is not as important as to finding the pieces with the same volume and after firing, they all go into the x ring or group. The X ring, group cases are the best you can make and I would keep those separate for record rounds.

They make chocolate and vanilla for a reason . You choose what you like.

Just my .02¢ worth.

DJ
DJ's Brass Service

use what ever word you want, if you reshape a case to a LARGER size, that brass has to come from some where. it does not magically apper from the water.... the case is stretched, thinned pulled into a new larger shape but still contains the same amount of brass that it had as a 6br case