fire forming the 6mm dasher??

[skeetlee]

what is the simplest way to fire form the 6mm dasher? Can i just jam a bullet into the lands and shoot a stiff load of varget? My dasher will be a no turn Dave kiff 104 lead made to shoot 105's. Whats the scoop?? Lee

 

[AckleyImproved]

Mate

I have used the jam and shoot method of fireforming, but really do prefer the false shoulder method. There is a few articles on here about the false shoulder method.

When I did the jam method, there was 5 out of 50 that did not fire, due to the firing pin pushing the projectile down the case! Had to go home, pull the projectiles and load again and shoot!

I used a bushing that was way under size to increase neck tension when doing it also, but it did not make any difference!

False shoulder with no turn neck is pretty easy. Neck up to 25cal, then back down to 6mm creating a shoulder on the neck to headspace on.

I know a lot of guys have had good results just jamming, but I did not!

I loaded 30.5grains of varget, false shoulder, and light jam for fireforming. This for me has been a light load for fireforming. but creates the shoulders well. *Disclaimer here, this fireforming load works for me, maybe not you.

Other guys will chime in and tell what they do!

Cheers

 

[JBR]

I'm shooting a 6BRDX which may be a little easier to fire form; just jamb the bullet and fire with mild load of Varget. Works very well but I have just ordered a Hornady Hydraulic forming die however to save on my barrel life.

 

[DukeDuke]

I fire formed my 6brx jamming the bullet in the lands. 105 a-max and 30gr RL15. Accuracy and velocity were outstanding 2900 fps. Easy to do even for a first timer like me.

 

[ridgeway]

This may not be much help since I turn for a .264 neck. But where the turning stops is the false shoulder and it touches the chamber. On top of that, the 105 VLD is jammed and fired with 29gr of Varget.

 

[falconpilot]

I use a .25 cal expander when making my false shoulders.

Steps I take -

1) Expand the necks using a 6mm mandrel - I do this first because I turn my neck,.269 neck)

2)I then turn my necks

3) Then I expand them with a .25 cal expander

4)Using a 6BR Redding Bushing Neck Die,I only use the 6BR die this time), I size the neck back down to 6mm just far enough that i can close the bolt...

Alot of people use a lighter load of powder fireforming, and everyone has a different opinion on this - I use 32.5 grs of Varget under a Sierra 107,I believe the 107 jacket is a little hard than the Bergers) jammed into the lands. I always get very uniformed cases doing this...

Good luck

 

[Bkluke]

I use the jam method with the 107 mk. 29 grains of Varget. I think it is the easiest way. Here are some things that I have learned, make sure you have good tight neck tension, I use a 266 bushing on my no turn necks, and I seat the bullet way long very hard jam, about .100. All my brass looks real good, nice sharp shoulder, and none were lost. Hornady has a hydraulic forming die that I might try later on. There is a good article in this months Precission Shooting magizine.

Brian

 

[AlanPF]

I think FalconPilots method is best if you are turning necks - why? Because the turned part of the neck ends up part way up the shoulder - I believe this will eliminate the possibility of doughnuts forming. Question - has anyone found a way of getting the case to retain its original length,or even get close to it) when fire-forming. I note that the Dasher length in the cartridge diagrams is virtually the same as 6BR.

Alan

 

[JRinCo]

Mr. Ridgeway,
Since I'm considering building one of these, wouldn't it be better to turn that neck just a little farther down the shoulder.
I mean just to minimize the donut effect.

 

[ridgeway]

No, not in my situation. That step actually touches the chamber to create the false shoulder. If you turn further down, you will simply create excess headspace and probably loose every case that gets fired.