Forming 6mm dasher brass

[BigKev]

This one is for the Dasher crowd. For the past few weeks I've been reading every article / post that I could find regarding forming 6mm Dasher brass from std. 6mm BR cases. I contacted Hornady in hopes of having a hydraulic forming die made only to be informed that it would be 16 weeks, and for what its worth I have no intentions on waiting until May to begin developing loads for this rifle. I've read multiple posts where the person forming their brass starts by necking up their 6br cases to 6.5 using an "expander" mandrel and then re-sizing them back down to create a "false shoulder" before fire-forming. However I unfortunately don't recall having read (possibly missed) exactly what die body they were using (is it caliber specific ?) and who made the expander button / mandrel ??. Any information pertaining to the above would be greatly appreciated. I'd like to thank you in advance for taking the time to respond to my questions.

BigKev

 

[techshooter]

BigKev:

I use a 25 caliber expander mandrel, then a 0.267" bushing in a Redding Type S neck sizing die to form the false shoulder. I let the bushing float a bit more than normal for this first time so there is a really positive crush when chambering the brass. I seat the 107 SMK bullets long so that they are a hard jam into the lands less 0.010", with 32 grains IMR4895 and a CCI450 primer, and go shoot a 600 yard prone match, or some prairie dogs. They shoot lights out, and there is no wasting the barrel. Full description of the rifle and the brass prep process here:

http://www.the-long-family.com/6_dasher.htm

Redding makes the bushing neck die and the body die as special order items, but there are other manufacturers out there besides Redding. I took a standard 6 BR Redding Competition Seating die and ran the Dasher reamer in the floating sleeve, which is not hardened.

Cheers,

 

[Flybuster]

I am using the method technshooter explains, .257 KM expander and Redding 'S' FL die, it works great. His site is very helpful.

 

[Skeeter]

I used the Hornady .257 Expandiron Mandrel in a Redding S type die then used a .267 neck bushing to make the false shoulder. I moved it in small increments until I could get a good crush fit when chambering.

Skeeter

 

[golfer2b2000]

Kev. I just bought a 6 dasher and know basically nothing about the wildcat cartridges. I do have a 6mmBR though. Once I understood what people were trying to tell me about creating a false shoulder, it was simple. I took a .260 body die I have, and ran the 6br case into it to open up the neck to the 6.5mm diameter. This way I didnt have to purchase a seperate mandrel. Then I took my 6 dasher die, with a .267 neck bushing and carefully kept taking down the neck till it chambered. Use caution also because if you take it too far down you may not get the primer to fire.(experience talking here)...But I just took the case apart and repeated the process. I now have 100 formed brass, so I should be in good shape for a while...Gene from Pa...