6BR to 6 Dasher conversion...

[ISS]

Can I just load 6BR brass, jam the lands and fireform it safe and sound? I have seen differences of opinion here.

thanks,

ISS

 

[madmixerman]

I have done it that way with a hard jam.

 

[wasskeet]

Peterson 6 Dasher brass works well for me - easy button.

 

[ISS]

Good thought, but I already have the 6BR brass.

thanks,

ISS

 

[HTSmith]

I get more uniform results with forming a false shoulder with a 25 cal mandrel. I'm certainly no expert.

 

[Longtrain]

I get more uniform results with forming a false shoulder with a 25 cal mandrel.

+1 Without a false shoulder, there’s going to be some movement of the case. You want it nice and tight from the shoulder to the bolt face. No unnecessary stretching of the brass head. Believe me after many, many Dasher cases, this is the way to go.

 

[LRPV]

I get more uniform results with forming a false shoulder with a 25 cal mandrel. I'm certainly no expert.

You must’ve stayed in a Holiday Inn Express last night then because you sure sound like an expert. Lol

 

[birdog]

False shoulder is best

 

[boltfluter]

I get more uniform results with forming a false shoulder with a 25 cal mandrel. I'm certainly no expert.

This works best for me.
Paul

 

[shoot4fun]

Can I just load 6BR brass, jam the lands and fireform it safe and sound? I have seen differences of opinion here.

thanks,

ISS

So, no one has asked what I believe to be a very important question.
Is the 6BR brass you have new or fired brass?
Next question is about the neck diameter of your Dasher chamber.
Is the Dasher a no-turn neck or tight neck?
How you approach fire forming Dasher brass depends on these answers.

 

[ISS]

New, and a no-turn neck.

thanks,

ISS

 

[NZ_Fclass]

I just went a different way - 6 BRX. Rifle just finished and fire forming was easy. 105g locally made pills with a light jam, 29g H4895 on some annealed Norma brass. I already have the dies!

 

[gunsandgunsmithing]

Another vote for the false shoulder method, here.

 

[60723]

Tried false shoulder and moderate jam. Both work. Last few I sent and had hydrosized. I like that better. Final fireforming very accurate.

 

[Longtrain]

Tried false shoulder and moderate jam. Both work. Last few I sent and had hydrosized.

I never had Dasher brass hydro-sized, although I understand that it does produce a good quality case. I have done some COW and other bulletless processes, they worked, but all required a regular bullet load to finalize the formation of the case with crisp shoulders, etc.

A false shoulder with a bullet load seems to solve most forming processes in one bang.

 

[shoot4fun]

I never had Dasher brass hydro-sized, although I understand that it does produce a good quality case. I have done some COW and other bulletless processes, they worked, but all required a regular bullet load to finalize the formation of the case with crisp shoulders, etc.

A false shoulder with a bullet load seems to solve most forming processes in one bang.

Once you have new brass hydro formed by @DJSBRS you won't want it any other way.

 

[jackieschmidt]

If your new 6BR brass is Lapua, I will buy it from you and you can take the cash and get already formed Dasher. Just an idea.

 

[MikeRu]

I’m maybe the oddball here but I’ve had very good luck jamming into the lands 10-15 thou, higher neck tension, Fed 205 primers, IMR 4064 28 gn., several different bullets but maybe heavier is better. No turn neck 272.

 

[PBoggs]

I get more uniform results with forming a false shoulder with a 25 cal mandrel. I'm certainly no expert.

Have you measured a difference in Neck length for the 2 different ways? Jam method making a shorter neck? And if so..negligible ?...In learning mode here.
Thanks

 

[Tommie]

Having used both methods, a false shoulder just seems safer than only bullet jam. Mechanical headspacing doesn’t rely upon neck/bullet friction to keep things where they’re supposed to be. Blowing the shoulder forward is a higher stakes game than forming AI brass with SAAMI brass. Adding a false shoulder involves more work but I’m happy to add the increased level of safety. Just my opinion.