NEW DASHER

[mattdienes]

Well I just received a new toy-6mm Dasher built by Mark King. My questions are: fireforming-false shoulder or jam and shoot?
what loads do you guys use when fireforming?And last,some pet loads using 105 bergers.I'm pretty familar with changing shoulders on case,AI) but not with these little cases,are there any tricks or do's or don'ts. Thanks Matt D.

 

[flatlander]

Matt,
I've fireformed over 1000 Dasher cases using the false shoulder method, with a case loss of around 1%; that includes a couple of cases that had visible neck flaws out of the box - both necks split on firing. I typically use around 32grs. of Varget with MOLY'd 105/107s to fireform, and get 2880-2900fps out of 28"-30" bbls. That load has given 600yd. accuracy plenty good enough to clean,with good X-counts) the NRA MR-1 600yd. HP target in all four of the Dashers I currently own. Because the false shoulder method gives good accuracy, I've fireformed the vast majority of my cases while shooting 600yd. any/any matches.

 

[mrjdasr]

I use the jammed bullet method with my 6mm brx
lost 2 out of 100 using lapua brass [cases cracked at the shoulder
load was 30 grns of h4895 with 107 smk's shot some 1/2 moa groups with this load fire forming your dasher cases should be the same
looking forward to meeting you in person. i'll be a new shooter at Williamsport this coming year when will 2008 schedule be available??

 

[Baron]

Matt,
I am surprised that you have not gotten anymore responses for this post. With as many Dasher shooters that frequent this board there should be a plethora of information heading your way. On the other hand could it be that everybody recognizes your name and your Smith’s name and are scared you might use it against them. I did! At the 07 IBS nationals LG overall 2 of the top five winners used King built Dashers. I’ve got a .266 NK .104 FB Dasher coming this week from Kiff, hoping to run with the Big Boys & Girls.
As for forming the cases. I plan on using the False Shoulder plus COW method before turning the neck. I figure I’ll try this method first and see how well it works. I used this method for my .334 NK .300 Ackley and had great results. 14 gr. Of Unique, fill to the Neck/Shoulder with COW, top with a ¼ sheet of Toilet Paper rolled into a cylinder and packed down with a ¼ drill bit. I got 90% formed cases and I’ve also got six firings,still counting) on the Norma .300 WBY cases shooting 97.5 gr. RL25 w/ 210 Bergers.
As for loading data I think that the 6BR Lapua cases, 105 VLDs or 107 SMKs, CCI BR4s and Varget is the right combination for the Dasher.
Good luck with your new Toy, I am sure it will be a shooter. Hopefully I’ll see you at the 08 Nationals.

 

[mattdienes]

Baron,
I talked to Mark and the br-4,105 berger and varget will be the starting point,he said start at 33gr go to 34. gr.I'm going to try the Jam method first, while i'm breaking the barrel in.
I will most likely make the nationals along as they are in Ohio,due to a long drive out west for hunting,I can not go if they are in Iowa.

 

[AckleyImproved]

Mate

I have formed my dasher cases using the false shoulder method. I have not lost one case yet.

That being said, its a lot of extra work, specially when neck turning, as I found the cases not real concentric after expanding.

I have a new batch of brass, and I plan on trying the jam method. If I lose a couple of cases I am fine with that, because it outweighs the extra work. I have a bushing that will allow very tight seating of the projectile which will aid the jam method.

I do know of 2 well known Dasher shooters that have givent he false shoulder method away for the jam method.

Time will soon tell.

I am shootign Sierra 107 naked, 32.9grains of RE-15, and BR4 primers.

Cheers
AI

Hope this helps a little.

 

[alf]

Matt,
I've posted this before, but we'll doer' again.
I've always used the false shoulder method.
Generally, any case loss is from factory flaws.
I think it's pretty tough to keep the necks straight no matter how you go about it.
Seating bullets in a extra tight neck can't help, either.
Once you blow 'em out, the crooked should be gone.
I've fire-formed over 2500rds using 32.5 gr. of VV-133 topped off with 55gr. moly Ballistic Tip going 3550fps.
This is in a wore-out PPC barrel re-chambered to 6 Dasher, cut to 21"
These were all shot at prairie dogs, so no waste of componants.
When I need match brass, I just grab some pre-formed.
Makes it easier to sort, also.
As far as powders, if you can't find your load with Varget or R-15, you'll have some extra work to do.
Seems like most shoot one or the other.
I shoot 32.6 grs. of Varget, moly plated,.2435) 105 Bergers VLD's hard in the lands.,a square mark + on the bullet) and Federal 205M's
Runs 2980fps in a 29.5" Rock barrel,.2367 X .2430 7.8" twist)
This barrel did not like the skinny Bergers or the old lot of fat Sierras.
My new barrel will be a tighter .236. My new Bergers are all .2430. I haven't measured my new "hot lot" of Sierras, yet.

Good shootin'
Al.