6mm Dasher Brass

[timeout]

Am thinking 6mm Dasher. Have been told can simply fire-form the brass from 6mmBR cases. Is this the way to go?
Thanks.

Yes. No false shoulder needed.

 

[Cakes]

Don't forget that fireforming Dasher brass can also be VERY accurate as well. I used a false shoulder with 108's and formed up a bunch at a weekend midrange match. Other than an occasional one dropping low, all the rounds If I recall correctly were 195-199 with a respectable X count. The only hic-up was one pierced primer which was a non-factor. Those batches turned out to be very consistent brass and have served me quite well. Eric in DL

 

[Longtrain]

Building my first Dasher a year ago, I pondered for a long time how to form the brass. I settled on the false shoulder method using a .257 mandrel and the neck sizing to a tight fit. I would recommend that you remove the firing pin and extractor from your bolt when checking on your case fit after neck sizing. Size a bit, check, add a bit more sizing, check again until you get a nice tight fit without cranking on the bolt handle, handle should close with a snug tension. I didn't even jam bullets, jumped them 10 thou. Only lost one or two cases due to neck splits per 100 cases.
BTW, shot all the FF loads in MR prone matches, very accurate.

 

[Keith Glasscock]

Neck splits can be prevented by close examination of the brass prior to firing. The folds are visible under magnification. I split 3 in 100, then started looking at them - threw about 2-3 per 100 out and no more splits.

 

[AR Shooter]

Thanks for the replies.
Will try a fire-forming load of 29gr of RE15 and a Sierra 87gr HPBT bullet jammed 0.005" in my blue-box 6mmBR brass.
Hope to have results this week.

 

[MJT]

I love my Dasher; it's amazing. I use a hydroforming die (6mm BR to Dasher) that Hornady made for me; they have a custom die shop. Easy to use and excellent results. I use rubbing alcohol instead of water so it does not rust the die. Just run a Q-tip though the die each time to dry the piston hole dry; prevents it from jamming.

 

[AR Shooter]

OK........ fire-formed with the 85gr Sierra HPBT & 29gr of RE15 jammed about 5-thou. No problems. Only brass prep was to run the case far enough into the FL bushing die to insure the new brass necks were round and do a bit of inside chamfer. Less is more in working brass for me. Zero split necks out of 48 fired.
Thanks to all for the input.

 

[ASbobcat]

Many ways to do it...A Hard jam with lots of neck tension on a standard BR load will work.

This is the easiest way and it works great.