Dasher Fireform questions

[Keith Glasscock]

I'm not new to the Dasher. I've managed to loosen the pockets on my current batch of brass, so I decided to start over with new brass. The only brass I've ever used was hydroformed. I've decided to not do that again due to the excessive case loss I experienced (I must be unskilled with a hammer).

My plan is this:
Fireform during mid-range F-class matches. I've already skim turned the necks and plan to do a false shoulder with a .002 crush (just to touch of pressure closing the bolt).

Please note that I will not do COW. I know it works well, no question there, but I live in a city and simply don't have a place to do it.
Here are the questions:
My current match load (with formed brass) is 33.3 (at 60*F) grains of RE-15 with the Berger 105 VLD bullet just .005 into the lands (.104 freebore with 1k through the tube).

I have Varget, RE-15, and H4895. Which would you use and why? How much?

Would you use the current seating depth, or push it into a full jam? Why?

Lastly, Would you use your standard neck tension (.0015) or a bit more (like .0045)?

Thanks,
Keith

 

[ShootDots]

I have tried the false shoulder method as well as the "Tight Jam" method. The False Shoulder method, in my rifles shot better than the Jam Method. I shot a 3 x 20 at 600 yards and came in 3rd. I also lost 2 pieces of brass which accounted for 2 "9's" on the target. However, the "end result" was just about the same. I do not think you would lose near as many pieces of brass if you would anneal the virgin brass PRIOR to forming, whether it is Hydro, False Shoulder or Jam Method. However, if you are going to fireform, use 30.0grs of Varget and still jam the bullets regardless of the false shoulder.

I sent my last 200 pieces to Darrel Jones brass service for: 1.) annealing; 2.) hydro-forming; 3.) neck turning and 4.) cleaning. I got them back in less than 2 weeks and I proceeded to win the next 600 yard match. I sent 5 extra pieces to ensure that 200 came back formed, and 200 came back formed with exactly 2 losses of the "extra" brass I sent. So, to me it is well worth the added cost as you would come close to it anyhow using your own bullets, powder and barrel life.

 

[6mmcldasher]

http://forum.accurateshooter.com/index.php?topic=3845823.0
some good info on fire forming .

 

[boltfluter]

Dots,

You make a good point about sending the brass out considering the cost of components today.

Regards, Paul

www.boltfluting.com

 

[ShootDots]

Dots,

You make a good point about sending the brass out considering the cost of components today.

Regards, Paul

www.boltfluting.com

There can not be very much difference in cost if you take into consideration the components AND barrel life, not to mention what is your own time worth!

 

[Terry Altom]

I've got a hundred or so that need done. Can I ask what was the case length of your returned brass?

I have tried the false shoulder method as well as the "Tight Jam" method. The False Shoulder method, in my rifles shot better than the Jam Method. I shot a 3 x 20 at 600 yards and came in 3rd. I also lost 2 pieces of brass which accounted for 2 "9's" on the target. However, the "end result" was just about the same. I do not think you would lose near as many pieces of brass if you would anneal the virgin brass PRIOR to forming, whether it is Hydro, False Shoulder or Jam Method. However, if you are going to fireform, use 30.0grs of Varget and still jam the bullets regardless of the false shoulder.

I sent my last 200 pieces to Darrel Jones brass service for: 1.) annealing; 2.) hydro-forming; 3.) neck turning and 4.) cleaning. I got them back in less than 2 weeks and I proceeded to win the next 600 yard match. I sent 5 extra pieces to ensure that 200 came back formed, and 200 came back formed with exactly 2 losses of the "extra" brass I sent. So, to me it is well worth the added cost as you would come close to it anyhow using your own bullets, powder and barrel life.

 

[ShootDots]

Yes Sir taltom, they "blew" within a few thousandths one way or the other of 1.540"... After 2 firings they were at 1.550 and I keep them trimmed to just under 1.550, say about 1.545..

 

[Keith Glasscock]

Ok, I was playing in the reloading room...

I noticed that the RE-15 powder capacity of 6BR brass is much more than my Dasher match load.

Has anyone tried shooting a full-house Dasher match load during fireforming? Does it damage the brass, etc.?

 

[6mmcldasher]

30.0 to 30.5 of varget with a 108g will bug hole , no need to go full house Dasher load .besides I don't think it would be good for the brass .
tune yourself a load starting at 30.0g and go shoot .

 

[bsumoba]

30.0 to 30.5 of varget with a 108g will bug hole , no need to go full house Dasher load .besides I don't think it would be good for the brass .
tune yourself a load starting at 30.0g and go shoot .

I think I use 30.5gr of varget with a 105gr hybrid for fireform loads. and these bughole

 

[Killshot]

I think I use 30.5gr of varget with a 105gr hybrid for fireform loads. and these bughole

Yup, last 600yd match I FF'd at I posted a 599-40X. 30.5Varget, false shoulder, +.010in, soft primers(not450s) =

 

[Keith Glasscock]

Thanks for the hints on primers. I had been planning to run 450's but went to the LGS and bought 205's for this.

I'll do the Varget 30+ and false shoulder with a little into the lands on a 105VLD.

Will report my results after the range trip Saturday.

 

[KMart]

Please excuse my lack of knowledge, but what is the reasoning for using soft primers for fireforming?

 

[LRPV]

Less resistance for ignition, less chance of shoving the case forward through the false shoulder with the firing pin.

 

[Travelor]

Busdriver, interested in selling your hydro form dies?

George

 

[jrm850]

Going from 450s to 400s for fireforming gained roughly .008" of case length for me. With 450s I was lucky to get 1.535"

 

[Keith Glasscock]

Busdriver, interested in selling your hydro form dies?

George

Sorry George,

They were borrowed. I returned them to their rightful owner.

 

[Keith Glasscock]

OK,

First range trip.

19 fired
30.5 Varget with a 205 primer.
Cases were:
Neck skim turned to .0122"
Expanded to .257
Annealed with the flame directed at the original 6BR shoulder
Sized with a .266 bushing to create a bit of resistance to bolt closure (I think I could go about .002 shorter)
Bullets (Berger 105 VLD) seated .007 into the lands
Velocities:
Magnetospeed showed 2848 average with an ES of 8 fps for the 5 rounds I cronoed

Groups:
100 yards prone F-open setup - .4's pretty consistently without flags. Most of the groups were round, but mirage was a factor as I had a miserable time trying to pin the target down to shoot at it.

Resultant cases:
Shoulders were pushed out, somewhat spherical. Corners are rounded compared to fully - formed 5x fired cases from same barrel.

Primers had some flat to them, but the corners were still visible.

Blow length ranged from 1.529 to 1.536" with just one case at 1.528 - the next shortest was 1.531

I know that the false shoulder didn't contribute to the short length as I had one case that I had pushed back so far that the bolt would fall closed. It came out 1.534". I also tried running a .020 jump, blow lengths actually came out a few .001 shorter (5 rounds)

I can work with the short cases - I already am aggressive about carbon rings. I also know that the cases will grow a few over the next 2 firings (about .010).

Other than the aforementioned brake cleaner (I don't think I want to do that at a match), what else can I do to increase the blow length?

 

[tdogg]

I'm new to fireforming but I was able to get cases in the 1.545-1.550 range with the cream of wheat method. All I did to headspace was trim the necks to the right neck length and use that neck trim shoulder to headspace the case in my tight neck chamber. Some Red Dot and small pistol primers were used to fireform. I had some that wouldn't fire using the COW method (some the neck trim shoulder wouldn't hold) and I tried the bullet jam method. Using the bullet jam method, I ended up with most cases in the 1.540-1.545 range.

I will say that I left a small amount imperial sizing wax on the cases for fireforming. I did lose 2-3 cases with split shoulders.

My next session fireforming (if the Norma brass doesn't pan out) I will use the COW method. I will probably use the false shoulder method to correctly headspace the case.

Cheers,
Toby