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Topic: Long Dasher / Short GT 40* (Read 387 times) previous topic - next topic

Re: Long Dasher / Short GT 40*

Reply #45
Looks like it has 2 better ideas.
The shoulder angle and a bit longer neck.
6 HUF AI


Re: Long Dasher / Short GT 40*

Reply #47
That's where I fall short, is the forming of new brass
into a possible wildcat.  The 6x47 AI would be something
I'd try if I knew what I was doing.
I'm sure it's just a matter of knowing a fews things.
Just never seen it done.
I can barely draw a straight line.

Re: Long Dasher / Short GT 40*

Reply #48
Tag me in on this one.
I've found you can take a long case like 270, draw it down through a 260 body die to any length in between,  then push it into a 6.5 Creed Die to match the rear of the shoulders.  Finally push it into a 40° A.I. die like your dasher (mine is the 6.5/257 Bob Ackley) up to that shoulder junction.  And because of the slightly larger diameter at the shoulder it will push out slightly and buckle if you try to go farther (like you found). 
Going straight from 20° shoulder to 40° seems like it will buckle every time.   Don't have any 35° stuff to play with but might make things easier yet.

Having your case at 40° before first fireform has to remove at least one fireforming step to finished cases.

From a hunters point of view I think with a couple more operations on brass like 260 you could form the creedmoor to a true Ackley so that standard 6.5 Creedmoor factory ammo would have a "crush fit" like P.O. Ackleys designs and work fine in an emergency hunting situation. 

The "260 creedington" chamber is just a hair short to do that with 260 cases.  If I were to start over the shoulder would have to be farther out to begin with to be a true "Ackley style" in order to get the crush fit with factory ammo.  Though not a concern for bench resters.
The custom die people definitely could come up with a die or set of dies to produce close to "perfect" forming.
11X Grandfather
Part time Savagesmith

Re: Long Dasher / Short GT 40*

Reply #49
Not trying to hijack again but the Creedington volume increased over 2 grains total after fireform when the shoulder angle was formed.  The diameter increase at the shoulder was part of the gain along with the .077 length increase.  So fireforming is mandatory for all gains anyway.
If the chamber was .010- .015  cut deeper the forming would not quite clean up the shoulder in the CM die but factory 260 ammo would now work in a pinch.  Final powder charge would probably gain over 1 more grain also (4 grains over CM).
Neck trimming would be minimized.
Just thinking out loud again.
11X Grandfather
Part time Savagesmith

 

Re: Long Dasher / Short GT 40*

Reply #50
This is along the lines of what I'm thinking. Start with at least a Creedmoor to get all the neck I can, ream short to compensate for pushing the neck shoulder back into the shoulder body. Then fireforming will suck a little of the neck back in to fill out the body shoulder.

I've got the reamers to do a 6 but nothing I have will pull off the 40* 6.5

I've been eyeing a 6.5x55AI that would do it on Grizzly and missed a 6.5-308AI on flea bay the other day.
Dave

Re: Long Dasher / Short GT 40*

Reply #51
Would running a 6 dasher reamer work with a 6.5 pilot bushing?  Then a 6.5 CM for the neck & throat.
The dasher reamer would enlarge the breech end a little .002-.004...
11X Grandfather
Part time Savagesmith

Re: Long Dasher / Short GT 40*

Reply #52
Would running a 6 dasher reamer work with a 6.5 pilot bushing?  Then a 6.5 CM for the neck & throat.
The dasher reamer would enlarge the breech end a little .002-.004...

This what I was counting on however all my 6.5 bushings have a larger inner diameter and will not work on the 6 mm reamers.
Dave

Re: Long Dasher / Short GT 40*

Reply #53
This what I was counting on however all my 6.5 bushings have a larger inner diameter and will not work on the 6 mm reamers.
Maybe make a special bushing or a sleeve? Or maybe the reamer mfg may have it?
Thoughts ??
11X Grandfather
Part time Savagesmith

Re: Long Dasher / Short GT 40*

Reply #54
Maybe make a special bushing or a sleeve? Or maybe the reamer mfg may have it?
Thoughts ??

Very possible. I'll check into it at some point.
Dave