Forster Co-ax user's

Lonewolf74

Well-Known Member
Joined
May 12, 2016
Messages
520
A few of the recent threads on hear have really got me thinking about something regarding this press. I've wanted one for a while and just sold my Dillon 550 to get the Co-ax, now I'm just waiting for them to get back in stock.

Anyway my question; I was planning on getting the shell holder adapter plate right off the bat because I use Redding's comp shell holder's to control shoulder set back. On a standard press it produces much more precise results to make firm contact with the shell holder.

However after digging in I realized using the shell holder adapter would take away the "free float" ability of the Co-ax set up, negating part of the reason for getting it.

So is the Co-ax precise enough to not need to make contact with the shell holder and still keep shoulder set back to +- .0005, .001 at most?

How do you guy's set them up or do you have any tricks for making contact with the shell holder but keep set back where you want it (such as shims)?

Thanks for any input
 

CA48

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Joined
Nov 18, 2009
Messages
1,059
Location
Texas
You do not need to make contact with the shell holder on the co-ax to get a consistent shoulder bump. Although I do have to slightly with some of my dies to push the shoulder back far enough after several firings.
 

1Moose

Well-Known Member
Joined
Nov 25, 2013
Messages
155
I use this press also and have no issues managing shoulder bump. I'm using the Hornady headspace gauges, and once I've adjusted the die with the lock rings (Forster recommends aluminum rings to prevent wear of the retention slot), things remain consistent. I FL size with carbide expander ball, but I don't anneal. I suspect I'll get to a point where the shoulder may not bump the same amount as it used to, but I suspect that'll be when I'll wish I was annealing, and won't have anything to do with the press.
 

Trickymissfit

Well-Known Member
Joined
Jun 11, 2010
Messages
4,148
Location
greenwood, IN
A few of the recent threads on hear have really got me thinking about something regarding this press. I've wanted one for a while and just sold my Dillon 550 to get the Co-ax, now I'm just waiting for them to get back in stock.

Anyway my question; I was planning on getting the shell holder adapter plate right off the bat because I use Redding's comp shell holder's to control shoulder set back. On a standard press it produces much more precise results to make firm contact with the shell holder.

However after digging in I realized using the shell holder adapter would take away the "free float" ability of the Co-ax set up, negating part of the reason for getting it.

So is the Co-ax precise enough to not need to make contact with the shell holder and still keep shoulder set back to +- .0005, .001 at most?

How do you guy's set them up or do you have any tricks for making contact with the shell holder but keep set back where you want it (such as shims)?

I check my headspace all the time in sized cases, and I'd guess +/- .001" on in annealed cases. Worst case would be a .0025" window. I did do one batch of .222 brass that came in well under .0008" window, or +/-.0004". Annealed brass for sure sizes more consistently. Spring back is the issue here, so you also need to remember that.
gary

Thanks for any input
 

Malcolm C

Member
Joined
Mar 10, 2007
Messages
7
FWIW, the only time any of my dies touch the shell holder jaws is when I am initially twisting the die down. As soon as they touch, I back them off a few thousandths. My run out is typically 0.0005" to 0.0015". I see the greatest run out when I neck size cases from my hunting rifles down in one step. I've been using the Co Ax for ~15 years without the shell holder adapter plate no complaints whatsoever. Once, I got a new die that was closer to SAAMI max while my chambers tend to be closer to SAAMI min. I could not bump the case shoulders with this die. In this case, I had a machinist turn it down 0.003" and solved the problem.
 

gohring3006

Well-Known Member
LRH Team Member
Joined
Mar 17, 2014
Messages
4,049
Location
Ohio
I have no problem bumping the shoulder with my CO-AX. But I quit sizing with my
CO-AX, I’ve been sizing with my Rockchucker and seat with my CO-AX. I really don’t have a good excuse as to why, I just do it that way now.
 

Lonewolf74

Well-Known Member
Joined
May 12, 2016
Messages
520
Thanks for the input so far guy's.

I'm going to get one and see for myself either way.

Just to clarify what I'm asking about is how consistent is the shoulder set back without the die touching the shell holder. Say you want to bump the shoulder back .002 will all the cases be bumped .002 with at most +-.001 variance amongst the lot?
 

cdherman

Well-Known Member
Joined
Aug 9, 2008
Messages
299
Location
Kansas City
Sizing and seating are great with the Forster. I do NOT like the priming set-up, FYI. fiddling with set screws, etc.... (you don't have to own a shell holder at all, with the Forster, if you don't mind setting the top "jaws" every time you change case base.)

I really love seating with the Co-Ax. I set the micrometer die using a locked ring. And after each loading session, I throw a sticky note into the die box with the last Base to Ogive setting and with which bullet. Often, it means I can pull a die out a year later and recreate the exact load without any fiddling with the depth.

Only negative with resizing with a Forster (and its a veiled compliment) is that its action is strong enough that sooner or later you WILL stick a case in die before you realize that you forgot to lube. And then it will yank the rim off that case trying to pull it back out.

For priming, I have a old RBCS RS-2 aluminum press. It was the entry model in 1980 and it came with a priming setup where you have a special die that accepts shell holders, which fits on the top of the press. You adjust the die so that the primer is fully seated at cam - over. Once adjusted, all of the primers are seated to the same identical depth. I like it so much, it stays on my bench for priming duty. I suspect dedicated primer tools are just as good, but its what I have, and seems to work. Only disadvantage is that you have to touch the primer. I either wash my hands carefully before hand or wear nitrile gloves.
 

CA48

Well-Known Member
Joined
Nov 18, 2009
Messages
1,059
Location
Texas
Thanks for the input so far guy's.

I'm going to get one and see for myself either way.

Just to clarify what I'm asking about is how consistent is the shoulder set back without the die touching the shell holder. Say you want to bump the shoulder back .002 will all the cases be bumped .002 with at most +-.001 variance amongst the lot?

Yes they will, and if it's not I would say it's the brass and not the press. You can set your dies up to just kiss the floating shell holder plate, and by the time it does it should be aligned already so it doesn't increase runout. But I feel the tolerances on this press are tight enough that there is no need for it even after camming over.
 

Axl

Well-Known Member
Joined
Apr 15, 2015
Messages
578
Location
SW Montana
I bought the shell holder adapter just in case I needed it but so far I haven't ever installed it. You should have no problem controlling set back.
 

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