Forster CO-AX

KEYBEAR · March 8, 2015, 10:01 PM

My old RCBS Rock Chucker was bought new I think in 1976 and getting a little worn . Last week I bought a new Forster CO-AX today I got to use it .

This press is nice and smooth as can be very lite handle pull and just a joy to use . I loaded 300 38 Specials for a friend and the press is a keeper . The Dies are super easy to set and snap in or out . I just love the no shell holder set up . Just wish I had bought one years ago . It cost more then some but well worth it .

Clark · March 8, 2015, 11:03 PM

I was really impressed by the co-ax press design.
http://www.freepatentsonline.com/3345903.pdf
I made a number of modifications, built a dozen sets with a manual mill and sold them online.

Original Forster parts vs my prototypes

Mavrick79 · March 9, 2015, 06:48 AM

What do your parts do differently from the originals?

**Unclenick** · March 9, 2015, 08:55 AM

It looks to me like it's a (relatively) quick change shell holder base. It eliminates the flathead screw that anchors the as-issued base, so just removing the two guide screws would let you swap a second base in. The sliding plate springs are retained in tunnels so they don't get loose or hop up and push the jaw plates out of the base. With four of these and two sets of S and LS plates, you could have all four possible shell holder head diameters available to pop in without having to fuss with anything other than the two guide screws.

Keybear,

I've been using one of these presses for 20 years and think they are great. The extra post-sizing steps I use for rifle loading (decapping before initial cleaning, post-sizing plain corncob cleaning to remove sizing lube, annealing and trimming when needed) has always made progressive loading less attractive than batch loading for precision rifle. The Co-ax die change system is perfect for this.

Note that the priming tool on top of the press is the only one made that I am aware of that forces primers to a fixed seating depth below flush with the case head. This can reduce velocity variation in rifle loads, sometimes significantly. I usually pre-seat primers lightly with a tray-fed hand tool while watching TV, then run them through the Forster press for final seating. This is especially good to do if the ammunition is for a floating firing pin gas gun to help minimize the chance of a slamfire. The hand tool pre-priming eliminates handling the primers one-at-a-time and as a result winds up being a tad faster for me in the end, despite handling each case twice. I also find the quick change die system makes extra steps less of a chore. Expanding rifle case mouths with a Lyman M die to improve seating straightness, for example.

You'll find liability warnings about loading for friends are pretty common. I always think it's best to let them learn to load for themselves on my equipment under my supervision. They then typically want to be able to do it for themselves whenever it's convenient and are inspired to get their own gear and join in the hobby. It's a good way to spread the interest in shooting sports in general.

Clark · March 9, 2015, 03:46 PM

I also wanted thicker shell holder jaw housing, so it would not bend with a stuck case.
I ran into a retired machinist, on line, that did the same mods I did, 10 years earlier.

------------------------------

Look at how great Clarence Purdie's invention was:
The dies snap in and out.
The jaws grab the case.
The leverage is to die for.
The case slides on a perpendicular slippery plate to center himself in the die.

-----------------------

And I lived with a Rock Chucker for 10 years before I coughed up the bucks for a co-ax.

KEYBEAR · March 9, 2015, 10:35 PM

I do intend to use the Forster to prime brass as i have an RCBS Auto Primer for that . All I do is size and seat bullets with it .

**Unclenick** · March 10, 2015, 08:19 AM

Keybear,

If you run some rifle rounds, try setting up the Forster to prime them and then run the loads primed on the Forster over your chronograph and see if you get an improved velocity SD over priming with the RCBS. In pistol I doubt you'll notice the difference.

Clark,

It seems like an improvement all around. I may steal that idea.

daboone · March 10, 2015, 09:11 AM

This is the guy's email address that is making the "Clark" upgrades. [email protected]
Here is his YouTube video: https://www.youtube.com/watch?v=9BpFD7NbvL8

I ordered these and found the Jaw to be a very well made and convenient replacement. No more lost springs.

March 8, 2015, 10:01 PM	#1
KEYBEAR Senior Member Join Date: January 11, 2012 Location: Indiana Posts: 1,059	Forster CO-AX My old RCBS Rock Chucker was bought new I think in 1976 and getting a little worn . Last week I bought a new Forster CO-AX today I got to use it . This press is nice and smooth as can be very lite handle pull and just a joy to use . I loaded 300 38 Specials for a friend and the press is a keeper . The Dies are super easy to set and snap in or out . I just love the no shell holder set up . Just wish I had bought one years ago . It cost more then some but well worth it .

March 9, 2015, 08:55 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	It looks to me like it's a (relatively) quick change shell holder base. It eliminates the flathead screw that anchors the as-issued base, so just removing the two guide screws would let you swap a second base in. The sliding plate springs are retained in tunnels so they don't get loose or hop up and push the jaw plates out of the base. With four of these and two sets of S and LS plates, you could have all four possible shell holder head diameters available to pop in without having to fuss with anything other than the two guide screws. Keybear, I've been using one of these presses for 20 years and think they are great. The extra post-sizing steps I use for rifle loading (decapping before initial cleaning, post-sizing plain corncob cleaning to remove sizing lube, annealing and trimming when needed) has always made progressive loading less attractive than batch loading for precision rifle. The Co-ax die change system is perfect for this. Note that the priming tool on top of the press is the only one made that I am aware of that forces primers to a fixed seating depth below flush with the case head. This can reduce velocity variation in rifle loads, sometimes significantly. I usually pre-seat primers lightly with a tray-fed hand tool while watching TV, then run them through the Forster press for final seating. This is especially good to do if the ammunition is for a floating firing pin gas gun to help minimize the chance of a slamfire. The hand tool pre-priming eliminates handling the primers one-at-a-time and as a result winds up being a tad faster for me in the end, despite handling each case twice. I also find the quick change die system makes extra steps less of a chore. Expanding rifle case mouths with a Lyman M die to improve seating straightness, for example. You'll find liability warnings about loading for friends are pretty common. I always think it's best to let them learn to load for themselves on my equipment under my supervision. They then typically want to be able to do it for themselves whenever it's convenient and are inspired to get their own gear and join in the hobby. It's a good way to spread the interest in shooting sports in general. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

March 9, 2015, 03:46 PM	#5
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	I also wanted thicker shell holder jaw housing, so it would not bend with a stuck case. I ran into a retired machinist, on line, that did the same mods I did, 10 years earlier. ------------------------------ Look at how great Clarence Purdie's invention was: The dies snap in and out. The jaws grab the case. The leverage is to die for. The case slides on a perpendicular slippery plate to center himself in the die. ----------------------- And I lived with a Rock Chucker for 10 years before I coughed up the bucks for a co-ax. __________________ The word 'forum" does not mean "not criticizing books." "Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist. Are we a nation of competing ideas, or a nation of forced conformity of thought?

March 10, 2015, 08:19 AM	#7
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Keybear, If you run some rifle rounds, try setting up the Forster to prime them and then run the loads primed on the Forster over your chronograph and see if you get an improved velocity SD over priming with the RCBS. In pistol I doubt you'll notice the difference. Clark, It seems like an improvement all around. I may steal that idea. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

March 9, 2015, 06:48 AM	#3
Mavrick79 Senior Member Join Date: August 25, 2013 Posts: 143	What do your parts do differently from the originals?

March 9, 2015, 10:35 PM	#6
KEYBEAR Senior Member Join Date: January 11, 2012 Location: Indiana Posts: 1,059	I do intend to use the Forster to prime brass as i have an RCBS Auto Primer for that . All I do is size and seat bullets with it .

March 10, 2015, 09:11 AM	#8
daboone Senior Member Join Date: August 23, 2011 Location: Phoenix AZ, Kealakekua HI Posts: 100	This is the guy's email address that is making the "Clark" upgrades. [email protected] Here is his YouTube video: https://www.youtube.com/watch?v=9BpFD7NbvL8 I ordered these and found the Jaw to be a very well made and convenient replacement. No more lost springs.