Forster Co-Ax

[mrawesome22]

Does anyone use this press to prime? The Forster catalog sure makes it seem like priming on this press is the best method on earth, but are they just hyping it up?

My wanting of this press relates to the floating system seems like it would be inherently more precise as far as alignment goes, and if I could get a priming system that got the primers out of my precious hand, and worked, that would be great also.

Are there springs or something where the die collar slides in? Do Hornady die rings work on this press?

Thank you and God bless.

[Ideal Tool]

Hello, mrawesome22. I have a Colt SAA .38 special that is a bit on the light side when it comes to primer strike. I usually hand prime by feel..but this puts primer farther inside pocket..no problem except missfires once in awhile with this one. Never used the Co-Ax priming before..ran 50 cases thru..this set-up has a built in stop in primer punch..seats all primers to a uniform .002" beneath case head. Result..no missfires & deep indentation on all 50. I like it! No springs..die locking ring "floats" in milled out slot for self-centering, & fast die removal.

[Ike666]

First of all, I love my Co-Ax and use it for all my precision rifle hand loads.

I usually handprime with an old Lee tool and ignored the priming tool on the Co-Ax for a long time.

Then I got some new Lapua .223 brass to use for my bolt action and decided I'd learn to prime with the press. Big Mistake.

I may just be too dense to figure out the instructions (which pretty much just say adjust and begin priming). I'm guessing there is more to the "adjust" part of the instructions than I'm able to understand. There are three little "leaves" that surround the primer ram to hold the head of the case. The ends of the leaves are beveled and seem to fit nicely into the extraction groove on the case. To adjust you place a case into the primer ram and hold it in place with the ram in the primer pocket. Then with the three little tabs loosened slide them in to the extraction groove trying to keep them all even. Tighten the tabs down and you should be ready to begin priming.

When I put my first case in and tried to prime I tore the heck out of the rim. Apparently the little tabs didn't have a sufficient hold on the extraction groove and when I ran the ram up it popped the case right out the top. I was PO'd; I'd destroyed a new pristine piece of Lapua brass (now the count is off, 99 instead of 100 - rats). I gave up at this point.

Now, I don't like to have a tool I cannot use right or effectively. I'm hoping one of you out there with more experience with the priming system on a Co-Ax will chime in and tell me where I went wrong. I've got to assume it is me, because everything on this press is so well engineered and logical in its function that I've got to be doing something wrong with the primer system.

BTW Mr. Awesome, if you don't already have the Co-Ax get one. Get one now. The accuracy of the system is terrific. Using a Redding Competition Seater I routinely get less than +/- 0.001 run out on the seated bullets. The quick change is just a big bonus to the free float system of the press.

[RyeDaddy]

I prime with my Forster and it is uniform and fast. Can't recommend the Forster Co-Ax enough. It costs more than other single stages but it's absolutely worth it. Full length sizing is a breeze, as is die-changing.

[Ideal Tool]

Hello, Ike666. I have had my Co-ax for nearly 20 years now..never used the priming function..I did exactly as you..adjusted fingers on case rim..eyeballing to center...& promply smashed the edge of primer pocket! Then the o'l light bulb came on...I started looking in my parts drawers..mind you, 20 years is a long time to remember..let alone find something you have never used! Ah! there it was..This time I was smart & put it with the extra Forster shellholders! It is about 1" long, knurled in center, blackened finish...One end goes into priming holder..other goes into empty primer pocket of case (there is a large & small tool) ...bring fingers in, and tighten..Perfect alignment!

[amamnn]

I have used the priming function of my co-ax and it works quite well. I can "feel" the primer seat using it just as well as my Lee hand primer. These days I use the K&M unit with the dial indicator for match rounds for two reasons.

1- my shoulder injuries have pretty much caused me to do only die work on the presses and sometimes I have to take long breaks from that--

2- it was very clearly proved to me that nobody I know nor I can accurately and consistently "feel" a .003 inch (the supposed optimum) crush of a primer-- but with the K&M described above you can see it you can also see the variation of primer cup height from one primer to another and the primer pocket depth variable. These things can and do confuse "feel" seating. If only I'd had the K&M 40 or 50 years ago.........


Still--for casual shooting applications I would not hesitate to use the Co-ax to seat primers.

[Ike666]

Ideal - actually I used the little case alignment tool with the brand new Lapua case. Adjusted the leaves to hold onto the extraction ring - and bam! tore the heck out of the rim. I've got a ton of swaged LC mil brass I don't care if I tear up, maybe I'll experiment with that and see if I can get it to work.

Amamnn, I've got a K&M neck turning set-up. Went to their site to check out the primer tool. Yeow! $112.00 for a one-shot at a time primer tool! I'm sure its got the precision you say - cool gauge on it and all. But, $112?

[Unclenick]

A lot of that's the gauge. The non-gauge unit is very reasonably priced (compare to the Sinclair, for example) and still has the exceptional feel and the spring-loaded primer sleeve that squares the primer entry into the pocket. The gauge is the better method, though. Federal says touch down plus 0.003" further insertion for large and plus 0.002" for small primers to set the bridge properly. It's apparently not uncommon for primers without a properly set bridge to experience ignition delays of a number of milliseconds—up to 20 milliseconds or so according one CCI employee—that adds to lock time and allow shooter and gun movement to add to muzzle disturbance before the bullet exits.

On the Co-ax priming system, I think its priming system is the best for floating firing pin military gas guns to mitigate slamfires prevention. I've not had a problem with the finger setup, but I'd check that your case's extractor groove floor isn't too narrow for the tips. Shouldn't be, but double-check. Just keep a little inward (toward the extractor groove) pressure on them as you tighten them up. (Note that Forster's Co-ax bench seating tool does not feature that fixed 0.004" primer seating depth below the case head, so it is not a substitute for the one on the Co-ax press.)

I actually tend to prime while watching TV. For the gas guns, I just prime to touchdown by feel, then run the cases through the Co-ax to finally set the bridge and ensure the primers are below flush with the case head.

I run 90% of my rifle loading operations in the Co-ax press and, like Ike, use the Redding Competition Seater in it. It's the only sliding sleeve type with a floating seater stem, and it really does produce small runouts. Expensive, but seems to be a case of getting what you pay for.

[jag2]

I read a post a few months ago by Unclenick and got curious about setting up the primer function on my Coax. I do use it occasionally for certain calibers and
am impressed how well it works.
The following is my belief but I can't swear I'm right: the three leaves you refer to are reversible, just like the jaws in the shell holder. Both ends of the leaves
have the protruding edge that holds the base of the cartridge but I think they are different. If you loosen the set screws on top enough they can be rotated 180 degrees. I was trying them out on 25-20 and they didn't seem to grip the cartridge very well. I tried reversing them and they worked fine. I've never removed them to check them out with calipers. Maybe Unclenick will know more about this. I've never seen it discussed anywhere, probably because not a lot of people prime on their Coax. Anyway, its easy to do so you might as well give it a try.

[Unclenick]

Good point. You can switch between the tall and shallow steps to better fit the extractor groove and the rim thickness. Also, if you got them upside down with the taper to the step on the bottom instead of the top, the rim would be held poorly.

[jagwire]

I have an old Bonanza press. From what I understand, Bonanza was the company that made the Co-Ax press before forster obtained the patent. The priming system on the Bonanza is awesome. I looked at a picture of the Forster press and I cant tell if the priming system was changed when Forster started manufacturing the Co-Ax. My press uses an RCBS type shell holder with a larger hole to allow the priming punch through it. I have never had any of the problems mentioned in the above posts. I picked up this press at a gun show a few years back for $85. The press looked like it had hardly been used.

[Unclenick]

Forster bought out Bonanza, which is how they got that press and the runout gauge and other products Bonanza used to sell. The yoke on the press has been changed, twice I think, to accommodate taller dies.

[Ike666]

Well, I took a good look at the primer tool on my Co-Ax. It was set up for small primers, but I'd left the positioning/retaining leaves on the large casehead size!

Using my handy-dandy positioning tool, I flipped them around and re-set the tool for .223 cases. I had some trouble getting the three leaves set with an even "bite" of the extraction groove. When I finally got it where I was satisfied and tested a piece of LC brass in it, I once again got severe deformation of the rim at the three points where the leaves contact the extraction groove. The brass was ruined.

I may be using the mechanical advantage of the press to "vigorously". I just don't know what I'm doing wrong. I love this press and the primer tool is an unnecessary component from my point of view - I just like to get things to work right.

I guess I'll stick with the Lee Autoprime hand tool. That I can operate correctly!

[B78-22250]

For numbers I use the lee hand primer. For accuracy I use my Sinclair priming tool. One gives me speed and a pretty good feel. The other gives me great feel but not any real speed. I think you should use the tool that suits YOUR needs the best.

[p5200]

I had the same type of problems trying to use the priming tool on my Forster. If I didn't apply pretty good pressure, it looked like the primers were too rounded and sticking up too high. I've been using an RCBS hand primer with pretty good results. I wondered about the Forster separate primers they make anyone used one of them?

[mrawesome22]

Well so far no one has convinced me the priming system on the co ax is the bees knees so I guess I'll just keep using my rcbs universal hand primer. I sure would like to get all those primers out of my hand though. Guess I am getting cautious in my growing years.

[Unclenick]

You could get their short handle attachment to cut down the leverage and let you feel the primer ram stop better. I would shine a flashlight through sideways and watch the ram and feel the pressure needed. Unless it came out with a high primer, you've got to be pushing too hard to bend rims.