Forster co-ax press question

Your concerns are unfounded. Lock ring strength? Try to strip the threads on a Forster ring or a Sinclair ring by applying force to those "3 or 4" threads. You can F/L size any "normal" cartridge with no thread problems (I haven't tried necking down/forming any wildcats, yet, but wouldn't be afraid to try.). You could probably take a bit off the ends of the shell jaws, but have you tried the 25 ACP yet? http://www.forsterproducts.com/product/shell-holder-jaws-for-co-ax-press/ Forster says you can use their LS jaw on the small end. The springs keep the jaws closed, but the "strength" does not come from the springs. IIRC the jaws are hardened and ground and any force is directly downward, no twisting, no need to "control" the case, and the jaws are held in place with a plate and two screws (I think one would have to use a 36" cheater bar to have enough leverage to strip the two screws trying to lift the pate or remove a stuck case). The jaws also "float, enabling correct die/cartridge alignment.

I've only had my Co-Ax for a few months and have had zero problems (except the handle is too long. I made a 6" handle but I have wound up not using a handle at all. The press leverage is enough for me to just hold the yoke and operate the press. I've sized 45 ACP, 9mm, and .44 Magnum so far. I did some 308 rounds but I used my 6" handle.). I ordered some extra jaws, LS I believe, and while I was waiting I made a shell holder for 9mm to work with the auto-closing jaws; I ground and reformed the base of a standard "universal" 9mm shell holder to fit in the jaws and I could reload 9mm while I waited o the proper jaws. (I put the shell holder in the jaws. lifted the handle a bit to hold the shell holder, inserted a case, and reloaded as usual).

A progressive press doesn't fit my lifestyle and my Co-Ax is a bit easier, more comfortable to use than my Lee Turret and other single stage presses. I may try a pair of Inline Fabrication linkage, but that will prolly just be out of curiosity as the stock linkage, access is fine. I did mount my Co-Ax on about a 30 degree angle to my left for access, but I have mounted other presses that way too.

My responce is a bit wordy, but I am very happy with my Co-Ax...:D
 
The concerns came from comparison. It is weaker design, and lock ring is not designed to provide strength. I need numbers, not just qualitative, sometimes emotionally charged, words, to be convinced that it is good enough. And I am after doing the calculations.

The jaws is still a thing, but I reckon there is a way to provided positive stop in tough going situations. So it is not a big deal anymore.

Thanks all for your inputs.

Why don't I stay with my Lyman? It is an old model that doesn't have the tension bar in the rear. Despite its beefy parts, its umbrella design dictates that it shifts under load. It will have the job done, but just not as precise as I want it to be. Besides I need a good spent primer catcher. I don't like the primer compound residual.

Thanks again, gentlemen.

-TL
 
I look at the pictures and drawings as an engineer and ask questions as I see it.
Click to expand...

If you are an engineer you can calculate how strong a 5/16 of 7/8"-14 threads are and measure how much force you are using to pull brass in and out of the die. The fact that no one has ever had any problems, even with aluminum nuts should tell you it is more than sufficient.

Pretty likely you have a couple hundred bucks so you can put one to use and answer your questions/concerns actively and ore accurately through use.

You spent a lot more than that at the college book store getting your degree and the resale value on your co-ax, if you don't like it, will be much better than any of your textbooks had.
 
Thank you for the enlightenment. I will take the $300 out of my kids' college fund, and I will them with straight face that it is for their best interest. :)

I didn't know folks can love their loading press so much. [emoji15]

-TL

Sent from my SM-G930T using Tapatalk
 
Last edited:
I didn't lube a case properly once, the Co-Ax did it's job and ripped the rim off the case, the jaws held and the lock ring didn't fail either.

I think you are way over engineering this.

It's a hell of a press and great for precision rounds.

The design is as good as it gets.
 
AVirginian said:
I didn't lube a case properly once, the Co-Ax did it's job and ripped the rim off the case, the jaws held and the lock ring didn't fail either.

I think you are way over engineering this.

It's a hell of a press and great for precision rounds.

The design is as good as it gets.
Click to expand...
Good to know. Thanks.

I am not engineering anything as I am not designing. I am just collecting information.

-TL
 
The concerns came from comparison. It is weaker design, and lock ring is not designed to provide strength. I need numbers, not just qualitative, sometimes emotionally charged, words, to be convinced that it is good enough. And I am after doing the calculations.
Click to expand...


Then I wouldn't recommend the Co-Ax for your uses (or any other multi-station press). All the presses made today are at least 10 times as strong as needed for reloading, but I have no numbers for engineer types, and have seen no destructive tests (perhaps you should be looking at a bullet swaging press? Corbin?). In all the time I've been around reloading (Started reloading in '69 with Lee Loader. Been on line looking at forums, reloading websites, and manufacturer web sites since 2008) I have not seen, read, or heard of any side by side comparison destructive tests with corresponding numbers/statistics. The Co-Ax is a very good, strong design and has many thousands of satisfied users (not an emotional reply, fact).
 
I have the older Bonanza CO-AX. Many many years of service. I load 8 different bottlenecked cartridges with it and never every has this old press failed. The only problem I ever had was with a spring in the shellplate flying off into infinity(?) when changing the jaws to accommodate a different caliber. That was on me not the press.

It's only shortcoming for me is the yoke doesn't allow sizing cast bullets. Now I use the 550 to size bullets.

I've owned 7 different presses made by Herters, Lee, Forster, RCBS, and Dillon. The only presses that remain in use are the CO-Ax and the 550B. But I gotta admit I never had a press that broke or wore out. The presses that remain in use are there because they make reloading simpler, easier and more productive.
 
The auto jaws work fine but I put the shell holder adapter on mine because I use Redding competition shell holders for some cartridges.
The adapter is available from Forster for about $30.
 
Thank you for the enlightenment. I will take the $300 out of my kids' college fund, and I will them with straight face that it is for their best interest.
Click to expand...

You would be buying a co-ax, that's more like buying a Dillon progressive, they don't loose value like if you were to buy a Lee loadmaster. You wont loose much on resale. Better yet go buy it from a walk in store and if you don't like it return it, you won't loose a cent that way.

FWIW if $300 is going to be the difference between your kid and college, it would be wise to abandon recreational shooting and reloading, it doesn't take long for the hobby to eat up a few hundred dollars.

Its kind of like shoes, the only way you are going to know if you like it, is to use it. That's why we have folks that like Lee, Redding, Lyman, Forster, RCBS, Hornady, Dillon, etc the best, because we are all different.

Personally I think the worst thing about the co-ax in access, there are some that change the linkage out but as an engineer you can see why the factory linkage would be superior.
 
Last edited:
tangolima said:
I have no doubt on the heat treat. That's not my concern. The jaws are movable, and are kept shut by a pair of springs. The flange in a conventional shell plate is fixed. Think crescent wrench versus fixed wrench. If the extraction groove in the brass is not positive, it will try to push the jaws open. Here the weakest link is the springs.
Click to expand...

Not actually an issue. The jaws slide perpendicular to the extraction force. The semicircular profile that slips into the extractor groove is chamfered on top, but has a flat, horizontal recess on the bottom where it contacts the rim, so there is no wedge angle to create lateral deflection during extraction. Additionally, when withdrawing a case, the jaws are pulled up against their cover plate so friction removes any remaining temptation for the jaws to slide. As I mentioned, I tore the head off a really fat .223 case that got stuck in a carbide small base die, despite lube (some odd things can happen; I was too dense that day to take the extra hard sizing effort I experienced seriously enough). And when I say the head tore off, I don't mean the rim bent or broke. The whole head ripped away at the pressure ring area and left jagged metal around the back end of the opened case body. I've etched a case whose head tore off out of a steel die before, but the carbide is expensive enough that I sent it back to Dillon and let them do it.

In the upstroke, the bottom of the case is on solid casting and there is no pressure on the jaws to slide except to the extent there might be any remaining misalignment between the case and die. In that case, the jaws can shift slightly on both horizontal axes so the case can self-center as it is pressed upward.

As an engineer myself, I can appreciate that you want to be sure you are not getting an inferior design, but this mature design is somewhere in the 50 year age range now and has been thoroughly debugged long since. It works a treat. The newest B-5 version has a taller yoke for taller dies and accessories. They also added a retainer to keep the jaw springs from flying loose when you change jaws. Otherwise, Forster says, they are unchanged.

The press's built-in priming tool is a worthwhile device if you shoot any floating firing pin military rifles. Though it seems a little awkward to set up at first, it forces primers a fixed depth below flush with the head, minimizing the chance of a slamfire in these weapons. There are bench priming and priming hand tools that can be set up to do this, and some newer ones are easily adjustable. But they run $120-$215 and you don't need the adjustments at service rifle accuracy levels. Shooting bugholes in benchrest, yes, maybe, but not for normal service rifle match shooting.
 
"They also added a retainer to keep the jaw springs from flying loose when you change jaws. Otherwise, Forster says, they are unchanged."

Sorry I didn't believe that.:o I just called and found out that was true! Thus I just ordered the new upgrade plate and 2 springs.

Thanks Unclenick!:D
 
Thanks much, unclenick. I knew you would give the best answer to any question.

I'm now quite convinced the design is sound. I will proceed with the order shortly if it doesn't get preempted by other priorities. A new press is rather down the list of things. The idea of upgrading it has been raised and put down several times in the past.

BTW, have tried case forming in your press?

-TL
 
+2 on thanks to Nick for alerting me to the "no fly" zone upgrade for the shell plate and springs on my old Forster. I will order the upgrade as soon as I post this reply.

It is my go to press for loading my most precise ammunition.

I cannot ever remember having a problem with the press and even if I don't apply (enough/any) lube, the press never falters. I have not yet ripped off the rim but have also never stuck a case (yet :D)

I have a multitude of presses and still find satisfaction when using it.
Speed ? - Not really
Accurate ammo - Yup
Built to hand down to my grandkids - Absolutely

Gary
 
We are truly relieved that although most of us do not have an engineer label we have correctly made a choice approved by you sir. I'll sleep well tonight.

As an aside and perhaps a concern to you, the weak link and what will in all likelihood give first when you go to apply the 10k pounds you are concerned with is the HANDLE.
Yes, it's a mere piece of 1/2" steel tubing, thin walled at that. I think with your degree however, you could easily engineer a titanium replacement. That of course will probably cause the weakness to migrate to another part which you may or may not have to address.

As a final thought, I'm thinking maybe you should just by a Sherman tank, modify the inside and adapt the press of your choice, tie it into the barrel and then you could jump up and down on the end of that and pretty much load anything you wished. Just a thought.......
 
Mechanical advantage. The force applied to the handle is magnified many times, especially near the cam-over point. 20lb of force on the handle can easily become over a thousand pounds on die. The handle is not necessarily the weakest link. Well, not that it is important.

I'm still amazed by the passion I feel. It took me surprised.

BTW, I didn't mean to be condescending when mentioned I am an engineer by trade. I'm one, but I wasn't spending all that time trying to show how sophisticated I'm. I truly wanted to seek information.

But engineer could mean a lot of things. To my kids, I drive a choo choo. Maybe I am. :) who says an engineer automatically comes with a college degree? Perhaps next time I will say I am a politician [emoji12]

Good day, gentlemen. I thank you for your help. I have found what I was looking for.

-TL
 
Last edited:
I do have an engineer label.

What I do not do is question 50 years of proof.

I had a mechanic who questioned a clamp on adaptor to a shaft.

B Lock as I recall. It can't work he says.

Well I says, there is you and me with an opinion and there is them who have been in the business for along time with a highly successful line.

Lets take them at their word. Sure Enough, worked perfectly.

And being a crabby old guy still working, you are taking this way too far. I have to wonder how you make it out to work without an engineer study of the driveway, the car, the pavement, traffic signals, stairs, doors and.....

If you want an engineering study of the Forster, by all means hire one.
 
Glad you got what you wanted to know. By the way, this press does not cam over. There are two small stops on the yoke that run into the vertical links just before the ram gets to what would be the top of an unstopped stroke. I think that's a good thing. A press that cams over (strokes past the peak ram position and starts the ram descending again) has such extreme mechanical advantage (theoretically infinite) at the very top of the ram position that it can damage itself too easily in inexperienced hands.

Regarding case forming, I've only done it accidentally in that press. I ran a .44 Mag case into it one time and didn't realize I'd slipped my only .41 mag sizing die in instead of one of the .44's. I never felt any problem during the sizing stroke, but the .44 Mag case sure looked like it had been doing battle with bulimia afterward. I see no reason it wouldn't work fine for forming. I just happen to have another press on another bench where forming projects are usually undertaken (Lee Classic Cast I got for $57 when they were new and Midway had a promo-sale going). I never fully trust formed brass until I've fired it once anyway, just because so few cases have truly uniform wall thickness. Firing a case in a blueprinted rifle will square it up nicely.

I suppose I look at the Co-ax primarily as my rifle match ammo baby, and other than the odd test load like that .44 Mag was supposed to be, it pretty much only sees match rifle loads. Not that it can't do more; it's just is how my work flow is set up.

I think you'll be very happy with the press when you can budget it. Until I got mine, I didn't realize how much I'd appreciate the quick die changing and the fact I seldom need to switch the shell holder jaws. It sounds really lazy, I know, but the fact is that I find time to run tests and loads on it that I would likely put off if I didn't have it. More often, though, it's just so quick that if I want to see if one lot of cases is going to need trimming on the next run through, I'll pop the die in, measure the case length and lube and size it and measure it again and drop a note in the bag with the rest of the batch as to whether I'll need to set the Giraud up for them on the next pass. Or I'll pop dies in to experiment or make some other measurement that I'd put off for the weekend if I didn't have it. It's a mental productivity improver in that sense.
 
You must log in or register to reply here.
Back
Top