Forster co-ax press question

[tangolima]

Originally Posted by AVirginian

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.

Good to know. Thanks.

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

-TL

[AVirginian]

By "engineering" I meant analyzing. I have never seen a thread on any reloading sight referencing the failure of a Co-Ax.

[mikld]

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.

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).

[daboone]

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.

[Fine Figure of a Man]

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.

[jmorris]

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.

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.

[Unclenick]

Originally Posted by tangolima

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.

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.

[daboone]

"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. I just called and found out that was true! Thus I just ordered the new upgrade plate and 2 springs.

Thanks Unclenick!

[tangolima]

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

[Whisper 300]

+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 )

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

[supercub99]

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.......

[tangolima]

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

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

-TL

[RC20]

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.

[tangolima]

Forgive me father, for I have sinned.

Sent from my SM-G930T using Tapatalk

[Unclenick]

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.

[tangolima]

Thank you Unclenick.

I didn't know whether the press cams over per se. But based on what I saw on the video, it does seem go rather near the top dead center. That is where my concern is as the mechanical advantage is huge, infinite theoretically. It can break thing before you know it.

Forming a straight wall case is much lighter duty than a full size bottle neck case. When I form 30-06 into 8mm Mauser, I lean on the handle of my t-mag. It cams over. The force exerted on the die is easily several thousand pounds. I know some seasoned reloaders consider using sizing die for forming a "bad habit". Although I don't totally agree with the thought, I can see the point. It is taxing on the equipment.

I see what the co-ax is best at. I should use it judicially, if I decide to buy it. I will put all things into consideration.

Thanks again for your calm and shrewd advice. It has been a pleasure as always.

-TL

[Unclenick]

You are welcome.

Yes, the low contact area pistol sizing ring is no comparison to rifle brass forming. Especially not pushing a shoulder back over a tenth of an inch. I still think the press is plenty strong for the task, and I am being, perhaps, overprotective of mine.

I notice, BTW, that Prvi Partisan has 8 mm Mauser brass for about $0.60 at Midway. I've heard their recent rifle brass production is pretty satisfactory, but haven't had a chance to try any.

[supercub99]

On a more serious note....or not...lol. Some of us have been in the troubleshooting/repair business all our lives and we are the ones that "fix" and make right what engineers were paid thousands to do right the first time. I won't diss on em but I can tell you that as long as things are breaking, someone's not designing, making, or engineering them right. In defense of the engineer, often times they do design it right but the guy selling it doesn't always follow through with the design presented...ie, they cheapen it down to a price point.

Anyway, it's a good discussion and lots of new info on the jaw holders. In regards to forming brass, I'm like Unclenick, I did run a .308 into a 6.5 Creedmoor die and was rather successful with not much resistance at all. Another time, I bought a new die, a Redding I think and apparently you need to run the de-capping pin out a lot more than what most, ie, 1/8". What happens if you don't run it out a 1/2 inch, is it snags on the expander ball and shoves the neck back into the case. Odd looking duck but again, no effort. I think you could easily form brass. On the other hand, I have a rock chucker sitting on the floor that again like Unclenick I would probably use that. Everything else he says about the Co-ax and how he uses it mirrors my use.

Reading these posts, one tends to go to the web sites and I have often thought a shorter handle would be handy. They are listed in both Forster and several after market outfits like Inline Fabrication. I thought maybe a trip to the hardware store and maybe find something I could adapt. I found these;
http://www.doublehh.com/index.php/pins/hitchpin/
They cost $3-6 bucks and can be cut off to desired length and you have a very nice handle. It is tough stock and took about five min. to cut it with a Milwaukee mini sawzall. I cut mine to 6.5 in. overall. I had to buff the end that goes in the yoke a hair as the paint makes it too thick to slip in. They look cool, work great and cost little......and are the right color to boot.

[jmorris]

Some of us have been in the troubleshooting/repair business all our lives and we are the ones that "fix" and make right what engineers were paid thousands to do right the first time.

You can't always blame that on an engineer. Many good designs are turned into bad ones just because "bean counters" tried to make the finished product cheaper and changed the original specifications.

That said there are good and bad engineers too. Some if asked by a black smith to design an anvil, would create a contraption with 52 moving parts that require some external power source, etc. Then there are some that would just recreate what has been working for hundreds of years.

[tangolima]

Originally Posted by Unclenick

I notice, BTW, that Prvi Partisan has 8 mm Mauser brass for about $0.60 at Midway. I've heard their recent rifle brass production is pretty satisfactory, but haven't had a chance to try any.

PPU brass is good, though probably not quite as good as the other more expensive brands. They were in short supply for a short time, now no longer a problem.

I do several conversions; 30-06 to 8mm Mauser, 30-06 to 7.7mm Jap, 6.5mm carcano to 7.62x45 Czech, and a few more in the future. Some are out of necessity, but mostly are because it can be done. I have a big pile of hxp 30-06 brass sitting idle. I am hesitant to pay for a brass if I can make it out of 30-06.

-TL

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[tangolima]

Originally Posted by supercub99

Anyway, it's a good discussion and lots of new info on the jaw holders. In regards to forming brass, I'm like Unclenick, I did run a .308 into a 6.5 Creedmoor die and was rather successful with not much resistance at all. Another time, I bought a new die, a Redding I think and apparently you need to run the de-capping pin out a lot more than what most, ie, 1/8". What happens if you don't run it out a 1/2 inch, is it snags on the expander ball and shoves the neck back into the case. Odd looking duck but again, no effort. I think you could easily form brass. On the other hand, I have a rock chucker sitting on the floor that again like Unclenick I would probably use that. Everything else he says about the Co-ax and how he uses it mirrors my use.

That's a very good data point, thank you. A 308 into a 6.5mm creedmoor is serious. Sounds like the press can do that sort of forming without much problem.

In the second instance, you were jamming the brass between the die neck and the expander ball. It happened to me a few times.

Talking about engineering profession (not a label), engineers make mistakes. They do most of the time because they assume incorrectly. They trust but are too lazy to verify.

Well, that's what I heard. I only drive the train

-TL

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[supercub99]

I take a certain comfort in having a driver when on the train, mainly the airport shuttles and metro's I've been on a few times. The ones with the empty seats at both ends? those can't get there soon enough for me. Now with you at the helm, I'm not so sure we'd get there in my lifetime...LOL..just kidding...ha ha.....

[jmorris]

They trust but are too lazy to verify.

That is why I was suggesting putting one to use on the last page, no better way to see how a shoe fits than to try it on.

If you have one of these near you, you can try it out for 90 days and if you are not "completely satisfied" return it and get your money back.

http://www.cabelas.com/custserv/cust...=ReturnsPolicy

[RC20]

On the note of engineers.

Ultimately in the end its the field success of failure that determines how good it was and often there are factors that the engineer has not a clue on. Not because they are stupid (though some are truly awful as in any profession) but they can't design to what they don't know is there.

I don't engineer, I repair. I asses. I come up with fixes (if possible)

I have come across fairly few pieces of total junk.

But, just as I could not do the design, no engineer can critique or properly assess a piece of equipment unless they designed it, saw it into the field and got the feedback.

If you think you can you are simply fooling yourself. Experience trumps opinions every time.

If the engineer gets it close enough we can adjust it or make it work they have done well.

If you want to read a story of reality, read the story on Boeing battery debacle. That includes the burning down of a building by an engineer.

While not the only lesson, having a company that provides Security system for Business aircraft are not who you want to design a battery charger.

[Unclenick]

There's a book from about 35 years ago that you might like called, To Engineer is Human, The Role of Failure in Successful Design. It's about numerous engineering failures, like the Tacoma Narrows bridge that taught us important things.

The main difference between and engineer and a basement crank inventor is just having the science and math and training to whittle down what can sometimes be a nearly infinite number of cut-and-try possibilities, and sometimes to prove an idea will never work and therefore to avoid spending time on it at all. It's a mixed blessing. The right training means you probably won't get a basic mistake on something that's been done thousands of times. But the training can also narrow your way of looking at things, so that every once in awhile a person without that training, not stuck inside "the box" will come up with something it would never occur to you to try.