Bonanza Co Ax

[rbuck351]

I just bought an old Bonanza Co Ax that seems to be all there and in good shape except for the priming system. It has a plate on top that holds a std shell holder but the primer posts are too big to fit through the hole in a std shellholder. Do they make a special shellholder for these and are they available?

[labradigger1]

I usually don’t prime on mine but i think you’re going at it wrong. Coax doesn’t use shell holders. They use 2 plates to hold the head of the shell. 2 different sizes are available (large and small) to cover most cartridges.

[smithnframe]

My Forster Coaxial press has an adapter for using standard shell holders.

[Loudenboomer]

Yes. They have an updated primer conversion for large and small primers. It uses a multi caliber 3 jaws adjustable shell holder.

[trebor44]

I usually don’t prime on mine but i think you’re going at it wrong. Coax doesn’t use shell holders. They use 2 plates to hold the head of the shell. 2 different sizes are available (large and small) to cover most cartridges.

What he said ^^^^^. I bought mine back in the early '80s and it came with the plates. These are still available from Sinclair. I like the plates and I think I may have used the priming function at least once. Also you can get the short handle or if you are creative you can cut down the existing long handle. The older aluminum rings (RCBS etc) work or they can be 'slimmed' down to fit any standard die into the slot. There is lots of info online about the Coax if you need more. Since this is a press preferred by Bench resters, the dies are expensive but can be found used in excellent condition.

Note that the plates are 'reversible' to fit large and small cartridges.

[mdi]

For priming the Co-Ax uses and adjustable shell holder assy. for priming. Put the "locating tool" tool in the press, place a shell in the priming station, run the centering tool up into the primer pocket and push the 3 sliding "jaws" into the extractor groove and tighten the screws. Go down to the fourth page; http://pdf.textfiles.com/manuals/FIR..._coaxpress.pdf

[rbuck351]

Apparently I'm missing one of the two sets of shell holder plates used for resizing and bullet seating but for priming mine has a plate at the top of the press that a std shell holder fits. The problem is the primer installation punches that fit the press are too large to fit through a std shell holder. My press does not have the three adjustable shell holder fingers that are shown in pictures of the Forster Coax. After thinking about this last night I tried to drill out a rcbs shell holder and found it to be harder than my cobalt drills. Next step was to drill and tap a 5/16 fine bolt for 8x32 threads and screw in a rcbs primer punch. Works great. Next is to figure out which shell holder plate I have and order the other. Thanks for the replys. Buck

[country gent]

The coax presses priming system is unique in that its a plate with 3 adjustable jaws They are set with a little round gage. the gage is inserted from underneath and a case set on it the jaws are then adjusted in to the case. allowing for a form fit to your batch of cases. I like it a lot the draw back is having to have the little gage to set it up each time a change is made.

The coax is a unique press in that the dies and shell holder both float and can self align very accurately. The shell holders are universal in the 2 ends of the std set cover 90% of the cases, there is a extra set to cover 22 hornet and 45-70 head sizes. The priming is also a nice reliable set up that just plain works. Individual shell holders arnt needed with this press to load or prime.

On older presses the big wear points are 1 the block under the cartridge's head will become dimpled from wear ( newer models have a wear plate under the shell holders) and the links, pivot pins will wear egg shaped over a lot of use. On mine I milled down the block .060 and fitted a wear plate made from heavy strapping. I then made new links and pins. It was like a brand new press.

[robbyPGP2014]

1 set will be marked with an s for small ,and the other will not have any kind off marking ,at least thats the way mine is.

[trebor44]

I just bought an old Bonanza Co Ax that seems to be all there and in good shape except for the priming system. It has a plate on top that holds a std shell holder but the primer posts are too big to fit through the hole in a std shellholder. Do they make a special shellholder for these and are they available?

Take a look here and do a google search: https://usermanual.wiki/Document/coa...573017551/html

[Pressman]

If I read the OP's issue correctly he is trying to use some sort of priming punch with a snap-in shellholder and the center hole is too small.
The answer is get a different shellholder. The center hole varies in size between brands, there is no set standard hole.

[15meter]

If I read the OP's issue correctly he is trying to use some sort of priming punch with a snap-in shellholder and the center hole is too small.
The answer is get a different shellholder. The center hole varies in size between brands, there is no set standard hole.

Or get old shellholders:

http://castboolits.gunloads.com/show...00#post4752900

post #25 from me, I ran across a batch of dead guy 60's vintage shellholders with larger through holes. All my newer shellholders are pretty well interchangeable.

There are a few thousand's difference between brands, but I have not had a less that 25 year old shellholder not work with either my RCBS bench prime or with a primer arm on Rockchucker's or a Lyman T-mag.

His press may have been old enough for the larger through hole shellholders.

[country gent]

There was a conversion that replaced the priming plate on the rods with one that accepted std shell holders. It included the plate for the snap in holders and 2 correct priming punches like what the op made. It was a simple unbolt bolt on modification.

[rbuck351]

Mine is a very early press and if what I read it may have came made for snap in shellholders. As I use about 20 different shell holders, I didn't think I would be able to find all that I would need. The shell holders for this press would need to be 5/15" OD vs the 1/4" OD of all that I have. Drilling and tapping two 5/16 x 1/2" fine bolts to fit rcbs punches was easy and cheap and they work very well.
The one size fits all bottom shell holder and the floating die setup are interesting and seem to work very well as does the spent primer handling. Interesting press and so far I like it although I would never pay what they want for a new one.

[smithnframe]

There was a conversion that replaced the priming plate on the rods with one that accepted std shell holders. It included the plate for the snap in holders and 2 correct priming punches like what the op made. It was a simple unbolt bolt on modification.

That's what I'm talking about!

[hd09]

I have one of the old Bonanza coax presses. They used a plate for shell holders on the priming area. Bonanza shell holders have a larger hole for the priming post. Don't know of other shell holder with the larger hole.

[Dan Cash]

Apparently I'm missing one of the two sets of shell holder plates used for resizing and bullet seating but for priming mine has a plate at the top of the press that a std shell holder fits. The problem is the primer installation punches that fit the press are too large to fit through a std shell holder. My press does not have the three adjustable shell holder fingers that are shown in pictures of the Forster Coax. After thinking about this last night I tried to drill out a rcbs shell holder and found it to be harder than my cobalt drills. Next step was to drill and tap a 5/16 fine bolt for 8x32 threads and screw in a rcbs primer punch. Works great. Next is to figure out which shell holder plate I have and order the other. Thanks for the replys. Buck

I suspect that the Bonanza shell holders have a larger hole in them which will admit the priming post. A good reason to spend more money and buy the Co-Ax bench priming tool.

[rbuck351]

Yeah, the Bonanza coax uses primer punches that measure .309 OD and I believe the shell holder would have an id of .312. RCBS uses .250 for id on their shell holders. I consider my presses to be giant bench priming tools and bench space is to valuable to add a miniature priming tool.
Adapting rcbs primer punches to fit the coax was too easy and works too well to mess with anything else.

[country gent]

Its not a hard conversion to do. A lathe (even a little mini lathe) a couple 5/16 bolts tap drill and tap then the "standard" priming punches. Cut off the bolts heads face square center drill and drill ( I drilled them thru. made tapping easier). Chamfer hole and tap. insert the new priming punch assembly and set to height. A set screw from underneath can be used to lock the punch in place also. I also prefer to use a slightly heavier spring under the cup

[dverna]

I never liked priming on the Co-Ax. If a primer goes off, your hand is over the case.

I started using a hand priming tool and used boht the Lee and RCBS. A couple of years ago got the RCBS bench tool and that is what I use for priming any quantity of rifle brass.