RCBS Model A Press - How To Tighten Up the Ram

[floydboy]

I am rebuilding an RCBS model A press. Everything is fine with little signs of wear except the ram has noticeable wobble. I have a model A2 and the ram is very solid with no wobble what so ever. I measured the ram to hole clearance in my A2 and it's .0010 at most. My model A has .0060 clearance between ram and housing. I also measured both rams and they are the same size. I am assuming my model A ram has no wear since it's the same size as my A2. That would mean my housing hole has worn. I would think both the housing and ram would have worn if that is the culprit. Could the hole wear that much be itself or was it maybe that large from the factory. I have experimented with wrapping the ram with some .0030 shim stock and that tightens it up nicely. Just have to come up with a way to keep it in place. The ram tilts forward so bad the boolit is canted enough to slightly hit the reloading die on entering the die. When I push back on the ram with my fingers or use the shim stock it enters fine.

Any thoughts on a quick fix without boring and bushing the hole? Is my shim stock idea practical? I can use brass or steel shim stock. Maybe the softer brass would be the better option? Thanks,,,Floyd:(

[littlejack]

I don't see why the shim idea won't work. As you said, just have to figure out how to keep it in place.
One idea: Make your shim tube to fit just as you want it. Remove the ram and clean and de-grease the ram bore in the frame.
Put epoxy on the outer side the shim, and in the bore of the frame. Replace the shim tube and the ram into the bore and let it set up. Make sure to have the ram greased, as to not get epoxied also.
Idea 2: Remove the ram. Drill and tap 3-4 holes in the frame around the ram bore hole, top and bottom. Put you ram back into the it's bore hole. Use brass set screws to center the ram in the bore. This would work like a steady rest on a lathe. Then, tighten lock nuts to hold the brass set screws in position.
Just thinkin out loud. Hope all works pout for you.
I had a RCBS Jr. press (my first press) years ago. It developed the same problem. I must have operated that handle hundred of thousands of times.
I called RCBS, and they said that it would not hurt anything, as the slop would alloy the cartridge cases to self align, but, it I couldn't live with it, send it back. I sent it back to them with a little extra $$$ and got a RC. Been using it ever since.
Regards
Jack

[country gent]

With just .003 clearence to fill maybe an steel epoxy filler. Do it just like bedding a rifle. Clean housing of any oil or grease completely. Coat the ram with release agent wax oil or such. Smear epocy mix inside housing everywhere you want it, then insert ram in place. a small ring of waxed shim top and bottom to hold centered and let cure. This will make for a close to Zero tolerence fit. Pack all holes slots with playdough or clay before starting to keep epoxy out of them. Lave a tab on the shim to allow it to be pulled out with pliers after curing. Keep this surface lightly oiled and it should last for a long time.

[WILDEBILL308]

I think country gent is on the right track.
Hear is another thought. I think the big thing is to keep the ram centered on the die center. I would get things set up to use the bedding material as a “liquid shim”. You might use a bit of stainless or brass shim stock abrade the out side/back to make it stick to the bedding material to give a good hard wear surface. When you are ready to start put a sizing die in the press and run a once fired case part way into the die. This should center the ram on the die. When you get it all mudded in run the case back in till it stops at the point you stopped before. I haven’t tried this but it should work. You might run it all the way into the sizing die but I don’t think it would make that much difference’s machinist might make a tool that would center the ram but I think this will work and probably be closer than factory.
Bill

[littlejack]

If you use Bills technique, make sure that the sizer die and the shell holder are in perfect alignment. If you don't, and when the epoxy sets, you will not be able to adjust. If things are not aligned, all other sizing/seating with any dies will be off center.
You could also have the ram "knurled", but I believe that the knurled steel ram would wear on the bore of the "cast" frame real fast.
Are you sure that you have the decimal points in the right place? That doesn't seem like much wear to
worry about When I mentioned the wear on my RCBS Jr press, I was talking .010 to .015 wear.
Jack

[HGS]

I too agree with the Country gent's idea having used the same idea on different projects, extreme temperature on the different parts will alter results.

HGS

[floydboy]

Yeah the measurements are correct. Ram is longer so it is more noticeable when in the totally up position. It may not be a problem. That's why I was wondering if it came from the factory that way. I may install a shim just in the front to keep the boolit from hitting the die and not worry about it. I'm just a little particular and this is one of my collector items and I just want it as close to perfect as I can get it. I use my A2 for case forming, resizing so this one will be regulated to boolit seating so won't see a lot of hard use during my lifetime. Just want it to be inline and do a good job. I always take the shellholder springs off the ram so the shellholder can float so as long as I can get the boolit to not hit the die I'll be happy enough. I've heard of people using axle grease to lube them to keep the play to a minimum. Probaly do some shimming and greasing an see what happens.

[beezapilot]

I'd drill a hole in the housing, tap it, put a nylon/ teflon button in it follwed by a bolt to adjust the play. But that knocks it out of the park on a collectable.

[floydboy]

Beeza,

In the front of the press is a threaded hole with a screw for mounting the primer are spring. It goes clear and is right where it needs to be. Maybe a little low but may work. I have thought of that and will probably try it along with shimming. It would be easy and for my intended use it should last a while. Even if I have to replace every now and then that's no big deal. Thanks for the suggestion. It reaffirms my thoughts on that solution.

[WILDEBILL308]

You might as well Wright off “collector value” if you do any thing to the press.
My idea was to get everything lined up / centered before you do the liquid shim.
Bill

[floydboy]

I'm not so worried about resale. I'll never sell it. shimming and using an existing hole would not be doing anything that can't be undone. if I come up with a better idea I can always change with little difficulty. I do like Bills idea of gluing the shim stock in place. I think it would make a very strong repair that would last. I am thinking of using a little JB weld to get the shimming to stay put. I don't know why a little on top and bottom wouldn't work and not be that hard to get out if needed. I think tinkering with a cartridge to align the ram is as good as one could get unless anyone has any other suggestions.

[John J]

hopes this helps

http://www.rcbs.com/downloads/Parts_Book.pdf

[Bogone]

Bump for a really good thread, should be a sticky.

[floydboy]

Well I got home this afternoon with more shim stock and nylon prepared to fix this thing. One thing I didn't mention when I started this thread is the press over cams. The cam actually pulls the ram back down a little bit. The stopping surface on the cam was over ground at the factory. This also tends to make the cam rock. I JB welded a piece of metal to make the cam stop earlier and this helped some. While cleaning the ram hole I noticed again it just doesn't look that bad. The ram measure exactly as my A2 ram. I can't believe the hole would wear this much and the ram not at all. I still suspect it came from the factory this way. I thought maybe my shell holder was ground wrong and switched some out. That didn't help. It them occurred to me the top of the ram that holds the shell holder might not be square. This would go along with my thinking the hole might just have been big. The casting is rough an was made back in the early days so quality control might not have been so good. I checked the top portion of the ram and sure enough not even close to square. Not having a lathe I took a file to it. covered one side of the file with some of the shim stock and screwed in a die and put the file on top of the ram, then the shim stock and raised the ram up to compress the shim stock against the die an used the downward pressure of the die to keep my file square to the ram. after about 30 minutes my shell holder is perfectly square to my die and my cases line up almost perfectly with the die. Now back to the wobble. I had read about using axle grease to tighten rams up. Went out to the shop and got some bearing grease and greased and put it all back together. That heavy grease worked wonders. It would barely move now. Since I had some small diameter nylon rod I decided to put a piece behind the screw I mentioned above. That took the rest of the wobble out. I am very happy now. Shells enter the dies in the center of the dies as good or better than my other presses. My repairs won't stand up to bullet swaging pressures but she will seat boolits all day long for the rest of my life and she sure looks pretty on my bench. Not the best use of money for boolit seating press but adds to my collection of nice old presses. Thanks for all the suggestions and help. You all were more help than you may know. I got a lot of good advice that one way or another help steer me in the right direction.

Thanks again guys....Floyd

[WILDEBILL308]

Glad to help.
Bill

[littlejack]

Good to hear that it was an easy fix.
What you found to be the problem, I will place that in my mental archives.
Regards
Jack

[W.R.Buchanan]

I was reluctant to comment on the liquid fix as what I have found is that when something doesn't sound right there is probably something else wrong that has been overlooked. I have a RCBS press from 1976 and it has loaded a zillion rounds of ammo and the ram is still tight. I keep it lubed.

If you were going to go the liquid shim route then I would recommend using Devcon metal filled filler putty instead of JB Weld. This is the stuff they use to fix moulding dies if they take a little too much off here or there. It is second to none in this department. Available with Aluminum Steel or Stainless Steel aggregate. It is basically epoxy with metal granules in it. Available at any Bearing house, or thru tool distributors.

Randy

[seagiant]

Hi,
I've played with a lot of old presses and never found a "loose" ram? Go figure!

[Pressman]

I am more than a little confused by this. The top of the ram is not square? The A uses a two piece ram, with the smaller diameter shellholder held to the main ram with a tapered cross pin. What part was not square?
Someone please help un-befuddle my mind, please.
Ken

[floydboy]

Ken,

Your exactly right about the set up. I removed the ram tube assy and put a square along side the large tube an when it crossed the top of the small tube it did not fit tightly against the top of the small tube. To make sure which part was out of square I then took the small tube out of the large tube. The large tube was perfectly square. The small tube was again out of square. The bottom of if was square but the top had about a 1/32" cant to it. After filing it square the bullet goes right up into the center of the die. As to the loose/wobbly ram am of the opinion it came from the factory that way. All the pins are very tight and show no wear and the ram itself measures the same as my A2. the hole in the frame is larger and seems to be the same diameter all around. It doesn't seem oval. The bearing grease took a lot of the slop out of it. I put a small nylon rod behind the screw in the front of the press that holds the primer return spring on and that tightened up what ever slop was left. You got any other ideas how to make a more permanent repair? Like I said earlier I'm just gonna use it for a seating press so I'm happy with it like it is. It'll last me the rest of my life and it is a nice addition to my collection.

Thanks,,,Floyd