I bought a Beta-MIG at an auction, I tried to look it up on the owners manual site and it didn't compute. The ser# is 396WS13531. It has the piecemaker 40-A gun and spool gun connection on the front but no spool gun. I paid $540.00 for it.
I went to local welding supply for tip and nozzle to see if it works and they don't carry the tips (5/16" thread) and seem confused about which nozzle. I made an adatper to use Miller 1/4" tip and I made a nozzle out of copper tubing and found out that it does work. I don't understand the confusion, this supplier has been in business for years.
timw, The confusion is that when Miller purchased Hobart, information, and parts, on the pre-Miller Hobart machines became scarce. But as far as gun parts, if you can find the part numbers, are readily available from manufacturers like Profax, OXO, American Torch Tip, etc. The Miller parts Guide has parts for many Piecemaker Guns, but not the 40-A
Once you find parts, I would get a pretty good supply of them, since as these guns die their natural death, parts will become more scarce, and more costly. Of course your other option is to replace the gun with something that parts are readily available for, such as Tweco, Bernard, Binzel etc.
Here is a link to a parts breakdown for your 40-A gun.... Piecemaker 40-A All you have to do is figure out which front end you have, and you are in business.
I bought a Betamig 200 over 20 years ago. Never had a problem with it. I put a 15' Tweco gun on. When I bought the gun there was an adapter listed for Hobart. I didn't buy it. I turned off a very small amount of stock and the Tweco plugged right in.
I have made adapters based on the Hobart so I can plug in Miller and Lincoln guns.