Mold repair?

I've got a MP 4 cavity brass mold that won't close completely if I install the pins in what I believe is the correct way. By that I mean, if the 2 positioning "bolts" that screw into the side of the hollow point pins are screwed all the way in, the mold won't close completely. If I just barely thread them into the hp pins, it's fine. I've tried it with different pins and get the same results.
Anyone have suggestions? I want to sell the mold as I no longer have a 44 but wouldn't until I figure this out.

Sounds like a bent pin or out of square. By leaving the pins slightly loose they are able to "float" slightly. Look at the shoulders the pins and the seats for wear burrs and any build ups. Be gentle it dosnt take much to throw them out. Look at the wear patterns on the pins this may tell you where to look on the shoulders and seats. Here fine stones and finesse are the key wood scrapers to remove built ups and a rubber eraser to lightly polish

Quote:

---

Originally Posted by country gent

Sounds like a bent pin or out of square. By leaving the pins slightly loose they are able to "float" slightly. Look at the shoulders the pins and the seats for wear burrs and any build ups. Be gentle it dosnt take much to throw them out. Look at the wear patterns on the pins this may tell you where to look on the shoulders and seats. Here fine stones and finesse are the key wood scrapers to remove built ups and a rubber eraser to lightly polish

---

Thanks for the help. That makes sense, I'll see if I can figure it out. I may just send it off to someone. I could do more damage than good.

The pins have an up and a down side, but yes, tightening the screws too much causes binding because one side of the pin is being forced to kinda sorta twist

I always just start the pin screws then close the mold before tightening them. I then open the mold and slide each pin in and out and apply a little 2 cycle oil to each screw with a q-tip. If they don't slide out and in on their own weight I tweek each screw until they freely slide. Once adjusted you should be able to gently tap the screws to dump the hp boolits.

I have the same problem with my 4 cavity brass mold! It is as the pins hold the mold apart. Just not seating properly, They stick in the bore they sit in. I believe its a over black oxide coating on pins that holds the die back! Still have to get after the problem, Shame to have to do it for the money we paid. And no amount of oil will fix it...I thought about turning the pins. Just do not know how to get a hold on the little rascals.

You are overthinking it, overtorquing the pin bolts will cause binding in the hollows where they are supposed to slide. Just get them to where you barely notice any resistance and you're done. The problem is over tightening then after time the threads will oxidize and it be difficult to remove the bolts. Also, I only use one c clip per pin and I place it on the lower bolt because they do tend to fall off and get lost so I wanna have a few left for that reason.

As a comment not diectly related to the OP... but a tip: The circlips are small and if they pop off they can get lost easily as mentioned by THE_ANTIDOTE. I have never had one come off in use, and they shouldn't if properly installed, however, during installation and removal they can be tricky so I use a disk magnet about 3/4" diameter on the shank of the pin when I am installing and removing the circlips. If I fumble the circlip the magnet catches it so it isn't dropped or lost. Any small magnet should work.

Works for me anyway.

As for the mould not closing if you tighten up the pins, I think that is reasonably common if you really tighten the pins but if left just slightly loose the mould should close properly. If not you should contact Mihec.

Longbow