Stripped sprue plate bolt

[jonk]

I have a group buy 6 cavity Lee mold for .325 bullets. Nice mold. However the bolt that holds in the sprue plate won't tighten down enough any more. This is the main pivot bolt, not the lock bolt at the front of the mold. It isn't so stripped that the plate falls off, but the plate will leave a gap on the cavity nearest the bolt, resulting in a bullet with a little teat on the base- and so I can't seat a gas check on it.

Now the question is, what to do with it?

I could send it back to Lee, who could do something to fix it I'm sure, but I have my own thoughts. Besides it is out of warranty so whatever they did, they'd charge for it.

1. Drill out the bolt hole to the next largest size, and tap it for that size. Insert new bolt. My concern is that the same issue might happen.

2. Clamp the bolt and mold in a vice (not too hard!) and drill a set screw into the bolt to keep it from moving up and down. But will this be enough to hold it?

What would you do?

[SierraWhiskeyMC]

Wiljen has your Option 2 covered in the "Classics & Stickies" forum under "Leementing"
http://castboolits.gunloads.com/showthread.php?t=32584

Of course, it's best to do that when you get the mold (after you know it's producing good boolits), so that you don't wear the threads out by tightening the thing up all the time.

I have a Lyman cast iron mold (#452460, 200gr SWC) I bought used that even though it's been "Leemented", the threads in the mold are just too far gone. I've been considering using a Heli-coil to repair the threads rather than tapping it to a larger size. However, if I find a machine screw locally that had a plain shank near the head, I might consider just tapping it larger.

[canebreaker]

You can get an insert with the same threads for it at a parts/ hardware store.
Drill the threaded hole out to the size they call for and screw the insert in. Then use your old bolt.

[high standard 40]

Helicoil is one brand of thread repair kit available at parts stores. A kit comes with a drill bit, and oversize tap, thread inserts, and a tool to install them. I've used one several times.

[sundog]

http://home.windstream.net/corkyconnell/mould_pics/mouldpic1_35pc.jpg

[johnly]

I have a group buy 6 cavity Lee mold for .325 bullets. Nice mold. However the bolt that holds in the sprue plate won't tighten down enough any more. This is the main pivot bolt, not the lock bolt at the front of the mold. It isn't so stripped that the plate falls off, but the plate will leave a gap on the cavity nearest the bolt, resulting in a bullet with a little teat on the base- and so I can't seat a gas check on it.

Now the question is, what to do with it?

I could send it back to Lee, who could do something to fix it I'm sure, but I have my own thoughts. Besides it is out of warranty so whatever they did, they'd charge for it.

1. Drill out the bolt hole to the next largest size, and tap it for that size. Insert new bolt. My concern is that the same issue might happen.

2. Clamp the bolt and mold in a vice (not too hard!) and drill a set screw into the bolt to keep it from moving up and down. But will this be enough to hold it?

What would you do?


I loaned out my 35-180 GB mold to a person (who is no longer on the board), and when it was finally returned the sprue blate screw hole was so messed up that you couldn't tighten the screw, nor could you remove it. I finally forced the situation and broke the screw off in the mold. A little session with the EDM and the broken screw was removed, but I still had some buggered threads to deal with. A steel screw into an aluminum block is just asking for trouble, so I put the mold on the mill and machined out the damaged threads and installed a steel insert.

[Catshooter]

Sundog's pic is the way I go. I also put a small piece of brass or copper under the set screw so it doesn't screw up the threads. Lee uses a 1/4 X 28 thread.


Cat

[wallenba]

I would drill, tap, helicoil, and install a stud and use a washer and jamb (jam?) nut to hold it on. No more turning in the hole.

[Dale53]

After I drill and tap for the lock screw, I drop one lead shot into the hole and screw the lock screw down until I reform the lead shot to the threads. It will lock the main screw VERY well without damaging the threads. Some moulds when delivered with a lock screw run a steel screw against the threads of the main screw. This damages the threads and the aluminum mould body threads just get cut out by the burrs. A single lead shot dropped in solves that completely. Cost is nil after you do the drilling and tapping.

Dale53

[Cloudpeak]

I've read here that some just drill a hole clear through the mold block and use a long bolt. A locking nut on the other end would hold the proper tension. (I don't know what is available in the hardware store for a locking nut. I have some aircraft metal lock nuts that would work well for this application.)

[Dale53]

Cloudpeak;
The problem with using a bolt clear through the blocks is that it will interfere with many mould rests on bottom pour furnaces. Best to leave the bottom of the mould "clean'.

Dale53

[Cloudpeak]

Cloudpeak;
The problem with using a bolt clear through the blocks is that it will interfere with many mould rests on bottom pour furnaces. Best to leave the bottom of the mould "clean'.Dale53

Good point. My Lee 4-20's rest will swivel out of the way so the bolt clears. No experience with other makes of bottom pour's. I suppose a guy could put the nut between the flanges if you could find a small enough nut (aircraft hardware is the answer, again). Or, you could do all the work required to put in a set screw;)

[machinisttx]

If it were me, I'd drill it out for an ez-lok thread insert. Helicoils suck, IMO.