View Full Version : Lyman 535 gr. Postell problems
05-06-2005, 05:47 PM
Loaned out my mould. I know, not always a wise thing to do. Anyhow it suffered some abuse. Went to cast today, and first off noticed that the guide pin holes were a little beat up. No problem....took the deburring tool to 'em and they cleaned right up. So I start to cast and the bugger wont open with a fresh bullet in it. As I applied pressure to the handles to open the mould the bottom would start to come but definitely bound up at the top of the mould. So I set the blocks on my casting pot and by applying a little pressure to the bottom of the blocks was able to open them. Because of the deep, square lube grooves this bullet doesn't just jump out of the mould, but normally just a light tap and it would fall free. Now I had to beat the snot out of the hinge to get this one to drop. So I kept playing with it , trying to ascertain what exactly I needed to do.
I think that driving the alignment pins a little deeper might help a bunch, but thought I'd check with you guys before I went to it.
05-06-2005, 07:37 PM
Adjusting the pins would be my first thought and won't hurt anything to try.
Drill a hole in an ingot to use as an anvil and a brass hammer and punch and tap it back until the mould opens easy. Do a "click" test and see if the halves move at all. If not, do the old "daylight between the blocks" test and if you don't see any, you're good and they should mesh up all right.
I had a pin drift out again the other day and had to adjust it.
I just hope that's what's wrong and it fixes it./beagle
05-07-2005, 12:19 PM
Rick, sounds like whoever you lent to mold to was slamming the blocks shut and messed up the pins and holes. Beagle says to re-adjust them and he is correct.
Always close the blocks gently.
05-07-2005, 01:56 PM
Beagle, 44man, thanks for the replys. Just finished "adjusting" the pins. I'm afraid there is another problem. Must have gotten the blocks way too hot, as they appear to be warped. Doing the daylight test the blocks mate fine in the center but are definitely gapped top and bottom. Measuring the bullets I cast yesterday, they seem to be o.k. Just a PITA to cast with. Am going to give it another try today.
05-07-2005, 06:14 PM
The only suggestion if they're warped is to cast the hell out of them and get them HOT. After running about 50 at a high temperature, slack off slowly and after the mould temps dorp some, let it air cool naturally.
If the alignment pins were missaligned, sometimes the blocks will cool in that position. Correcting the pin problem and then getting the mould halves real hot and then letting them cool normally MAY let the blocks settle back as they were suppose to be.
I've seen bent sprue plates that had bad hardware and bent hollow point pins fix themselves in this manner after the problem was corrected.
Only suggestion I can offer./beagle
05-07-2005, 08:01 PM
Beagle, could the same results be achieved heating the mould w/a propane torch?
Cast a couple hundred this afternoon, mould is still hard to open. Played w/the melt temp.some and found a temp where bullet release was somewhat better. Thanks to Bruce B's (?) speed casting method, this single holer will produce a fair amount of bullets compared to my old method. Also, I'm tempted to lap the mould a little to see if that might help with bullet release.
05-08-2005, 09:37 AM
Yes, get it very hot. You can use a propane torch but keep moving it all around the mold and never stop in one place. Have some BIG heavy rubber bands handy and as soon as you have the mold hot, wrap the bands around the handles to hold the mold shut tight as it cools.
Always cool your molds slowly when done casting. I set mine and a piece of wood with just the back edge touching. The rubber band trick can be used every time too.
05-09-2005, 11:45 AM
Rick...should work the same. You have to get it hot and then ease off on the heat. Maybe even letting it gradually cool on the top of the pot after you shut it down.
Before you start lapping, get some spray moly. Bring to casting temp and attempt to locate the problem area. Once that's accomplished. Give it a short burst inside the cavity on the offending area. Then try again. You may have to repeat several times before you get it to dropping right.
Expect the bullets to have a rough surface as some of the moly won't adherr to the mould. After you have it dropping the bullets all right, let it cool.
Take a piece of soft wood (pine is preferred) and sharpen it and burnish the insides of the cavity to remove all of the excess moly. A set of the 3X jewellers visors is handy so you can get down close and see what your doing.
The moly will usually fill the space that's causing the bullet to hang.
Burnishing it with the pine splinter removes the excess moly and it takes on a shine like a pair of "Kiwi polished boots" and should cast well after that./beagle
05-11-2005, 08:01 PM
Guys, I heated the mould and wrapped the handles, and the warpage is about gone...definitely a lot better. Beagle, I really couldn't isolate the problem area. Ended up spraying the entire cavity, but it still wouldn't drop without some cajoling. Would it still pay to burnish the cavity as per your suggestion, or should I just do a light lap job?
05-12-2005, 12:02 AM
............I have that mould and experience no problems in having the boolit drop out. Usually a tap on the hinge does it. You have some other problem going on if you have to beat it to drop the slug. Polishing the cavity would be a good option. We don't want to remove any metal. Take a few cast slugs and drill a hole in the base and then tap in a suitable hex wrench. Use a cordless drill (one of those cheap battery jobs turns just the right RPM.
You can use JB paste, IOSSO bore paste, or Bon Ami cleanser. With the later wet the slug and add some of the powder by sprinkling it on. When it's done, it might also help to blue the cavity, and a cold blue works fine.
05-16-2005, 08:02 PM
Well, after following the sage advice I've recieved, I'm happy to report that the mould is coming around! Bullets are dropping free more often than not. I still have a little more tweeking to do, but the prognosis looks good. Just finished casting a couple hundred more this evening, and it appears to be a little temperature sensitive. What I mean by that is it would drop the bullets very easily for a while, but if I changed my cadence a little they would tend to hang up a little. Think I can see why and will address that issue soon. Thanks fellas for the great advice! This is just one reason why I like this board so much.
05-17-2005, 11:30 AM
Rick...Glad you got it going. I was wondering yesterday how you were coming along with it.
Moulds are pretty forgiving....especially the iron moulds. They just need TLC and don't expect any abrupt changes in their lives...much like people./beagle
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