Mould life?

[Harter66]

1st I'm no metal genius I know enough to get in trouble and ask questions that leave the guy that wrote the book going "that's just how its always been,I guess".

Thought train derailment explained.
When a metal is annealed it is generally returned to its "soft" state. Not 100% true but close enough for my question. Generally annealing is done by raising temperatures to roughly 70-80% of melting or so case by case. So far so good. Some metals will work harden when heated and cooled to 25-50% of melting. See copper wiring pulling near to maximum safe loads.

Based on the above and its applied theory, aluminum moulds should walk the line user by user of being annealed w/every use and likely to be worn/damaged much easier than some others.

Brass moulds should, applying the above,actually to some finite point be more durable w/every use. Excepting normal wear,electrolysis, etc. At that finite point, 1000s of cycles perhaps 10s of 1000s , the brass could be shattered if dropped. That could be avoided w/ an annealing cycle every 20-30 years I suppose.

An iron mould should have a near infinite life as the heat cycles are of such a low temperature ,compared to the melt temperature of the mould, the the closing impact would do more working.

So am I all wet or on track? Realizing of course that the brass and iron moulds will likely never reach that life span so its really non-issue, just a gee wiz sort of musing.

[grouch]

You very well could be on a right track, but I think it's academic, since molds from all three materials - even Lee's - should last most of a lifetime.
Grouch

[btroj]

If I ever wear one out I will be sure to let you know.

Take care of them and they will last long enough to give more bullets than you want to shoot.

[runfiverun]

i have a couple of mehanite molds that have been used so much that i have all but worn the vent lines out of them.
one i recently lapped out to make corect diameter boolits from again.
i'd dare saay an aluminum mold would have been trash canned before this point.

[Willbird]

Not that you WANT to drop a hot mold, but if you drop a hot aluminum mold....eww it is not pretty, only did that once but it for the most part trashed it. Many aluminum molds these days however use steel-steel to align the blocks and hold the blocks.

[Springfield]

I suppose they will eventually wear out but I have cast over 60,000 44-40 bullets from my 2 6-cav LEE aluminum moulds

[John Boy]

Have many out of production Lee aluminum's, one that is a 44-40 that cast 1000's of bullets.
My vote - No on the theory

[cbrick]

Hhmmm . . . Do they get cabin fever in Hawthorne, NV?

I dunno but when you get any one of the three mold materials to that point please let us know the result. :mrgreen:

Rick

[M Hicks]

That is a pretty interesting point. I think it could make them more fragile in the long run but treating them right and taking care of them should produce a lifetime of service.

[fcvan]

I have a Lee 356-125 2R purchased new in 1985. With range lead it drops at .358 and weighs 126 grains. This boolit works great in 9mm but became the boolit of choice in 38 special loads. The agency I worked for used S&W M10 revolvers and so most of my shooting buddies owned at least one. Lots of shooters means lots of cast boolits. To make things interesting, I taught a lot of guys how to reload and so lots of boolits were needed.

I would cast a minimum of 2000 boolits a week. I would then trade 500 boolits for a 1000 primers, 500 boolits for a pound of powder, and could did shoot 1000 rounds a week for free. Well, less my time for berm mining, casting, lubing, and loading. My routine was an hour each morning at the reloading bench before work.

I also had friends who didn't own reloading equipment but wanted to learn. I would teach them to cast and sort and then turn them loose with my pot and molds. These folks learned to assemble ammunition und supervision until they were proficient.

That sure is an awful long buildup to get the point. I have cast over 500,000 bullets that mold. The mold looks like heck, was used and abused by folks learning how to cast, but still casts good bullets today. About two years ago, the mold finally quit on me. The tension screw on the sprue plate stripped out. I drilled the hole for the screw a little bigger, and replaced it with a stainless steel bolt slightly larger than the previous screw. The mold is old and ugly looking but the boolits it casts are purty. I don't think I'll get another 500,000 out of it, but I'm sure willing to give it a try.

[cbrick]

I would cast a minimum of 2000 boolits a week. I have cast over 500,000 bullets that mold.

If ever there was a case to be made for a gang mold (or two) that's it right there. :mrgreen:

Rick

[MtGun44]

"Some metals will work harden when heated and cooled to 25-50% of melting."

WORK hardening has zero to do with heating or cooling, but with working, as in permanently deforming
the metal.

Bill

[Harter66]

Mt,
Probably not correct terminology. In the op I offered a clarification of my thought train and reasoning of the "question".

Cbrick,
Yep getting a little of the old cabin fever. Too much thinking time on my hands.
I have figured out some valuable things things, like female psychology explains everything that made last year miserable and there's no point in trying to figure that out w/o a straight jacket and padded walls.

[Willbird]

If ever there was a case to be made for a gang mold (or two) that's it right there. :mrgreen:

Rick

I agree, I cast 10k 9mm bullets on a saeco 4 cavity...I am convinced it game me a repetitive motion injury. I think we should teach new casters to do it ambi, and change hands between runs. It is amazing how fast bullets pile up from a good 6 cavity mold. It would be fun to run a casting contest some time for an 8 hour work day with two 10 minute breaks and a 20 minute lunch, and 1 and two person teams, most good lube sized bullets wins. I think the end result would be a LOT of bullets :-).

[Dave C.]

Most moulds will last a life time when used with care.
Lee 6 cavity molds have a life span of about 50 thousand
boolits. This is not a rant, for the cost of a new one you
can't go wrong. I am on mould #3 38 TLWC. I also have
#4 on the shelf ready to go in another 10 years or so.

[fcvan]

When I was casting 2k plus a week I had a routine to keep from doing the same thing over and over. I generally cast with 2 molds and at the time that was generally the 356-125 2R and the 452-228 1R. I would cast 100 of each and refill the pot. While the pot warmed up, I would charge 100 pieces of primed brass, then lube and seat. At the same time I was stockpiling 100 of the caliber I wasn't loading. By the time the boolits were seated the pot was warmed up and ready.

Nowadays, I still cast with two molds while listening to the NRA news podcast (or a baseball game :) ) I try to stretch every 20 minutes and get a drink of something. I break every hour for at least ten minutes, and eat something every 3-4 hours. To keep the pot temp constant I usually set a 1lb ingot on the top edge of my Lee 10lb bottom drop and by the time the pot needs it the ingot is pre warmed a bit.

I don't use a thermometer, but judge the temp by the look of the boolit and by how fast the sprue cools. If the melt is running warm I don't pre heat the ingot as long and/or slow my cadence down a bit. The longest I have cast at one setting was 12 hours. Knowing I was going to be casting all day, my breaks at 20 minutes were 5-10 minutes with more stretching etc. To keep the molds to temp I have a tin can lid cut to fit the top of the pot and the molds are placed on top.

I can't cast all day with my Lyman and SAECO molds, they are too darned heavy. I cast with them for about an hour and then take a break while my Lee 2 cavity molds heat up. I don't know how long I could cast with a 6 cavity Lee as I don't own one. I have considered getting one but don't know which boolit I would need that I don't already have. That MiHec 22 NATO sure is tempting, even though it is only a 4 cavity. I did pick up a second 401-175 TC so I can really crank them out if needed. Other than that, double cavity molds have served me well. That is so long as I don't beat the heck out of them, keep them lubed, and keep the temp just right.

[kywoodwrkr]

Research phase diagrams for the various metals. Time Temperature transformation is another key work search to use.
For steels you could decide on a carbon content at minimum and the add in other elements.
There are whole books with nothing but diagrams put out by the steel companies.
Very useful in hardening materials.

[Harter66]

Lots of good info about longevity for this having been a cabin fever sort of question.

In reflection excluding Al moulds heat cycle and closing bump are probably equal contributors to hardening and negligible.

[Bent Ramrod]

You're letting the moulds cool slowly after using them, rather than quenching them, I would assume. I can't see how an infinite number of these heating and cooling cycles would either harden or soften any mould beyond the level it achieved the first time the mould was used.

Maybe some of the Master Caster guys could enlighten us on how a mould, properly used and not abused, wears out or becomes unserviceable. I doubt I'll ever wear one of mine out in the time left to me.