MP alignment pin question

[oldhenry]

The mold in question is a 6 cav. alum. MP clone of the classic Lyman 452374 that I obtained through a GB on this forum.

I have only 2 casting sessions on the mold. The 1st. being short because I cast outside & the S. GA heat only allowed morning sessions up until lately.

Incidentally, the boolits produced in both sessions were a joy to cast & are beautiful. Sizing the latest bunch lead me to think that the alignment pins may need adjusting. Sure enough (a south expression) one end is high & light can be seen between the halves. Closer examination reveals that the cylindrical section of the male alignment pin on the high side stands proud slightly. See attached photo.

Question: what is the best method to retract that male pin without doing damage? I do not want to drive it back (punch against pin) as the end is cone shaped (small) & could be easily damaged. Alternatives I've considered:

1. Place the halves together & with the male side down drive the female pin down which hopefully would move the male pin back.
2. Place the halves together on a level hard surface & with another hard level surface on top of the halves, give the top hard level surface a rap.

All suggestions are welcomed.

Henry

[wv109323]

I would use a C clamp to see if I could move it. A clamp would be more comtrolled than a hammer.

[Minerat]

Send a PM to Mehi and ask him.

[oldhenry]

I would use a C clamp to see if I could move it. A clamp would be more comtrolled than a hammer.

I have a vise with 5" jaws that would use the same principle & I could pad each side: however, I fear that I may warp the blocks using that method.

I'm following Minerat's advice: I've PM'ed MiHec.

[Minerat]

Let us know what he suggests, please. I might need the info in the future.

[oldhenry]

Let us know what he suggests, please. I might need the info in the future.

He suggested that I put the two mold halves in a vise & press the halves together. I tried this method twice without any success )I padded one side with 1/4" steel plate & the other side with 1/8 aluminum.

With nothing to loose: I placed the 1/4" plate on the concrete floor of my shop & put the mold on the plate. On top of the mold I held the 1/8" alum. plate. I gave the 18" plate a solid strike. 1st. attempt did not produce any movement. 2nd. attempt did the trick.

I haven't cast with te mold since, but will let you know the results. From the appearance of the mold I think it's OK now.

[hermans]

I just had the same problem with one of my MP aluminum 8 cavity molds. Noticed that my boolits were slightly out of round. On inspection I noticed that the two halve were slightly "loose" when held together firmly by hand. I measured the the two male alignment pins, and they were both about 0.5mm lower on this mold that on some of my others, also from MP.
I tried to drive the alignment pins with a pin punch, but they did not move and I was afraid of damaging the mold if I started hitting it really hard.
So I put the two halves in my padded vice with a M6 bolt in the hole of the male pin and cranked up the vice, did the same with the other pin. They both did move a little, just enough to make the fit nice and tight.
Did my first cast this afternoon, and the results were perfect round boolits.

[Minerat]

That's a pain to do but good to know. Thanks for the followup.

[justindad]

I just had the same problem with one of my MP aluminum 8 cavity molds. Noticed that my boolits were slightly out of round. On inspection I noticed that the two halve were slightly "loose" when held together firmly by hand. I measured the the two male alignment pins, and they were both about 0.5mm lower on this mold that on some of my others, also from MP.
I tried to drive the alignment pins with a pin punch, but they did not move and I was afraid of damaging the mold if I started hitting it really hard.
So I put the two halves in my padded vice with a M6 bolt in the hole of the male pin and cranked up the vice, did the same with the other pin. They both did move a little, just enough to make the fit nice and tight.
Did my first cast this afternoon, and the results were perfect round boolits.

I did this same thing with good results. The male pins seem to push out the female sleeves if you go too far. I’ll add that you might benefit from adding some lube to the pins in case the male & female parts stick together.

[Mal Paso]

Aluminum expands faster than the steel inserts, I think that's why they move. Heating the mold in a 400F oven before putting it in the vise helps. I cross pinned mine so they can't move.

[Mal Paso]

Wow, slow news day. Here are the pictures from reseating the pins and cross pinning.

[white eagle]

check to make sure your handles are not the issue first

[Petander]

Dang,my new 2 cav MP brass mold lets the light come through in between the halves, especially closer and around the handle end cavity. That bullet is not round either.


I heat cycled it normally, three times, then when casting I wondered right away why my bullets have that dreaded seam... yes light comes through.

I have almost ten MP molds, first time any problem. I did not warp it, I have quite a bit of experience with brass molds by now. I will measure things tomorrow, hoping it's a pin problem. It has MP handles that came with it. Feels right to cast with. But...

[winelover]

I have reset the pins on MP's brass molds using a 5" bench vise with copper jaw protectors. I just do the side with the pins.

Winelover

[Petander]

I have reset the pins on MP's brass molds using a 5" bench vise with copper jaw protectors. I just do the side with the pins.

Winelover

I will try the same.

So this is a double mold. The two bullets to the left are from the front cavity, the other two with more "seam/whiskers" are from the rear cavity. Mold is very hard to open when solidified bullets are in. So you have to whack which in turn destroys bullets more,especially HP:s.



There's a visible light crack between the halves,more pronounced around the rear cavity. I hope it's the pin. I can't really see or measure any differences with the pins. I have about ten other Mihec molds with zero problems. No banging or whacking either.


https://i.postimg.cc/zG3ZP4QX/IMG-20211026-WA0000.jpg

[winelover]

Probably the pins.............unless you have a build up of tin on the cavity edges. I prefer to use locking mold handle, on brass molds, to avoid this condition. With the heavier brass molds, hand fatigue comes into play, allowing ones hand to relax pressure upon closing.

Winelover

[Petander]

Yes it was the pins. No more light crack.

But. There's still lots of light coming through the "first" cavity around th HP pin. Lead flows in there. I can not see any light here when I look through my other MP molds.

Still very hard to open and this cavity won't drop bullets with any reasonable "whacking".

https://i.postimg.cc/9QY3Kwmh/IMG-20211026-WA0003.jpg

[winelover]

Did you try another style pin in the first cavity, to see if the light issue is consistent? I regularly use two different styles of pin in my MP molds. Yesterday, I cast 44 caliber MP 250 RNFP solids with cup points. The other day it was the solids with HP's.

Winelover

[Petander]

Did you try another style pin in the first cavity, to see if the light issue is consistent? I regularly use two different styles of pin in my MP molds. Yesterday, I cast 44 caliber MP 250 RNFP solids with cup points. The other day it was the solids with HP's.

Winelover

I tried all three pins, they are the same size.

Now I got it dropping slightly better by removing burrs from the cavity edges. A magnifying glass was needed.

Even the small hex key was faulty,half round. No big deal but indicates that this mold has skipped the quality control somehow. My other ten MP:s are fantastic.

https://i.postimg.cc/jdhD5xTh/IMG-20211028-WA0000.jpg

[Petander]

PC coating hides all the problems.

But eg. the need for hitting the mold to drop bullets, it's not right. And still thre is the seam.. There has been a bad day at the factory. I have made mistskes,too. No problem.

I already ordered a new one.We can talk about things after The World normalizes a little.

https://i.postimg.cc/rFGD11k7/IMG-20211028-WA0002.jpg

[justindad]

I did this same thing with good results. The male pins seem to push out the female sleeves if you go too far. I’ll add that you might benefit from adding some lube to the pins in case the male & female parts stick together.

After using my mold with reset pins a bit, I noticed the alignment pins were a little sticky. The male pins were too far out, but not so far as to let light come through the two mold halves. So I cut cigarette papers into strips, placed two strips over the female alignment bushing, then attached the mold half with the alignment pins to drive in the paper strips, then add two more strips (4 strips per hole), then assembled the two halves to drive in the papers without cutting them. Then I pushed the pins out a bit with an arbor press, reassembled the mold halves, and then pushed the pins in until I knew the male pins were touching the female bushings. Now the pins fit perfectly and detach smoothly, although my bushings moved ~0.020”.

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