MiHec 10mm/40s&w - 170gr / 150gr WFN/HP, 4-cav, Brass

[RED333]

Timberhawk, after you cast a few measure at 90* to the seam, please.
This is so unusual that I just cant believe it, the mold maker has always made a good mold.
That said I am sure MiHec will make it right if that is what is needed.

[Oreo]

Do the cavities look aligned perfectly when looking top down with the sprue plate open?

Also, you can check the boolits at the parting line. Misaligned mold halves produces a characteristic parting line defect on the boolits. Any chance of getting a good close-up picture of the boolits' parting line?

[Oreo]

One common easy problem I'm trying to positively identify or eliminate is the alignment pins. They must be pressed into the mold halves to the proper depth or else the halves don't align properly. I've had the pins get pressed-in too deep on one of my MiHec molds so that the halves wouldnt align right. So it's a problem I have personal experience with, and fixing is easy.

[timberhawk]

Okay, I've had some problems as discussed in the thread above.
I came home and very carefully cast twenty sets of bullets with the mold I just received from MiHec. I made sure I had the mold closed tight at each casting. No daylight or any other indication the mold was not completely closed. No fins at all, even at the hollow cavity pins. I kept the bullets segregated by cavity.
The mold is casting goofy shaped bullets like the mold haves do not match. The mold cavities "visually" look like they match.
There is no step in the bullet at the seams.
The two best cavities are casting .4025x.4047 and the two worst are casting .4029x.4056. All of the bullets from each cavity were within .0002 of each other.
They are not oval, with the largest and smallest diameter opposite each other at the seams.
The smallest vs largest measurements and not at 90 degrees to each other, but through the center of the bullet directly on either side of the seam.
I posted a drawing of where the extreme in measurements occur. All measurements were made with a micrometer that measures directly to .0001 inches.
Also, as a side, I've been casting bullets for over thirty years. I'm by no means an expert, but I'm not a newbie either.
I think the mold is defective, but I open to ideas from the other members.
Sorry if I rambled.

[timberhawk]

This is the worst bullet. You can just feel the seam with your fingernail.

[Ole]

Timberhawk I don't know if this will work with this particular problem, but I have a very old/used Lee 125 RNFP mold that drops 'em big with a little bit of a flange at the base. When I size these bullets to .357, I run the bullets through the sizer base first. Otherwise I get base wings similar to the ones you pictured. When I push them through the Lee sizer base first, the bullet base wings go away.

[timberhawk]

[timberhawk]

Timberhawk I don't know if this will work with this particular problem, but I have a very old/used Lee 125 RNFP mold that drops 'em big with a little bit of a flange at the base. When I size these bullets to .357, I run the bullets through the sizer base first. Otherwise I get base wings similar to the ones you pictured. When I push them through the Lee sizer base first, the bullet base wings go away.

I tried that, but these are so large, it crushed the hollow point.

[Oreo]

Timberhawk, I'm curious about a specific detail to do with the hp pins. Have you any other MiHec hp molds?

What crossed my mind was that if the locating pins are screwed tight into the hp pins then what happens is the hp pins don't slide freely and in many cases won't even seat properly in the mold block which could cause some weird boolit defects. One solution is to leave the locating pins a little loose so they wobble on the hp pin. It totally solves the problem. It's a subtle thing that gets most folks the first time they use a MiHec hp mold.

[mckenziedrums]

That's a good call Oreo... I bought a 45-70 mold last week second hand and whoever assembled it cranked those things down. I actually ended up stripping them a bit trying to get them backed out and loosened up so they could float properly.

[Oreo]

MiHec used to ship them that way, with the locating pins cranked down tight. A lot of folks were stripping out the heads of those pins trying to break them free. I'm much happier that MiHec ships them unassembled now. A

[mckenziedrums]

Ah that makes more sense then. This hadn't been used at all... guessing it was preassembled then. Had to take some of them out with pliers and smooth down the pins after. Not fun at all

[timberhawk]

I have three other MiHec molds and learned you have to leave the screws loose on the hollow point pins.
The screws are loose on my pins, but it was a good thought.

[nighthunter]

Timberhawk .... looking at your mold pics I see lead along the cavity edges on the faces of the blocks. This will hold your mold open as thick as the buildup is and give you an out of round bullet. I suggest you get the mold heated up and then use a soft brass brush to remove those spots of lead. Anything on the faces of the mold is going to create problems.

Nighthunter

[Oreo]

Yes, definitely need to clean that lead build-up off.

[Blanco]

At the request of Oreo Our brother of the silver stream, I am reposting the results of my preliminary test of the 170 Gr. version of the MP mold. Thursday evening my Brother-in -law was agitating me about going shooting. I loaded up some of my freshly loaded Penta Point version of the new boolit. When I recieved my mold I was thoroughly impressed. This is a massive Golden He man mold with the thickest sprue plate I have ever seen.
Hats off to Miha he knows how to build them to last. I made up close to 150 gorgeous penta points and tumble PC coated them. then loaded them up. If you PM me I will share my recipe.
I knew I was going to have to test some at the range and I was really excited to try them out. I shoot a S&W M&P PRO series pistol. I loaded ten rounds up and sent the target out 10 yds. This pistol has a short trigger reset feature that I forget about. after the first shot the reset for the next shot does not take much motion of the trigger. The second shot was that SURPRIZE that you see out on the lower left of the target. after that it settled in for a really nice grouping. I have to say I am very impressed this is some of the best shooting I have ever managed with cast handloads.
I did manage to shoot a total of 50, and I will be making up more of these over the weekend.
I have to add ..
I am in no way a great shot, but its great when everything comes together to make you look good.
Had I really taken my time and concentrated and pracitced breating control nd all the other Gun Karate stuff, I might have been able to put all 10 shots through a dime sized hole at 50 yds.
This was just me shooting like I normally do.

[Blanco]

FYI
I wanted to add that this is the first brass mold I have ever used. I left it on my hotplate mold warmer at 400 deg. for 20 minutes before starting to cast. It took about 25~30 attempts before the mold came up to temperature. My mold likes to run hot. Once it got fully saturated it cast beautiful boolits, I will admit I was getting a bit frustrated with it but I kept at it til the magic happened.

[RED333]

Yep, brass mold likes it hot, good shooting.

[Oreo]

Thanks for posting that here Blanco.

Yes, these molds need to be run hot hot hot.

[harley45]

I agree on the hotness issue!