Slightly Disappointed with new MP Mold

[novalty]

After waiting what seemed like month, I finally got notification that MP Molds had the 452374 slick-sided mold Id been wanting in .452”. So with only 11 in-stock, I placed an order and had he had it to my door in 3-days—amazing. This 6-cavity aluminum mold arrived looking as fantastic as the other 5 molds I have from MP. As standard procedure, I cleaned with dishsoap and a soft toothbrush to remove any machining oils, and then heat cycled 3 times. Started casting and the bullets started dropping out of the cavities as soon as I started to release pressure on the handles. I use primarily COWW alloy, and for my other molds typically drop the advertised diameter but typically a couple grains over. Like my HG#275 clone from MP cast .358” and 137gr. So I was shocked to find that the 452374 was dropping .454” and weighing 239gr. The mold works well, and bullets look great, but just disappointed they don’t drop the diameter that I had specifically ordered. I did contact MP and Miha did respond back promptly that it was still good to use, and to use 230gr load data. So hopefully, they will still shoot well.

 

[Josh]

I've been in the business, and I'll tell you right away that hitting a 0.002" window for an unknown alloy with a set of aluminum blocks that are shrinking and swelling with heat is excellent.

I could check my moulds at the shop and still have guys say they're a thou or two off. Your alloy isn't his alloy, your block temp isn't his block temp, your alloy temp isn't his alloy temp.

The extra 9 grains is from removing the grease groove, you can't call it a "clone" and shorten the bullet to remove the weight. Honestly, the easiest thing to do is add more pure lead to your alloy, that will make the bullets slightly smaller, you can also cast with your blocks cooler. Either way, it's not a perfect science to hit a tolerance with that many end user variables.

 

[CWLONGSHOT]

I can understand a issue with a mold dropping undersized bullets.. But within a few .001 I dont just see issue with large. I mean we all size these. We all know it can size this few .001 without issue.

Dont mean to be down on you. I understand not getting what you order or want. But not sure you know its not a issue at all.

In this case and might be just me, but I prefer a "small 45" mold drop 454 over 452 as I can size 452, 451 or 454 and use in any of my "small" 45's. (Small cause 45 I have also run .458) I see you powder coat so I realize this will further increase diameter a few thousandths. Again it does here, to, and is a non issue for me. Should be same for you.

Hope this is understandable and taken as constructive.

CW

 

[novalty]

I agree having slightly over is far better than undersized. Out of curiosity, I measured the cavities with my calipers and they are .454”. So I am not sure that it’s my alloy that is causing the oversizing, especially since I have 5 other MP molds and they drop spot on with the same alloy. Just feel as though I ordered a .452”, I should have received a .452” and maybe the slightly smaller diameter would have resulted in a grain weight slightly closer to the desired 230gr. Not trying to bad mouth MP Molds, it is an excellently machined mold, and I will gladly buy more and continue to own MP Molds exclusively.

 

[CWLONGSHOT]

Roger Copy... Unsure, did you mention that to Mihec?

 

[novalty]

Roger Copy... Unsure, did you mention that to Mihec?

I wasn’t smart enough to measure the cavities before I emailed him. I just mentioned they are dropping .454”, and that his .358” mold was dropping spot-on with same alloy.

His response. “.454 is ok. Sizing down to .452 is no problem (bullet was designed that way)

I personally sizing to .453 for my 1911 - use load data for 230 grains.”

Even though they came to .456-.457” with the PC, they still went through my Star sizing die to .452” fine. So I’m sure the biggest issue is just for my OCD. Maybe this will be the motivating factor for me to finally get a levergun in 45 Colt.

 

[Ian]

Why Miha would cut a slick-sided .45 ACP mould any larger than .450" is baffling to me. The whole point of a specialty mould for bullets designed to be powder coated or Hi-Tec coated is that we either shouldn't have to size them at all, or very little after coating.

I had Accurate do me up a .45 Colt mould at .450" with plus .002 minus zero tolerance and I load them after coating with no sizing at all.

Powder coated .45 ACP bullets do best sized .451" in my experience.

 

[bruce381]

I would like bigger than smaller but yeah lead temp and alloy may get you a thousands or so I would not worry about. Think of it as this size will will cover all 45 cal guns you have or MAY buy in the future.

 

[Tomme boy]

I think my mp452-200hp brass mold dropped 0.454". Everyone in that group buy did the same thing. No one seemed to have a problem with it. If I want exact size I have Accurate cut me a mold.

 

[Snakeoil]

Read all the replies and they all hinted at this, but nobody came out and said it. If the maker does not ask what alloy you are using and you don't tell him, you can't expect perfection. If you want a mold to drop a certain size with your alloy, you MUST give the maker the alloy mix.

I did this will Accurate just a few months ago. The bullet was tapered and I gave him a spec for each of the 6 bands. He hit 4 of them right on the money. One was out 0.0005 and the other 0.001. I was truly impressed.

The other point is you kinda knew going in that it might be a crap shoot. You said he had 11 in stock. So, it is a standard spec mold for him. Does he specify the alloy used to determine his mold spec on his site? That might have warned you of what was to come.

All in all, bigger is better than smaller as you and others have already said. I'm sure you'll be pleased.

I understand the OCD issue. Got a touch of that myself. Deciding on the specs and the tolerance range for that mold had me talking to myself. But, in the end, I learned a lot and got exactly what I wanted. And that damn bullet turned my old .32-40 High Wall into a fine target rifle.

Oh and those pictures make it look like you are in the gumdrop business.

 

[novalty]

Read all the replies and they all hinted at this, but nobody came out and said it. If the maker does not ask what alloy you are using and you don't tell him, you can't expect perfection. If you want a mold to drop a certain size with your alloy, you MUST give the maker the alloy mix.

I did this will Accurate just a few months ago. The bullet was tapered and I gave him a spec for each of the 6 bands. He hit 4 of them right on the money. One was out 0.0005 and the other 0.001. I was truly impressed.

The other point is you kinda knew going in that it might be a crap shoot. You said he had 11 in stock. So, it is a standard spec mold for him. Does he specify the alloy used to determine his mold spec on his site? That might have warned you of what was to come.

All in all, bigger is better than smaller as you and others have already said. I'm sure you'll be pleased.

I understand the OCD issue. Got a touch of that myself. Deciding on the specs and the tolerance range for that mold had me talking to myself. But, in the end, I learned a lot and got exactly what I wanted. And that damn bullet turned my old .32-40 High Wall into a fine target rifle.

Oh and those pictures make it look like you are in the gumdrop business.

I can't seem to find it on their website now, but I do remember seeing that MP Molds are designed around wheel-weight alloy. As stated this is my 6th mold from MP, and all 5 of the ones I currently have cast to the indicated diameter with the wheel-weight alloy that I am using. MP Mold makes molds in batches, and they offer a couple versions of this design: hollow-point, traditional lube groove, and alternative coating style w/o lube groove. They also offer this mold in two-different sizes: 452" and .454". The .454" style has been in-stock for months and I setup a notification request when the .452" version was available. My contention is that I ordered a .452" mold, and the cavities are cut .454", at least according to my Mitutoyo calipers. So my alloy is dropping the size of the cut, and my reason for concern is that the mold is setup for alternative coatings, which typically add .002"-.003" in thickness (at least what I've experienced.) The mold does cast exceptionally well, and like my other MP molds is beautifully made. I'm just hopeful that it will shoot well. Will try to get some loaded up and tested tomorrow.

 

[Rick]

If your looking for accurate measurement's calipers are a poor choice. They were never designed or built for that, even the higher dollar calipers only claim an accuracy of plus or minus .001". You should use a decent micrometer to measure closer than that.

 

[fiver]

if it shoots like his 9mm version your only complaint will be the diameter.

 

[Snakeoil]

I might have misunderstood your original post. If you ordered .452 you should have received .452. It sounded like the bullet dropped was your concern.

 

[Tomme boy]

He bases his molds off WW lead.

 

[JonB]

Try shootin some, if they don't cut the mustard, flip the mold, someone else will probably love it.
.
I probably shouldn't even mention this, but I am not a fan of slick-sided cast bullets

 

[bruce381]

Is this a good spot for a thread drift? anyway been casting this weekend with his MP H+G clone 68 200gr SWC.
Oh man this is 3rd or 4th time and has settled down to dropping perfect .454, 198gr plus minus .6 grian bullets. This is so satifiing I just cast 20 lbs LOL.

 

[novalty]

I also have the HG#68 clone, and it cast at .452” and 205gr with my COWW alloy.

 

[TXTad]

View attachment 34058

What is that sheet under the bullets?

 

[novalty]

Not sure what you are referring to. The bullets in the picture are in a clear plastic bin, and there is no sheet underneath it.