Miha .45-270 SAA

[FN in MT]

Finally had some time...and most importantly...the AMBITION to get set up and give this mold a try. I have had issues in the past with the brass H&G #68 with bases not filling out.

I read a few posts stating one needs to run BRASS on the HOT side.... so got a hot plate to warm the molds and turned up the pot to 850. by the 3rd pour I had a few good slugs..by the fifth pour they were ALL nice.

If I let the temp drop too much ; bases would round out not fill out and come out FLAT. I settled on 850 ...Hot enough?

With basically straight WW's and a bit of tin...I got a consistent 285 grs out of the slugs. Exactly what I wanted for a plinking bullet in the .454 Casull and hotter .45 Colt loads in my FA M-83.

Any other hints on casting with the MIHA molds?? Can I go TOO hot??

FN in MT

[longbow]

It isn't so much about getting the alloy hot as keeping the mould hot. Too much heat on the alloy will cause extra oxidation and drossing.

I can't state temperatures because I don't have a thermometer or electric pot. I cast "by eye" judging alloy temperature by the colour of the film on it.

I find that my iron moulds are not picky at all about temperature as long as they are "warm". On the other hand, my brass Mihec, Accurate and aluminum NOE moulds all like to run hotter. I pre-heat the moulds on a steel plate over a propane burner until the sprue pate lube starts to smoke and I run a higher flame under my lead pot until the lead has a slight golden colour in the film.

Then I start casting and get into a rhythm of consistent casting where I have to wait about 10 seconds before the sprue puddle hardens enough to cut.

I cast at a steady pace like than and get virtually perfect boolits.

Also, I find that regular fluxing and drossing helps with fill out and maybe more so with these moulds.

I include the NOE aluminum mould here because it seems to think it is brass and behaves the same.

All these moulds cast the best boolits I have ever seen. Oh, and I am normally casting range scrap or wheelweigts. No added tin or fancy alloys.

This works well for me so I hope there is something of use to you there.

Longbow

[FN in MT]

Good post...Thank You.

It's taking my "puddle" on the sprue plate about 3-4 sec's to solidify.

I then wait another few sec's to hit the plate and cut the sprue.

I was concerned I was too HOt...I guess I'm not. And a great tip too on running the mold hot and not my alloy.

Do you guys think 850 for the pot is too hot? (measured with a Lyman thermometer)

FN in MT

[handyman25]

I got this mold on the last group buy. I run my alloy at 810 and cast at a steady speed. Sprue solidifys at about 5+ seconds. going to pre heat the mold hotter and cast faster with a lower pot ally temperture.

[FN in MT]

I got this mold on the last group buy. I run my alloy at 810 and cast at a steady speed. Sprue solidifys at about 5+ seconds. going to pre heat the mold hotter and cast faster with a lower pot ally temperture.

Have to admit...I have issues with sticking that pretty brass mold on a HOT...hotplate! As if it's going to melt it...LOL.

Just not used to any sort of mold other than IRON. The MIHA brass molds have been an education. This one is #4.

Just sized/lubed the 250 I cast this aftn. They are VERY uniform in weight...right at 285 grains.

Hoping to find an accurate load with H-110 at 1100 fps or so for my 625 S&W. I know thats at the 23K level or +P level. But the current N frame's are supposed to be fine with +P in the .45 Colt . At least as per Brian Pearce.

We shall see.

FN in MT

[longbow]

You can overheat a mould so don't get carried away!

I mentioned that I pre-heat and usually until I see the sprue plate lube start to smoke. If I cast right away, the mould is hot enough at that point to take the boolit a long time to solidify if my lead is also up to temperature.

I would not want to heat the mould more than that and if left over a naked flame or sitting directly on an electric element you could overheat or at least locally overheat and possibly warp the blocks. So yes, pre-heat but there is a limit.

I adjust casting speed (steady brisk pace) to keep the mould hot and sprue puddle hardening a few seconds after I put the ladle down and pick up my dowel to open the sprue plate so at least 5 seconds and more like 8 to 10 seconds. If the sprue puddle stays soft too long I turn down the heat under the pot a bit.

Others may have different techniques but this has worked for me.

Longbow

[FN in MT]

Should I cut a piece of 1/8" plate to sit on top of my hotplate? Then heat that up as it will distribute the heat better to the mold blocks?

Versus the blocks sitting on 2 or 3 small areas of the coils.

Thanks for the good advice.

[longbow]

I have a piece of 3/16" mild steel plate about 4" square to cover the burner. I sit the mould on that.

I guess I should buy a thermometer so I can tell people what the temperature is. I have never used a thermometer for mould or melt and never had any trouble so just haven't bothered.

I have never damaged a mould (iron, steel, brass, bronze or aluminum) doing this. I just can't tell you exact temperatures.

Not the most helpful info I guess.

As long as the mould is evenly heated and not beyond the melting point of lead (621 F for pure lead) I cannot think it would be damaged. You don't actually want it that hot anyway or the boolit would not freeze.

Maybe that helps some.

Longbow

[FN in MT]

Another rainy , mid thirties day..perfect for casting and a big ol cigar in the garage.

Have a small piece of 1/16" steel sheeting I placed on the hotplate..Worked pretty good.

Got the other MIHA mould working today; #258 225 gr Keith style .41 mag mold.

I'm getting the temperature management DOWN...apparently THE way to get the brass molds to cast properly. These guys are a real departure from all the iron Lymans I have.

Appreciate the help.

FN in MT

[Dale53]

I have been using the brass Mihec moulds since they hit the market. I pre-heat on a hotplate (about 450 degrees mould temp). By the second cast the bullets are coming out perfectly. My alloy is WW's+2% tin. My alloy temperature with a good thermometer is 725 degrees except with the hollow point moulds - then it is 750 degrees. I have NO problem with fill out and no handling problems.

These moulds are as good as it gets.

I use the same technique with aluminum moulds.

I use the same technique with iron moulds. Allee samee...

FWIW
Dale53

[FN in MT]

The brass molds ARE a learning experience.

Found out today that my small ROWELL bottom pour ladle is also part of the equation. Someone mentioned using the rowell and I tried it today. Seems to keep the ladle temp up better allowing me FOUR good bullets each time. Versus my little lyman ladle.

And now after three uses the mold is probably getting broken in or seasoned a bit too.

Things are surely working a hell of a lot better now, compared to my first sessions with my initial mold the H&G #68 clone. I couldn't cast a good slug to save my life. I was running the pot too cool same temp that worked for me with iron molds.

Life is awfully good now!

Appreciate all the good advice Gentlemen!

FN in MT

[Dale53]

My moulds are not set up to measure pre-heat temperature with a thermometer. What I do, is put the mould on a cold hot plate set just over medium (YMMV). My idea is to heat my mould until it is just UNDER casting temperature and bring it up to casting temperature by casting. A little experience will have you setting the hot plate so that one or two moulds full of metal will have them casting properly. I start pre-heating the mould at the same time I turn on my casting pot (RCBS 22lb bottom pour).

My hot plate has a steel top. If yours is an open CalRod burner, then you should put a piece of sheet metal over the calrods. I don't believe differential heating to be good for the mould, whether aluminum, brass, or steel. I surely don't want to warp my mould.

My metal alloy does not exceed 725 degrees for solid bullets and 750 for hollow points. My desire is to cast with the lowest temperature that I can get away with. I don't wish to burn the tin out of my alloy.

An important part of my casting strategy is to have a small manicurist's fan blowing on my mould to cool the sprue and maintain mould temperature. Otherwise, the mould gets too hot and it takes too long for the sprue to set (encourages the bad habit of opening the sprue too soon wiping molten lead over the top of the mould).

I cast reasonably fast and don't stop until the pot is empty. All of this activity is designed to be efficient and maintain proper temperatures of mould and metal to quickly produce match quality bullets.

I used to cast all day long (I was much younger). Now, I cast a pot full at a time (about 20 lbs of finished bullets). I just do it more often. I have a heated and A/C shop so can cast during most weather conditions. If I am feeling particularly frisky, I may cast two pots full at a sitting. I have a dedicated casting station so there is little prep involved - I am ALWAYS ready to roll! LOL

Dale53

[HDS]

I have to say it was real easy to cast with a brass mold. Once I got it up to heat it wasn't difficult to keep the pace. I pre-heat them on a covered-type heating coil. I also use a bottom-pour.

[mannyCA]

Using straight WW's have given me very consistent 285 gr +/- .5 grain weights. I too, use a hot plate to preheat the mold, but I have about a 3/8" piece of flat aluminum which sits on the coils of the hotmplate as a sort of "table" for the mold to sit on. I also use it to preheat ingots before they go into the pot.

[Iron Mike Golf]

I kinda do like Dale53, but different. Hah! I run a hotplate with an old circular saw blade for a trivet. No temp indicator on the hotplate. I run the hotplate 3/4 in the summer and full on in the winter (I cast in an unheated garage, near the door).

Alloy is 92-4-4 and I run that at 675. I shoot for getting the mold a bit over temp. 20 min or so pre-heat along with the pot. First cast is usually culled for over frosted. I set the mold on a cold surface (usually a piece of 1/4 inch aluminmum plate on the cold floor) for 20-30 sec.

When casting good, 3-4 sec for sprue to set, 5-6 more sec, then dump. I go for a satin sheen on the boolits (a real light frost).