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View Full Version : Miha 5.56 nato boolits



Bullshop
03-23-2014, 08:35 PM
Can someone tell me what was the original intended diameter of these boolits? I thought I heard .227" but the first run was rejected because they were undersize at .226".

I was gifted a set of these molds from the first run that was rejected and replaced by Miha. I cast some from the 65 gn design today and was surprised to find that they are not undersize but oversize.
Boolits from this mold mic .231" on the base drive band, .230" on the lead drive band, and .227" on the nose just in front of the lead drive band.

Its not an issue of the blocks not completely closing because the boolits are only about .0002" out of round which is darn good compared to most molds.

So did I hear it wrong about the original run being undersize? I cast these with an RCBS pot at full tilt and very close to 5 cycles per minute and quench from the mold. Is my casting technique causing these blocks from the first run of this boolit design to drop larger diameter than others? I sometimes wonder this because I read here about someone using some of the same molds I have and complaining that their boolits are undersize when mine from the same mold are not.

So will someone please fill me in and bring me up to date on exactly why the first run of these molds was rejected?

What I thought I read was that they were under spec at only .226" and so too small for NATO spec chambers. I thought for other than NATO chambers .226" is good so I asked and received these molds.

With the diameters I am getting these will be on the tight side for a 22 Savage Hi Power.

Please do not take this as a knock on the quality of Mihec molds. They are without doubt of the highest quality I have used.

Jailer
03-23-2014, 08:53 PM
Nope you got it right. The rejects you have are from a run that was oversize.

I have a set of those same blocks sitting on my desk and they cast the same size as yours. They are just too pretty to scrap though.

Bullshop
03-23-2014, 10:27 PM
OK thank you for that. I just had heard it wrong.

gtgeorge
03-23-2014, 10:34 PM
You are maybe confusing with the 75gr nato Miha did as a 1st run that was undersize?

Bullshop
03-23-2014, 10:55 PM
I have the 75gn as well. I will try that one next. I am considering trying to PP the 65 for 243 cal. Tapering from .231" to .227"
might make a nicely tapered PP boolit.

Bad Water Bill
03-24-2014, 02:24 AM
The big problem here is that B S is casting in that shed he showed us with the coyote hides hanging all over the drafty sides.

Those boolits will relax when you bring them inside to warm up a bit.

All things bulk up when they are that cold don't you know?:kidding:

gtgeorge
03-24-2014, 05:13 AM
All things bulk up when they are that cold don't you know?:kidding:
And here I thought they shrunk up in the cold. :???: