Mihec 359640

[Kirk Miller]

Could anyone here let me know what the correct band diameters are for the 359640 mould? My concern is that the front band on my new brass mould is casting at .351-.353. Is this correct? If it is then I won't worry about it. It's just counter intuitive to me for them to be so small.

Any advice or help would be appreciated.
Thanks
Kirk

[KVO]

I have a 4 cavity mold from the same group buy as yours. The front crimp groove and major ogive diameter is .352" on mine as well, with the drive bands at .358". I haven't shot any yet. I was surprised too, as my 360-640 starts off at full diameter right at the ogive, though it rapidly tapers down. The 360-640 shoots excellent for me. This design (359-640) has a sterling reputation for accuracy so I plan on letting the targets tell me if the smaller front diameter is problematic. It would be nice to have someone with a 359-640 from a previous mold to chime in. I'm trusting that it's to spec just based on all my other MP molds being on the money. The 359-640 has a relatively long bearing surface length with the big lube groove, so the shank may be long enough to support the boolit though the throat and into the forcing cone (presuming we are shooting in a revolver) with the nose acting somewhat like a bore rider... Or I could be completely wrong. We'll find out soon!

[Kirk Miller]

KVO, Thanks for the heads up. That is very positive information. I too will have to get out and test on paper and see for myself If the 359640 shoots as well as my original BRP 360640 mould does.
That 360640 mould is by far the most consistently accurate .358 mould I have ever used.

Thank you again
Kirk

[Wasalmonslayer]

This mold is designed that way so that it will chamber and load in rifles, levers, pistols.
Some guns will not chamber a loaded round with much full diameter driving band out front.
It has a lot of bearing surface after the crimp groove.
Give it a go you should really like and it should shoot very accurately.
I have three of these molds and shoot them a lot!!
Very accurate in all platforms with no chambering issues.

[Kirk Miller]

Wasalmonslayer, thanks, I will give it a go.
Kirk

[Forrest r]

Not hand/cherry picked targets by any means. Nothing more than the test targets used to test loads for a then new 686. Was looking for a plinking load. 6-shot groups @ 50ft.
3.3gr of bullseye
3.5gr of international clays
mixed 38spl cases/federal primers with the bullet crimped in the bottom crimp groove/loaded long
https://i.imgur.com/kmoJtW1.jpg

[KVO]

Forrest r,

I noticed your load notes identify the above as a 158gr, I presume either the deep round or penta HP? Have you noticed an appreciable difference in accuracy between different pins and the same powder charge with the 359-640? I have occasionally seen a change in HP pins have a significant effect on accuracy, sometimes no change at all. e.g. My Mihec 44 caliber H&G #503 clone shoots the same loads well with any combo of pins or solids. Compare that to my NOE clone of the Lyman 358-156, the deep pins and solids shoot great, but the cup point pins double the group size in just about every load I've tried in three different guns. Bizarre, as it's only a tiny percentage of the total weight. I even wondered if I cast those with bad technique like the blocks weren't closed all the way and the HP was off center, but they all mic'd round?

Kirk Miller, apologies if this seems like too much of a thread hijack!

[Kirk Miller]

KVO, No apologies necessary. Any and all information on or about cast boolits is great. Thanks also to Forrest r. Your wisdom, knowledge and experience is always welcome.
Kirk

[Forrest r]

I'm sure there is a difference in accuracy between the hp designs of the 358640's. I personally haven't seen any but I'm only using that bullet for short range plinking (25yd and closer).

On the to do list is testing the 503's @ 100yds to see if there is any difference in hp's. @ 25yds it doesn't matter.

I use 2 different sized hp pins for the 358156 hp's, a deep .125" pin, shallow .125 pin & a .156 pin for cupped (3 different hp's). Never did notice any difference in accuracy between the 3 but again I've only tested them out to 25yds.

Sorry for the thread drift. I have a lot of different hp molds. Just do 99% of my pistol/revolver shooting at close range anymore (25yd or closer).

[KVO]

Finally tried some of the 359640's today. Shot from a Dan Wesson 6" EWK barrel topped with an Ultradot MatchDot II. 25yd benched.
226078
226079
226080

So far off to a good start. The 360640 (single crimp groove) is shooting slightly better in this gun, but there's more experimenting ahead. Best results with the 360640:
226081

[Forrest r]

looks like you have a good start. that 359640 is an excellent bullet that is accurate and hits hard.

Is that EWK bbl a 1 in 12 twist?

[KVO]

looks like you have a good start. that 359640 is an excellent bullet that is accurate and hits hard.

Is that EWK bbl a 1 in 12 twist?

Yes sir, 1:12 as per the manufacturer. It's my first purchase from EWK, very high quality product and would recommend them.