MP Version/H&G 503 .44 Magnum bullet

[John in WYO]

Does anyone have any experience to share about the H&G 503 or the MP version of this bullet?
Accuracy, etc?

I’ve been shooting the Lyman 429421 and the RCBS 44-250K since 1979 in my S&W 4” 29-2. The six cavity Aluminum MP mold has caught my eye....

John

[bluejay75]

10.5 Unique is my most accurate 44 magnum load with this boolit for reduced power. Ragged hole at 75 yards with a cut down Handi rifle and 4x scope.

23.5 H110 also shoots really well. Less than 2.5 inches at 75 yards. I think my alloy was too soft. Would touch 3 together and throw 2 out of the group. But I have other boolits that shoot better at higher velocity.

[megasupermagnum]

I own the NOE version, have shot an Accurate version, and handled an Arsenal version. I've only seen pictures of the MP version. From what I see, MP makes the best hollow point, I'm not all that impressed with the NOE. The nose isn't the same as a real Keith, and the lube groove is tiny. If no interest in a hollow point, take a hard look at the Arsenal molds version. I think they might have the closest version to a true Keith bullet that I have ever seen, although pictures of the MP show it to be nearly identical.

[sw282]

l have an original California made H&G 503 4 cavity. lts the .429'' version.. Great mold. l have cast maybe 25thousand boolits with it over the past 5-6 yrs.. From plain old everyday range scrap the come out around 254gr.. l could not ask for a better mold. The boolits perform well enough to consistently take down 55 pound steel IHMSA rams @200 meters... l started PCing them about a year ago with HF Red. No change in Accuracy between PC and lubed... Great benefits from the cleaner burning PCs too

[frank505]

The MiHa 503 is a wonderful casting mold. I really like the penta for varmints. Don’t know how they group on paper but they seem to be accurate at distance.......

[Gamsek]

https://uploads.tapatalk-cdn.com/20190611/264bb84242693c61354e245a391f9fdb.jpghttps://uploads.tapatalk-cdn.com/20190611/a8cdc8b13ff4ac4e14c38f775950a5b1.jpghttps://uploads.tapatalk-cdn.com/20190611/df39e7dedbb52c59809ca134813eba99.jpg

I have 4 MP 44 moulds and this is the most used. Accurate. https://uploads.tapatalk-cdn.com/20190611/abb6d9d0c8c884c18559f2a72e936cb3.jpg

Closest to what Keith wanted. Read Glenn’s article.

[Mal Paso]

The 429421 is pre 44 Mag, the #503 is post 44 Mag. I am currently casting the Arsenal #503 Mold as the alignment pins on the MP mold floated out and the mold won't close. NOE's 44 selection all have small crimp grooves that go away with sizing.

Both the MP and Arsenal molds have full forward drive bands which in rare instances can cause the round not to chamber if the cylinder throat is smaller than the forward drive band. Late S&W have tight throats but they moved them forward so not a problem. The #503 forward band is just inside the throat in my Colt and I consider that a good thing.

The MP 432640 is very accurate too and not so fussy with throats.

[John in WYO]

Thanks to each of you.
Gamesmanship, great pics!

[John in WYO]

Gamsek, auto correct got me.

[Lefty SRH]

The MiHa clone 503 is an excellent mold and boolit. It has shot great in my 44spl and 44 magnum.
I have two molds, a solid version and an HP version

[Shuz]

I have the MP 503 clone in a brass 2C with all the pins,and an aluminum 6C solid. They both work very well, but I love how fast I can generate a pile of boolits with the 6C. This design, in all hp's and solids, shoots well in all the Smith and Ruger revolvers that I have. The solid casts a 260g boolit from 10:1 alloy(ww:lino) and in front of 17.8g of WC820 is a real handful from my 329PD!

[Gamsek]

Gamsek, auto correct got me.

No problem:)
https://uploads.tapatalk-cdn.com/20190612/cac25c9b56e0ce13f02968197758b2c1.jpg

[Texasflyboy]

My experience.

http://www.hensleygibbs.com/TCD/hollowpointarticles/Design503.htm

[FISH4BUGS]

I use a 4 cavity #503 for both 44 special and 44 mag. I don't recall the 44 special load but it is ww231. The 44 mag is over 8 gr ww231. Very pleasant mid power load for the 44 mag.
8.5gr ww231 gets a bit snappier but still mid range pleasant load.
I have always used 5 lbs ww with 1lb linotype as my alloy.
The 45gc is loaded over ww296 but I don't recall how much at the moment.
The 44 special is shot from a 1950 44 HE and the 44 mag is from a 5 screw pre-29.
The #503 is my go to mould for the 44's.....kinda makes you into a big bore fan.... :)

[boatswainsmate]

i just made a pile of them yesterday. It was the first time using the mold but I think they turned out great. it's my favorite practice bullet with 12 grains of HS6 behind it.
https://i.ibb.co/9hTwtV5/DSCN4491.jpg (https://ibb.co/PMhTQ9H)