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Colt should move its molding marks to the right side of the components

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524 views 16 replies 13 participants last post by  KWend54  
#1 ·
Everyone wants to photograph the left side of a Colt DA (to show the roll mark and pony), unlike a Smith which everyone now wants to photograph the right side to hide the lock.

Anyway, I wish the people at Colt understood this and designed the mold mark to be on the right, not the left:

Image
 
#10 ·
Circular marks such as that are usually ejector pin marks caused by MIM molded parts being ejected from the mold.
Can't tell if it's a sprue mark or ejector pin. If it's an ejector pin, it a wee bit too long! I made many plastic injection molds over the years and usually cut the ejection pin a thousandth or two long, and dressed the pin down to the mold cavity surface so ya could hardly tell.
 
#7 ·
Everyone wants to photograph the left side of a Colt DA (to show the roll mark and pony), unlike a Smith which everyone now wants to photograph the right side to hide the lock.
Most pistols, automatics and revolvers, have all their photogenic features on the left side. The right sides are usually pretty plain. Colt did some 1911 slides with their info on the right.
 
#9 ·
That was my point: the mark indicates that the part is not a forging, it's a casting. Did anyone here realise that some Colt parts were not made from forgings? I recall the hullabaloo when the Trooper Mk 3, of which I bought one immediately they were introduced, was made with 'sintered' rear sights. Not a thing any more?

Somehow my PPC shooting scores didn't improve with the new Colt over the old Shooting Master I had been shooting. Go figure. :).
 
#14 ·
It's not a sprue mark, it's a MIM mold ejector pin mark. Sprue marks are where molten metal enters a mold in a casting. A MIM part isn't molten when it fills a mold, it is a compressed metal powder/binder slurry that is somewhat brittle and fragile when it ejects the mold in what is known as its "green" state. The ejector pin mark can't be just anywhere, located in inconspicuous places for best appearance. It has to be in locations where it is necessary to eject the green part from the mold so that the part stays intact. The ejectors must also be on the opposite side of the direction the part must exit the mold and in spots where the part must have applied pressure distributed so the green part doesn't get broken on ejection. The part is positioned in the mold in an orientation that makes the most sense from the standpoint of ease of ejection.