Henry Rifle Forums

What are "MIM" parts, and why does that make a difference?
In this case then, is the "MIM" an issue?

North Country Gal wrote:I watched most of it. He may be boring, but have to say, he knows his stuff about the internals on an 1860. Basically, his conclusion was that the Henry gets high marks for its internal machining and finish and for the superb piece of walnut on the stock. Overall, he seem impressed with the fit of the action.

He was surprised to see so many MIM parts in the action on such an expensive gun (so was I), but he did not criticize the gun for that. He did say the MIM parts appeared to be of high quality. Left it to the viewer to decide if the MIM was an issue.

What are "MIM" parts,

Google 'metal injection molding' and read up a bit on it.
Pretty interesting actually.

His biggest criticism of the Henry seemed to be that the external finish was over-polished to the point of the edges losing definition, especially the octagonal barrel.

I never really considered this part - until I brought my Henry home and compared it to my WInchesters' barrels - which of course are very well defined with sharp edges and very well machined 'flats'.
While the Henry barrel does not have the Winchester level of definition I do not consider it a condemnation of it at all and the softer barrel definition and considerably higher luster of the bluing actually 'blends' well with the smoothness of the brass receiver and it's somewhat lack of sharp definition.
It all 'melts' well together and gives the rifle it's own 'look'.

PT7 wrote:What are "MIM" parts, and why does that make a difference?
In this case then, is the "MIM" an issue?

as best I understand it, MIM is a method of injection molding parts .... its been a round for a good while and is a well established process .... through it a company can mass produce parts at a lower cost .... as with any process, the quality of part correspond to the care taken .... Henry clearly requires parts that they can warranty for a lifetime .... to me that speaks volumes

PT, as JEBar says, MIM has been around long enough now to be a legit way to make gun parts. In fact, you'd now be hard pressed to find standard production guns that didn't have some MIM parts. The exceptions tend to older, long-established guns that have been in production for many, many years (Browning SA-22) or some semi-custom or custom guns where customers specifically don't want MIM parts and are willing to pay the price to insure the gun has no MIM parts.

When MIM parts started to become common in production guns, about ten years back, it started a wave of protests with some gun owners, but the storm has pretty much died down, now that MIM parts have proven themselves to be worthy. For some, though, it remains controversial. Be warned.

The advantage of MIM parts is that they can be made to tighter tolerances that standard cast or tooled parts. This in turn, reduces the amount of fitting required, which, in turn, reduces labor costs. MIM also tends to give us more consistency in the fit of our guns. I've especially noticed improvements in the triggers on the same model of guns when the manufacturer switched to MIM parts in the trigger. Triggers on these guns have become more consistent, gun to gun, when the manufacturer went to MIM parts.

Some gunsmiths are not fond of MIM because a MIM part cannot be safely filed down. MIM parts consist of a hard outer shell and a softer inner core. Once that hard outer shell on a MIM part gets too thin, the chance of breakage greatly increases. MIM parts can be stoned, but we kitchen table gunsmiths should not grab a file and work a MIM part.

Wasn't sure where to put these pics so brought up this old thread. Buffalo Arms website has pics of the guns they sell and these 2 photos are same style and size so interesting comparison view maybe. The stock is obvious with the HRA having the early, fatter belly and the Uberti using the later version slimmer one. There is a company that makes replacement stocks and you need to specify when ordering which style you have. Receivers might be a little different too, hard to tell in photo. The HRA definitely has high end wood, and is super shiny. I'm more of a patina guy myself.


Uberti 1860



HRA 1860