FEG SLIDE METALURGY QUESTION

[craig]

I think I read somewhere, that the front portion of Feg Slides have been hardened more than the rest of the slide, sometimes evidenced by a variation in finish coloring.

Is this true ? -  If so, does this create a problem when having a dovetail cut to replace the staked military sight?  I'm considering having this done eventually, I'm sure it would benefit, to be able to let a smith know what to expect, to avoid trouble.

Thanks, Craig

[jaypee]

I don't know the answer to the metallurgy question, Craig, as this is the first time I've ever heard of a variation in hardening. But I've had dovetail slots cut in two FEG PJK9HP slides, both front and rear, by Novaks without any problems.

[craig]

Nov 9, 2017 9:15:14 GMT -5 jaypee said:

I don't know the answer to the metallurgy question, Craig, as this is the first time I've ever heard of a variation in hardening. But I've had dovetail slots cut in two FEG PJK9HP slides, both front and rear, by Novaks without any problems.

That's a good enough answer for me ! 

     I think the hardening issue was mentioned somewhere in a bluing finish question I read, where the front portion of a slide appeared a different color than the rest. The hardening answer made some sense, that the manufacturer would rather have a replaceable barrel wear, than the slides barrel bushing. I did hear one gunsmith complain about the hardness of a Norinco 1911 slide that he damaged a cutting bit on.

Thank You, Craig

[tpelle]

I have this FEG that I purchased last year that is very finish-worn. Here is a picture:



If you look at the slide, from the front back to about the start of the roll mark you can just barely make out in the picture that the front of the slide is a slightly different color.  Unfortunately it really doesn't show up too well in the picture, but in person the color change is more apparent.

When I saw this it immediately put me in mind of the way they used to anneal M1 Garand receivers by dipping the heel of the receiver in a pot of molten lead. M1 receivers so treated were a slightly different shade in that area than was the rest of the receiver.

The reason that they did this on the M1s was because the receiver was actually too hard! In firing, the bolt would impact the rear of the receiver and the receiver would sometimes break. By annealing just the rear of the receiver in this way, they would actually REMOVE some of the hardness so that the receiver would "give" a little when the bolt hit it instead of shattering.

Here is picture I found on the web showing a Winchester-made M1 Garand receiver with the annealed area visible through the parkerizing:



The darker area is where it was dipped in the lead.  This was a kind of stop-gap measure on the M1s to salvage receivers that would have otherwise been scrapped.  Eventually they got the heat-treat "recipe" right and could discontinue this.

Here's a Harrington & Richardson (Korean War era) receiver that actually broke.  The broken off piece is sitting on top of the remains of the heel, right in front of the rear sight:




You will quite often see a similar annealing effect on bottlenecked rifle cartridges, where the area at the bottleneck shoulder will look "scorched".  This is exactly what it is, as during the manufacturing process they run the cartridges through the flame of a gas torch.

[gt40doc]

If you look at the Colt 1911A1 slides, you will find a similar situation where the forward portion was hardened, and color of the parkerized finish shows it.....anyway it does on my 1911A1 gun slides.

[abninftr]

I'll toss in a little bit of metal hardening/heat treating info just to confuse anyone who isn't already confused. (said tongue in cheek)


First off, hardening metal is a balancing act. Too hard and the metal becomes brittle. Too soft and it will 'deform' meaning it will peen, stretch, bend, etc. from hammering or use.

Secondly, Annealing metal is a process of heating and slowly cooling, unlike hardening in which the metal is heated and quickly cooled, to reduce brittleness from being worked. Bottleneck cartridge cases are annealed to prevent cracking from becoming brittle whilst the bottleneck is formed. Like wise, other objects may be annealed after forging, and before hardening for the same reason - to prevent brittleness.

Notice that I used the terms 'hardening' and 'annealing'. Both are forms of 'heat-treating' metals.

That said, it is possible, in fact it is very common, to have objects 'zone' hardened. For instance, the tip of a firing pin may have one Rockwell Hardness, while the shaft may have a much lower one.

For your reading pleasure:
metalcutting.com/heat-treating-metal/
americanmachinetools.com/heat_treating_metals.htm
www.thebalance.com/annealing-explained-2340013
en.wikipedia.org/wiki/Rockwell_scale

[ruber]

Great posts, thanks for sharing!

All the recent discussions on the FEG’s is making me want to pick one up. I like the old weathered ones but the only ones i find around here have been refinished and people ask a premium for them...

[craig]

Mar 10, 2018 13:53:08 GMT -5 ruber said:

Great posts, thanks for sharing!

All the recent discussions on the FEG’s is making me want to pick one up. I like the old weathered ones but the only ones i find around here have been refinished and people ask a premium for them...

Still some surplus FEGs on Gun Broker.  Everything gets more expensive as time goes by. Check out the Turkish Regents, they look nice & are reviewing well.

the BR9 new, is about $100. more than a used FEG.