Rust, spare parts and mechanical illiteracy

This is about a Volquartsen Scorpion, a semi-custom Ruger Mk III.

Last week, the firing pin broke. I field-stripped the gun and then found out the rebound spring also was broken in two.
In the process, I noticed parts of the main spring assembly were covered in what I think is a mix of rosin, sweat salt and rust.
This crap comes off easily, the blueing underneath is almost undamaged.
The only heavily rusted part is the bolt stop pivot pin. It's made of a rolled piece of whatever at the base of the bolt stop pin (see attachment).

Volquartsen sent me replacements for the broken parts for free, and I asked them to include a new mainspring assembly in the shipment.

First question: if I put the original mainspring assembly back in the gun to use it until it breaks, will rust expand to the rest of the gun from this beachhead?

Question 2: what will happen when this rolled sheet pin crumbles ? Will it unlatch something and subsequently damage something else?

Question 3: let's say I put the new assembly in the gun so I can shoot it while attempting to fix the rotten pin problem. Can I replace it with whatever will do the trick? Or is there a reason you need a rolled sheet pin in there instead of… what about a nail?

Real gunsmiths will reply, but I’d toss the old mainspring. New VQ Scorpion is $1400-1800.  VQ MS replacement is $70.  Sounds like you got your money’s worth if the MS was that crudded up, the FP and recoil spring (assembly) are toast, and MS roll pin is corroded.

Without going through the mental gymnastics in my head, I’d be more concerned about whether you can disassemble the pistol if that roll pin goes “poof”.  

What are you gaining by jacking around with the old MS.  If you are bound and determined (maybe a thrifty Scot, or worse, German), a bag of assorted roll pins is a few bucks.  Or your local Ace may have them,where you can buy a single one for 11 cents.

Reason it’s a roll pin, my guess, is so it stays in place due to outward spring tension. If a solid pin, sure it will stay inside the grip once assembled, but if it migrates to one side then it’ll be another issue to keep lined up while reassembling the pistol.

One question, how did the pistol get so crudded up? Seems that it would take a lot of sweaty handling and shooting without any maintenance to get to the point it has.

Thanks Rodj,
The reason for sweat and rosin mixture is that I shoot a lot, in Texas.
I run a bore cleaner several dozen times and wipe out the gun with an oily cloth after every session, but I just don't have time to field strip it for thorough cleaning and then reassemble it every week.
MkIIIs are not user-friendly in that regard: I just learned that the "trick" to reassemble the guns are not the same for the VC and my old Ruger 22/45.

My other guns do just fine with 2-3 thorough cleanings a year, but I acquired this Scorpion less than 1 year ago. The mess I describe here is the result of the last summer.
And this is exactly why I thought about using the old MS for as long as possible. I may very soon be in a position I will not be able to get replacement parts easily. It will not be Germany for sure, possibly Scotland, but probably much farther east, I don't know yet. I'll have to make what I have run for as long as it can.

Hey Jambat,
I figured it had to do with summer shooting in a humid, warm environment.  (I’m in Austin, btw).  My comment about Scots and Germans was joking about their reputation for thrift and you wanting to rehab your rusty MS. However, the thought of being in a European country would worry me, too.  

One thing that just occurred to me that could also be hiding in that MS is rust underneath the detent where the actual spring resides in the mainspring housing. If it and the detent itself freeze up after sitting with the hammer uncocked, it may be very difficult to cock the hammer against a frozen detent. Then again, you should still be able to field strip it and swap in a new part.

Punching out the old roll pin and replacing with a new one should be easy.  In any case I’d give the old detent and spring a good flushing with Kroil, followed by some oil if you can work some into the actual spring area.

All my comments assume that a VQ is essentially the same as the base Mk III n terms of internal parts and mechanical interworkings.

Good luck and if you’re in the area, happy to help replace the roll pin as I have RP specific punches.

Buena suerte.

Ruger makes a stainless version of this assembly. Not sure if it would work in a Scorpion but it looks the same from memory. Maybe get the stainless one and worry less.

The blued assembly as a whole is not rusting yet, but I'm concerned about contagion.
I wouldn't be surprised if the stainless version had the same crappy pin.

Why would you design a part with a rolled sheet pin instead of a standard plain rod pin?

Jambat wrote:The blued assembly as a whole is not rusting yet, but I'm concerned about contagion.
I wouldn't be surprised if the stainless version had the same crappy pin.

Why would you design a part with a rolled sheet pin instead of a standard plain rod pin?

I explained in my first reply and it’s not a “rolled sheet pin”, it’s just a “roll pin” “slotted pin” or a “spring pin”. It’s not a crappy pin, it’s made of spring steel, and is a semipermanent pin, so it won’t migrate when taking down the mechanism and replacing it many times.  It’s not supposed to be punched out.  They are incredibly durable. Ruger /VQ maybe didn’t anticipate such a lack of maintenance that would result in so much salt and sweat being in there for a long period of time. And the sweat would take a long time to evaporate due to where it got in that mainspring housing.

Rust is not the contagion and won’t spread on its own.  It’s fairly stable.  Water and salt are the problem.

Jambat wrote:

Why would you design a part with a rolled sheet pin instead of a standard plain rod pin?

Because roll pins, and spring pins are stronger and retain better than a plain rod pin.  Unless the pin is needed as a “precision” pivoting surface like a trigger or hammer, a roll pin is less prone to walking.  If I designed a mechanism using a rod pin, I’d have to “capture” the pin by embedding both ends behind other parts.  Spring pins are also stronger for a given weight generally as well.

Thank you gentlemen, it took renewed effort and some explanation on your part but I get it now. I am grateful for your patience and knowledge.
I thought those "empty" pins were used just to save metal. I thought VC engineers had tried to get away with a Chinese toy designer's deception. I had no idea. I am glad I asked.

Do those roll pins come in standard sizes like screws? Do you need special tools to set them in place? Would it be a stupid idea to try and replace the rotten one ?

Do those roll pins come in standard sizes like screws? YES

Do you need special tools to set them in place? You can remove and replace with regular punch (you’ll need a set of steel punches to match the pin’s outside diameter very closely ti punch it out. And a small hammer. You’ll want a small vise or a wood block with a hole to lay the part on, and punch the pin out. You can get special roll pin punches that have a little “nipple” on the end that fits inside the pin and helps align the punch. HARBOR FREIGHT is your friend. Or a neighbor that will lend you punches.

Would it be a stupid idea to try and replace the rotten one ? ABSOLUTELY NOT. Easy peasy. Just watch a YouTube video to get the idea of this isn’t your forte. You may bash or bend your first pin trying to drive it into the hole perfectly straight. Get several. They are cheap. When you are ready to drive the new pin, place the middle piece in between the strut legs to support but don’t worry about alignment. Get the pin started and lightly tap till it’s just even with the inside surface, slide the middle part into place / align the hole, then start driving the pin into the middle piece. Don’t smash, just tap and only tap hard enough to get it to move. If the pin is too long, cut it off flush. A bit short is okay as long as it’s through all three holes.