I picked up a oops kit some gas rings and spare firing pin what other parts would be recommended not for a build but common things that wear out or might break.

I have always referred back to this thread for guidance;

What-Parts-Break-in-a-Carbine-Course

I just went thru this again and am refining my spare parts stash. I used to only keep a spare complete bolt but decided I needed other wear/high break potential parts on hand to keep my gun running as long as possible.

Assuming you are using quality components (MPI and a reputable brand) and everything is clean, lubed, accessories on with Locktite in place on the rail, etc.

Index mark all fasteners (such as those on a rail) with paint pen or marker.
If we are talking spare parts that you may rely on to keep your gun running when you cant order any, you don't want to lose anything you need to use your rifle or carbine effectively rifle component or accessory wise. The index marks may help you notice if one is coming loose.

This is what I came up with and am in the process of building with all the spares I have. I am not a gunsmith or an armorer so YMMV.

Small Kit
This is a kit small enough you would actually probably have the small parts in a container like a prescription bottle(s) or pouch and be able to carry it easily. Supposedly some of these are the most often failed components from everything I have read including the post by Pat Rogers RIP.

Parts
Spare Bolt, complete
Gas rings, three
Cam pin
Firing pin
Firing pin retaining pin (a few)
Extractor
Extractor spring and insert
Extractor pin (a few)

Tools
IN addition to a quality multi tool
Broken shell extractor (or a small bent tip screw driver to get broken casings out of the chamber if you have nothing else)
Small pin punch for extractor pin, gas rings and to help get the firing pin retaining pin out
Cleaning kit (stripped down military kits work fine) rod can be used to push a stuck casing out of the chamber
Large bandanna so when you are doing basic maintenance or repairs in the field you have something to put those real small parts on

Consumables
Lube (appropriate for your weather and area conditions)
Cleaning patches or bore snake
A rag (old t shirt works)

Medium Kit
Think of this as a kit that will be used to maintain your rifle or carbine without the use of a bench, vise or other larger tools but something you will not normally carry on your person.

Parts
Spare Bolt, complete
Gas rings, three
Cam pin
Firing pin
Firing pin retaining pin (a few)
Extractor
Extractor spring and insert
Extractor pin (a few)Ejector
Ejector spring
Ejector retaining pin (a few)
Disconnector
Disconnector spring (a few)
Hammer / Trigger pins
Hammer Spring
Trigger Spring
Buffer retainer
Buffer retainer spring
Action spring (buffer spring)
Buffers of various weights
Selector detent (a few)
Selector detent spring (a few)
Bolt catch
Bolt catch spring
Bolt catch plunger
Sight components or spares (posts/springs)

Tools
Assuming you have a multi tool also have any hex, torx or other special wrenches or tools you would need for any accessories or rail system. You can buy individual ones at places like McMaster Carr or get a kit like the fix it sticks.

Appropriate punches and other basic hand tools like a small hammer or pliers

Large bandanna

Consumables
More cleaning patches and rags
Locktite, Blue
Paint Pen or Sharpie Marker for index marking fasteners


Big Kit
Think bigger replacement components (buffer tubes, delta ring, end plates, etc.) or small parts that rarely go bad and anything you would need a wrench, vise or bench for.
Mallets, large double faced hammer, reaction rod or bench clam shell, bench block, tube wrenches, barrel nut wrenches, etc.
Gauges.

Valhalla Tactical  has a few different spare parts kits $30-40. They cover the most likely items needed.   I believe they are in stock as well.

Wow thats alot of info! Thanks guys I will see about acquiring these to stash away. I remember back in the late 80s-90s when there would be tables parts in little bins but now days the last few shows have been slim pickins.
Even online alot of places are sold out, now that folks are getting their checks I expect to see even less.

Thanks again!

n/m

Good video on this topic.

I keep an oops kit, trigger and hammer, and a complete Aero BCG.

Of course, I have multiple of each caliber rifle too, 5.56, 300 Blk, & 50 Beowulf.

So basically two complete rifles of each caliber is my first backup plan.  Second are the oops kits & the complete BCG’s.

https://youtu.be/VO9H3TjCq8M

@machinegunseabee  has a very extensive list that covers the rifle issues very well....