I'd like to get some opinions regarding what and how many spare/replacement parts are good to have on hand. Right now I think I have a decent collection but would like some opinions as to would be the ideal set of extra parts.

Right now I've got the following:


Complete LPK
Two complete bolts (FN, AIM)
Firing pin
Cam pin
Extractor o-ring
Two extra c-clips (for my CMC trigger)
Three gas rings
Two main springs
Two H buffers (H2 in my rifle)
Two charging handle (BCM and standard)
Four complete BCGs (BCM, Colt/FN)
Aimpoint Comp M4
Surefire ST07 remote activation switch

My only two ARs are both large pin Colt lowers, so I'm not sure what good the LPK would do me. I'm also thinking about selling some of the BCGs since I already use BCM BCGs in my rifles and have two spare bolts, I don't see the benefit of having four complete carrier groups.

Are there any parts you recommend I add? I'm thinking maybe some extra extractor assemblies or extractor springs/inserts. I'm also thinking of adding two carbine weight buffers so I can swap if needed based on ammunition used. My goal is to have on hand any part that might wear out or become damaged during use, so that I can quickly replace it and get my rifle running again. I want to avoid the situation where I can't use my rifle for any period of time due to not having a small part on hand.

There is no right or wrong answer and only you can answer what you need. I have four AR's and I keep two complete BCG's ready to roll, a complete LPK or two, and countless other parts and pieces that I collected over the years. Works for me, I can probably build at least one if not 2 complete rifles out of all my parts and still have leftovers.

I only changed out the below for my SR15 Mod1 after 12,000rds

-Firing Pin Retaining Pin
-Gas Rings
-Buffer Spring

Never had an issue with the rifle at all with very low maintenance and limited lubrication.
Figured it is time to change out some of the parts

I only have one rifle, and for spares I have a bolt, cam pin, firing pin, and lower parts kit.

I also have an entire "spare" upper assembly, stock, two pistol grips, handguard, and some other misc stuff laying around. Not stuff I specifically bought to be spare parts, just extras that I ended up with over the years.

With the exception of a few misc. pins and springs all my backup parts have become backup guns.

In all seriousness, with the price of AR's at this time, why not ?

Your photo indicates a total dollar amount of parts almost comparable to another complete AR.

For me I have a bad habit of buying spare parts and letting it collect in a box.  I often help stimulate the economy buying parts just because I find a good deal.  Then every once in a while to do an inventory of what I have.  I have a bad habit of finding enough or almost enough parts to build another rifle.  Then usually finish it.  Then the quest for spare parts begin again.  

I try to keep at the very least 2 of the major stuff; upper parts kit, lower parts kit, complete buffer tube assemblies, bolts, etc...

Is the lower parts kit that you have for a standard lower, or for a Colt lower with oversized pins?

You need to get a couple of lower parts kits with parts that fit your Colt lower (with oversized pin holes).

How about buying a standard lower and assembling a spare lower (get a set of conversion pins so it can be used with your oversized pin Colt Uppers)?

Fund the new parts by selling a couple of the spare BCGs.

In over 40 years of shooting ARs, I haven't broken anything, but I have lst an uncountable number of pins and springs taking them apart for cleaning.  I'd recommend a set of replacement pins and springs..

Not my video, but I feel it's appropriate. There's no telling how much money this guy has sunk into this box.

I have a shitload of spare parts I keep in a few tackle boxes. Also keep a few of everything in a smaller box in my range bag.

I generally keep about 20 of each spring,detent,and screws on hand along with a dozen or so complete bolts and carriers along with all the parts to rebuild them.
Fireing pins I keep about 40 of and also keep spare crush and peel washers and some A2 flash hiders

Pretty much I could build a bunch of rifles with what I keep on hand, will I ever need it all? Hopefully not but I like to keep the stuff on hand.

Also keep a few spare barrel Assembly's greased up in a crate.


I have a problem

A spare LPK and spare BCG, spare buffer and spare buffer spring is about all you would need per rifle. Beyond that, maybe a spare barrel and call it good. I think you're already ahead of the game. Maybe spare receivers, but it's highly unlikely you'd need those unless you shoot remanu's.

I have 4 ARs and right now I have the following parts, with more to be added.

2 LPKs
4 action springs
3 bolts
1 complete BCG
1 BCG rebuild kit(cam pin, firing pin, retaining pin, extractor&pin, gas key& screws)
2 gas tubes and pins
1 barrel nut/delta ring
1 charging handle
2 handguards
2 sets of gas rings
1 crush washer
1 upper build kit(FA and port door parts)
a kit containing a spare for every spring, pin, and detent on the gun

I'm probably going to add a stripped upper and another lower but have put that off because everytime I get a stripped lower it turns into another rifle.

At least a couple of all the small parts needed for a build and a lot more than that for wear items.
I keep most if not all major parts on hand also.
I personally think there will be times in the future when all things AR may be hard to get again.

Be very careful....

You're a receiver extension, lower, upper, and barrel away from another rifle.

Actually I am already there.
It just would not be in the configuration that I want to build next.
However I am expecting a package this week that will rectify that unfortunate state of affairs.