At this point, if you're buying an AI you are going in with full knowledge that trying to obtain any replacement part is going to be easy at best, require a long wait and backorder most of the time, and possibly impossible to get at the worst. Lots of stories about the continuing difficulties obtaining parts. They sell the rifle as a "system" and are set up for service at Mile High or AINA, and while the service department usually has most spare parts in stock for quick turnaround when you send a rifle in for work they can be reluctant to sell certain parts like fire control components so end users can't mess with the rifle; for certain repairs or parts like a lock ring it's service department only and they will not sell the parts.
There are some parts that AI will not sell you as an individual, but even worse there are other parts that the dealers can't even obtain from AINA because AINA doesn't have part numbers for them on the parts diagram/listing. Other parts like LH rifles or bolts seem to only be rarely made in batches and sell out quickly. On top of that AI only takes orders from their dealers on a quarterly basis so if you need a part and the dealer doesn't have in stock and you just missed that quarterly ordering window you automatically have 3 months added to your wait time until the next quarterly order window opens.
I just went through this trying to get a couple of spare firing pins for my AXMC. Neither mile high nor euro optic could get them from AINA because the part number I wanted wasn't listed on the parts diagram, and AINA couldn't find or provide a part number over the phone to order it and told me I had to buy a complete bolt assembly or a firing pin and shroud assembly. Sporting Services UK managed to get a part number from AI UK after a week of back and forth with AI UK and got them ordered for me, but it's a minimum 16 week lead time. Luckily I got the order placed 2 weeks before AIs quarterly order deadline closed or I would have had another 12 weeks added to my wait time until the next quarterly order window opened. It should not be so difficult to source a spare firing pin.
With all the info out there, buying an AI means you are knowingly getting into an abusive relationship. AI hits you because they love you, lol. I have 3 of them and every time I have to deal with AI trying to source spare parts it makes we want to sell them. Luckily it's very rare that something breaks, otherwise I would have sold them long ago because no way would I tolerate a rifle being down for months while I'm waiting for parts. I've actually never had any of the 8 AIs I've owned I've the years go down, but I like to keep a few common spare parts on hand that I can easily replace myself (firing pin, extractor, ejector, etc) and it's been a pain in the ass to try to buy them nearly every time, as most of those parts have no part numbers published on the customer facing side of things because they're all typically service department only parts they want you to send the rifle in for.
I guess you need a different mindset for buying an AI; where most R700 style action makers are happy to sell you any part to do the job yourself, AI prefers you send in the entire rifle for any action related work and prefers not to sell service parts to end users. If you're not ok with that approach, you may want to consider something else.
