[MrFix]

'Accessory Rail' is simply the standard of mounting accessories.

All firearms subscribing to the concept can use all attachments subscribing to the concept.

Before it's introduction, most accessories were made for specific firearms such as "Scope for Kalashnikov Rifles" or "Foregrip Light for H&K MP5" etc. By making attachments universal, you do not need to stick to a single platform, so you can just produce 1 product that reaches infinite audience, rather than audience of one type of gun only.

Attachment-wise etc, I would've used locally made optical sight. The tools and machinery usually can provide a scope with solid, if fixed, magnification, while TL7 concepts allow them to gather light to cancel out darkness penalties and have lit up reticles for night shooting.

Another thing is a folding bipod, which should be doable without advances in machinery. For most real life TL5 and TL6, bipods were either just shooting sticks or reserved for MGs, so introduction of smaller folding bipod as a concept can help the gunfighter marksman.

But most importantly, since a single shot musket that reloads by next christmas is not a gun you want to spend all of your inheritance on, the TL8 development worth importing is the quick detach mount for picatinny rails.

In short, it's a device that enables you to quickly attach and detach attachments from your rifle by the mean of a clasp. Usually you need a screwdriver and some time to do so. I believe it cannot be produced locally because the mount must be able to hold 'zero' - alignment of sight's point of aim with weapon's point of shooting. Without proper 'zero', which happens when scope doesnt point in the right place, the gun fires not where you point.

As such, an imported set of quick detach adapters allows the shooter to make his shot, spend a few ready maneuvers detaching the accessories off the musket and then running off/attaching them to a different gun/pocketting them and engaging in melee.