All Iron Blight Weapon Attachment Locations

The verified Iron Blight route contains ten named weapon attachments: TT-33 Laser Sight and Extended Barrel; OTs-48K Scope; PP-91 Kedr Dot Sight and Extended Mag; RMB-93 Laser Sight and Extended Barrel; OTs-20 Gnom Muzzle Brake and Laser Sight; and SR-3M Suppressor and Scope. Follow the campaign order below and keep each part in your inventory until it is attached to the compatible gun.

To install a modification, open the weapon interface and click a green attachment dot. The button turns gray when the compatible attachment is not in your inventory, and a part made for another gun will not install. This behavior was confirmed directly by the developer in the Steam discussion included with the supplied material.

Attachment checklist in campaign order

Approx. time	Attachment	Compatible weapon
17:51	Laser Sight	TT-33
57:49	Extended Barrel	TT-33
1:09:36	Scope	OTs-48K
1:24:54	Dot Sight	PP-91 Kedr
1:35:06	Laser Sight	RMB-93
1:43:24	Muzzle Brake	OTs-20 Gnom
1:47:03	Laser Sight	OTs-20 Gnom
1:54:27	Extended Mag	PP-91 Kedr
2:12:43	Suppressor	SR-3M
2:22:41	Extended Barrel	RMB-93
2:23:39	Scope	SR-3M

The source chapter list contains eleven entries because several weapons accept two upgrades. Timestamps are relative to a 2:39:51 optimized full-game recording; your blind playtime will be longer, but the pickup order remains a useful checklist.

TT-33 Laser Sight

The TT-33 Laser Sight is the first named attachment, found around 17:51 in St. Toma Dormitory with the Hammer. That pairing makes the room important even if you are not currently using the pistol, because the Hammer supports exploration while the sight is optional combat equipment. Leave enough grid room for both pickups.

Install it through the TT-33's green attachment point. Pressing the general interaction key over a different slot will not force compatibility. If the point is gray, verify that the Laser Sight remains in your carried inventory rather than storage.

TT-33 Extended Barrel

The TT-33 Extended Barrel appears around 57:49 after entering the Prasnova District, in the same labeled section as the Crowbar. The Crowbar is the progression priority, so do not sacrifice it to keep an optional firearm part. Return supplies to storage or reorganize before leaving the area.

Combining the barrel with the early Laser Sight turns the TT-33 into one of the easiest weapons to keep upgraded across the campaign. Its compact size can also make more sense than a second long gun while Prasnova begins adding larger tools.

OTs-48K Scope

The OTs-48K Scope is found around 1:09:36, immediately after the PP-91 Kedr pickup in the verified route. It belongs only to the OTs-48K; a green dot on another firearm will not accept it. Retrieve the rifle from storage before attempting installation if you left it behind for the Dormitory.

The scope favors deliberate sight lines, but an optic does not solve the rifle's inventory footprint. Carry it when the coming route supports ranged shots, and store the combination when tight interiors make the TT-33 or a shotgun more practical.

PP-91 Kedr Dot Sight

The PP-91 Kedr Dot Sight appears around 1:24:54, after the Midtown Key. It is the first of two verified Kedr modifications and arrives well before the Extended Mag. Install it as soon as practical so the loose part no longer occupies its own inventory position.

Use the optic to improve target acquisition without turning every encounter into sustained automatic fire. The Kedr can empty scarce ammunition quickly, and the game's sound-aware threats punish unnecessary bursts.

RMB-93 Laser Sight

The RMB-93 Laser Sight follows the RMB-93 itself by only a few minutes, appearing around 1:35:06. The next chapter marker pairs the OTs-20 Gnom with the Connector Key, so the inventory will become crowded quickly. Attach the sight before continuing and free the loose slot.

This upgrade is for the RMB-93, not the TT-33 or OTs-20 Gnom. Similar attachment names describe their function, while the weapon prefix determines compatibility. Check the complete item name before assuming a gray point is a bug.

OTs-20 Gnom Muzzle Brake and Laser Sight

The OTs-20 Gnom Muzzle Brake appears around 1:43:24, followed by its Laser Sight at about 1:47:03. Because both upgrades sit near the OTs-20 Gnom pickup and the Large Backpack, this is the most compact attachment collection window in the route. Keep the gun available if you want to install both immediately.

The Workshop Alley Key shares the broader sequence and remains more important than an optional modification. If space runs out before the backpack expansion, keep the key, one healing option, and a ready weapon; recover the loose attachment only when the room can be revisited safely.

PP-91 Kedr Extended Mag

The PP-91 Kedr Extended Mag is found around 1:54:27, shortly before the Punch Card machine. It reduces reload pressure by increasing ready capacity, but it also encourages players to load more scarce ammunition into one weapon. Continue using controlled bursts rather than treating the larger magazine as a reason to clear every enemy.

Install it before entering the Punch Card office so the loose component does not compete with the new progression tool. Check the weapon manually after attachment; the upgrade does not guarantee that the magazine is already full.

SR-3M Suppressor

The SR-3M Suppressor appears around 2:12:43, roughly ninety seconds before the SR-3M itself. Keep it even though the compatible gun is not yet in hand. The short gap means storing or discarding it only creates an unnecessary return.

Sound matters in Iron Blight because the official design notes warn that gunfire may attract additional horrors. The suppressor supports a quieter late-game firearm setup, but it should be treated as risk reduction rather than complete silence.

RMB-93 Extended Barrel and SR-3M Scope

The RMB-93 Extended Barrel appears around 2:22:41, and the SR-3M Scope follows at roughly 2:23:39. Both are late-route upgrades. Completion-focused players should collect them before moving toward the final key marker, while story-focused players can weigh the detour against their current ammunition and health.

Install each on its named gun through the green dot interface. These final parts are a useful check that the weapon screen distinguishes compatible equipment correctly: an RMB-93 part should never activate an SR-3M slot, even when both guns are in the same backpack.

Why an attachment will not install

The most common cause is interaction method. Open the weapon details and click the green dot for the relevant slot; repeatedly pressing E over the inventory item is not the confirmed installation method. A gray dot means the required part is unavailable in the carried inventory.

The second cause is compatibility. Laser sights, scopes, and barrels are weapon-specific even when their generic names look similar. Compare the full prefix, move the correct part from storage to the backpack, and retry from the matching gun screen.

If a valid button still fails, close the inventory, save in a safe place, restart the current Steam build, and verify game files. Patch 1.02 included fixes for settings and loading behavior, so testing on the latest version is preferable to repeating an older workaround.

Verified source

Locations and order were checked on August 31, 2026 against the supplied all-weapons-and-mods recording. The installation method comes from the developer reply in the Steam Community attachment discussion. Continue with the weapon guide for acquisition order or the inventory guide for deciding which upgraded guns to keep.