The most useful data on this deck is on the Weapon Mods Ranges card, and its current values are in constant development - but I've been successfully using them instead of the previously published values that were based purely on the already classic Gear Attribute Sheet spreadsheet.

After I published my first list, a selected group of savvy users (specially /u/ac1dhylde, but also many other members of /r/thedivision, on a series of threads) noticed some outdated values on the sourced data, and the current maintainer of the spreadsheet announced that he would correct the discrepancies on it, and I'll import the new data when he publishes it.

In the meantime, I took some samples of recent weekly vendor data dumps by Ruben Alamina, extracted their extreme values and used them to adjust the original data.

I shared my new set of attribute values with /u/ac1dhylde, who compared this revised numbers to his inventory of 257 mods, validating the bulk of my results against a wealth of post-patch-1.8 mods.

Since then, I've been slowly expanding some ranges when I get some dropped item that does not conform with the previously seen values.

Recent changes

History of recently dropped weapon mods observed in-game and which stats prompted an update on the previously available range.

Exceptional values seen on only one or two types of mods are noted on the table as a parenthesized annotation of the out-of-range value. When I see the exception being repeated on a lot of different mods, I correct the previously recorded range.

• 26.05.2018 - 2 corrections on the Weapon Tips card - thank you, /u/decrement!
• 21.04.2018 - Got a Vertical Grip - OD Green with 42.5% Optimal Range. Updated the card with this new boundary.
• 08.04.2018 - Adjusted ranges (considering observed values described below) on Optimal Range, Reduced Threat, Headshot damage, Stability
• 08.04.2018 - Noticed that there's a record of a PEQ-15 Laser - Green with 3% Stability, on one of Ruben's recent vendor roundups.
• 07.04.2018 - Stability (major) was observed at 14% on an "Angled grip" (without qualifiers). That's a first for me. Updated the card. EDIT on 13.04.2018: Also on a Muzzle Brake that's on sale this week.
• 06.04.2018 - Critical Hit Damage (minor) was observed at 4.5% on a Ti-RANT Suppressor on rubenalamina's weekly vendor roundup. That's a first for me. Updated the card.
• 06.04.2018 - There's a new version of the Gear Attribute Sheet around, superseding the one that I originally based this cards on, that was in need of updates. Good luck and godspeed to the maintainers!
• 01.04.2018 - Headshot Damage was seen by me at 18% on a VX-1 scope (12x). That's a first: I've recorded it before at 18%, and even at 18.5%, but always on Omega Rifle Suppressors. EDIT on 06.04.2018: there's a 18.5% HSD "VX-1 scope (12x)" on today's rubenalamina's weekly vendor roundup.
• 31.03.2018 - Critical Hit Damage (major) was observed at 19% also on a Loud Vent Brake that dropped for me today. That's 3 different mods already. EDIT on 08.04.2018: One more Loud Vent Brake today. EDIT on 13.04.2018: There's a C79 Scope (3.4x) on sale this week with 19% too. EDIT on 14.04.2018: I got it on a C79 Scopes (3.4x) and an SR-7 Suppressor dropped from named bosses today.
• 30.03.2018 - One more example of 17% primary Accuracy on a laser - this time on a PEQ-15 Laser - Green on rubenalamina's weekly vendor roundup.
• 30.03.2018 - Headshot Damage was seen at 18% on an Omega Rifle Suppressor - Tan on Ruben's list. Previously (March 23) I've seen it go up to 18.5%, also on an Omega. EDIT 01.04.2018: seen again at 18.5%, also on an Omega.
• 30.03.2018 - Critical Hit Chance was seen at 4% on an Omega Rifle Suppressor - Tan on today's Ruben's list. Previously (March 23) seen on an Extended Magazine.
• 30.03.2018 - The new layout that gets a little extra-wide on desktops and larger tablets (and has an extra tags column on the Weapon Mods Attributes card) went live.
• 27.03.2018 - Secondary Accuracy was observed at 2.5% on a 552 Holosight - Tan. It usually has a fixed 2% value on most mods, but on March 23 I recorded a strange case of 4.5% on an Angled Grip - Red. Are these 2 excepcional values, or evidence of an extended range? Let's wait for more examples. EDIT: on 30.03.2018 /u/Shomakh observed that there's also an PEQ-15 Laser - Red on sale this week with 2.5 accuracy as secondary. EDIT on 13.04.2018: There's an ACOG Scope (4x) - FDE on sale this week with 2.5 accuracy as secondary.
• 27.03.2018 - Accuracy was observed at 17% by /u/The_D0lph1n on an ACOG Scope that dropped for him yesterday. It had previously been recorded on Flash Hiders and on Lasers. Maybe not an exception after all, but just a somewhat rare peak value. EDIT: 4 hours after writing this entry, I got another 17% accuracy mod: it was a Flash Hider, again.
• 26.03.2018 - Optimal Range was observed by me at the sad low rate of 42.5% on a Vertical Grip today.
• 26.03.2018 - The (previously in beta) adjusted version of the Weapon Mods Card (corrected with vendor dump data and directly observed drops) became the new Weapon Mods Card. The old version of the Weapon Mods Card is still available for historical purposes.
• 25.03.2018 - Rate of Fire was observed at 5.60% on a Quick Release Magazine that dropped for me today. EDIT on 13.04.2018: also on a Quick Release Magazine that's on sale this week.
• 25.03.2018 - Critical Hit Damage was observed at 19% also on a PRO red dot sight that dropped for me today. EDIT on 07.04.2018: and one more today.
• 25.03.2018 - Reload speed was observed at 31% on a Quick Release Magazine that dropped for me today. EDIT on 13.04.2018: Also on a Handstop - OD Green that's on sale this week.
• 24.03.2018 - Critical Hit Chance at 8% is something I've yet to see on the samples available to me, but both DiscoStu83 and Malus333 tell me they recently got it on dropped muzzle mods and optics mods. Hope I get one soon too. You know... for science! EDIT on 21.04.2018: /u/illformed also confirms 8% CHC on a recently dropped High Velocity Magazine. Wish I had his luck!
• 24.03.2018 - Accuracy was observed at 17% on a Flash Hider and on 3 lasers - specifically on 2 PEQ15 Laser - Orange and a Small Laser Pointer. At this point I can't say if they are special cases, or if the general range goes up to 17% for every item that can use the major scale of this attribute.
• 24.03.2018 - Headshot Damage was observed at 18% (possibly can go up to 18.5% - /u/ac1dhylde believes so, and I'm looking into it) on VX-1 scopes. I've seen this stat going up to 18.5% on Omega Rifle Suppressors.
• 24.03.2018 - According to the original data source, both Pulse CHC and Pulse CHD should have a fixed value of 2%, but both have been observed today by me, on dropped mods, varying on a range of 1.5%-2%.
• 24.03.2018 - Imported data from last night's weekly vendor data dumps made by Ruben Alamina. Most stats were already ok.
• 23.03.2018 - Secondary Accuracy was observed at 4.5% on Angled Grip - Red. EDIT (31.03.2018): It's such an strange value that I'm not even showing it on the main card's table anymore.
• 23.03.2018 - Secondary Critical Hit Chance was observed at 4% on Extended Magazine.
• 23.03.2018 - Critical Hit Damage was observed at 19% on Small Grip.
• 23.03.2018 - Headshot Damage was observed at 18.5% on Omega Rifle Suppressor.
• 23.03.2018 - Imported data from 4 recent weekly vendor data dumps made by Ruben Alamina.

Previous version

The old version of the Weapon Mods Ranges card is still available for historical or comparison purposes.