You would need to contact the maufacture (of the filter) to find out how to intrepret the date code. If stored properly you MAY get 5 years past experiation. That said its not worth much, I pay $25-30 for expired filters.
I am not sure, that will be something only the manufacturer can answer. The filters I purchased have a 5 year shelf life. I am sure you can go past 5 years.. that said at a certain point they will break down, use your own judgement.
The point I was trying to make, do not buy surplus filters and pay full price. A lot of government agencies etc. will dump their filters when they are close to expiration and restock. I noticed most of the CBRN filters on Amazon were almost expired, reviewers were complaining, some had gotten expired filters.
Just a warning on buying 40mm filters online. A lot of the filters for sale online are surplus filters which are close to expiration or are expired. This would be fine if your were charged surplus price, problem is you are not. The sellers are charging full list or in a lot of cases even more. I have seen this on the big box sites like Amazon.
Make sure you verify the expiration date. I just received my order of 3M FR15’s, I ordered directly from 3M (through a supplier), they are 5 months old. That is normal, not 3 or 4 years old, or worse yet expired.
I found a bunch of Canadian Military surplus filters at the gun show so I am stocked now. I also have a bunch of 3m half masks and filters. I ran a dry run with my 3m 7800B and I was surprised to learn that I have to cock my ar/vcog a full 45 degrees to get a sight picture. I googled this issue and learned that is it common with a lot of masks, some more, some less. Does someone have first hand experience with a lower profile mask. I would like to sell mine and purchase that style. Thanks !!
I am still batting zero, I have made a lot of phone calls and nadda. I sorta regret buying a 7800b now, I should have bought the 7800 which takes a proprietary 3m filter and a adapter for 40mm, super easy to get and cheap. The 40mm is hard to get here, no seems to carry it and if they do its the most expensive variation.
I have a 3M 7800b which takes the 40mm filter. What is the cheapest 40mm filter that will combat the coronavirus? It seems like a simple question but I can’t seem to get a answer. I dont want to waste my CBRN filters if there is a outbreak nor do I want to waste money on a overkill filter since I will need to buy alot of them. My understanding is that the filters are one shot use. Go to town, come home and replace filter for next trip. Can you give me multiple options if possible. Thank you !!