How we check fitment before a Polymer80 kit ships

Fitment questions are the most common reason an order goes wrong, so we answer them before the box leaves. This is the check, written out so you can run the same one.

1. What slide do you own

The model is stamped on the left side of a factory slide. Aftermarket slides state the Gen 3 model they copy in their own listing. That single fact decides the frame: G43 to PF9SS, G26 or G27 to PF940SC, G19, G23 or G32 to PF940C, G17, G22 or G34 to PF940v2, G20 or G21 to PF45.

2. What generation

Gen 3 works. Gen 4 slides use a different recoil assembly and Gen 5 changes the front cut, and neither drops onto a PF940 frame without a conversion. If the answer is Gen 4 or Gen 5, we say so before you pay rather than after.

3. What parts kit

The parts kit follows the same model as the slide. We check that the kit you have includes a locking block, because several budget kits leave it out and the frame kit does not supply one.

4. What magazines

Frame decides the magazine, and a PF940v2 will not take G19 magazines. Cheap to get right, annoying to discover at the range.

5. What tools

Drill, vise, flat file. Everything else is in the kit. For an AR lower we ask whether you have access to a drill press, because the fire-control pocket is deep and a press makes the walls square.

What we do not claim

We do not publish round counts we have not shot or durability numbers we have not measured. Where a note says untested, it is untested.

This is general information, not legal advice. Laws on unfinished frames and receivers vary by state and city and change often. Check the current law where you live before ordering.