09/03/2026
The M3 Grease Gun was the US Army's answer to reduce the cost of the Thompson M1928 and M1 submachine gun. The Thompson cost around $200 in the 1940's verses the M3 cost approximately $17.50. The M3 was built by Automotive Guide Lamp as they were the experts in sheet metal stamping. This "cheap, throw away" worked so well that it remained in US inventory until the mid 1980's.
All,
This kit started out as an original Open Bolt M3 Grease gun. I built this out to be a closed bolt, hammer fired gun to comply with ATF regulations. When I did this, the hammer fire system interfered with the kick starter cocking system and prevented the bolt from being retracted more than an inch. At this point, I removed the cocking system and machined the bolt to allow the M3 A1 style cocking procedure. I also machine the ejection port to allow the bolt to be retracted further. The stock is a M3A1 stock that came in the kit. Many of the original M3 stocks were bent during use and were replaced. The hammer fired system uses a modified AR style trigger group. You can see the AR type safety lever on the left side of the fi***rm.
