Service charge to modify a USGI trigger housing that you supply, to swap semi automatic internals from an Ohio Ordnance Works 1918A3 SLR trigger pack that you supply. Ohio Ordnance has sold thousands of semi automatic BAR type rifles, many of which had post WW2 trigger housings or new made housings. For customers who want to have WW2 or simply a USGI trigger housing fitted for the Ohio Ordnance Works Semi Auto Trigger Pack, we offer this machining service. Send us a USGI trigger housing, your complete Ohio Ordnance semi auto trigger pack - and we will machine the USGI trigger housing, install the components and adjust as needed. You get back both trigger housings and all supplied parts. We can also install a milled USGI change lever at the same time for an additional $30.