These manuals will be very helpful in a repop attempt.
# FM 23-82 106-mm Rifle M40A1 (June 1958); 235 pages, 78 illus. Price 23.00 {Item No.4121}
# TM 9-1015-221-20 Rifle, Recoilless, 106-mm: M40A2 and M40A4 (Organizational Maintenance Repair Parts and Special Tools List)(May 1986); 29 pages, 13 illus. Price 3.00 {Item No.2299}
# TM 9-1015-221-34 Field Maintenance 106-mm Rifles M40A1 and M40A1C; 106-mm Rifle Mounts T173 and M79; and Tripod T26 (March 1959); 115 pages, 50 illus. Price 12.00 {Item No.2561}
# TM 9-1015-221-35P Direct Support, General Support, and Depot Maintenance Repair Parts and Special Tools List for Rifle, Recoilless, 106-mm: M40A2 and M40A2 (14 July 1969); 77 pages, 33 illus. Price 8.00 {Item No.2815}
These were found on this site:
http://www.military-info.com/MPHOTO/p060l.htm
Also from a museum site:
EXHIBIT #24
106-MM RECOILESS RIFLE M40A1 USA
Using Newton’s third law of motion (one action is equal to opposite reaction), the recoilless rifle fires a high-velocity perforated round which allows ignition gases to escape rearwards, while also pushing the round forward out of the barrel. So this meant that the operators still had to get out of the way when the gun fired if they wished to live long and prosper. First manufactured in 1953 to replace the smaller 57-mm model, it was also mounted on a short-legged tripod (M79) or a pillar mount on a mechanical mule (M92)
DATA
Caliber: 106-mm
Barrel Length: 11 ft, 4 in.
Weight: 266 lbs
Armor penetration: 2 in at 1,100 yds.
Rate of fire: 7-8 rounds per minute
Max range: 4.3 miles
Max effective range: 750-1,000 yds.
Traverse on carriage: 360 degrees
This was from this site:
http://www.tpub.com/content/explosives/ ... 34P_10.htm