[Gunner]

Hi Tony:

I'm still sure its an M1. Commonwealth 6 pounders didn't have the shield flap clamps and didn't have the "firing segments" which was an American idea to reduce bounce on recoil. The segments (really visible on the US 37mm ATk gun) were steel arcs that rotated on the axle. When in action, the segments were rotated down and the gun pulled onto them so the tyres just barely touched the ground... no rubber, no bounce.

A couple of other features to look for:

The device for pulling the gun onto a portee is a clevis as opposed to the Commonwealth lunette (towing eye located in the centre of the lower round shield part);

The hole for the sight is square whereas the Commonwealth version is shaped like an upside down teardrop;

One of the US style segments is very visible in Juan's second photo and both show in the third photo; and

The US style trail clamping mechanism to hold the two trails together for towing was copied from the 105mm M101 (photo 3); and

The towing arrangement uses the much more efficient US style drop down lunette, again copied from the 105mm M101 (photo 3, again). The US drop down lunette raised the spades higher off the ground so that they didn't catch on small crests and it allowed for towing by a wide range of vehicles as it allowed for more swing between the gun and the tractor.

If there's one thing that our 'Mercan brothers are good at its taking a good idea and making it better. The M1 had more ground clearance and used a common truck tyre and rim as opposed to the Commonwealth orphan size (not used on anything else), it had a more efficient trail clamp, better towing mechanism and was simplified for production to remove alot of steps to save both time and strategic materials. The only drawback to the M1 (in my opinion) is that they never adopted the longer barrel with the muzzle brake. I'm not totally convinced about the usefulness of the segments, either.

I agree that it would help to see a side on photo... Juan, do you have any side shots?

Cheers! Mike