Can anyone ID this hammer? (May need an M&P FCG for the rescue)

[nighttrainnc]

My buddy got an Anderson LPK which was **** from the fitment I saw, and the " J-Pin" (aka J-Spring that locks into the groove in the center of the hammer pin) protruded so much that it made it impossible to insert a hammer pin being it took up 1/4th of the hammer hole, blocking the pin's path.

He took it to his smith and the smith tried to fit it and with no luck, he and gave him another Hammer to use instead.

The replacement he gave him is either a "Low Mass" Hammer, OR a "Cut Down" hammer to resemble a low mass.

I'm not a fan of mixing FCG parts, especially being this one isn't standard, so confused on what to tell him.

Wondering if anyone can ID the 2nd Hammer in the pics? (It lacks the hook at the back of the hammer)

Any potential issues mixing this with an Anderson Trigger/Disconnector?

He asked me to look for an M&P factory trigger for him being he doesn't frequent forums.

Anyone have a spare M&P15 FCG by chance?

IF indeed a low mass type, or cut down to resemble a Low Mass type, any Pros and Cons?

LEFT is the Anderson, RIGHT is the replacement that I'm weary about telling him to use due to Anderson using odd specs on their Disconnector.

Pasteboard - Uploaded Image
Pasteboard - Uploaded Image
Pasteboard - Uploaded Image

 

[bamashooter]

Doesn't matter if it "resembles" or not, low mass is low mass. They're very common and widely used. A low mass hammer lets you use a lighter hammer spring which in turn gives you a lower weight trigger pull. Also supposed to give you more reliable ignition of primers vs. a lighter hammer spring on a standard (heavy) hammer.

 

[nighttrainnc]

Doesn't matter if it "resembles" or not, low mass is low mass. They're very common and widely used. A low mass hammer lets you use a lighter hammer spring which in turn gives you a lower weight trigger pull. Also supposed to give you more reliable ignition of primers vs. a lighter hammer spring on a standard (heavy) hammer.

Ok,.thanks for the update, that's the best response I've gotten anywhere.

I believe it has a normal spring (same color as any others in an LPK, brassy) but when using your thumb as the stop for it, it definitely seems to have more forward power.

If used with a normal spring, any Cons? (Pierced Primers, etc?)