Dropped the hammer on the separated DDM4 lower, damage?

**ta0117** · 02-15-21, 01:26

I replaced the stock trigger on my DDM4V9 with a Geissele SSA trigger and since I didn’t know any better, when testing it out I was dropping the hammer with the lower separated a handful of times (maybe about 7-8 times?). Now I read the Daniel Defense manual that the hammer should never be dropped with the lower separated from the upper since the hammer can permanently damage the lower.

Doing some quick research, some are saying that the hammer can crack the lower or the bolt catch. The Geissele hammer is shaped so it doesn’t seem to touch the bolt catch and only hits the lower. Looking at the lower I don’t see any damage on the surface, but I’m worried if I caused microcracks to form in the lower and what that means in the long term for this gun.

Is there any way for me to detect potential cracks under the Cerakote finish?

**PracticalRifleman** · 02-15-21, 05:46

If you see a crack there’s a crack. If you don’t, there’s not.

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**georgeib** · 02-15-21, 08:09

Agreed with the above response. You're probably ok. Don't sweat it, and try to avoid it in the future.

**Inkslinger** · 02-15-21, 08:38

I wouldn’t worry about it to much, it’s probably fine.

**PracticalRifleman** · 02-15-21, 08:39

Originally Posted by Inkslinger

Magnetic particle inspection. I would worry about it to much, it’s probably fine.

Not sure MPI works on non-ferrous materials. Maybe I’m wrong?

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**Inkslinger** · 02-15-21, 08:41

Originally Posted by PracticalRifleman

Not sure MPI works on non-ferrous materials. Maybe I’m wrong?

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It doesn’t, I was being sarcastic. I deleted it as to not have the trolls lose their minds.

**AndyLate** · 02-15-21, 09:29

Originally Posted by PracticalRifleman

If you see a crack there’s a crack. If you don’t, there’s not.

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This. Don't make a habit of it.

Andy

**ta0117** · 02-15-21, 10:49

Now I ride the hammer forward with my thumb, but these the kind of quirks that first time AR owners aren’t familiar with.

There doesn’t seem to be damage so that is reassuring. I do plan on this rifle lasting me a long time, which is why I’m concerned about the long term health.