Why do some disconnectors have the rear fin and some do not? Is the fin part of the full-auto FCG design that doesn't get used in a semi-auto? I have a FCG with a disconnector that doesn't have the back fin but it works just the same.

your picture sucks


here's a picture stating whats what from bushmaster.com

Yes that's correct, the tail that's missing on your semi-auto disconnector is deliberately removed so its no longer considered a machine gun part... The function of the tail is to be under the full-auto selector so when the selector is switched to full-auto mode, it holds the tail down which in turn prevents the disconnector from catching the hook on the rear of the hammer...

just noticed that the whole rear half is missing behind the hook.


what parts kit did it come from or did someone do that themselves? i have never gotten one like that.

Quoted: just noticed that the whole rear half is missing behind the hook. what parts kit did it come from or did someone do that themselves? i have never gotten one like that.

Yeah me neither, you'd think the spring would squeeze out from under it from no support to the back side...

Quoted: Quoted: just noticed that the whole rear half is missing behind the hook. what parts kit did it come from or did someone do that themselves? i have never gotten one like that. Yeah me neither, you'd think the spring would squeeze out from under it from no support to the back side...

doubt the slot in which the spring sits in would allow it but it is a possibilty.

Quoted: Quoted: Quoted: just noticed that the whole rear half is missing behind the hook. what parts kit did it come from or did someone do that themselves? i have never gotten one like that. Yeah me neither, you'd think the spring would squeeze out from under it from no support to the back side... doubt the slot in which the spring sits in would allow it but it is a possibilty.

I agree, but you never know... Kind of like using a standard rifle barrel extension with a upper receiver that has extended ramp cuts... Might work OK know but eventually it could cause a problem...

Quoted: Quoted: Quoted: Quoted: just noticed that the whole rear half is missing behind the hook. what parts kit did it come from or did someone do that themselves? i have never gotten one like that. Yeah me neither, you'd think the spring would squeeze out from under it from no support to the back side... doubt the slot in which the spring sits in would allow it but it is a possibilty. I agree, but you never know... Kind of like using a standard rifle barrel extension with a upper receiver that has extended ramp cuts... Might work OK know but eventually it could cause a problem...

true.

Old Colt semi disconnector. The trigger will two recesses for the disconnector spring one will be further forward near the trigger pin.

Quoted: just noticed that the whole rear half is missing behind the hook. what parts kit did it come from or did someone do that themselves? i have never gotten one like that.

My circa '78 Colt SP1 rifle came with that "short" disconnector.  I noticed it when pulling the FCG to install a RRA 2-stage trigger.  IIRC the rear of the trigger was also cut away, implying a "long tailed"(i.e. M16) disconnector would also fit.

Paladin

Thanks for the replies, gentlemen.

Quoted: Old Colt semi disconnector. The trigger will two recesses for the disconnector spring one will be further forward near the trigger pin.

The disconnector is marked with a C, so it must be Colt. The trigger is grey and has the two recesses. This disconnector spring sits in the one closest to the trigger pin and I assume the other recess is for a normal disconnector.  The only other markings are on the hammer which looks to be a circled 7 or L and another circle within a circle but it could be a C in a circle with blurred lines. The disconnector works fine without the tail.  This is actually the nicest trigger I have compared to CMT and Bushmaster FCGs. Very smooth and crisp, no grit.

Next question: Why do semi disconnectors have shorter tails than auto disconnectors?  Do they mill off just enough so it can't be used with a full auto selector? If so, why have the tail at all? So you can use regular triggers with the normal recess location or just for support?  Thanks again.

Quoted: Next question: Why do semi disconnectors have shorter tails than auto disconnectors?  Do they mill off just enough so it can't be used with a full auto selector? If so, why have the tail at all? So you can use regular triggers with the normal recess location or just for support?  Thanks again.

That question was already answered...

Quoted: Yes that's correct, the tail that's missing on your semi-auto disconnector is deliberately removed so its no longer considered a machine gun part... The function of the tail is to be under the full-auto selector so when the selector is switched to full-auto mode, it holds the tail down which in turn prevents the disconnector from catching the hook on the rear of the hammer...