Want to install a Timney 667-s 3lb trigger in my sport,don't know if the small pin trigger is right for my rifle.Has anyone here made the change?if so what is the difference between large and small pin designation.

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Retired Plumber

That will be a nice looking set up.....the Timney should just drop right in, not sure exactly what your issue is?

Small pin is what you need.

The issue he's having is in RED.

The difference in large v.s. small pins is because of the 1986 Firarms Owners Protection act that banned the sale of full-auto firearms to civilians and how Colt dealt with it. Colt purposefully used larger diameter pins in their consumer AR-15's. It makd the Colt consumer lower out of mil-spec, hence incompatible with military and LE full auto parts. Colt confused things further by making some of their consumer AR's small pin or large pin.

99.9% of the time if you're not using a Colt lower, you are most likely using small diameter pins.

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-John

^^^this......so again, I'm not sure exactly what the issue is? Your trigger in question is a direct drop in, and takes 5 minutes to install.

The OP's original post again:

A trigger will drop in, just as long as you buy the correct trigger with the appropriate diameter size trigger & hammer pins. The OP asked if the small pin would work. Timney sells both large pin and small pin variant triggers. I comprehended the OP's question to be of two parts. Which pin size should I select, and why are there two pin sizes to begin with. I answered both questions, not just one.

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-John

Thanks JaPes, for your very informative response to the original poster's question. I too, had wondered what the difference was between the small and large pin lowers on AR-15's but was afraid to ask myself and advertise my ignorance.

Don't be afraid to ask a question here. You aren't "advertising your ignorance" by asking a question and trying to find out info.

Asking questions is the only way to learn.



That's just my 2¢. Opinions differ.

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-John

I tend to learn by making mistakes...LOL

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Grover Oathkeeper

OMG. Oneyeopn has returned!

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-John

Glad to see that members name.

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NRA member since 1974