I'm thinking of getting a Timney trigger for my M&P Sport. As I look at them I see a small pin or large pin, 3 lb or 4lb. I shoot my sport primarily for target shooting, plinking, that sort of thing, maybe a ground hog if opportunity arises.
Which should I get? What is the large/small pin thing about? For my kind of shooting, 3 or 4 lb? Thanks for your input.

Small pin.

Large pins were on some Colts so you couldn't use full auto parts in them.

Small pin is what everyone else who makes them uses.

3lb.

__________________
Straight shootin'
SWCA#2439

OK, thank you

Large Pins were used on "named" Colts primilarily those mfg during '80s and '90s ( is those marked "Sporter" and "Sporter Target" vs a Mdl number).

Wanting to cover themselves during the first round of Evil Black Rifle hysteria, Colt made various changes in the rifles sold to the general public to distinguish them from the nasty evil rifles sold to mil and LE . The primary changes : Large trigger pin ( to not accept full auto fire controls. Redesigned bolt carrier, with open bottom side ( to not be compatable with full auto). Large size front takedown pin ( to not accept evil upper assemblies, however the aftermarket introduced adapter pins in both direction about 10min later).

At the time one of the main anti gun memes was " easily converted to full auto" , and Colt wanted to differentiate their products from the other AR-15s. The Numbered Rifles with origonal dimentions were at the time by company policy only sold through their LE distributors, while the Sportsters were sold thru the usual distributors and dealer network.

After things settled down after the passage of the '94 AWB, and their modifications proved moot, Colt quietly made no objections as the numbered rifles increasingly gravitated into normal retail sales.

At the time there was grumbling about Colt selling inferior nutered rifles to the public. I won't address the political aspects here, but the Sportsters were well made high quality rifles. My 1994 Sportster 20in A2 will shoot 1.0 moa with the iron sights.

Interesting. Thanks for the info.

The way I understand it is Colt for years was able to renew the patent on the M16/AR-15 design.

There were a number of other companies, such as DPMS, Bushmaster, Aramalite etc, who also sold "AR-15s" back in the day but to be able to do so without being sued they had to change certain key dimensions.

They were the hammer/trigger pins, buffer tube, and upper/lower receiver pins.

Colt's were "mil-spec" and the other makes were commercial spec. Now as time went on about 2006 or so Colt was unable to renew the patent and all of the makes that were subcontracts decided to market their own guns, such as LMT, Bravo Company, LWCS etc.

So most guns nowadays are all "mil-spec" size pins and buffer tube. I have an old Bushmaster and bought it because I knew if I bought a Colt I'd be limited on parts and accesarries.