AR-15 sear block

[Deserthunter]

I'm having the sear block removed from my pre-ban 7.62 x 39 , 1990s Colt AR-15 so I can install a new upper with an automatic bolt, which will not work in an AR with sear block. My Colt also has the larger diameter, 0.169-inch, hammer and trigger pins.My question is whether I am good to go with my current trigger group or do I need to do anything with it to accommodate a new upper. I know removing the sear block allows the opportunity to install a more precision trigger that uses the larger l diameter pins, but can I simply keep the trigger setup I have without issues regarding a new upper. I want a new upper so I can get rid of the fixed carry handle and have a more modular rifle

 

[MistWolf]

Instead of machining the old lower and fighting with the odd sized trigger & hammer pins, I'd simply get a new lower to go with your new upper.

In fact, I suggest taking a look at the set upper & lower set from PSA that uses AK mags

 

[Jackal]

Just use an AR15 style bolt carrier. You gain literally zero performance with the M16 carrier.

 

[wally]

Just use an AR15 style bolt carrier. You gain literally zero performance with the M16 carrier.

Or nothing you can't equal by swapping in a heavier buffer.

I'm regularly seeing stripped lowers on sale for $40-60, so I'd suggest a new lower to go with your new upper. I'll second the suggestion to look at the PSA kit that uses AK mags, unless maximum economy and/or the reuse of your existing mags is important.

Also I'd suggest not buggering up any Colt logo gun, there are a lot of Colt collectors that pay prices that seem unreasonable to me.

 

[1911 guy]

What they said. By the time you pay for machine time and anodizing, you've got the price of another stripped lower. Buy the lower now, put the Colt in drawer for later.

 

[MachIVshooter]

Instead of machining the old lower and fighting with the odd sized trigger & hammer pins, I'd simply get a new lower to go with your new upper.

In fact, I suggest taking a look at the set upper & lower set from PSA that uses AK mags

+1

I might mess with modifying an oddball lower, but all it costs me is a few minutes on my mill. Paying someone to do it when you can buy a new lower for well under $100? No way, especially when some pony fanboy would likely pay you better than twice that for your goofy thing.

 

[Zach S]

I'd have to agree with the above posts. Even though I have access to a bridgeport mill at work and can do the machining myself, I think I'd just buy another lower and be done with it.

No lost lunchbreaks, standard FCG pins, does your rifle have the large or milspec pivot pin?

Removing the sear block might actually reduce the value of the rifle. Not being a Colt diehard fan myself, I can't say for sure, but the original box is a big deal for some folks, I'd assume that a permanent alteration would be as well.