Colt History Questions

**Doc Safari** · 02-21-19, 15:37

This is just out of curiosity.

I owned some Colt Sporters in the 1990's then took about a ten-year break before owning another Colt AR.

1. What year did Colt discontinue the "double screw" front takedown pin (or variations thereof), and go to the standard, proper one?

2. What year did Colt start installing the proper M16 bolt carriers in their AR's and not SP1 carriers with unshrouded firing pins and cut down rear shrouds?

3. I'm assuming that all modern Colts have the proper M16 bolt carrier and there isn't some oddball 5.56 model still being produced with nonstandard bolt carriers?

4. What year did Colt start using standard sized FCG pins?

5. What year did Colt stop installing a separate auto sear block and went to simply not machining out the "web" in the lower receiver where the auto sear would have gone?

6. Are there any parts still in a Colt AR that are there to make it a legal semi-auto, but might cause some sort of reliability problem due to it not being the actual military part?

Thanks in advance for the answers.

**26 Inf** · 02-21-19, 23:09

You should be able to figure it out by googling the models listed here: https://en.wikipedia.org/wiki/List_o...rifle_variants

or here: http://www.biggerhammer.net/ar15/variants/ Get busy youngish man!

maybe your best bet, got to go behind enemy lines, though: https://www.ar15.com/forums/ar-15/-/123-304266/?

Also, you would probably enjoy the Vickers Guides.

Good luck!

**everready73** · 02-22-19, 07:38

If you check out Chris Bartocci youtube he has a few videos on Colt and their history. Not sure all the answers would be in the vids, but they have pretty good info

**jsbhike** · 02-22-19, 08:11

Assuming the full auto bolt carrier was after this letter.

http://www.calguns.net/calgunforum/a.../t-328749.html

**Doc Safari** · 02-22-19, 08:53

Originally Posted by everready73

If you check out Chris Bartocci youtube he has a few videos on Colt and their history. Not sure all the answers would be in the vids, but they have pretty good info

He does have some very informative videos. I've only been able to watch a few unfortunately.

**Doc Safari** · 02-22-19, 08:55

Originally Posted by jsbhike

Assuming the full auto bolt carrier was after this letter.

http://www.calguns.net/calgunforum/a.../t-328749.html

That letter is a farce of ambiguity. Leave it to the dot-guv to say nothing while appearing to say something.

**jsbhike** · 02-22-19, 09:13

If there is a way to determine when the who does what to milspec vs. who doesn't list started floating around I think the changes were slightly before that. I think the changes may have been after losing some government contracts to FN also.

**scottryan** · 02-22-19, 15:31

1. What year did Colt discontinue the "double screw" front takedown pin (or variations thereof), and go to the standard, proper one?

About 1999 but some lowers were drilled for a pushpin before that.

2. What year did Colt start installing the proper M16 bolt carriers in their AR's and not SP1 carriers with unshrouded firing pins and cut down rear shrouds?

Around 2007

3. I'm assuming that all modern Colts have the proper M16 bolt carrier and there isn't some oddball 5.56 model still being produced with nonstandard bolt carriers?

All of them should have a regular M16 carrier

4. What year did Colt start using standard sized FCG pins?

About 2009

5. What year did Colt stop installing a separate auto sear block and went to simply not machining out the "web" in the lower receiver where the auto sear would have gone?

About 1998

6. Are there any parts still in a Colt AR that are there to make it a legal semi-auto, but might cause some sort of reliability problem due to it not being the actual military part?

A notched semi auto type 2 hammer intended to be used with an exposed firing pin semi carrier. Colt still puts this crap in the lower. It can be replaced with a type 1 semi auto hammer from Specialized Armament.

**Doc Safari** · 02-22-19, 15:39

Originally Posted by ME

. What year did Colt start using standard sized FCG pins?

Originally Posted by scottryan

About 2009

I bought a "restricted marked" 6520 last fall that was purchased for the PA State Police (I have provenance). Colt says it was made in 2009. Being purchased by a law enforcement agency, do you think it has standard sized pins being that it was a dedicated law enforcement firearm?

A notched semi auto type 2 hammer intended to be used with an exposed firing pin semi carrier. Colt still puts this crap in the lower. It can be replaced with a type 1 semi auto hammer from Specialized Armament.

Are you saying my LE6920 bought last fall probably has this hammer?

What problems might it cause?

(I know there are other sources on the net, but for convenience if you have pics and would like to post them, I think the readers would appreciate it).

**scottryan** · 02-22-19, 15:50

I bought a "restricted marked" 6520 last fall that was purchased for the PA State Police (I have provenance). Colt says it was made in 2009. Being purchased by a law enforcement agency, do you think it has standard sized pins being that it was a dedicated law enforcement firearm?

Is this one of the Canadian marked 6520s? If so, it is probably large pin.

Are you saying my LE6920 bought last fall probably has this hammer?

Yes

See this link

http://www.specializedarmament.com/%...emi-auto-only/

What problems might it cause?

Does not allow the bottom of the carrier to slide smoothly over the hammer.