blocked lower receiver

steventNC · 08-18-2004, 02:45 PM

What year did Colt start with the "block" in the lower receiver to prevent someone from putting the full auto stuff in the SP 1's?

bren10man · 08-18-2004, 03:30 PM

I think about 1992 or 1993.

I have a May 1994-purchased Colt Lightweight Sporter (with 2 additional uppers)..it has the block, no bayolug, and has the raised area around the mag catch, and flash hider.

I have a 1992-purchased (collateral on a loan to a friend of mine) Colt Delta HBAR. It has no block, no bayolug, and has the raised area around the mag catch (unlike green-label guns), and flash hider.

mjmensale · 08-19-2004, 11:13 AM

Colt started using the block in 1992 when they introduced the Blue Label series of guns.

I don't believe SP1s ever came with a block, which is why they are sought after by guys with RDIAS's.

Moe

hucares · 08-19-2004, 05:43 PM

Can someone show a pic of a blocked and unblocked receiver?

bren10man · 08-19-2004, 06:19 PM

The Delta HBAR that I have is blue label (I have the aluminum hard case and it has the blue label sticker on it) and it has no block.

Delta's were the cream of the crop AR15's until Colt brought out the Competition HBAR in 1992.

You do have a "transition model" that collectors call the white and blue label guns (post green label/1989-90) that have no block. My "collateral" Delta HBAR fits that mold perfectly.

BTW, the Delta does not have the Delta logos on the grips (like the green label Deltas or the 10mm Delta Elite pistols). But, it is still a Delta, as the blue label is marked Delta HBAR.

[img]

[/img]

Here is a pic of the different blue label Colt lowers (Pre 13 SEP 94)
Top is a Colt Delta HBAR Model 6601DH, purchased new in 1992.
Bottom is a Colt Sporter Lightweight model 6530, purchased new in 1994.

As you can see, the 1992 gun has no block (area to the left of the red Accuwedge). The 1994 gun as a block, and marked Colt (area to the left of the red Accuwedge).

steventNC · 08-21-2004, 06:09 AM

ok, I am a dummy,what does RDIAS,s stand for?

steventNC · 08-21-2004, 06:35 AM

Sorry that I didn't mention it but those are some good and clear pictures.

bren10man · 08-21-2004, 10:57 AM

Don't thank me, thank my wife for taking them.

She gets one of my 2 pre-ordered Colt M4's next month (provided the ban dies a painful and sudden death).

carguym14 · 08-21-2004, 05:59 PM

Quote:

Originally Posted by steventNC

ok, I am a dummy,what does RDIAS,s stand for?

Registered
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carguym14 · 08-21-2004, 06:00 PM

And your'e not a dummy!

mjmensale · 08-22-2004, 09:14 AM

Those Colt blocks can be removed BTW.

Not because you have plans on an illegal conversion but because there is no law requiring them in the first place.

There are three variations of securing the block in place and the ease of removal (and cost to do so) is dependant on the version. The simplest is the single blind pin on the right side receiver.

You can remove them yourself with the right tools and a steady hand or have a smith do it. I had the one on my Sporter Target removed by Kurt's Kustom Firearms.

Moe

fubar · 08-22-2004, 09:44 AM

yes you can remove the block. http://www-2.cs.cmu.edu/afs/cs/user/...f_letter30.txt

make sure that the hole on the side of the receiver emains plugged. it's in the same location as the M16 autosear hole.

bren10man · 08-22-2004, 11:15 AM

Does anybody have detailed instructions on how to do it? I hate that thing, it is in the way.

I don't want to tear-up my lower.

Paladin · 08-22-2004, 11:51 AM

I would be concerned about weakening the lower during the removal of the block.

My postban Comp.MT HBAR has a block, and the only effect I see is preventing the use of an M16 carrier assembly. Some aftermarket triggers also won't fit. But JP makes one that does, and it's still a sweet 3#'s after many rounds of use.

The block does NOT belong there, and it is kind of annoying...but removing it may not be worth the trouble, especially if having to weld up the holes, grind it flat, and refinishing the lower is required. May as well leave the Colt lower alone, and buy a new aftermarket one.

Paladin

mjmensale · 08-22-2004, 06:43 PM

Quote:

Originally Posted by bren10man

Does anybody have detailed instructions on how to do it? I hate that thing, it is in the way...I don't want to tear-up my lower.

1 - Package up your lower receiver and send it here -

http://www.kurtskustomfirearms.citym.../page/8932.htm

2 - Wait

3 - Get back de-blocked lower and enjoy.

The lower doesn't get weakened and doesn't require refinishing. Kurt will either leave the cut-off pin(s) in place or replace it with a black delrin plug.

The block is made of hardened steel and attached in one of three ways. Hard to tell which way it's installed until you start working on it.

I've heard of guys on ar15.com claim they removed them using a Dremel tool. Well, I watched Kurt remove mine and he wasn't using no Dremel tool. It's not an operation for hand tools! Kurt drills out the pins. He doesn't grind away the block itself, which is what the Dremel guys are saying they're doing.

Hardened steel next to aluminum. Slip up and guess which one gets damaged?

Moe

fubar · 08-22-2004, 09:17 PM

you wont weaken the lower by removing it.

so many people are removing the blocks, i figure i'll leave it in my colt and it'll be worth more. i took the easy way out and bought another receiver that doesn't have the block.

08-18-2004, 02:45 PM	#1
steventNC Senior Member Join Date: May 2004 Posts: 217	block in lower receiver question What year did Colt start with the "block" in the lower receiver to prevent someone from putting the full auto stuff in the SP 1's?

08-19-2004, 06:19 PM	#5
bren10man Join Date: Feb 2004 Posts: 2,245	The Delta HBAR that I have is blue label (I have the aluminum hard case and it has the blue label sticker on it) and it has no block. Delta's were the cream of the crop AR15's until Colt brought out the Competition HBAR in 1992. You do have a "transition model" that collectors call the white and blue label guns (post green label/1989-90) that have no block. My "collateral" Delta HBAR fits that mold perfectly. BTW, the Delta does not have the Delta logos on the grips (like the green label Deltas or the 10mm Delta Elite pistols). But, it is still a Delta, as the blue label is marked Delta HBAR. [img][/img] Here is a pic of the different blue label Colt lowers (Pre 13 SEP 94) Top is a Colt Delta HBAR Model 6601DH, purchased new in 1992. Bottom is a Colt Sporter Lightweight model 6530, purchased new in 1994. As you can see, the 1992 gun has no block (area to the left of the red Accuwedge). The 1994 gun as a block, and marked Colt (area to the left of the red Accuwedge).

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08-18-2004, 03:30 PM	#2
bren10man Join Date: Feb 2004 Posts: 2,245	I think about 1992 or 1993. I have a May 1994-purchased Colt Lightweight Sporter (with 2 additional uppers)..it has the block, no bayolug, and has the raised area around the mag catch, and flash hider. I have a 1992-purchased (collateral on a loan to a friend of mine) Colt Delta HBAR. It has no block, no bayolug, and has the raised area around the mag catch (unlike green-label guns), and flash hider.

08-19-2004, 11:13 AM	#3
mjmensale Join Date: Oct 2004 Posts: 3,092	Colt started using the block in 1992 when they introduced the Blue Label series of guns. I don't believe SP1s ever came with a block, which is why they are sought after by guys with RDIAS's. Moe

08-19-2004, 05:43 PM	#4
hucares Join Date: Jun 2002 Posts: 412	Can someone show a pic of a blocked and unblocked receiver?

08-21-2004, 06:09 AM	#6
steventNC Senior Member Join Date: May 2004 Posts: 217	ok, I am a dummy,what does RDIAS,s stand for?

08-21-2004, 06:35 AM	#7
steventNC Senior Member Join Date: May 2004 Posts: 217	Sorry that I didn't mention it but those are some good and clear pictures.

08-21-2004, 10:57 AM	#8
bren10man Join Date: Feb 2004 Posts: 2,245	Don't thank me, thank my wife for taking them. She gets one of my 2 pre-ordered Colt M4's next month (provided the ban dies a painful and sudden death).

08-21-2004, 06:00 PM	#10
carguym14 Join Date: Nov 2003 Posts: 466	And your'e not a dummy!

08-22-2004, 09:14 AM	#11
mjmensale Join Date: Oct 2004 Posts: 3,092	Those Colt blocks can be removed BTW. Not because you have plans on an illegal conversion but because there is no law requiring them in the first place. There are three variations of securing the block in place and the ease of removal (and cost to do so) is dependant on the version. The simplest is the single blind pin on the right side receiver. You can remove them yourself with the right tools and a steady hand or have a smith do it. I had the one on my Sporter Target removed by Kurt's Kustom Firearms. Moe

08-22-2004, 09:44 AM	#12
fubar Join Date: Jul 2002 Posts: 6,010	yes you can remove the block. http://www-2.cs.cmu.edu/afs/cs/user/...f_letter30.txt make sure that the hole on the side of the receiver emains plugged. it's in the same location as the M16 autosear hole.

08-22-2004, 11:15 AM	#13
bren10man Join Date: Feb 2004 Posts: 2,245	Does anybody have detailed instructions on how to do it? I hate that thing, it is in the way. I don't want to tear-up my lower.

08-22-2004, 11:51 AM	#14
Paladin Join Date: Jun 2003 Posts: 401	I would be concerned about weakening the lower during the removal of the block. My postban Comp.MT HBAR has a block, and the only effect I see is preventing the use of an M16 carrier assembly. Some aftermarket triggers also won't fit. But JP makes one that does, and it's still a sweet 3#'s after many rounds of use. The block does NOT belong there, and it is kind of annoying...but removing it may not be worth the trouble, especially if having to weld up the holes, grind it flat, and refinishing the lower is required. May as well leave the Colt lower alone, and buy a new aftermarket one. Paladin

08-22-2004, 09:17 PM	#16
fubar Join Date: Jul 2002 Posts: 6,010	you wont weaken the lower by removing it. so many people are removing the blocks, i figure i'll leave it in my colt and it'll be worth more. i took the easy way out and bought another receiver that doesn't have the block.