To thread or not to thread?

iraiam · January 25, 2013, 11:53 PM

I finally have all my parts either on hand or on the way for my Colt Match Target HBAR rifle that I have owned since 1995, I'm upgrading the stock upper assembly to the following.

New flat top A2 upper
Mil Spec carry handle
New F stamped FSB with Bayonet lug

I am considering threading the barrel for an A2 flash hider, I figure I might as well if it has a bayonet lug.

what do you think?

I found a new love for this rifle since I started shooting the Hornaday Superformance 5.56 match ammo out of it.

SVO · January 26, 2013, 11:19 AM

If you still have the stock trigger, I'd say put the money toward up-grading it rather than threading the barrel. I'm sure it has some purpose, but I'm not sure what benefit one gets with a flash suppressor, other than protecting the crown of the muzzle.

wyop · January 27, 2013, 02:35 PM

With a proper crown job, there's no need for a flash hider to protect the crown that affects accuracy (ie, where the bullet exits the muzzle). Put a 11 degree crown on the barrel and, as SVO suggests, invest your money into a good trigger.

AR15barrels · February 6, 2013, 03:26 PM

Threading the barrel is easy, but swapping front sight bases is more involved.
Is your new front sight base un-drilled?
That makes it easier.

The issue is that there is no standard location for the pin holes.
When a barrel is made, they pin the fsb on to it while it is all fixtured up.
Then they never take it apart again.

I specialize in AR work and can do everything you are looking for, but I would not take a front sight base swap to most gunsmiths as they will not have a specific fixture to ensure that the job is done right...

iraiam · February 7, 2013, 03:07 AM

Yes, I have a setup similar to the one pictured, my mill is smaller but I can and have changed an FSB that was un-drilled and used the existing taper pin grooves on the barrel.

I won't have to take any of this work to a gunsmith, as I have all the necessary machine and tooling at home, at least everything I need except time that is.

AR15barrels · February 7, 2013, 03:17 AM

Quote:

Originally Posted by iraiam

I have all the necessary machine and tooling at home, at least everything I need except time that is.

When you reach the point where you are threading 50 barrels a week, you will get it down to about 5 minutes per barrel...

iraiam · March 7, 2013, 11:51 PM

Well, progress anyway. It is pretty much complete but I still have not received my free float A2 fore end kit.

I went ahead and crowned it, threaded it for the flash suppressor and drilled and reamed the new "F" FSB in place, I indexed the flash suppressor so a crush washer is not needed.

I also got rid of one of the annoyances of this rifle, the barrel was HEAVY, it is still a heavy target barrel, but I re-profiled it to something a little more tolerable.

while I was reaming the forward pin hole on the FSB, I noticed that the hole was not quite 90 degrees. At first I thought I made a mistake when I drilled it, but when I finished, the original groove in the barrel was still perfect. I checked the old FSB and found the same crooked taper pin hole.

I have been told that a crush washer behind the flash supressor is absolutely necessary to keep it from coming loose, is there any truth to this? it's very tight and indexed perfectly.

**4V50 Gary** · March 8, 2013, 10:04 AM

I just threaded two AR barrels last week. They had to be turned down to .499" and then threaded to 1 in 28 thread. I had to set back the flash hiders to time them.

As for the crush washer, if it's done properly (that is the flash hider will tighten down with the solid part at 6 o'clock, it's not really needed. Crush washers were designed for armorers who don't have machine skills. Gunsmiths can either cut the right # of threads or adjust the flash hider such that one is not needed.

BTW, I used crush washers because that's the way ARs are supposed to look.

tobnpr · March 8, 2013, 10:27 AM

What type flash hider needs to be timed? All I've seen (including the two I've installed- and the one in the pic above) do not require timing like a brake does.

I guess if you want to set the ports at 90 degrees, but none of that affects performance.

iraiam · March 8, 2013, 10:32 AM

not timed, just indexed so the ports are 90 degrees, might as well be done right.

AR15barrels · March 8, 2013, 09:57 PM

Quote:

Originally Posted by tobnpr

What type flash hider needs to be timed? All I've seen (including the two I've installed- and the one in the pic above) do not require timing like a brake does.

I guess if you want to set the ports at 90 degrees, but none of that affects performance.

An A2 comes to mind.
And pretty much every other one that does not have balanced numbers of ports.
Sometimes you time a flash hider just to get the logo up on top or the wrench flats on the side.
Believe it or not, there are some customers that are into the cosmetics of the gun even more than the function.
They love to post their pictures on forums...

iraiam · March 16, 2013, 02:39 PM

OK, now I'm getting somewhere, I installed the free float forend kit, I'm glad I re-profiled the barrel, it would have been insanely heavy with the bullish barrel under the fore end and the free float tube on it.

a better scope may be in order sometime, but this has been a good one. I cant see even a ghost of the front sight through the scope. I need some range time now.

January 25, 2013, 11:53 PM	#1
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 401	To thread or not to thread? I finally have all my parts either on hand or on the way for my Colt Match Target HBAR rifle that I have owned since 1995, I'm upgrading the stock upper assembly to the following. New flat top A2 upper Mil Spec carry handle New F stamped FSB with Bayonet lug I am considering threading the barrel for an A2 flash hider, I figure I might as well if it has a bayonet lug. what do you think? I found a new love for this rifle since I started shooting the Hornaday Superformance 5.56 match ammo out of it. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason

February 6, 2013, 03:26 PM	#4
AR15barrels Member Join Date: August 23, 2006 Location: Los Angeles, CA Posts: 53	Threading the barrel is easy, but swapping front sight bases is more involved. Is your new front sight base un-drilled? That makes it easier. The issue is that there is no standard location for the pin holes. When a barrel is made, they pin the fsb on to it while it is all fixtured up. Then they never take it apart again. I specialize in AR work and can do everything you are looking for, but I would not take a front sight base swap to most gunsmiths as they will not have a specific fixture to ensure that the job is done right... Last edited by AR15barrels; February 7, 2013 at 03:15 AM.

February 7, 2013, 03:07 AM	#5
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 401	Yes, I have a setup similar to the one pictured, my mill is smaller but I can and have changed an FSB that was un-drilled and used the existing taper pin grooves on the barrel. I won't have to take any of this work to a gunsmith, as I have all the necessary machine and tooling at home, at least everything I need except time that is. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason

March 7, 2013, 11:51 PM	#7
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 401	Well, progress anyway. It is pretty much complete but I still have not received my free float A2 fore end kit. I went ahead and crowned it, threaded it for the flash suppressor and drilled and reamed the new "F" FSB in place, I indexed the flash suppressor so a crush washer is not needed. I also got rid of one of the annoyances of this rifle, the barrel was HEAVY, it is still a heavy target barrel, but I re-profiled it to something a little more tolerable. while I was reaming the forward pin hole on the FSB, I noticed that the hole was not quite 90 degrees. At first I thought I made a mistake when I drilled it, but when I finished, the original groove in the barrel was still perfect. I checked the old FSB and found the same crooked taper pin hole. I have been told that a crush washer behind the flash supressor is absolutely necessary to keep it from coming loose, is there any truth to this? it's very tight and indexed perfectly. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason Last edited by iraiam; March 7, 2013 at 11:56 PM.

March 8, 2013, 10:04 AM	#8
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 15,551	I just threaded two AR barrels last week. They had to be turned down to .499" and then threaded to 1 in 28 thread. I had to set back the flash hiders to time them. As for the crush washer, if it's done properly (that is the flash hider will tighten down with the solid part at 6 o'clock, it's not really needed. Crush washers were designed for armorers who don't have machine skills. Gunsmiths can either cut the right # of threads or adjust the flash hider such that one is not needed. BTW, I used crush washers because that's the way ARs are supposed to look. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

January 26, 2013, 11:19 AM	#2
SVO Senior Member Join Date: December 21, 2009 Location: Texas Gulf Coast Posts: 587	If you still have the stock trigger, I'd say put the money toward up-grading it rather than threading the barrel. I'm sure it has some purpose, but I'm not sure what benefit one gets with a flash suppressor, other than protecting the crown of the muzzle.

January 27, 2013, 02:35 PM	#3
wyop Senior Member Join Date: July 15, 2012 Location: Wonderful, Windy Wyoming Posts: 132	With a proper crown job, there's no need for a flash hider to protect the crown that affects accuracy (ie, where the bullet exits the muzzle). Put a 11 degree crown on the barrel and, as SVO suggests, invest your money into a good trigger.

March 8, 2013, 10:27 AM	#9
tobnpr Senior Member Join Date: August 1, 2010 Location: Tampa Bay Posts: 2,260	What type flash hider needs to be timed? All I've seen (including the two I've installed- and the one in the pic above) do not require timing like a brake does. I guess if you want to set the ports at 90 degrees, but none of that affects performance. __________________ Custom Gunstocks for the Mosin-Nagant and Stock Duplication www.biggorillagunworks.com

March 8, 2013, 10:32 AM	#10
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 401	not timed, just indexed so the ports are 90 degrees, might as well be done right. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason

March 16, 2013, 02:39 PM	#12
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 401	OK, now I'm getting somewhere, I installed the free float forend kit, I'm glad I re-profiled the barrel, it would have been insanely heavy with the bullish barrel under the fore end and the free float tube on it. a better scope may be in order sometime, but this has been a good one. I cant see even a ghost of the front sight through the scope. I need some range time now. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason Last edited by iraiam; March 16, 2013 at 02:47 PM.