To thread or not to thread?

I

iraiam

New member
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.
 
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.
 
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.
 
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...

fsb-installation.jpg
 
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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.
 
Well, progress anyway. It is pretty much complete but I still have not received my free float A2 fore end kit.:mad:

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.


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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.
 
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.
 
tobnpr said:
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.
Click to expand...

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...
 
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.:D

001_zpsecfa3d79.jpg


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Target (ressurected my own thread)

I'm happy with my match rifle now, I had very poor choices for 100 yard targets with me today, but with all the stuff I did to this rifle, it is far more accurate than it was before.

Today I replaced the front sight post with a thinner one (.050") and re-sighted in with the RRA NM carry handle.. I wound up not replacing the original Colt 2 stage trigger, but did some work on it to make it much better, it's still a 2 stage trigger, but I consider it match ready.

I didn't want to shoot too much of my Hornaday 5.56 75gr match ammo as I'm down to about 120 rounds and waiting for the opportunity to buy more of it. It's good stuff!


AR15_08242013_color_zps80fa8df5.jpg
 
Quote "Today I replaced the front sight post with a thinner one (.050") and re-sighted in with the RRA NM carry handle.. I wound up not replacing the original Colt 2 stage trigger, but did some work on it to make it much better, it's still a 2 stage trigger, but I consider it match ready."


You will find out that honing a stock Colt trigger is not the best idea.

After a few 100 rounds the soft metal will make for a mushy trigger
 
Thanks for the tip, I'm not sure if what I did counts as "honing", but I did polish the mating surfaces to a high shine finish, as well as replace the trigger spring with a spare I had on hand one that was not so ridiculously stiff.

I'll keep my eye on it though, It won't be that big of a deal to just slap a new FCG in if needed.
 
Thanks for the tip, I'm not sure if what I did counts as "honing", but I did polish the mating surfaces to a high shine finish, as well as replace the trigger spring with a spare I had on hand one that was not so ridiculously stiff.

I'll keep my eye on it though, It won't be that big of a deal to just slap a new FCG in if needed.

Does take a a lot to cut past the surface case hardening.

My rifle was purchased in 90 and is still stock.
Minus a new FCG
I bought a NM FCG and that is hardened and can be polished/honed
 
Nice to see you made your Colt a non-California piece. It certainly looks better that way. I myself threaded two barrels for those naughty bits that go on the end of the muzzle. :D
 
Nice to see you made your Colt a non-California piece. It certainly looks better that way. I myself threaded two barrels for those naughty bits that go on the end of the muzzle.
Click to expand...

Yes, not being able to legally have an evil muzzle device for a decade made me do it.
 
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