View Full Version : I messed up a Colt 14.5" barrel while drilling it for an extended FH
I need help and sage advice. Last night I decided to assemble two 14.5" uppers I had in the safe, one a Colt and the other an FN (no marks on it I can see other than NATO 1x9). Anyway I decided to do the Colt first and as I was drilling the pin hole in the threads for the extended A2 FH pin I must have dozed off because I drilled straight through the barrel and chrome lining into the bore. Have I ruined this barrel? Is it worth/safe to shoot? Is the accuracy potential for this barrel gone? Is there any way to salvage it without having it cut down to a shorter length?
I don't have the answer to that--perhaps call a gunsmith and ask?
If I'm wrong someone wil be along to correct me.
You have a hole in the barrel already, the gas port.
I think the big concern will be not to seat the pin so deep that it protrudes into the bore. There is where the problem lies.
Once the pin is in place and welded, there shouldn't be any gas leak problems.
The next thing is to make sure to get the burrs, from the drilling, out.
When I made a barrel a number of years ago, after drilling the gas port, I scrubbed the bore with a couple new bronze brushes. After say 10 strokes, I ran a patch throught the barrel slowly, soft side facing out. I then looked down the barrel to see if there was any material hanging up, if there was, I would repeat the process until the patch no longer caught on any burrs.
This worked for me.
As far as the integrity of the chrome lining, I don't have an answer for you, the barrel I did was chrome molly.
Again, if I am totally out of my lane, someone will be along to correct me.
IF no one here has a striaght answer, I would call colt and see what they have to say and then take it to a gunsmith to look at, as mike 556 mentioned. Sounds like it should be dead to me if the chrome/rifling weas drilled through, but I am no professional.
Hope it works out for you; I guess you could always cut it and re-crown it and have a nice SBR barrel...
On the thread re: Battle Comp muzzle device I was told that this would ruin the bbl.
:sad:
I would imagine you could salvage it by havingi t cut down, re-crowned and re threaded but then you will have an SBR bbl.
On the thread re: Battle Comp muzzle device I was told that this would ruin the bbl.
:sad:
I would imagine you could salvage it by havingi t cut down, re-crowned and re threaded but then you will have an SBR bbl.
Alex V,
Do you know who said this and did they give a reason why.
I'm always looking to expand my data base.
TIA
You might want to pm gotm4 and ask him
Belmont31R
08-19-10, 16:33
The gas port is not the same as drilling a hole through the threads. The gas port is very small, and not close to the muzzle.
While I think you could probably make something work Id be worried about accuracy dropping off. That hole, even if welded, is close enough to the muzzle part of the bullet would be going through the muzzle as its passing the hole. Especially if you drilled through a land which is what the round is actually touching in the barrel for the most part.
If it were me, instead of paying to fix the barrel and maybe have it work as normal or not, Id just put in a new barrel. DD or BCM sell them pretty cheap, and they are quality tubes. I don't necessarily see the point in spending the cash for a "maybe", and then possibly having to buy a new barrel anyways if it doesnt work out.
I don't really think theres a lot of experience in this topic, and if one or two worked out that were welded over that doesnt mean yours will. Besides welding on barrel steel will change that steels characteristics. Welding works by heating the area up so the base metal can accept the welded metal into it. You are heating up the area right around the weld to above temps that change that steels characteristics. One reason why high temp silver solder is not a popular method to perm attach muzzle devices is because you are getting the steel up to red hot temps.
The gas port is not the same as drilling a hole through the threads. The gas port is very small, and not close to the muzzle.
While I think you could probably make something work Id be worried about accuracy dropping off. That hole, even if welded, is close enough to the muzzle part of the bullet would be going through the muzzle as its passing the hole. Especially if you drilled through a land which is what the round is actually touching in the barrel for the most part.
If it were me, instead of paying to fix the barrel and maybe have it work as normal or not, Id just put in a new barrel. DD or BCM sell them pretty cheap, and they are quality tubes. I don't necessarily see the point in spending the cash for a "maybe", and then possibly having to buy a new barrel anyways if it doesnt work out.
I don't really think theres a lot of experience in this topic, and if one or two worked out that were welded over that doesnt mean yours will. Besides welding on barrel steel will change that steels characteristics. Welding works by heating the area up so the base metal can accept the welded metal into it. You are heating up the area right around the weld to above temps that change that steels characteristics. One reason why high temp silver solder is not a popular method to perm attach muzzle devices is because you are getting the steel up to red hot temps.
Thanks for the info Belmont31r.
Logging this into the grey matter data base.
Hopefully this thread will bring more knowledge to eveyone.
Canonshooter
08-19-10, 17:54
Any disruption of the rifling at the muzzle will usually adversely effect accuracy. I don't recall where I read that, but it's one of the reasons that cleaning a barrel from the muzzle end must be done with care.
Once the hole filled is filled with the welded-in FH pin, I don't think there would be a safety issue. How much - if any - the accuracy is effected will only be revealed with a trip to the range. The toughest part will be cleaning up the hole of any burs inside the barrel.
I agree - rebarrel and save this one for a SBR project.
If you were to cut just behind the hole you drilled and re-threaded for a muzzle device, what length barrel would you have?
Any disruption of the rifling at the muzzle will usually adversely effect accuracy. I don't recall where I read that, but it's one of the reasons that cleaning a barrel from the muzzle end must be done with care.
Once the hole filled is filled with the welded-in FH pin, I don't think there would be a safety issue. How much - if any - the accuracy is effected will only be revealed with a trip to the range. The toughest part will be cleaning up the hole of any burs inside the barrel.
I agree - rebarrel and save this one for a SBR project.
Any disruption of the Crown will affect accuracy! Porting a barrel does not make it less accurate. Put the pin in and make sure its not into the rifling. it will straighten itself out. Make sure to weld the pin and grind down or polish afterwards. My guess is, it will be fine. if not , what did you lose by trying it.
Thomas M-4
08-19-10, 18:10
Can you not SBR it in your state?
IF no one here has a striaght answer, I would call colt and see what they have to say and then take it to a gunsmith to look at, as mike 556 mentioned. Sounds like it should be dead to me if the chrome/rifling weas drilled through, but I am no professional.
Colt isn't going to help him.
I need help and sage advice. Last night I decided to assemble two 14.5" uppers I had in the safe, one a Colt and the other an FN (no marks on it I can see other than NATO 1x9). Anyway I decided to do the Colt first and as I was drilling the pin hole in the threads for the extended A2 FH pin I must have dozed off because I drilled straight through the barrel and chrome lining into the bore. Have I ruined this barrel? Is it worth/safe to shoot? Is the accuracy potential for this barrel gone? Is there any way to salvage it without having it cut down to a shorter length?
FN doesn't make 14.5" barrels
You should have built an SBR instead of pinning and welding a flash hider. I see you live in Kansas.
Your $400 barrel is now $50
Get rid of it and move on.
thunderdog
08-19-10, 18:26
People port barrels all the time and don't have issues. Pin the flash hider in place and shoot it.
Thomas M-4
08-19-10, 18:35
Simple SBR it or sell it to some one that will.
Having a hole near the crown of my expensive colt barrel :no: doesn't make sense.
Your $400 barrel is now $50
$400 is a little high, but I will give you $50 for it Davy35D:). They only thing I can see it doing is affecting accuracy.
edmorseiii
08-19-10, 19:08
Cut it back and pin a KX3 on it, I know Rainier Arms stocks a 13.7 inch WOA barrel for this purpose. It's an idea.
http://www.rainierarms.com/?page=shop/detail&product_id=1642
FN does not make 1/9 barrels as far as I know. Not bashing on you, but this is why we send barrels to ADCO and other places. Last time I checked M4 barrels were about 400.00-425.00.
I think the best you can hope for is cutting it down and recrowning it. You may also need to do something with the gas port.
Since SBR's are legal in Kansas I would go that route. Or try and sell it and get a 16" barrel.
I need help and sage advice. Last night I decided to assemble two 14.5" uppers I had in the safe, one a Colt and the other an FN (no marks on it I can see other than NATO 1x9). Anyway I decided to do the Colt first and as I was drilling the pin hole in the threads for the extended A2 FH pin I must have dozed off because I drilled straight through the barrel and chrome lining into the bore. Have I ruined this barrel? Is it worth/safe to shoot? Is the accuracy potential for this barrel gone? Is there any way to salvage it without having it cut down to a shorter length?
Accuracy is pretty important don't you think?
$400 is a little high, but I will give you $50 for it Davy35D:). They only thing I can see it doing is affecting accuracy.
As stated, there are muzzle devices out there that will still allow you to cut back this barrel without having to register it as an SBR. The Noveske KX3, the PWS CQB Comp, the LeVang linear comp...I believe any of these would allow you to cut the barrel back far enough to remove your new hole.
Thanks for the responses. I do live in KS and I probably shouldn't have been a tight wad and just SBR'd it. I was trying to avoid extra expenses. I called a reputable gun shop in North Kansas City and spoke with them about it. On their advice I bought some lapping compound and will make sure the entry wound is free of any burrs and then I will pin the break and weld it. I fired 30 rounds through the rifle today and it cycled fine. It even has a test Osprey piston in it and there was no noticeable degradation in gas pressure to cycle the action. It was interesting to feel the jet of gas on my legs when I was firing seated unsupported though. I wonder if there is a loss of velocity with gas being ported off at the muzzle? With unzeroed sights at 25 meters I was getting standard sized (for me) groups. Thanks again for the help and I think I will pick up another barrel or two from BCM, just in case. Thats a good point.
Glad to hear it still functions, but I hope you aren't shooting this on a non-SBR lower...
I think I would be figuring out how to make it legal while cutting it back far enough to remove the hole, like jsebens suggested. You're flirting with disaster if you don't.
Robb Jensen
08-19-10, 21:51
I think the barrel is toast at it's current length. I'm certain this will play hell on the accuracy. I'd make a 10.5" or 12.5" out of it.
Here's how I do perm. attached flash hiders:
Drill the flash hider at 6 o'clock all by it self on a milling machine with a 1/8th drill.
Install on the barrel and index properly.
Dimple the barrel through the flash hider on the mill with the same drill.
Cut a segment of 1/8" pin and then TIG weld the pin in place.
Clean down the slag and cold blue with G96 cold blue.
Accuracy is pretty important don't you think?
Yes.. Someone said about safety, I was just stating that it will only affect accuracy.
pilotguyo540
08-20-10, 00:26
I vote to give it a shot. What the hell do you have to lose at this point? Worse case you lost some accuracy learned a lesson and moved on. Best case is you are fine. Debur the hole if you can.
It seems to me that cutting down and recrowning the bbl would be a lot more expense and more likely to cause problems if not done properly.
It seems that you were trying to avoid a tax stamp in the first place. Your choice of course. If I had the option I would sbr anyways.
The most important lesson here is to always learn and practice on the cheap stuff :D
justin_247
08-20-10, 12:07
I'll pay you $50 for it. I plan to cut it down and SBR it.
I'll pay you $50 for it. I plan to cut it down and SBR it.
I don't think he wants to sell it for $50, but If he does, I'm pretty sure I'm first in line;)
justin_247
08-20-10, 12:35
I don't think he wants to sell it for $50, but If he does, I'm pretty sure I'm first in line;)
$51. :)
Alex V,
Do you know who said this and did they give a reason why.
I'm always looking to expand my data base.
TIA
Not an explination, more of a blanket statement so not sure how much help it will provide.
DO NOT LET YOUR FRIEND WELD THIS UNLESS YOU ARE ABSOLUTELY SURE YOU AND HE KNOW WHAT YOU ARE DOING!!!
If he tries to draw a bead all the way around the muzzle device then yes he will absolutely ruin the barrel.
All you are doing is drilling through the muzzle device (already done on the BC) threading it onto the barrel, and torquing to spec, then just barely drilling through the hole and into the threads...I emphasize just barely as it is damn easy to drill all the way through the threads and into the bore which will ruin the barrel.
You then make a pin that is the same diameter as the holes, fit it so it is the same depth as the over all hole, and spot weld over the top of it. It's really quite easy and anyone with a rudimentary knowledge of welding should be able to do it.
I have used a MIG welder for this as well as a TIG and it worked just fine. You are right though, it is a 1-1.5 second weld.
Also, seems like some are saying it will be fine, but others the opposite, so take the above with a grain of salt I suppose.
As for me, I would be in the camp of those who say get another bbl and use this guy for a SPR project down the road. There is no way in my limited oppinion that a .125" or so hole [I assume you used roughly a 1/8" drill bit] so close to the crown of the barrel will not adversly effect the accuracy of the bbl. As the projectile passes that are, there will surely be a void there, causing gas pressure to drop on that side of the round, would that not induce yaw? I mean there maybe what, .5" or .625" left after it passes the newly made hole and before the bullet is in free air. I would imagie this causing yaw. But then again, I am as noob as noob gets when it comes to the firearms world, though I do try and read as much as I can on here.
Not an explination, more of a blanket statement so not sure how much help it will provide.
Also, seems like some are saying it will be fine, but others the opposite, so take the above with a grain of salt I suppose.
As for me, I would be in the camp of those who say get another bbl and use this guy for a SPR project down the road. There is no way in my limited oppinion that a .125" or so hole [I assume you used roughly a 1/8" drill bit] so close to the crown of the barrel will not adversly effect the accuracy of the bbl. As the projectile passes that are, there will surely be a void there, causing gas pressure to drop on that side of the round, would that not induce yaw? I mean there maybe what, .5" or .625" left after it passes the newly made hole and before the bullet is in free air. I would imagie this causing yaw. But then again, I am as noob as noob gets when it comes to the firearms world, though I do try and read as much as I can on here.
99.99% of AR's have a gas port hole drilled as well
shoot it, see what happens. i predict it will either immediate keyhole, or begin to keyhole within a couple thousand rounds
if it was me, i'd put it in the cabinet and wait for the next SBR project. the muzzle is no place for damage
99.99% of AR's have a gas port hole drilled as well
Yes, but it is further from the cown and once again, only a guess, but if the OP intended to use 1/8" pin that makes the are of the gas port 1/4 that of the are of the inadvertant hole the OP made.
Once again, only a conclusion based on oppinion, but going from a .003117 SqIn hole roughly in the middle of a barrel to a .012272 SqIn hole very close to the crown would cause a problem in accuracy.
Just an oppinion tho.
shoot it, see what happens. i predict it will either immediate keyhole, or begin to keyhole within a couple thousand rounds
if it was me, i'd put it in the cabinet and wait for the next SBR project. the muzzle is no place for damage
I would not even bother shooting it. The OP will spend time and possibly money having the muzzle device attached, only to have a BBL that keyholes. Cant re-use a pined/welded muzzle device after it is removed and some of them are by no means cheap... Why waste it? Just throwing more money away if the bbl turns out to be ruined.
I would not even bother shooting it. The OP will spend time and possibly money having the muzzle device attached, only to have a BBL that keyholes. Cant re-use a pined/welded muzzle device after it is removed and some of them are by no means cheap... Why waste it? Just throwing more money away if the bbl turns out to be ruined.
yea, that's the smart attitude, and why i said the "if it was me..." part. but since it's NOT me, i'd like to see what happens. :laugh:
AlexV makes a good point. If I weld it and in a few hundred rounds accuracy starts to suffer (and we can logically assume that accuracy is effected even now with this so close to the muzzle) then where would I be? I'd have to sell it and get a fraction of my investment out of it or destroy the A2X FH and pay for barrel shortening/recrowning, plus the NFA stamp. What SBR lengths/muzzle attachments do you recommend that give good performance? Is there a significant velocity and accuracy difference between a 12.5" plus an A2 FH and an 11" and a Noveske pig? Maybe a 13.5" or 14" custom length and a Noveske pinned (by a pro this time) would be 16.1" loa? Do you think this barrel can be cut down and have a FSC556 attached and still be 16.1"?
if it's a factory colt, your thread shelf should be wide enough to simply turn the barrel back 3/8ths-1/2"
if this is the case, you could do that, and then perm an extra long muzzle device. i would not do a KX3- they're heavy and wasted on non-CQBRs. i think the levangs are pretty long, and there's others.
ADCO will turn it back for $75. tell them not to turn down the shelf behind the threads, and not to **** with the gas port, though.
Why does this always happen to COLT barrels?
This isn't the first time someone who has no business working on firearms has made this mistake. I've read of this at least 2 other times on ARFcom.
Why does this always happen to COLT barrels?
No shit.
The last **** up I saw was someone that redrilled the taper pin holes on a like new XM177E2 barrel I bought off the internet hoping to score big.
I wept.
Hey guys I feel bad enough about this whole thing as it is... The second barrel I did turned out great. Unfortunately it is a no-name 1x9.
I've emailed ADCO and sent them a pic. Just waiting to hear back.
I don't remember where I read it, but someone had sent out a barrel that was drilled for a carbine length gas system and had the hole plugged and re-drilled for a midlength. something like that might be doable with this barrel.
The other possibility is to deburr the hole, install the muzzle device so it covers the hole and redrill & pin it at another location. Test fire it & see how it works. You lose nothing if it doesn't shoot good and if it does, you've bought yourself time to shop for a replacement barrel.
Simplest thing is to just deburr & pin it. The pin does not have to come all the way up to the surface inside. As pointed out in earlier posts, and supported by your test firings, the hole won't cause keyholing. Ports in barrels don't
motorwerks
08-21-10, 02:37
ADCO was going to be my vote to. I think it will be fine. Hell my Bushmaster 14.5 measures out to be 14.75 so with any luck they can take the threads back a little farther, and crown it.
I'm about to attach a vortex hider so Ill try and learn from your mistakes. :laugh:
No shit.
The last **** up I saw was someone that redrilled the taper pin holes on a like new XM177E2 barrel I bought off the internet hoping to score big.
I wept.
There was a guy on ARFcom years back who ruined a Colt barrel by trying to drive the Taper pins out the WRONG Friggin way. :mad:
Motorwerks,
I hope something good comes out of my buffoonery! Here is a link I had saved in favorites and forgot about. :fie: Maybe it will help others. It is from the other board.
http://www.ar15.com/forums/topic.html?b=3&f=4&t=391053
Here is a picture of the damage.
http://i33.tinypic.com/4hvdbo.jpg
I would think that would be pretty easy to correct having ADCO mill it back, re-thread, and attach one of the longer muzzle devices that are available.
First thoughts would be a Noveske KX3, but I'm sure there are other options. Would an AAC M4 three prong be long enough?
motorwerks
08-21-10, 23:47
Hears what I would do. Lock a BCG into it, drop a cleaning rod down the bore, mark it with a sharpie, pull it out and measure from the end of the rod to the sharpie mark. You will at this point know what you have to work with. At this point you will also know how much ADCO has to work with. My Bushmaster measured out at 14.75 So with a Vortex flash hider I'm out to like 16 3/8-ish. With any luck your colt is the same way and they can scrub that off and pin a vortex in house and spare that thing. It would be a shame to see that barrel go to waste.
EDIT: I just looked at that picture a little closer.... I hope to hell colt builds their 14.5's at 15. :)
How long does it take ADCO to respond to email queries? I get they are closed three days out of the week. It has been several days and counting.
motorwerks
08-25-10, 23:14
that sucks maybe give them a call???? :confused:
How long does it take ADCO to respond to email queries? I get they are closed three days out of the week. It has been several days and counting.
If you post in their forum on TOS you will more than lilkely get a very quick response. The owner and his shop guys answer questions there about work all the time and after "normal" business hours etc..
I finally got in contact with ADCO today on the phone. I spoke with Steve and according to him the hole in the muzzle won't do much of anything to the rifle's function and accuracy. On his advice I pinned a BCM A2X FH and welded the spot. His exact words were, "I dare you to notice any difference in that upper and another Colt without the extra hole." Keyholing and the like will happen only after the throat burns out. He says the hole in the muzzle will fill with carbon and I won't notice any difference. I'm not recommending others here drill through into the bore but I'm very glad my faux pas was catastrophic in the end. :jester:
Great news Davy,
I thought that would be the case.:smile:
That is good to hear. :)
Who knows, you may be a trend setter...;)
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