Gunsmithing Threading a barrel without can

[coldboremiracle]

My gunsmith refuses to thread my barrel sans can in hand, at first I thought it was maybe because he didn't want a bunch of threaded barrels runnin around, but he says its because it has to be hand fit. I understand his reasoning, wanting to make it fit perfectly, but I know there are tons of people out there that thread barrels and ship them off to wherever without wondering whether or not they'll match the can in question. He says" Somebody else might do it for you, but I wont!"
Any Ideas? or maybe a good smith in my area that would attempt such a huge challenge?

 

[Wild_Bill]

Re: Threading a barrel without can

it is best to have the can so you can fit it perfectly but if the gunsmith cuts the thread to specifications it should work but i can also see his point if the thread is loose on the can and his on the small size of thread tolerence then the can would wobble around when screwing on and it may not alighn perfectly but it should still be safe but in the other end of the sizings if he cust a thread on the large size for tolerence and the can is tight it might gall and ruin the can and barrel thread.

If you have the can it is best to let the gunsmith have both to fit them if not get it threaded for a muzzle break of the same thread i am sure he will do that for you but it will be on you if the threads are out of spec.

 

[Pat M]

Re: Threading a barrel without can

Wait til the can shows, i've run across cans that are a little loose , and it's better to make it just right.

 

[gamma]

Re: Threading a barrel without can

Yes your gunsmith knows what hes talking about. Your thinking here is probably if the thread is M18 for example and your smith cuts a perfect M18 thread that should be it right? Not so, Ive seen batches of cans with massive variations and although your thread is exactly the recommended size it could still be either too tight or too loose so its always best to thread the barrel with the can in hand. Ive done it a few times and got away with it but Ive also had guys come back saying the can is too tight and wont go on.

 

[coldboremiracle]

Re: Threading a barrel without can

well, I have A can, just not THE can I planned on putting on this stick, maybe I'll have him thread it for this one(5/8-24) and when the new one shows up, he can re-thread it for that one(1/2-28) that is if I ever get it.

 

[wnroscoe]

Re: Threading a barrel without can

All suppressor threads are not equal, class 2 & 3, .500" & .625" alike. Take the .625" or 5/8x24 Class 3A/3B. "B" being the internal (suppressor) thread and "A" being the external (barrel) thread. There are dimensional differences from one manufacturer to another.

If you have your barrel threaded for suppressor manufacturer 1 and use the threads in that can as the gauge and later in life try to screw a suppressor on from manufacturer 2, you just might lock it on or gall the threads in the process.

I've seen it several times with different manufacturers. There are members here with multiple cans from multiple manufacturers. I've been told that one can fits great, the next is either loose or tight. I've even received calls from guys that had a friends can stuck on their barrel after only screwing it on three threads.

<span style="font-weight: bold">The answer, use either a Class 2A or Class 3A Go Ring gauge when threading barrels. While Class 2B & 3B threads run same/same the barrel threads are what changes and dictate the fit. This is how we can thread a barrel without the suppressor in hand and guarantee the threads are in spec.</span>

When different suppressor manufacturers use different thread plug gauges to cert their suppressor threads the fit of the gauge varies from one to another, the suppressor thread fit then varies and hence the galling of the threads or a stuck suppressor.

 

[trilogymac]

Re: Threading a barrel without can

I think threading a barrel to the can is BS. Use the correct gage and then the next guys can will fit as well.

I threaded a barrel to a can only once. Then I had to go back and rethread to a gage before selling it in order to insure it would be universal.

If a smith will only thread to the can, I find someone else, or if time permits, I do it myself because it tells me he is to cheap to purchase the correct tools for the job.

Just a thot

Trilogymac

 

[LRI]

Re: Threading a barrel without can

I've been a gunmaker for over 10 years.

If your gunsmith is telling you that he wants your can because he wants to fit the threads, give him the can and hang onto this guy. It means he gives a crap about his work.

FWIW I too will not thread a barrel under any circumstances without the mating component in my hand to fit the two together. People can tout about Class A,B,C threads all they want. You change a pitch diameter by a couple thousandths and a thread fit goes from exceptional to mediocrity. PITCH diameter is what really matters because ultimately this is what the class of thread is governed by. (along with the OD/ID but that isn't nearly as important) Does it matter on paper, don't know and don't care. It matters in the fit and finish of the final product. thread fits are important enough to me to rationalize buying a $65,0000 CNC turning center to do all my barreling work on.

Send him the can.

 

[JJones75]

Re: Threading a barrel without can

its not BS to wait to have the can in hand to thread it , I've had wo suppressors that were supposedly threaded to fit a class 3A thread and they were way loose for my liking , like Roscoe said they can be differances from maker to maker , tools wear and tolerances stack.

you smith wanting the suppressor in hand shows that his is passionate about doing a perfect fit , I'd wait till the can shows up and let him do it.
properly fit threads will have alot less POIif the can gets loose and alot less chance of the suppressor getting loose while shooting , on that same note , if the suppressor has a tight bore and the suppressor backs out a couple threads and the threads are not tight then you could end up adding an extra hole to your suppressor via a baffle strike

 

[wnroscoe]

Re: Threading a barrel without can

Wow Chad, 6 posts in and you’re already taking shots at someone that’s only giving the facts.

Check the thread fit of multiple suppressors and get back to us on your findings. I don’t need a $65k CNC Center to know the thread fit varies from suppressor to suppressor. That’s the problem, programs and programmers vary, Ring & Thread Gauges don’t.

I've yet to have a loose suppressor or baffle strike.

 

[trilogymac]

Re: Threading a barrel without can

Well William, You and GA George obviously need to get your shi# together. Hummmm, how many barrels have you boys threaded for me WO a suppressor?

OH CRAP, Scott is out in the shop threading a GAP AR10 on the CNC now, better go stop him, all he has is the gage!!!!

Trilogymac

 

[wnroscoe]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trilogymac</div><div class="ubbcode-body">Well William, You and GA George obviously need to get your shi# together. Hummmm, how many barrels have you boys threaded for me WO a suppressor?

Trilogymac </div></div>

More than a few

How many baffel strikes have you had? 0
How many suppressors have you had shoot loose? 0


Granted, if a guy only has one can and thats all he'll ever have, use it as the gauge and go for a class 3 fit. If I thread for a suppressor though and the suppressor isnt in hand, I'm threading for that manufacturers specs, Class 2 or 3 and using the ring gauge to cert my threads.

 

[LRI]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Wow Chad, 6 posts in and you’re already taking shots at someone that’s only giving the facts.

Check the thread fit of multiple suppressors and get back to us on your findings. I don’t need a $65k CNC Center to know the thread fit varies from suppressor to suppressor. That’s the problem, programs and programmers vary, Ring & Thread Gauges don’t.

I've yet to have a loose suppressor or baffle strike. </div></div>


Oky doke Rosco. We talked on the phone so I'll summarize here.

1. Personally, I don't care what anyone else does as it doesn't affect how I do things. What I mean by that is nothing I said/say should be taken as a personal attack. If I have an issue with anyone I will address them directly. I think my history on other high volume gun forums demonstrates this as I tend to stick to the side of good ol common sense and fact.

Ok, now that we've gotten that out the way.

Gauges are references and I can appreciate wanting to offer a broader range of options for a customer. The problem with the gun world is we are all chest beating Alpha males with our own ideas on what works best. There aren't many standards to reference to.

As discussed on the phone and this is what I'd like everyone to take from this dissertation:

A gun is a pressure vessel. Pressure applies a force at a right angle to whatever it contacts. It also takes the path of least resistance. When the trigger gets pulled and the boiler room starts cooking the path of least resistance is pushing that bullet forward. Duh, we know this.

The last half inch of a barrel is where I get concerned. I've installed more muzzle brakes than I can count. I've made hundreds of the dumb things too. I generally only install an aftermarket brake from one manufacturer; Vaise. The reason is they will turn/single point the threads on the brake to whatever pitch I ask from them. (Great guys!)

There's a reason for this. I want the maximum wall thickness from the major ID of the barrel to the root diameter of the external thread I'm going to be putting on the barrel. The reason for this is I personally feel (and as covered in the phone call, I have no scientific data, it's an opinion I've developed over the course of installing a bunch of these things) that over time the pressure from shooting will begin to bellmouth the bore and lead to a progressive deterioration in accuracy. It's been long stated that muzzle braked guns don't shoot as well as ones w/o brakes. I don't personally think it's all the brake's fault. I think it may just have to do with the thinner wall thickness.

To further emphasize this. I once worked in a competitive high performance automotive machine shop that contracted to a successful NHRA Competition Eliminator dragster team. At the compression ratios those engines ran we would see the bore distort over time around TDC. We began to use taller deck blocks with very heavy deck thicknesses and the problem went away, engines made more power, and we won more races.

An ultra high compression (to the order of 18.6:1) engine develops around 10Kpsi of cylinder pressure on the power stroke. A rifle barrel is exponentially higher. So, what I'm proposing seems pretty reasonable to me.

I support the idea of minimizing the gap between the external pitch diameter of the barrel threads and the internal pitch diameter of whatever is being attached to the end of the barrel because I personally feel it will aid in mitigating any possible expansion of the bore.

Blue sky high minded crap? Certainly possible. I will confess that as being possible since it's a personal opinion.

Temper it though with knowing that for three years I personally either barreled, or supervised the barreling, every single rifle that went out the doors of Nesika Bay Precision and Dakota Arms, Inc. (around 40+ barreled actions a week) A good portion of these rifles were chambered in some of the highest performance cartridges that anyone dares to shoot from a shoulder. I'd like to think I learned something from that experience.

That's my opinion on the matter. Sorry if I offended anyone, it certainly wasn't intended.

All the best,

Chad

 

[RADcustom]

Re: Threading a barrel without can

Maybe you should consider a QD mount.

 

[coldboremiracle]

Re: Threading a barrel without can

Dont like em.

 

[KYS]

Re: Threading a barrel without can

i have a AAC Titan thats on a Lawton rifle it was threaded by GAP. when it gets about 20 rounds under under it and hot it will loosen. Not to thrilled about it but it has never come loose enough to spin off freely.

 

[gamma]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Wow Chad, 6 posts in and you’re already taking shots at someone that’s only giving the facts.
</div></div>
Ah man lets get with the programme here, this man is only giving his opinion here based on his experience which looks pretty good to me. I think he's qualified enough to stand by the post he made. I mean how long do you have to be on here before your allowed make a comment about something. I dont see anything wrong with Chads comment here, why is he getting snyde remarks. William, your a valued member on here and I think your posts are always excellent but I think your being a bit hard on Chad here. He's only trying to help people the same as the rest of the members on here.

 

[wnroscoe]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mikki</div><div class="ubbcode-body"> I think your posts are always excellent but I think your being a bit hard on Chad here. </div></div>

Being this topic is several hours old and everyone has spoken their mind, this is a non issue as far as I'm concerned.

Thanks for the kind words.

 

[jrhtx]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trilogymac</div><div class="ubbcode-body">Well William, You and GA George obviously need to get your shi# together. Hummmm, how many barrels have you boys threaded for me WO a suppressor?

OH CRAP, Scott is out in the shop threading a GAP AR10 on the CNC now, better go stop him, all he has is the gage!!!!

Trilogymac </div></div>

Not trying to stir thing up but this is what Scott and Bill were cutting and threading. They started before I arrived and did not have the suppressor or QD mount. It was fit to a gage, not the mount.

The rifle is a GAP AR 10T cut to about 19”. Just in front of the GAP logo.

 

[csi:cyberspace]

Re: Threading a barrel without can

Well, I don't know boo about machining and things, but I do know that Hooper threaded 3 PSS barrels for me, and each of them fit to my SRT suppressor equally well with my AWC Thundertrap. Perhaps I got lucky, but I figure it's more likely that Hooper did a great job for me. Oh, and he didn't have <span style="font-style: italic">either</span> suppressor to work by.

 

[Hooper]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: csi:cyberspace</div><div class="ubbcode-body">Well, I don't know boo about machining and things, but I do know that Hooper threaded 3 PSS barrels for me, and each of them fit to my SRT suppressor equally well with my AWC Thundertrap. Perhaps I got lucky, but I figure it's more likely that Hooper did a great job for me. Oh, and he didn't have <span style="font-style: italic">either</span> suppressor to work by. </div></div>

Thanks for the kind words. It is best to have the suppressor in hand. Thread specs can be a tad different amoung the various suppressor manufacturers. Moreso with a Titanium suppressor as a tight fit will be a disaster if no antiseize is applied to the threads.

I use wire gauges to measure with as I have found this to be the best method for me to assure correct specs. I also have go and no go rings for final quality control check.

I recently changed to carbide tool holders and bits for more efficient work. Big improvement from ground HSS and makes my life easier. No more down time sharpening tools.

It really is hard to guarantee the suppressor will fit if the suppressor threads are slightly undersize.

 

[toddk]

Re: Threading a barrel without can

Use a gunsmith that knows something about tolerances and can thread to 2A/3A and gauge it. I want my next can/brake/flash hider to fit, if I want it tighter I'll bring the can and ask for it tight.

Not threading to 2A/3A if the customer asks means one of two things. He thinks he knows better than the customer or he does not have the proper gauges to do the work.

 

[trilogymac]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TMK</div><div class="ubbcode-body">Use a gunsmith that knows something about tolerances and can thread to 2A/3A and gauge it. I want my next can/brake/flash hider to fit, if I want it tighter I'll bring the can and ask for it tight.

Not threading to 2A/3A if the customer asks means one of two things. He thinks he knows better than the customer or he does not have the proper gauges to do the work. </div></div>

Amen to that!

 

[RollingThunder51]

Re: Threading a barrel without can

..

So true.....

Thread Gauges. If you are getting a can and the can's threads are not to spec than what more do you need to know about the can? Highest point of failure? alignment....alignment? fail.

Read some of the suppressor threads here and you wonder if some have ever seen, let alone used thread gauges.

Custom fits is great, it is the finest kind no doubt..done by thoughtful, disciplined gunsmiths...and the result of a requirement to attend to far too much crappy, high volume, low quality initial work.

..

 

[wnroscoe]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TMK</div><div class="ubbcode-body">Use a gunsmith that knows something about tolerances and can thread to 2A/3A and gauge it. </div></div>

That’s absolutely preposterous. Who in their right mind would even think of using such tools as gauges to check the thread fit?









I would, thats who

 

[ColoWyo]

Re: Threading a barrel without can

Speaking from personal experience, I would highly recommend sending the can in with the rifle.

 

[ohnomrbillk]

Re: Threading a barrel without can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TMK</div><div class="ubbcode-body">Use a gunsmith that knows something about tolerances and can thread to 2A/3A and gauge it. I want my next can/brake/flash hider to fit, if I want it tighter I'll bring the can and ask for it tight.

Not threading to 2A/3A if the customer asks means one of two things. He thinks he knows better than the customer or he does not have the proper gauges to do the work. </div></div>

Amen. Trying to sort that mess out right now.

 

[Kevlars]

Re: Threading a barrel without can

I know that this topic is old.. but I too have been looking for a place to thread my barrel. I contacted my gun manufacture and he told me the best person to thread the barrel is the maker of the barrel as there machining would be a perfect mate. Since I am getting a Thunder Trap made by AWC, I contacted them ... and they are doing it for $150 including a custom thread protector. My weapon is a Tactical Rifle with a Chimera action in .308 with a 20 inch barrel.

 

[WCW308]

Re: Threading a barrel without can

try Hooper. http://www.hooperordnance.com He threaded 2 barrels 1/2 X28 w/o SAS can available for him & the can fits PERFECTLY on both bbls. No slop.

 

[coldboremiracle]

Re: Threading a barrel without can

Yes this thread is old, I was surprised to see it back up top.
FWIW almost a year later, I did have the barrel threaded class 3A by strictlyRUM here on the hide. He did a fine job, my can fits just right, no slop, and not too tight either. The problem became much less of one when I decided to just thread the barrel (Kreiger 1.30 straight taper .224 1-7.7 twist) for my 30 caliber can. So Jason cut it at 20 and threaded it the 5/8-24, it's smooth and quiet. Thanks to all those who opined.

 

[dksac51]

Re: Threading a barrel without can

A good smith will refuse to do the work unless he has both in his shop.
As a retired smith, I would only do first class work, if you wanted to make it tough on me by sending only 1/2 of a threading job, my policy was that you could take it somewhere else, I didn't need your business because if there's any problem, you will be the first to cry and want me to eat the cost.
I'd pass on you everytime. Things are either done right or not at all, period.

You have good smith, but not for long if you make it rough on him. Most smiths learn to pass on customers who are a PITA, it's just not worth the money made.
I don't know you, and you may be a great person, but make it easier on your smith.
I always has plenty of work and people who made it rough on me just cost me more time, which is money and it just was not worth working with them.

If someone turned out to be a pain, I'd refuse to take any more work from them.

John K

 

[coldboremiracle]

Re: Threading a barrel without can

The guy is a good gunsmith, he does top notch work. The only problem I have is that he only does things his way, and by that I mean he would constantly try and talk me out of what I wanted/came in for. And not some crazy way out of the norm stuff either. I understand that some guys want to have both ends of a threading job in hand, that's fine, I'm talking about normal procedures seen on this site daily.
I don't use that gunsmith anymore, not because I don't like his work. More because he seems to have the same opinion as all the other gunsmiths around here; I'm right, and every one else is wrong, including the customer. Now I have had customers before too, and I know that the customer is NOT always right, especially with a rifle. But I was not asking for a bullpup 338lapua/AK conversion with a 4.679 twist and the tatical coffee mug holder on the side. I was asking for a simple job; blueprint, thread and chamber a 1.300 Kreiger blank with a 7.7 twist for a .223. He didn't seem to know what a remington match or wylde chamber was, which really made me wonder. And he also tried telling me that I'd never make it to 1k with a humble .223 (thing I'd been doing for a long time with another rifle in .223)
In the end like I say, the man knows what he is doing, but his mind is focused on one design, and all others are inferior to him. That's okay, I went another way, and am very glad I did, because now I have one of my many dream guns EXACTLY the way I dreamed it up.


Didn't mean to step on any toes