Gunsmithing Can this thread protector be fixed ?

[Insayn]

I have had this barrel for over a year. When I had the work done I asked for it to be threaded 5/8x24 and a thread protector to be added. This is what I received. It didn't bother me at first because the rifle had a generic brake on it, now I want the thread protector to match the barrel contour/diameter because the brake is off. Can the existing thread protector be turned down and shortened to match the contour while not having to down my rifle?

 

[wnroscoe]

Re: Can this thread protector be fixed ?

Yes, it can be blended to match the barrel. Your rifle will have to be sent to the smith and you will loose the paint job. The rifle will have to be re-painted once the work is complete.

 

[kingjoey]

Re: Can this thread protector be fixed ?

Yeah, it'd just need to be threaded onto a 5/8"x24 holder and turned down in a lathe and then refinished. The only info that would be needed is the OD of the barrel where it meets the thread protector. I would also cut a deep countersink in the end to reduce the amount of gas blowing around and along the sides of the bullet as it is trying to stabilize. There's no reason to have a 'tube' for the bullet and propellant to be passing through. Ought to 'crown' that until its only about .040" thick by the muzzle of the barrel

 

[wnroscoe]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body">Yeah, it'd just need to be threaded onto a 5/8"x24 holder and turned down in a lathe and then refinished. The only info that would be needed is the OD of the barrel where it meets the thread protector. </div></div>

If he didnt want it blended to match the barrel then yes, your suggestion would work.

 

[JJones75]

Re: Can this thread protector be fixed ?

Thats an awfull job!!!

Send your barrel to Mr. Roscoe and let him make a new cap correctly.

 

[JJones75]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body">Yeah, it'd just need to be threaded onto a 5/8"x24 holder and turned down in a lathe and then refinished. The only info that would be needed is the OD of the barrel where it meets the thread protector. I would also cut a deep countersink in the end to reduce the amount of gas blowing around and along the sides of the bullet as it is trying to stabilize. There's no reason to have a 'tube' for the bullet and propellant to be passing through. Ought to 'crown' that until its only about .040" thick by the muzzle of the barrel</div></div>

If your turn a threaded stub and thread that up on their then turn it down the OD of the cap will be consistant with the threads.
When a barrel is properly threaded it is indicated off of the bore , threaded and an oversize cap made , then the barrel is reindicated off of the OD of the barrel and the cap is turned to match the OD
I know a fella that killed a $1500 suppressor cause some half assed smith diden't thread the muzzle properly

 

[Hink]

Re: Can this thread protector be fixed ?

In theory, JJones' plan works; and every time.

Thing is....many times, the bore is not concentric to the barrel OD. So while turning down a thread protector to the barrel OD sounds like a fairly simple process, turning down a thread protector to the barrel OD while maintaining a smooth transition to the barrel is not possible without having the barrel at the 'smith to properly transition the barrel OD to the thread protector. The finish is lost in the process, but the quality of a properly completed transition is lost on most 'net viewers -- a properly completed thread protector is lost when installed; the seam is completely invisible.

If it were mine, I'd concentrate more on shooting and less on what the rifle looks like -- the inside of the rifle is the business part, not the outside.

 

[kingjoey]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJones75</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body">Yeah, it'd just need to be threaded onto a 5/8"x24 holder and turned down in a lathe and then refinished. The only info that would be needed is the OD of the barrel where it meets the thread protector. I would also cut a deep countersink in the end to reduce the amount of gas blowing around and along the sides of the bullet as it is trying to stabilize. There's no reason to have a 'tube' for the bullet and propellant to be passing through. Ought to 'crown' that until its only about .040" thick by the muzzle of the barrel</div></div>

If your turn a threaded stub and thread that up on their then turn it down the OD of the cap will be consistant with the threads.
When a barrel is properly threaded it is indicated off of the bore , threaded and an oversize cap made , then the barrel is reindicated off of the OD of the barrel and the cap is turned to match the OD
I know a fella that killed a $1500 suppressor cause some half assed smith diden't thread the muzzle properly </div></div>

Not exactly. If you thread that cap all the way onto a holder and put a live center in the existing hole, you should have little/no runout. Obviously you don't want your holder to have more threads than the cap does, then you're centering on the threads and can have about .002-.003" runout. I'd be willing to bet that the smith made the protector separately and it may be off-center up to a few thousandths depending on the condition of the lathe and chuck it was made on. Since it's getting turned down and the barrel was cut on centers, cut the cap on centers to the same OD and they will match up perfectly. When you load the holder and part, check the runout on the holder first to make sure the chuck is centered, then check the runout on the part to see that it is centered as well, then turn. When we do TP's here we've always done them installed on the barrel so that they are perfectly concentric, but a lot of smiths use generic blanks or punch them out separately and you can get a lot of misalignment that way.

 

[Insayn]

Re: Can this thread protector be fixed ?

I shoot the rifle all the time and it has been this way for awhile. Since I have a couple of other rifles I can concentrate on and ammunition is free, I figured I could get some small stuff done to this one, including asthetics. Since it will be best to drop the whole thing off I might as well get a blended brake put on too. I am not worried about the finish, it is only Alumahyde II.

 

[kingjoey]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body">Thing is....many times, the bore is not concentric to the barrel OD. </div></div>

Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center

It isn't very common though

 

[wnroscoe]

Re: Can this thread protector be fixed ?

Some want their cake and to eat it too. When the work you can see is sub-standard, what does that tell you about the work you cant see??

Just for comparison;

 

[Insayn]

Re: Can this thread protector be fixed ?

That's another thing, since looking at Wnroscoe's pic. If you look at my protector there is a gap between the front of the protector and the crown of the rifle barrel.

 

[JJones75]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body">
Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center

It isn't very common though</div></div>

I have a Hart that is about .002" off and a Douglas that is .003" off from the bore to the OD

Some say "its just a couple thousadnths no big deal" well thats when you end up with sub standard work. I want my smith to make sure the threads are concentric to the bore not the OD of the barrel or just take for granted that the "custom" barrel is perfect and do it the "easy" way

 

[GasLight]

Re: Can this thread protector be fixed ?

my bad... dumb question

realized you don't need the barrel running true to the bore when you profile the thread protector LOL...

 

[wnroscoe]

Re: Can this thread protector be fixed ?

I dial in the OD of the blank first to speed things along and then move to the bore with a range rod. Krieger and Bartlien very seldom have more than .003" difference between the ID & OD, most are .0015" or so. I have seen several other makers barrels though that were +.010" off.

IMHO, muzzle threads should be cut concentric to the bore and never between centers.

 

[wnroscoe]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave</div><div class="ubbcode-body">if the bore and the OD of the barrel are not concentric, how far back do you have to turn the barrel away from the muzzle to get the OD concentric with the bore and not look like it was turned down? </div></div>

Use a range rod to dial the bore in and then perform your work. The therad cap should be over sized and pre-made, ready to go. Once the cap is fitted and flush against the barrel shoulder re-dial the barrel by it's OD. Now, turn down and blend the cap. With care, it can be made to look seamless.

 

[GasLight]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DebosDave</div><div class="ubbcode-body">if the bore and the OD of the barrel are not concentric, how far back do you have to turn the barrel away from the muzzle to get the OD concentric with the bore and not look like it was turned down? </div></div>

Use a range rod to dial the bore in and then perform your work. The therad cap should be over sized and pre-made, ready to go. Once the cap is fitted and flush against the barrel shoulder re-dial the barrel by it's OD. Now, turn down and blend the cap. With care, it can be made to look seamless. </div></div>

Thanks William! You caught me before I could change my post

 

[wnroscoe]

Re: Can this thread protector be fixed ?

No problem Dave.

 

[Aries64]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">
...IMHO, muzzle threads should be cut concentric to the bore and never between centers.</div></div>
IMHO, thats' not just opinion. Thats' common sense machining and the way it should always be done. Threads cut concentric with the bore eliminate brake and baffle strikes.


Keith

 

[tullius]

Re: Can this thread protector be fixed ?

Sloppy work by the smith, go elsewhere next time. However, why are you using a thread protector? In other words, why would you want to take off whatever is threaded on there in the first place?

 

[Bacarrat]

Re: Can this thread protector be fixed ?

It's the little details that matter. APA installed my brake and blended it to the contour to the barrel. Someone asked me if they EDM the brake onto the barrel. lol

 

[Aries64]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body">Yeah, it'd just need to be threaded onto a 5/8"x24 holder and turned down in a lathe and then refinished. The only info that would be needed is the OD of the barrel where it meets the thread protector. </div></div>

If he didnt want it blended to match the barrel then yes, your suggestion would work. </div></div>
Roscoe is correct again - nice blend too. Who doesn't want the thread protector to match the barrel? Having the barrelled action on hand is key, especially with a tapered barrel.

<span style="font-weight: bold"><span style="font-style: italic">Profile of approximately 5" of muzzle end of Tac Ops Heavy Contour barrel with Thread Protector installed:</span></span>

<span style="font-weight: bold"><span style="font-style: italic">Thread Protector's bevel matches the barrel's crown angle and has a tapered outside edge:</span></span>

<span style="font-weight: bold"><span style="font-style: italic">Class 3A (External) threads:</span></span>

<span style="font-weight: bold"><span style="font-style: italic">Class 3B (Internal) threads:</span></span>

Keith

 

[Hateca]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body">Thing is....many times, the bore is not concentric to the barrel OD. </div></div>

Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center

It isn't very common though </div></div>

It's very common, 99% of every barrel will have run-out, and it's not necessarily a manufactures screw up.

When one deep drills a barrel blank the hole is going to wonder. It can be better or worse in relationship to the OD depending the barrel maker, caliber, or where one cuts the barrel for OAL perfectly.

Turning a barrel on centers does not remove run-out in the barrel bore. If anyone threads a barrel between centers and thinks this is the correct way of doing it does not need to be cutting barrel threads especially if one is planning on using a suppressor.

One cuts the barrel threads off of the bore after the barrel has been cut to the final OAL. One turns down the brake and or thread protector off of the OD of the barrel, there is no other correct way of doing this if the brake or protector is going to match the barrels OD.

 

[Hooper]

Re: Can this thread protector be fixed ?

The newest Remington Tacticals I have had in the shop recently had little runout OD vs. Bore. With lathe running and looking down the bore to the breach, I could also not detect any runout back there.

Back on topic:
If you had that protector turned down to the approx diameter of the OD of the barrel, then knurled, the OD mismatch if there was any would not show near as bad.

I have had a few Savages in the shop that when you screwed the TP on, it looked like a crankshaft rod journal going up and down. But the threads were concentric to the bore.

You still may want to have it opened up on the end though. I built a mandrel to hold thread protectors for just this occasion. Works great for making thread protector blanks as well.

If this threads goes on any further, someone is bound to start talking about skinning cats.

 

[subgunr]

Re: Can this thread protector be fixed ?

meow.....................

 

[wnroscoe]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hooper</div><div class="ubbcode-body">If this threads goes on any further, someone is bound to start talking about skinning cats. </div></div>

True. There is more than one way to do that though........I start at the cheerio

 

[Jrb572]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJones75</div><div class="ubbcode-body">Thats an awfull job!!!

Send your barrel to Mr. Roscoe and let him make a new cap correctly. </div></div>
You won't be dissapointed send it to him. I had a thread protector made by him. I had a thread protector I was not happy with. I did not like the step in the barrel for my FTE break. Now it looks like it supposed to when the thread protector is on. One smoth barrel.

 

[wnroscoe]

Re: Can this thread protector be fixed ?

Something like this

 

[Jrb572]

Re: Can this thread protector be fixed ?

That's the one. The original one that came on the rifle looked like complete crap. But I guess they figured I wouldn't shoot the rifle without the break. The orginal cap was done by a different smith when the rifle was rebarrled.

 

[rifleman1981]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Some want their cake and to eat it too. When the work you can see is sub-standard, what does that tell you about the work you cant see??

Just for comparison;

</div></div>
+1 for a talented smith taking time to do something the way it ought to be done, and looking like it should look after it's finished

 

[machinisttx]

Re: Can this thread protector be fixed ?

That's a horrible job. Looks like something a green trainee would put out. There are several ways to go about fixing what you have, some of which I saw listed in earlier posts(I didn't read them all). It would be faster to just turn a new one though. I'd offer to do it, but I never have finished setting up my lathe here at home.

Side note: Insayn's barrel wouldn't be needed, even if the bore was not concentric to the OD, assuming the measurements were known. It's not that hard to offset the material centerline to bore/turn/thread and match the dimensions. Alternatively, a quick and dirty program could be written at a CNC mill and the whole thing could be machined out with only one setup required. More than one way to skin a cat.

 

[Hateca]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: machinisttx</div><div class="ubbcode-body">
Side note: Insayn's barrel wouldn't be needed, even if the bore was not concentric to the OD, assuming the measurements were known. It's not that hard to offset the material centerline to bore/turn/thread and match the dimensions. Alternatively, a quick and dirty program could be written at a CNC mill and the whole thing could be machined out with only one setup required. More than one way to skin a cat. </div></div>

"Assuming the measurements are known" and assuming the owner can get the correct measurements to begin with, or is even capable of getting the correct measurements.

Most rifle builders don't have $60,000 + CNC machines sitting in their shop either. If the OP wants the cap to blend with the barrel with the least amount of fuss he needs to send the barrel.

 

[machinisttx]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: machinisttx</div><div class="ubbcode-body">
Side note: Insayn's barrel wouldn't be needed, even if the bore was not concentric to the OD, assuming the measurements were known. It's not that hard to offset the material centerline to bore/turn/thread and match the dimensions. Alternatively, a quick and dirty program could be written at a CNC mill and the whole thing could be machined out with only one setup required. More than one way to skin a cat. </div></div>

"Assuming the measurements are known" and assuming the owner can get the correct measurements to begin with, or is even capable of getting the correct measurements.

Most rifle builders don't have $60,000 + CNC machines sitting in their shop either. If the OP wants the cap to blend with the barrel with the least amount of fuss he needs to send the barrel.
</div></div>

$60k+ for a machine is ridiculous for anything other than a production shop(the machine I currently run was about $900K). These machines work fine for anything I can think of that a gunsmith would need in a CNC mill. prototrak knee mill The benefits of a conversational CNC, and the same ease of use as a standard bridgeport type manual knee mill.

 

[Insayn]

Re: Can this thread protector be fixed ?

Well, I dropped off the rifle at my gunsmith right after Thanksgiving and picked it up today. It wasn't a lot of work or a bad turnaround in my opinion.
He refaced my crown and put a flat 90 degree edge at the bore, made a muzzle brake that blended with the barrel and fixed the thread protector by eliminating the dead space and knurling it.

 

[762frmafr]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bacarrat</div><div class="ubbcode-body">It's the little details that matter. APA installed my brake and blended it to the contour to the barrel. Someone asked me if they EDM the brake onto the barrel. lol

</div></div>
I had GAP put a Thruster brake on one of my guns and I get all the time..."Who drilled holes in your barrel?" dumbasses....

 

[sbeckman]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body"><span style="font-weight: bold">Thing is....many times, the bore is not concentric to the barrel OD.</span> </div></div>

Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center

It isn't very common though </div></div>

Not to derail the thread too badly, but I was trying to think through the manufacturing processes and understand how this happens?

I'm only familiar with one manufacturer of cut rifle barrels so my question is based on that process.

1. Blank is drilled undersize. This can leave the bore off axis, primarily at the muzzle.

2. Bore is reamed to something less than final bore diameter.
So it can still be off center.

3. Barrel is profiled between centers at specified length. This would seem to make the OD concentric with the bore?

4. The bore is finish reamed to final diameter.

5. Rifling is cut.

It would seem that the bore should be pretty concentric at this point?

If the barrel is bent somehow in the profiling process or the hole isn't straight, at the ends at least, the hole would be concentric, no?

Don't know about button rifled barrels but I would think that the profiling would be done after the drilling, reaming, rifling so that the same result would happen?

Something no doubt I'm missing here?

Thanks

 

[Hateca]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sbeckman</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body"><span style="font-weight: bold">Thing is....many times, the bore is not concentric to the barrel OD.</span> </div></div>

Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center

It isn't very common though </div></div>

Not to derail the thread too badly, but I was trying to think through the manufacturing processes and understand how this happens?

I'm only familiar with one manufacturer of cut rifle barrels so my question is based on that process.

1. Blank is drilled undersize. This can leave the bore off axis, primarily at the muzzle.

2. Bore is reamed to something less than final bore diameter.
So it can still be off center.

3. Barrel is profiled between centers at specified length. This would seem to make the OD concentric with the bore?

4. The bore is finish reamed to final diameter.

5. Rifling is cut.

It would seem that the bore should be pretty concentric at this point?

If the barrel is bent somehow in the profiling process or the hole isn't straight, at the ends at least, the hole would be concentric, no?

Don't know about button rifled barrels but I would think that the profiling would be done after the drilling, reaming, rifling so that the same result would happen?

Something no doubt I'm missing here?

Thanks

</div></div>

If it was turned between centers the bore would only be concentric at the very ends. After that, cut the barrel anywhere along its length and the bore may not be concentric at the ends any longer. The bore can wonder the entire length of the barrel. Just because it's concentric in one spot doesn’t mean it will be in another.

 

[sbeckman]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">

<span style="font-weight: bold">If it was turned between centers the bore would only be concentric at the very ends</span>. After that, <span style="font-weight: bold">cut the barrel anywhere along its length and the bore may not be concentric at the ends any longer.</span> The bore can wonder the entire length of the barrel. Just because it's concentric in one spot doesn’t mean it will be in another. </div></div>

Thanks, makes perfect sense.

So, the process that I've seen addresses this.

3. Barrel is profiled between centers <span style="font-weight: bold">at specified length</span>. This would seem to make the OD concentric with the bore?

From your description, and that this obviously can and does happen, seems to imply that barrels are typically profiled and then cut down rather than being profiled <span style="font-weight: bold">at</span> the specified length.

 

[Hateca]

Re: Can this thread protector be fixed ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sbeckman</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">

<span style="font-weight: bold">If it was turned between centers the bore would only be concentric at the very ends</span>. After that, <span style="font-weight: bold">cut the barrel anywhere along its length and the bore may not be concentric at the ends any longer.</span> The bore can wonder the entire length of the barrel. Just because it's concentric in one spot doesn’t mean it will be in another. </div></div>

Thanks, makes perfect sense.

So, the process that I've seen addresses this.

3. Barrel is profiled between centers <span style="font-weight: bold">at specified length</span>. This would seem to make the OD concentric with the bore?

From your description, and that this obviously can and does happen, seems to imply that barrels are typically profiled and then cut down rather than being profiled <span style="font-weight: bold">at</span> the specified length.
</div></div>

Exactly. This is why it's best to have any barrel attachment on hand when do turning, threading, or blending. This is why one shouldn't just simply use a steady rest and chuck to do chamber and threading jobs. It can be done but there are steps that need to be taken prior to doing it this way.

Most will chamber or thread through the head stock using the chuck and spider so the run-out for the first few inches of barrel one is working on can be dialed out. One wants the bullet to start and leave straight. One doesn’t really care what the outside looks like it's the inside that matters.

Of course if the run-out is large then it can be a cosmetic issue but for the naked eye to visually see run-out looking down at the muzzle the run-out would have to be really large. I've seen this but it's rare and usually has no effect on accuracy of the barrel if it was dialed out during the work.

Most barrel installers will cut close to the finish length and will find where TDC of the run-out is and time that to the TDC of receive when the barrel is installed. Run-out in the bore not being properly timed to TDC or BDC is what causes most of the issues with lost windage in a scope.

This isn’t usually an issue with custom barrels, which are pretty straight, and are most commonly seen in factory barrels because they not only have lots of run-out issues but are also bore straightened at the factory with a press.

 

[Insayn]

Re: Can this thread protector be fixed ?

Side bar about the crown. There was a lot of carbon buildup from the chamber the old thread protector or brake left. The crown was a 11*. He told me he likes the portion of the crown closest to the bore to be perpidicular to the bore before it angles off for a more consistent gas escape as the bullet leaves the barrel (my own intrpretation). Is that feasible?