Was wanting to thread some of my barrels n was wondering what i need to use to dial the bore in any help ? thanks
Gunsmithing muzzle threading
- Thread starter themayor
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Re: muzzle threading
I use PTG range rods with the appropiate bushing(s) and indicators that read to at least .0005" or better yet .0001". Works for me.
I use PTG range rods with the appropiate bushing(s) and indicators that read to at least .0005" or better yet .0001". Works for me.
Re: muzzle threading
how exactly do range rods with bushing work i get what you do after they are in the bore but get how mount in the with the bushings n how do you know what bushings to get?
how exactly do range rods with bushing work i get what you do after they are in the bore but get how mount in the with the bushings n how do you know what bushings to get?
Re: muzzle threading
http://www.pacifictoolandgauge.com/products/gaugesnbushings/indicatorrods.htm
This is who's stuff I use
http://www.pacifictoolandgauge.com/products/gaugesnbushings/indicatorrods.htm
This is who's stuff I use
Re: muzzle threading
Just put a file and a die on it. It'll work....
OK, in seriousness:
The range rods will function though I find them to be less repeatable than just reaching down the bore with a long fingered indicator. For muzzle work anything with an indicator finger over 1/2" will work dandy.
Save yourself the cost of the range rods and spend the money on a really good 0.0002 or 0.0001 indicator
Just put a file and a die on it. It'll work....
OK, in seriousness:
The range rods will function though I find them to be less repeatable than just reaching down the bore with a long fingered indicator. For muzzle work anything with an indicator finger over 1/2" will work dandy.
Save yourself the cost of the range rods and spend the money on a really good 0.0002 or 0.0001 indicator
Re: muzzle threading
How are you using the indicator on the bore? Im sure im probably missing something but I had to ask out of curiosity. I dont have any real gunsmith experience but do have some machine tool experience.
How are you using the indicator on the bore? Im sure im probably missing something but I had to ask out of curiosity. I dont have any real gunsmith experience but do have some machine tool experience.
Re: muzzle threading
I think you are seeing a dial indicator in your head. It is designed to measure movement in a line passing through the center of the dial, and is the most commonly seen indicator. The type of indicator used to measure directly on the bore surfaces is a dial test indicator. This type of indicator measures movement at 90 degrees to to dial. You can do a search online and see the difference.
When I thread a barrel for a muzzlebrake or a suppressor I use my dial test indicator directly on the bore. I indicate a place as far in the bore as my indicator will reach, and a second place just inside the crown. When those two places are both running .0002" or less with the lathe warmed up, I start cutting.
I think you are seeing a dial indicator in your head. It is designed to measure movement in a line passing through the center of the dial, and is the most commonly seen indicator. The type of indicator used to measure directly on the bore surfaces is a dial test indicator. This type of indicator measures movement at 90 degrees to to dial. You can do a search online and see the difference.
When I thread a barrel for a muzzlebrake or a suppressor I use my dial test indicator directly on the bore. I indicate a place as far in the bore as my indicator will reach, and a second place just inside the crown. When those two places are both running .0002" or less with the lathe warmed up, I start cutting.
Re: muzzle threading
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Orwapitihunter</div><div class="ubbcode-body">I think you are seeing a dial indicator in your head. It is designed to measure movement in a line passing through the center of the dial, and is the most commonly seen indicator. The type of indicator used to measure directly on the bore surfaces is a dial test indicator. This type of indicator measures movement at 90 degrees to to dial. You can do a search online and see the difference.
When I thread a barrel for a muzzlebrake or a suppressor I use my dial test indicator directly on the bore. I indicate a place as far in the bore as my indicator will reach, and a second place just inside the crown. When those two places are both running .0002" or less with the lathe warmed up, I start cutting. </div></div>
And just how are you making these readings with the indicator bouncing off of the rifling?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Orwapitihunter</div><div class="ubbcode-body">I think you are seeing a dial indicator in your head. It is designed to measure movement in a line passing through the center of the dial, and is the most commonly seen indicator. The type of indicator used to measure directly on the bore surfaces is a dial test indicator. This type of indicator measures movement at 90 degrees to to dial. You can do a search online and see the difference.
When I thread a barrel for a muzzlebrake or a suppressor I use my dial test indicator directly on the bore. I indicate a place as far in the bore as my indicator will reach, and a second place just inside the crown. When those two places are both running .0002" or less with the lathe warmed up, I start cutting. </div></div>
And just how are you making these readings with the indicator bouncing off of the rifling?
Re: muzzle threading
I think the indicator that I had pictured was correct but the bouncing from land to groove is what i was concerned about. When ive indicated parts before i was spinning the headstock by hand so i assume thats the same case here. The indicator moving that much especially on a .0001 indicator seems like it may be hard to follow but that could just be how im picturing it. Im sure if you turned it slow enough it wouldn't be an issue. The pressure on the finger is probably so little it wouldn't damage the bore too considering it probably has the ball tip.
I think the indicator that I had pictured was correct but the bouncing from land to groove is what i was concerned about. When ive indicated parts before i was spinning the headstock by hand so i assume thats the same case here. The indicator moving that much especially on a .0001 indicator seems like it may be hard to follow but that could just be how im picturing it. Im sure if you turned it slow enough it wouldn't be an issue. The pressure on the finger is probably so little it wouldn't damage the bore too considering it probably has the ball tip.
Re: muzzle threading
You have to read just the grooves or just the lands. A rigid base is essential to get good reads, as the tip will try to deflect and ride the curve. With a bit of practice it all makes good sense.
You have to read just the grooves or just the lands. A rigid base is essential to get good reads, as the tip will try to deflect and ride the curve. With a bit of practice it all makes good sense.
Re: muzzle threading
Yep it bounces. But rolling it slowly by hand it is no problem to read the bottom of the grooves. The indicator that I use has .008" total travel which can handle the approx. .004" difference between the top of the land and bottom of the groove. The tip of the indicator has a small ball that helps it climb over the land. The amount of pressure the tip of the indicator puts on the bore is slight. I haven't seen any damage to the bore.
Yep it bounces. But rolling it slowly by hand it is no problem to read the bottom of the grooves. The indicator that I use has .008" total travel which can handle the approx. .004" difference between the top of the land and bottom of the groove. The tip of the indicator has a small ball that helps it climb over the land. The amount of pressure the tip of the indicator puts on the bore is slight. I haven't seen any damage to the bore.
Re: muzzle threading
Would be nice if someone made a series of rods that were bore sized and had relief's ground in them with specific land count and twist. Just insert with twisting motion. That way one could get away from any possible muzzle erosion.
Would be nice if someone made a series of rods that were bore sized and had relief's ground in them with specific land count and twist. Just insert with twisting motion. That way one could get away from any possible muzzle erosion.
Re: muzzle threading
We have a large set of pin gauges from our machine work and FAL building days(from .060-.500 in .001 steps)and if a range rod isn't handy in the dia needed we'll carefully select a pin to ride the lands and indicate off of that. The only issue is that it only provides about .80" to read off of.
The idea of a set of range rods reverse rifled to fit specific calibers, number of lands, twist rates, and varied bore size is novel. But could you imagine the size of that set just for one bore size? Holy cow!
We have a large set of pin gauges from our machine work and FAL building days(from .060-.500 in .001 steps)and if a range rod isn't handy in the dia needed we'll carefully select a pin to ride the lands and indicate off of that. The only issue is that it only provides about .80" to read off of.
The idea of a set of range rods reverse rifled to fit specific calibers, number of lands, twist rates, and varied bore size is novel. But could you imagine the size of that set just for one bore size? Holy cow!
Re: muzzle threading
Rifled pins wouldnt be practical for the reasons mentioned above. Deltronic pins are available IIRC in .0001 increments but are a little pricey. Kenda like you I had a hard time visualizing how reading directly with the dti would work. After just giving it a try it is an incredibly simple and effective way to indicate the bore before machining. I plan on trying the long gritters style indicating rods in the near future and evaluating any potential advantages to this method.
Rifled pins wouldnt be practical for the reasons mentioned above. Deltronic pins are available IIRC in .0001 increments but are a little pricey. Kenda like you I had a hard time visualizing how reading directly with the dti would work. After just giving it a try it is an incredibly simple and effective way to indicate the bore before machining. I plan on trying the long gritters style indicating rods in the near future and evaluating any potential advantages to this method.
Re: muzzle threading
Is it possible to just have large balls (Ha ha!) on the end of an extended indicator that will just ride the lands and show a very minimal jump in the grooves?
The pin guage option is great to have for many reasons but if you have a set then you know how expensive they are for a quality set. Not really the most cost efficient solution.
Is it possible to just have large balls (Ha ha!) on the end of an extended indicator that will just ride the lands and show a very minimal jump in the grooves?
The pin guage option is great to have for many reasons but if you have a set then you know how expensive they are for a quality set. Not really the most cost efficient solution.
Re: muzzle threading
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kenda</div><div class="ubbcode-body">Is it possible to just have large balls (Ha ha!) on the end of an extended indicator that will just ride the lands and show a very minimal jump in the grooves?
The pin guage option is great to have for many reasons but if you have a set then you know how expensive they are for a quality set. Not really the most cost efficient solution.</div></div>
I suppose you could set it up to read only the tops of the lands. When I set up the muzzle end I dial to the bottom of the grooves I know this is like separating the fly sheit from the pepper but it makes sense to me. I like looking at the land ht and checking for consistency. I recently had a barrel that had 2 lands that were as much as .0018" shorter than the other 4 lands.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kenda</div><div class="ubbcode-body">Is it possible to just have large balls (Ha ha!) on the end of an extended indicator that will just ride the lands and show a very minimal jump in the grooves?
The pin guage option is great to have for many reasons but if you have a set then you know how expensive they are for a quality set. Not really the most cost efficient solution.</div></div>
I suppose you could set it up to read only the tops of the lands. When I set up the muzzle end I dial to the bottom of the grooves I know this is like separating the fly sheit from the pepper but it makes sense to me. I like looking at the land ht and checking for consistency. I recently had a barrel that had 2 lands that were as much as .0018" shorter than the other 4 lands.
Re: muzzle threading
My .02 is that indicating the lands is not the most accurate way to indicate the centerline of the bore with the centerline of the spindle, that method would be ok just for a brake but i still wouldn't recommend it. I beleive the correct way is to use use a indicator rod from ptg with the correct pilot and then use two indicators to find centerline and also correct for a barrel that isn't strait- no barrel is-.
My .02 is that indicating the lands is not the most accurate way to indicate the centerline of the bore with the centerline of the spindle, that method would be ok just for a brake but i still wouldn't recommend it. I beleive the correct way is to use use a indicator rod from ptg with the correct pilot and then use two indicators to find centerline and also correct for a barrel that isn't strait- no barrel is-.
Re: muzzle threading
I guess it all depends on which camp you are from.....grooves vs lands. A land is going to be what the rifle is bored to, but the groove is what the bullet is gonna slug up to. I know that an indicator riding on the surface it is indicating has a lot more chance of reading 100% than a bushing that has to have clearance to get in the hole to start with. Another way to skin this cat is by using a loose fitting bushing and a weight to keep it on top of the lands, indicate off of that. It allows the machinist to choose an infinite depth to choose from.
I guess it all depends on which camp you are from.....grooves vs lands. A land is going to be what the rifle is bored to, but the groove is what the bullet is gonna slug up to. I know that an indicator riding on the surface it is indicating has a lot more chance of reading 100% than a bushing that has to have clearance to get in the hole to start with. Another way to skin this cat is by using a loose fitting bushing and a weight to keep it on top of the lands, indicate off of that. It allows the machinist to choose an infinite depth to choose from.
Re: muzzle threading
The guy that shot and built the last two world champion BR rifles, indicates off the grooves. Uses a long ( 2" approximately ) nose on the Starrett Last Word indicator and shoots for zero runout. Holds the barrel in a spider.
Does the same exercise on the spider on the opposite end of the barrel/headstock.
He usually gets the zero runout too. Said that it is just patience to get it most of the time.
The guy that shot and built the last two world champion BR rifles, indicates off the grooves. Uses a long ( 2" approximately ) nose on the Starrett Last Word indicator and shoots for zero runout. Holds the barrel in a spider.
Does the same exercise on the spider on the opposite end of the barrel/headstock.
He usually gets the zero runout too. Said that it is just patience to get it most of the time.
Re: muzzle threading
Mike, that is what I do too. I bought a b&s .00005" indicator and plan to get a long stylus for it. I figure I am too hamfisted to dial anything in to that level, bit the loss in accuracy of the long stylus should be made up by the gauge accuracy. I have the starrett teeter totter that can be used to reach in about 2.5" too.
Mike, that is what I do too. I bought a b&s .00005" indicator and plan to get a long stylus for it. I figure I am too hamfisted to dial anything in to that level, bit the loss in accuracy of the long stylus should be made up by the gauge accuracy. I have the starrett teeter totter that can be used to reach in about 2.5" too.
Re: muzzle threading
The amount of slop you are talking about is pretty dang minimal, but when you add the cost of a stack of rods and bushings to end up with a measurement that you can't duplicate every time you set it back up....it starts to make sense. Pins, rods, centers and direct reading gauges.....they have all produced winners, but imo, only a direct measurement can be dead repeatable and account for a crooked bore.
The amount of slop you are talking about is pretty dang minimal, but when you add the cost of a stack of rods and bushings to end up with a measurement that you can't duplicate every time you set it back up....it starts to make sense. Pins, rods, centers and direct reading gauges.....they have all produced winners, but imo, only a direct measurement can be dead repeatable and account for a crooked bore.
Re: muzzle threading
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kenda</div><div class="ubbcode-body">
The idea of a set of range rods reverse rifled to fit specific calibers, number of lands, twist rates, and varied bore size is novel. But could you imagine the size of that set just for one bore size? Holy cow! </div></div>
I would envision this as only being practical for a shop or manufacturer that is working with a huge number of the same barrel/rifling type.
My thought on this is that the customary range rod indexes on the rifling which is supposedly the "untouched" part of the barrel blank while the "grooves" are what is formed by the rifling process. Which one affects the bullet "direction" most? Which "index" is the most accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kenda</div><div class="ubbcode-body">
The idea of a set of range rods reverse rifled to fit specific calibers, number of lands, twist rates, and varied bore size is novel. But could you imagine the size of that set just for one bore size? Holy cow! </div></div>
I would envision this as only being practical for a shop or manufacturer that is working with a huge number of the same barrel/rifling type.
My thought on this is that the customary range rod indexes on the rifling which is supposedly the "untouched" part of the barrel blank while the "grooves" are what is formed by the rifling process. Which one affects the bullet "direction" most? Which "index" is the most accurate?
