Setting up a gun barrel in the lathe

morning this is josh at mass gun works here in the sunny cold snowy converse indiana um i've had some questions about ways to hold rifle barrels in the lathe and i've come up with some solutions and i was going to share those with you there's a guy named kurt vaughn who has a youtube channel bond precision excellent gunsmith uh this is partly inspired by a conversation i was having with him about holding rifle barrels that are too short to go through my headstock so what we're gonna do is i'm gonna walk you through a couple different setups one thing that i've had to learn to overcome is if i have a certain way to do something that i like but the thing that i need to work on is not going to allow me to do it that way i have to figure out a different way to do it okay okay some point i need to thread a barrel right but it's too short for me to do it the way that i traditionally do it okay and the way that i traditionally was taught to do it is this way so i pass the barrel through the headstock i have a hollow spindle that turns this chuck it's approximately inch and a half in diameter and that gives me the ability to manipulate that barrel on the front and the back and i use a dial indicator with a gauge pin or a what to call range rod in the bore of the barrel and i want to try and get both ends of that barrel running true or concentric is the technical term um so that that's the way that i was taught to do this so i'm gonna have my camera person come in here real quick and we're gonna take a shot and you can see that i have this held in a four jaw chuck and i have roughly dialed it in with a 1 000th indicator where i didn't get it perfect because you know i'm not actually cutting i'm just filming this barrel is running about two to three thousands to run out right now i could get it down to say two to three tenths of a thousandth so that's that's really really dialed in so now we'll come around to the back and on the back this lathe is a grizzly g0709 yes and it is a gunsmith specific lathe um one of the things that makes it a gunsmith specific lathe is it has this thing called a spider that's built into the spindle essentially i have a four jaw chuck on the front and on the rear okay and this allows me through four points of contact to push this barrel up and down and side to side and i can hang a dial indicator off of here and i can dial this side in and i can dial this side in or if i want i can just use a pin and i can do everything from the front so you know there's lots of different ways my limitation that i have so this is a 27 inch barrel blank okay it's it's really not an issue for me to do this this way in this lathe but i'm going to take this barrel out i'll show you a little problem find the chuck key all right slide this out the back by the way this is a 50 caliber barrel blank from green mountain barrels it is beautiful and i am in the middle of a project i'm going to build myself a bolt action based off a savage 110 receiver and we're going to build a 50 action express bolt action it's going to be awesome so we're going to set this aside right now and okay so we're going to measure through my head stock and we're going to see what my limitation is here now to do this properly i have to be able to pass the barrel all the way through and i have to be able to get the end of it onto these spiders okay so i'm hooking the end of the bore i measure into the front the jaws before jaw chuck and i need at least um probably an inch and a half to two inches sticking out that way i can safely work without getting my tool too close to my chuck and risk striking check with the tool which would completely ruin my day so to the to the front face of the chuck we're at exactly 21 and 3 8 of an inch long okay so i need about 23 inches of barrel to comfortably work in a manner that i feel safe to do it with this method okay so you ask well why does that well riddle me this batman um say we're threading an ar-15 bear okay this barrel is 16 and a half inches long i'm five inches shy of being able to run through the headstock like i was taught to okay so the the biggest thing that i have to overcome is how i do this all right well there are two different methods one that i just kind of realized and one that has kind of been a mainstay of how things are machined on lathe since they were invented it's called going between centers so we go between centers and i'll set that up you have a face plate with a dead center and a live center or a dead center over here and you're gonna pinch your work in between two points and typically you're going to find a hole in the center of either side and that's where you're gonna pinch it okay um with an ar-15 barrel that's that's a little difficult because if you see inside that extension i've got about a half inch of distance i have to overcome before i can get into the bore so i can have a good center point of rotation okay and they do they do make some different centers um that would allow you to reach in there and overcome that but it's probably not going to work real well with this one so we're going to keep the camera running and i am going to as quickly as i can get this changed over this leg has what is called a d1 style cam lock spindle so i instead of having to chuck the threads on i have these cams that i turn and they lock the chuck in place the great thing about this is i don't have to worry about being careful when i'm wanting to turn something with the chuck going uh counterclockwise because there's no risk of the chuck spinning itself off of the threads that are holding it to the lathe okay i'll show you the back of the chuck this is called d15 and the the d1 i believe is the type someone can correct me out there in youtube land if i'm wrong the next number is the size typically you'll see like a d14 d16 d14 has three pins d16 has six pins and d15 is kind of like an in-between size okay face plate make sure we have all of our chips out of the way so we don't run into a concentricity issue because we have a chip between the face of the plate and the nose of the spindle cause a problem ruin your day put that on there because this is a demonstration i'm not actually working i'm not going to run through tightening all the pins basically what you want to do is you want to you want to tighten them and then we're going to go back around and just double check and make sure all good and tight so with a six pin head i typically do every other pin um in an order like i'm tightening um lugs on on a car wheel so i have two things my spindle is a morse taper five i have a sleeve that's going to adapt from that to morse taper three so i'm gonna make sure these are good and clean slip them together this is just a friction fit okay i'm gonna slap that in there so there's one center then we're going to get our live center you could do this with a dead center on this end as well but you would need to have some lubricant okay to keep from getting too hot because since that center's dead it's not moving your part is you're creating a lot of friction okay there's two different types i have a standard and a long reach i use this one when i thread but just for the purposes of demonstration we're going to use this so we're going to take our tail stock put our center in and i need a volunteer as you know we'll just use our arrow once again because that's what's there for this is a different one this is a 223 barrel blank i'm probably going to use this for like a 22 250. so we're going to take that put it in there so i know you're thinking well how's it going to turn well you have this thing called drive dog okay drive dog clamps are on the outside of the object and if you'll come over here and show the surface of that plate there a little bit more okay this is going to lock in right here okay as the lathe rotates this dog is gonna hold that barrel i'll actually set this up so you can see how it works okay so we're going to get this locked down we're going to very very gently feed this in until we find our hole right there okay all right so that is there lock this so this doesn't retract turn this around so we get this tightened up and typically i'll take a a shim of wood or something and put it in between the drive dog and the top surface of the barrel we didn't mar it up but essentially that's how that works okay so as this turns turns here i've got these in the bore so this outside surface is running concentric as as best as it can to the line of the bore now when i'm cutting threads on a barrel to fit into receiver or to [Music] fit it for a muzzle break or a suppressor it is extremely critical that i am cutting my threads in line with the bore axis and not in line with whatever the outside of the barrel is running okay because these barrels some makers are great some makers or so so you can have as much as five thousands of run out on the outside surface as it compares to the bore okay so it's why you want to make sure you're doing everything and you're cutting threads on a barrel based off the bore all right and this is an old school method this has been around for thousands of years this is how it's been done forever running through the headstock is a relatively new method when you look at how long lathes have been in use okay it's a good method it's a very good method but as i showed you before i'm limited by the length of my headstock so now we're going to move on to method number three and if any of you out there have questions or you have a method that you come up with that works for you please share in the comments my biggest goal here is not to be like an ultimate purveyor of knowledge but just to share things that i've learned and to give you guys a conversation starter if you have something that has worked well for you in the past you'd like to share with the group now this is my public service announcement i know not everybody's going to agree with me and haters gonna hate all right so keep it respectful if you don't agree with what i'm doing it is what it is don't make me feel like an idiot you know everybody's learned okay so i've got a wood block here to protect my bedways take my surface plate off sorry face plate nothing one thing that i forgot to incorporate into that setup and i'll throw it in this next one okay this is called steady rest right and i'll show you what this does here in a minute but basically this is going to provide a way to keep your work from wobbling because as i move away from the supported end with my tool and i'm putting pressure in it's going to start to bow my work okay it's going to be minimal on a piece of metal okay especially steel you may not be able to see it with your naked eye but it is there this provides support somewhere in between my points and allows me to have minimal deflection okay so i'm going to put this on one thing i want to do before i do that is make sure that these ways are clear chips because this is going to ride on the ways the last thing i want to do is get some chips in the way and scratch up my bedways because the bedways are the life of your lathe and if they suck guess what the lane sucks okay so make sure that's good and clean so this clamps down basically i can put any position i want um with within the limitations of the track on the bedway and the side up here so we gotta pop this out and i have a center get router tool it doesn't take much force to pop these out see and then i don't like to keep these stuck together so there we go i am going to switch the long reach center for this one because this is how i typically do this and i want to show you a way that i truly do it and not just simulate okay so these are called 5c collets all right they are made to grip round parts and they're they're pretty stinking accurate um my collet chuck that i have i don't have a collet closer that's a lever that holds back here and it runs through and it like sucks the collet into the headstock i went the less expensive route and i got one of these collet chucks and i have been able to consistently turn up on my witness marks dial this chuck in within less than a half of a thousandth of run out based on the nose of the chuck and again i'm just going to tighten two of these because it's just a demonstration so let me get my calipers okay the limitation here is these collets are only going to flex uh say five out so if i have a part that i want to hold that is 745 000 so it's 5 000 shy being exactly three quarters of an inch i could most likely grip that with a three quarter inch collet okay because i've got a little bit of give there so this ar-15 barrel as we've stated is too short to go through my headstock and because of this barrel extension is probably not a really good idea for me to try and run it between centers just because i'm not getting good contact with the actual four axis okay now that being said this extension is threaded and tightly fitted to this barrel okay this surface needs to be in line with the bohr axis okay so if i grip here in theory and this is proved out to be true for me many times i am gripping something that is close enough to concentric with this bore axis that i'm not going to have a huge risk of something on this end being off from the axis of the bore okay so the trick is i need to have the right size collet so what size do we want so i have sarah coded this actually my son cerakoted it did a great job um right now i am looking at put that back where it was um one inch and one and a half thousandths okay so i happen to have a one inch collet is in this collet chuck now so i'm gonna open up my steady rest i want to take this barrel and i'm going to put it in this collet chuck okay we're going to get that up close to that pin right there the indexes that way you know you put that in straight every time and we're going to tighten down our collet chuck okay now i do not in any way shape or form just want to leave the rest of it to chance so i'm going to put my live center in here now i'm not going to cram it in there okay i'm gonna just get it seated okay now it did move just a little bit but what i've done if i i have essentially mounted this barrel between centers okay this is just a different method same concept and because i'm gonna be working on this end i'm gonna and i should have done this earlier when i set up the other barrel so you get the full money but we're going to take this and say i've got my threading tool in here okay see i've got my threading and tooling here run this in and you can see i'm only working on the front half inch of the barrel you can see that i've got sufficient room okay i got sufficient room to work even with this thing here so what this does it's got some bearings on it to rotate i'm sure a lot of you are getting bored by this because you're like oh no i know i run away little machinist blah blah blah yes some of us are not we need visuals so we run these down until they just start to rotate typically you're going to start with the ones on the bottom do the top and last i do it backwards so sue me okay and we are supported okay i've got some lock screws i can lock that place so that being said i can take um take the center out if i need to and i can work on that and it it'll it'll be in there um just to further demonstrate this i still have my 1000s indicator let me be clear about something if i am working on a rifle and i want to have an extremely high degree of accuracy i will dial this in to um you know tents okay if i am working on a barrel and i am simply fitting it for a suppressor or i am um this may not work out too well fortunately my little thingy here is in the way where i am putting muzzle brake on it if it's not a rifle that requires uh extreme precision like somebody's you don't want to shoot a thousand air competition they're just they got an ar or a 300 blackout that they're only going to shoot out to 200 yards i will dial this in to a half of a thou that way that i ensure that i am not going to have a baffle strike okay baffle strikes are bad they will destroy your suppressor and if you're the gunsmith that did that unfortunate work you're in trouble jimmy uh because you potentially put someone's life in danger and they will sue you okay so we've got the range rod now we have put our bare between centers and i have run this rod in the bore and my goal here is just to show you how close i am uh just by supporting it with the steady rest and that collet and i've used the live center as a reference point to get the other end zero if i can i'm sorry i'm a little anal okay so we we may see uh one to two thousand run out but as soon as i pop that live center back in there that's gonna go away over here cameraman focus in on the dial indicator and we're gonna pray and hope that we don't look stupid okay do you see how little run out we have i am less than a thousand and i know that the camera may not be able to pick that up but i i'm probably between a half and a three quarter of a thousand using this setup okay so let's go ahead and trade places um go ahead and back up so you get the whole thing in view so anyway the point of this whole video here was i just wanted to show an alternate method for uh holding a barrel in a way that will allow you to cut accurate threads or accurate enough so you're not you know causing a bath strike on a suppressor which honestly that's my biggest worry so i try to do every barrel the same way every time okay this may or may not be accurate enough for you if you're wanting to do chambering i have collets that are big enough that i can fit a savage barrel in there it's a 1.055 by 20 thread and i don't remember what nominal size 1.055 is i want to say it's like 1 32nd ish but i have a collet that's that size and i can hold the savage barrel in there by the tenon put a center it thread it i have had to work on some savage barrels where the customer wasn't threaded i have to cut it down to 19 inches before i can do the threat not going to fit through my headstock i'm not going to be able to dial in like i was taught same thing with the remington okay remington is a inch and a 16 by 16 thread okay i have an inch and a 16th 5c collet specifically for that and again because of the diameter of the barrel profile i have to cut the barrel down so i have to meet on the end put the threads on now i can't go through my headstock now i have a problem this setup right here is quick it's reliable and it's consistent okay that's the biggest thing and i i've got about two to three thousands of cerakote on the end of this extension if this was a fresh barrel with no cerakote on it it would probably have less runout okay um but anyway you get the idea so again if you have questions comments want to start a discussion um feel free to leave it in the comments below this video my email is mast gun works m-a-s-t g-u-n-w-o-r-k gmail.com feel free to email me questions um i'm no expert i'm learning like everybody else but this is something i found that works great so until next time i have some other things that i plan to throw out there i just got a multi-fix tool post for this baby i'm going to be selling this alors style potentially and all my tooling goes with it so if you need a tool post send me an email and i'll be more than happy to make your deal this is my milling machine i know i've done some videos with them in the past this is a wells index 645 i've recently learned some neat things about it that i didn't know and i'm going to make some videos about the different features that are on it right now so and you know i briefly exposed the uh the tormach pcnc 1100 that i have over there and i'm still in the process of learning god love john saunders nyccnc he's a great teacher i'm still mucking through learning fusion 360 in cam and when i get better at that i'll start making some videos about uh cranking out parts on that so thank you guys that have been follow me and subscribe to the channel if this was helpful hit the like button love to have you subscribe so we'll see you next time

Channel: Mast Gun Works

Views: 8,758

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Id: qNCH2FvYcQg

Length: 34min 54sec (2094 seconds)

Published: Tue Feb 02 2021