TJ barrels for Impact - I Placed the order - more about grinding

[ironmonger]

A few years ago I was facing a similar situation. I was building a gauge pin to align a barrel using the method that SoCalTrail was referring to. While machining the gauge pin on my lathe is not impossible (my lathe has excellent headstock bearings) it is tedious.

The target diameter was .2168"

I started with a piece of .219 drill rod. The standard .22 cal bore dimensions are .217 (5.51) Bore Dia and .222 (5.64) Groove Dia. YMMV.

So I had .002" plus .0002" Tto remove for slip fit.

I did some research online and came up with this etchant for iron:

I used an iron etchant that is a 50/50 mixture of Copper Sulfate brine and Sodium Chloride brine. I found the mix on an artist website. It etches iron at about .001" per 10 minutes at room temperature. You need to clean the surface of any oxides, and grease. I wiped mine down with acetone. Hang it in the solution and set your timer. I snuck up on the size that I ended up with, .2175", gave a nice fit in my bore. 10 minutes then 5 and 2.5... this ain’t an exact science, but it's easier to take of a little bit and test fit it. Or you can let it go too long like my first one and have a pretty piece of scrap. It's going to look bad when you pull it out, all fuzzy and red, but wipe it off and dry it and drag out the mike. Hit with some oil before you store it.

A gauge pin needs to be a gentle fit so as not to scratch the bore.

The exact same method could be used to reduce the OD of your barrel to what ever size you need. I the case of a barrel I would plug the tube with a wax coated tapered wood dowel or a rubber plug. you don't want to etch the ID. Practice on a spare bit of barrel if you purchased more than you need.

This same method can be used reduce the diameter of a reamer or a drill bit by a few tenths.

But all this aside, any machinist or gunsmith would remove half a thou with a file or a strip of 1200 grit wet or dry soaked with a little oil backed up with a wood block . If you apply a little bluing or felt tip marker to the area in question it is pretty easy to see where you are in the polishing process.

What ever you decide, good luck with the build.

paul

 

[Azycray]

jarmstrong wrote:

Lee Vash [email protected]

I do not know if Lee can help you ,but it does not hurt to inquire.

I wrote to Lee and he responded in detail, I'll quote part here:

"The difficulty with the machining the barrel of that OD across it's length on a lathe is that the further you are away from the chuck holding the barrel in the lathe, the less rigid it is and tool chatter and deflection becomes a problem. The worse case scenario is the barrel would deflect and bend on the unsupported section and turn into a "helicopter" in the chuck beyond a certain distance. The best thing to use is a centerless grinder to take the small amount of material off....."

He confirmed what Steve at Pomona had told me, he had done it before but it is a long and tedious process and other colorful descriptions explaining that it is not a job he would enjoy. Both Steve and Lee's description of what it would take to do it on a lathe would cost more in labor than the cost of the grinder. So that seals it, I'll be sending the barrel to a centerless grinder and then to be fitted. I'm not sure how long this will take to get back and working since I also plan to send it to Ernest at FX for a power tune. But when I do get it back I will start a new thread to share the performance of a TJ barrel with slugs on helium.

 

[AirgunLR]

I know the ideal person who machines the TJ barrels with the best precision that is needed I have a 355mm long TJ and I shoot at 250 meters you can enter my instagram account @ airgunplusrd1 and see how I shoot at 125 meters and group of 0.8715 "inch at 100 meter with the 25.39gr .25 jsb my rifle is a warpcobra from what Jim gaske made and I talked to him that a friend wanted a barrel and he told me that he is not working on it. that there is a good machinist who now has all his tools and gave me bill greathouse's contact. He is a very good person and works perfectly well, dedicating himself to what he does

 

[AirgunLR]

I would like to try a TJ barrel for my Impact but have not had any success reaching them. I've searched and cannot find a web site. I've called and left a message because they don't answer the phone, but no return call. How does someone figure out what they need and what it will cost? I thought they made barrel liners, do they also make aftermarket barrels for air guns? How long of a barrel can you get? Do they fit it or do I have to send it to a gunsmith after I receive the barrel? Thanks for any help you can provide, RJ

I know the ideal person who machines the TJ barrels with the best precision that is needed I have a 355mm long TJ and I shoot at 250 meters you can enter my instagram account @ airgunplusrd1 and see how I shoot at 125 meters and group of 0.8715 "inch at 100 meter with the 25.39gr .25 jsb my rifle is a warpcobra from what Jim gaske made and I talked to him that a friend wanted a barrel and he told me that he is not working on it. that there is a good machinist who now has all his tools and gave me bill greathouse's contact. He is a very good person and works perfectly well, dedicating himself to what he does

 

[mtnGhost]

I've machined a few TJ .30cal barrels for the MKII that I had. It's a lot of work and the CrMoly barrels are hard on lathe tools. Don't be surprised if someone quotes you $1500 for the work.

 

[AirgunLR]

I've machined a few TJ .30cal barrels for the MKII that I had. It's a lot of work and the CrMoly barrels are hard on lathe tools. Don't be surprised if someone quotes you $1500 for the work.

In the United States there were only two people who machined TJ barrels, they were Jim gaske and Roy, Jim retired as much as they know and Roy does not know about him yet. but i talked to jim and he recommended bill to me greathouse he told me he now has all his tools to choke the barrels bill made me a TJ .30 to shoot slug for my RTI and now a friend told me to ask him what the price was for a TJ barrel for an impact and he told me that the price is 400 dollars, it is not every turner who knows how to machine a TJ barrel preparing a TJ barrel for what they know is very easy, it is not difficult as you think. That would happen with a I learned or someone who is going to steal your money, I am going to send him photos of the .30 barrel for the RTI 

 

[mtnGhost]

I've machined a few TJ .30cal barrels for the MKII that I had. It's a lot of work and the CrMoly barrels are hard on lathe tools. Don't be surprised if someone quotes you $1500 for the work.

In the United States there were only two people who machined TJ barrels, they were Jim gaske and Roy, Jim retired as much as they know and Roy does not know about him yet. but i talked to jim and he recommended bill to me greathouse he told me he now has all his tools to choke the barrels bill made me a TJ .30 to shoot slug for my RTI and now a friend told me to ask him what the price was for a TJ barrel for an impact and he told me that the price is 400 dollars, it is not every turner who knows how to machine a TJ barrel preparing a TJ barrel for what they know is very easy, it is not difficult as you think. That would happen with a I learned or someone who is going to steal your money, I am going to send him photos of the .30 barrel for the RTI 

I'd be real skeptical of $400 to turn a barrel on centers for all of the operations needed to fit a TJ in an Impact. What's his hourly rate?

 

[AirgunLR]

I've machined a few TJ .30cal barrels for the MKII that I had. It's a lot of work and the CrMoly barrels are hard on lathe tools. Don't be surprised if someone quotes you $1500 for the work.

In the United States there were only two people who machined TJ barrels, they were Jim gaske and Roy, Jim retired as much as they know and Roy does not know about him yet. but i talked to jim and he recommended bill to me greathouse he told me he now has all his tools to choke the barrels bill made me a TJ .30 to shoot slug for my RTI and now a friend told me to ask him what the price was for a TJ barrel for an impact and he told me that the price is 400 dollars, it is not every turner who knows how to machine a TJ barrel preparing a TJ barrel for what they know is very easy, it is not difficult as you think. That would happen with a I learned or someone who is going to steal your money, I am going to send him photos of the .30 barrel for the RTI 

I'd be real skeptical of $400 to turn a barrel on centers for all of the operations needed to fit a TJ in an Impact. What's his hourly rate?

friend if you do not know and you have not heard of Jim gaske go to google and you will find a user talking about him, Jim was one of the pioneers in mechanizing the TJ for his pcp weapons Warpcobrarifle and Flex. if today you have people who mechanize a TJ barrel. Well, I challenge you to use your TJ that I will use my TJ to make groups smaller than one inch at 150 meters. I only have 355mm in length you can use the length you want. I know the TJ barrel I have and I challenge anyone to make a 1-inch group at 150 meters. Everyone who today is machining TJ barrels is learned in front of Jim Gaske even Travis the one from JSaririfles that if he is a scammer he does not know about mechanization I bought him a TJ and he made me crap just as they believe a lot that they can mechanize a barrel TJ as I told you before, only in the United States there were two that mechanized these barrels super well structured Jim gaske and Roy, but today since they retired Jim prepared bill greathouse a good machinist

 

[BillG]

RDairguns023

Thank you for the kind words. I'm so glad that you got the performance that you are looking for.

As to the proper machining and prep for a good barrel, as has been discussed quite a while back. Well plainly stated, it true but.....is it relevant, that's the question. Personally, I feel like my barrels are too expensive until I set back and recall what all I have done to one. If I were to go thru all that was described, no way would they be affordable. The reality is concentricity is important to the mating, the crown(for perpendicularity and device mounting). I have yet to find a barrel that has better than .002" concentricity, LW or TJ. This can be an issue with the .25cal. In fact, I'm contemplating only offering them in .560 OD or larger to eliminate the inherent possible issues. Typically the blank is .499-.498 OD. So, I have to keep track of where that is. Better stated, I have to be aware and keep it in the vertical orientation to the receiver. This is further complicated in that this also has to be matched to any total indicated run out. I correct TIR to be .005 over 19". It is a PIA but not extraordinarily complicated, just requires attention. It is much easier if the bore is dialed in as center and the parts that aren't concentric, simply cut away until to size. This may make some of you go nuts but it is a fact nonetheless. The bullet could care less about the rout it takes between chamber and muzzle. The unrealized reality of barrel, especially hammer forged barrels, is they are not straight nor concentric. I believe the nature of the process imparts a very long helix to the barrel. It simply isn't reasonable or cost effective to believe or try to work that out of the barrel. Removing material simply displaces stress imparted by the manufacturing process. In the end you end up chasing a ghost or better, a shadow. You can't catch it even though it is attached to your feet. what we can control or manipulate is how true the bullet is accepted to that bore . Not just concentricity either. AT the chamber end, we have to be concentric with the bore as well as aligned axially. This is to ensure that the bullets center of form is true the the chambers center of axis. In turn, this has to hold true with the chamber and bore alignment. I have developed tooling and process that aid in my ability to achieve these conditions much more quickly than Jim used to be able to do. I wouldn't say the process changed, It just got more efficient. IMO, jim was simply working himself to death and I believe the attributed to some burn out. The bullet should have a congruent center of form and center of gravity, Bullets, cast and definitely swaged are darn good with this. Pellets on the other hand, can be a bit off, more than we'd think. This is another subject/variable for another day. For the sake of theory, we will assume that the bullets are true and perfect. So now we are aligned at the bore, in the chamber with a ever so slight rifling engagement. Ready to launch. Once fired this bullet will travel a path like a proverbial cork screw, stretched really long. It will maintain that concentric and axial alignment along this path as long as the bore is consistent. BTW, TJ barrel are very consistent with a mirror finish in the bore and grooves. Now comes the release. The crown should be concentric to the bore. More importantly, it MUST be perpendicular. The reality is, As long as this perpendicular plain and bore opening are relatively true with the chamber / bore alignment, you'll get good performance. What happened between these two factors really matters not. Did it start correctly, did it end correctly and relatively congruent with where it began? Did it leave with enough spin to stabilize the bullet ? You can grind between centers put a lot more effort and even precision into the problem. You may get a better result, I'll never know because IMO, the juice isn't worth the squeeze. Think about it, if the result are exactly the same, was it any better? 

What you need is a decent lathe and mill. I use a manual gunsmith Lathe and It's an import (Grizzly). It has improved spindle bearings and hardened ways. I have made some tooling that is specific to the task and it is easy enough to change out for other types of work. BUT... it is faster to dial thing in. You need really good metrology equipment and inspection tooling. Some of my measuring equipment will pick up my heart beat if I lean on the machine. You need patience and a real contemplation as to how to go from A to B. Have the process written and follow it. You need to ensure that your machine is trued and trammed correctly. I've gone to help guys set up machines in their garages and have the equipment straddle a crack in the floor. I tell them, either move it or I don't help. Yes, it is that big of a deal. Most of all, be intellectually honest with yourself. "Good enough", Has to be established before the work starts. If you find yourself saying good enough during the work and it doesn't match the determined standard, prior to the work beginning done or what is written, You are lying. You are cheating the people you are doing the work for and worse, yourself.

There isn't anything special about me other than I love solving the problem. I'm a tool maker by trade and training. I like to shoot but don't get to as much as I would like. when I'm not doing airgun stuff I'm making tooling for forming. Mostly tubing for power steering, AC and hydraulic lines. most of your automobiles out there have components that I've made tooling to make. I work more in the R&D and product development side of it but get dragged into production stuff when there is a problem. I like airguns because it is pioneering. The stuff we are seeing today would have been considered impossible 20yrs ago. I think there is more to be had. Airguns don't pay anywhere near as well as tooling but they are a lot more fun and now I can afford Beer LOL... Don't over work it but try to out think it. 

Bill

 

[qball]

Does anyone know that inner bore diameter of .22 TJ barrels? I got a TJ barrel from a member and so far shoots pellets fine but when I tried .217 slugs I lost 200FPS on the same exact gun and setting. I put one slugs into the barrel to see how it fits and it's extremely tight so I guess the bore is smaller than .217? I have some .216 slugs in route and hoping they would fit. Has anyone shot .22 slugs through their TJ barrels and mind sharing your results?



Thanks

 

[AirgunLR]

RDairguns023

Thank you for the kind words. I'm so glad that you got the performance that you are looking for.

As to the proper machining and prep for a good barrel, as has been discussed quite a while back. Well plainly stated, it true but.....is it relevant, that's the question. Personally, I feel like my barrels are too expensive until I set back and recall what all I have done to one. If I were to go thru all that was described, no way would they be affordable. The reality is concentricity is important to the mating, the crown(for perpendicularity and device mounting). I have yet to find a barrel that has better than .002" concentricity, LW or TJ. This can be an issue with the .25cal. In fact, I'm contemplating only offering them in .560 OD or larger to eliminate the inherent possible issues. Typically the blank is .499-.498 OD. So, I have to keep track of where that is. Better stated, I have to be aware and keep it in the vertical orientation to the receiver. This is further complicated in that this also has to be matched to any total indicated run out. I correct TIR to be .005 over 19". It is a PIA but not extraordinarily complicated, just requires attention. It is much easier if the bore is dialed in as center and the parts that aren't concentric, simply cut away until to size. This may make some of you go nuts but it is a fact nonetheless. The bullet could care less about the rout it takes between chamber and muzzle. The unrealized reality of barrel, especially hammer forged barrels, is they are not straight nor concentric. I believe the nature of the process imparts a very long helix to the barrel. It simply isn't reasonable or cost effective to believe or try to work that out of the barrel. Removing material simply displaces stress imparted by the manufacturing process. In the end you end up chasing a ghost or better, a shadow. You can't catch it even though it is attached to your feet. what we can control or manipulate is how true the bullet is accepted to that bore . Not just concentricity either. AT the chamber end, we have to be concentric with the bore as well as aligned axially. This is to ensure that the bullets center of form is true the the chambers center of axis. In turn, this has to hold true with the chamber and bore alignment. I have developed tooling and process that aid in my ability to achieve these conditions much more quickly than Jim used to be able to do. I wouldn't say the process changed, It just got more efficient. IMO, jim was simply working himself to death and I believe the attributed to some burn out. The bullet should have a congruent center of form and center of gravity, Bullets, cast and definitely swaged are darn good with this. Pellets on the other hand, can be a bit off, more than we'd think. This is another subject/variable for another day. For the sake of theory, we will assume that the bullets are true and perfect. So now we are aligned at the bore, in the chamber with a ever so slight rifling engagement. Ready to launch. Once fired this bullet will travel a path like a proverbial cork screw, stretched really long. It will maintain that concentric and axial alignment along this path as long as the bore is consistent. BTW, TJ barrel are very consistent with a mirror finish in the bore and grooves. Now comes the release. The crown should be concentric to the bore. More importantly, it MUST be perpendicular. The reality is, As long as this perpendicular plain and bore opening are relatively true with the chamber / bore alignment, you'll get good performance. What happened between these two factors really matters not. Did it start correctly, did it end correctly and relatively congruent with where it began? Did it leave with enough spin to stabilize the bullet ? You can grind between centers put a lot more effort and even precision into the problem. You may get a better result, I'll never know because IMO, the juice isn't worth the squeeze. Think about it, if the result are exactly the same, was it any better? 

What you need is a decent lathe and mill. I use a manual gunsmith Lathe and It's an import (Grizzly). It has improved spindle bearings and hardened ways. I have made some tooling that is specific to the task and it is easy enough to change out for other types of work. BUT... it is faster to dial thing in. You need really good metrology equipment and inspection tooling. Some of my measuring equipment will pick up my heart beat if I lean on the machine. You need patience and a real contemplation as to how to go from A to B. Have the process written and follow it. You need to ensure that your machine is trued and trammed correctly. I've gone to help guys set up machines in their garages and have the equipment straddle a crack in the floor. I tell them, either move it or I don't help. Yes, it is that big of a deal. Most of all, be intellectually honest with yourself. "Good enough", Has to be established before the work starts. If you find yourself saying good enough during the work and it doesn't match the determined standard, prior to the work beginning done or what is written, You are lying. You are cheating the people you are doing the work for and worse, yourself.

There isn't anything special about me other than I love solving the problem. I'm a tool maker by trade and training. I like to shoot but don't get to as much as I would like. when I'm not doing airgun stuff I'm making tooling for forming. Mostly tubing for power steering, AC and hydraulic lines. most of your automobiles out there have components that I've made tooling to make. I work more in the R&D and product development side of it but get dragged into production stuff when there is a problem. I like airguns because it is pioneering. The stuff we are seeing today would have been considered impossible 20yrs ago. I think there is more to be had. Airguns don't pay anywhere near as well as tooling but they are a lot more fun and now I can afford Beer LOL... Don't over work it but try to out think it. 

Bill

my dear friend, it is a pleasure and a great honor to speak of you. you deserve to be recognized by everyone who likes air pistols and more. In the market there are no good barrels like yours, I feel very happy every time I take a long-distance shot and hit where I put the center of the scope, in this airgun market there is more business than reality. most kegs are not as good as yours. I only see that the youtube only make groups at 50 and 80 meters. they don't make good groups like you do, barrels at 100 and 150 meters, I want everyone to know what a great man you are. congratulations friend God bless you and thank you for being here welcome

 

[AirgunLR]

Does anyone know that inner bore diameter of .22 TJ barrels? I got a TJ barrel from a member and so far shoots pellets fine but when I tried .217 slugs I lost 200FPS on the same exact gun and setting. I put one slugs into the barrel to see how it fits and it's extremely tight so I guess the bore is smaller than .217? I have some .216 slugs in route and hoping they would fit. Has anyone shot .22 slugs through their TJ barrels and mind sharing your results?



Thanks

I think the bullet is not as tight as a .22 surely there is a loss of air around the bullet, which you feel slides more smoothly .22 vs .217

 

[qball]

So I figured it’s either too tight or too loose so I tried to push a slug through and it won’t move at all, I tried from the muzzle end and even worse because of the choke so pretty sure it’s too tight. I’m actually surprised that the pellet didn’t jam when I tried to shoot it. 


hope to have the .216 slugs here by next weekend to test. 

 

[AirgunLR]

So I figured it’s either too tight or too loose so I tried to push a slug through and it won’t move at all, I tried from the muzzle end and even worse because of the choke so pretty sure it’s too tight. I’m actually surprised that the pellet didn’t jam when I tried to shoot it. 


hope to have the .216 slugs here by next weekend to test.

Friend, the slug is still mounted on the grooves but now with that slug that you are using the diameter is reduced from .22 to .217 the slug is not blocking all the air that it should use when you shoot you have a waste, which slug you use in. 22 and when grains and what rifle is using

 

[qball]

So I figured it’s either too tight or too loose so I tried to push a slug through and it won’t move at all, I tried from the muzzle end and even worse because of the choke so pretty sure it’s too tight. I’m actually surprised that the pellet didn’t jam when I tried to shoot it. 


hope to have the .216 slugs here by next weekend to test.

Friend, the slug is still mounted on the grooves but now with that slug that you are using the diameter is reduced from .22 to .217 the slug is not blocking all the air that it should use when you shoot you have a waste, which slug you use in. 22 and when grains and what rifle is using

I see what you are saying but if I can’t push it at all then that’s a different story. Slugs can‘t be reshaped as easy as pellets because Of the large contact area. The slugs are already .217 so the barrel must be quite a bit tighter, hope .216 would shoot well....fingers crossed. Also I don’t hear the swooshing sound when too much air rushes out and best I can do is 600 FPS, needless to say it’s no where near accurate. Btw it was on my impact.


has anyone shot slugs through a .22 TJ barrel? 

 

[AirgunLR]

So I figured it’s either too tight or too loose so I tried to push a slug through and it won’t move at all, I tried from the muzzle end and even worse because of the choke so pretty sure it’s too tight. I’m actually surprised that the pellet didn’t jam when I tried to shoot it. 


hope to have the .216 slugs here by next weekend to test.

Friend, the slug is still mounted on the grooves but now with that slug that you are using the diameter is reduced from .22 to .217 the slug is not blocking all the air that it should use when you shoot you have a waste, which slug you use in. 22 and when grains and what rifle is using

I see what you are saying but if I can’t push it at all then that’s a different story. Slugs can‘t be reshaped as easy as pellets because Of the large contact area. The slugs are already .217 so the barrel must be quite a bit tighter, hope .216 would shoot well....fingers crossed. Also I don’t hear the swooshing sound when too much air rushes out and best I can do is 600 FPS, needless to say it’s no where near accurate. Btw it was on my impact.


has anyone shot slugs through a .22 TJ barrel?

friend you will never be able to slide a slug with ease as you do with a pellet the pellet is marked in two small parts, the slug how you can see it is marked most of it always be much tighter, the TJ barrels have the grooves very alive and you grip a lot to the slug, another question your barrel TJ is for pellet Or slug, ?? and I recommend that you better try with the slug, 22 Or .223 look friend most of that slug .217 .216 are made for the STX fx barrels because its grooves are very weak and can come out easily. Unlike a TJ barrel that the grooves are alive and fit much more to the slug and due to the diameter, being smaller, there is space in the barrel and the air escapes that can give it the speed you need

 

[qball]

No idea if the barrel is for slug or not, it’s .22 and 1:18 twist rate, got it second hand. Not the fastest but should be fine, will see how the .216 slugs do since it’s on the way already. If that doesn’t work I’ll try .218. 

 

[AirgunLR]

qball 

Friend, our Tj barrels with the choke that they have at the end of the barrel, that takes away the speed of the bullet and if you use the slug with a smaller diameter, you will have less speed, I recommend that you use .22 or .223 so that you do not waste air, this slug They are not made for a shock barrel, they are made for STX OR a polygonal LW I recommend that instead of reducing the diameter of the slug you go up to .22 O.223 anything warns me, you can follow me on my instagram account @ airgunplusrd1

 

[qball]

Thanks I’ll try the larger diameter slugs after .216 since it’s on the way anyways. 

 

[AirgunLR]

Gracias, probaré las babosas de mayor diámetro después de .216, ya que de todos modos está en camino.

friend is that the .216 is not larger diameter is smaller diameter of the barrel. where is your problem is in the strangled the slug in that part they stop all they will plow the same but the .217 .216 will give you little Fps because it loses air when shooting because the slug is not sealing the caliber of the barrel that is .22 look The slug with a caliper and you will see that the diameter of the barrel will be wider, as I told you, this slug was not made for the Tj, if not to try to give precision to the STX barrels and more speed, the STX barrels will never be even half precision of a TJ barrel, the more bullets it adjusts to the barrel, the better precision you will have, I recommend using .22 or .223 and increasing the power of your weapon because you never think you can use a slug with the same power that you use for pellets, I recommend using regulated high pressure and you will see how your slug will fly at the speed of light