Sleeving FX .25 STX Supreme liner

[nervoustrigger]

All I can say is fortunately I don’t hold a grudge.  I say my piece and then tomorrow is a new day.

[Rallyshark]

All shenanigans aside, I think the silicone sealant would be fine to use on an FX gun with an FX shroud.  After all, the shroud is what actually stiffens the setup.  On a non-FX gun, I agree the fitment should be tight and rigid, since there is no shroud and nut setup to tighten things up.  At that point, the carbon(and or steel) sleeve is handling all the stiffness.  I prefer to go with a snug fit between the liner and the carbon layers in that case. 

I've found easier for me to open up the ID of the carbon until the liner fits inside, as opposed to using some sort of bushings or o-rings.  I use the slow cure 2 ton epoxy when the fitment is very tight, and JB Weld when there is a little more wiggle room.  I have no doubt the Loctite solutions would work just as well.  I usually use enough carbon to take my barrel OD up to at least 16mm, and also use another 20mm carbon sleeve and bushings to go around that(due to the guns I'm doing it on).  20mm is the perfect tight fit going through the barrel/rail supports, and it really stiffens the whole gun up.  I also make an LDC adapter to fit onto the last couple inches out of 7075 to keep the weight down.  I secure that with eight 4-40 set screws and JB Weld.  So far that has worked very well for me, with my limited machining skills 

[mackeral5]

Begs me to ask.  I have a Bulldog upper I want to tension.

It is a Bulldog upper, barrel shortened 1 inch to remove the flat at the muzzle, barrel sticks out of the shortened shroud and is threaded 5/8-18 with a nut and does not vent into the shroud. 

What would you fellows use to fill the shroud around the barrel, and how much pressure would you tighten the barrel nut on the muzzle?

Hope Mike does not feel I am stealing his thread, just felt with all the experts here would be a good time to ask before everyone goes to fist-i-cuffs.

Regards,

Roachcreek

IMO, the key to accuracy in the Bulldog is ensuring the shroud/rail stays 100% in sync with the barrel.  Im sure there are many methods to accomplish this task.  In the absence of being able to fabricate my own aluminum spacers, I use additional rear shroud adapters from Crosman and make brass shims so that they fit the 5/8 sections the barrel.  The rear shroud adapter is made to much tighter tolerances, then it also has the oring groove to make it even tighter of a fit..... On my TJ barreled gun, it is sleeved up to 19mm, so I actually bored out  2 rear shroud adapters to fit.  The shroud attaches to the adapters with both the top screw and I added a SHCS to each side.   Amazingly, the scope holds zero after a complete teardown, I believe due to this shroud/barrel attachment method. 

Some of the BD tuners create a shoulder on the barrel, just forward of the breech, and tension against that shoulder vs. against the breech.  Considering what I stated above about the Bulldog barrel/shroud/rail relationship this method makes perfect sense to me.....

[Glem Chally]

Its funny Matt chose to call out Ernest here where Ernest doesn't post. (That i know of)

Why don't you post this stuff on AGN Matt?  See if you can get him to explain himself to you.

[Lani52]

I have an extra aluminum barrel block,  I replaced after I cross threaded the retaining screw,  I considered using it for that until I saw it was slightly under sized at the muzzle end.  Simple task to drill and tap it a size larger and shim it

Also considerably less mess that a nearly blind man trying to pour JB weld down the tube around the barrel, I mean what could go wrong?

Should I put tension on it with the barrel nut?

My Bulldog also goes to zero after tear downs and reassembly, but I remove the barrel/shroud assembly in one piece via the barrel retention screws.  I have lasers on all but one airgun for the one and only  purpose of re zeroing  the poi after I play musical scopes or tear downs, which I do so often. 

Thanks Mike,

Roachcreek

[Rallyshark]

I have an extra aluminum barrel block,  I replaced after I cross threaded the retaining screw,  I considered using it for that until I saw it was slightly under sized at the muzzle end.  Simple task to drill and tap it a size larger and shim it

Also considerably less mess that a nearly blind man trying to pour JB weld down the tube around the barrel, I mean what could go wrong?

Should I put tension on it with the barrel nut?

My Bulldog also goes to zero after tear downs and reassembly, but I remove the barrel/shroud assembly in one piece via the barrel retention screws.  I have lasers on all but one airgun for the one and only  purpose of re zeroing  the poi after I play musical scopes or tear downs, which I do so often. 

Thanks Mike,

Roachcreek

That's a good idea with the lasers!  It had not even occurred to me to use them in that way.  That certainly could make life easier after a tear down to get the scope back in the ball park quickly. 

[mackeral5]

I have an extra aluminum barrel block,  I replaced after I cross threaded the retaining screw,  I considered using it for that until I saw it was slightly under sized at the muzzle end.  Simple task to drill and tap it a size larger and shim it

Also considerably less mess that a nearly blind man trying to pour JB weld down the tube around the barrel, I mean what could go wrong?

Should I put tension on it with the barrel nut?

My Bulldog also goes to zero after tear downs and reassembly, but I remove the barrel/shroud assembly in one piece via the barrel retention screws.  I have lasers on all but one airgun for the one and only  purpose of re zeroing  the poi after I play musical scopes or tear downs, which I do so often. 

Thanks Mike,

Roachcreek

RC, I have very limited experience with tensioning.   I will say I would much prefer a tensioning method that involved using belleville washers vs just tightening against the shroud.  I don't have any experience to base that opinion on, but it just makes better sense to me, with regards to predictability and repeatability.   I was not a fan of the WAR tensioning method, for example.  I think how tight you torque it has to do more with thread pitch than anything else.  Edguns are tensioned firmly against the shroud, I do not believe they have any form of belleville washer/spring, I've read they are torqued between 15 and 20ftlbs. 

I would focus on making the shroud/barrel one stiff, stable unit vs. tensioning, but that is just me.  This is primarily due to the way the BD is set up, with the scope mounted to the shroud vs. breech.  For a breech mounted scope I can definitely get my head around the value of barrel tensioning. 

[JoeShmoe]

Anyway, not that anyone was really hung up on this in this thread besides me, but permeability seems to be a selling point for a relatively new kind of carbon fiber. So, regular stuff isn't going to let oxygen seep through at any appreciable rate. Your caulk in the middle of your sleeve might not ever harden, but the ends would still hold it in place without too much trouble.

Anyway, probably not the best idea.

If anyone needs permeable carbon fiber I found some for you. https://www.compositesworld.com/articles/porous-carbon-fiber-permeable-adsorptive-and-conductive

[mtnGhost]

Hmmm, I figured that I would sleeve a couple of my 22 cal STX liners in an attempt to form solid units. I found some cheap uni-directional tubing that would slip comfortably over the liners, and some pricier high modulus (HM) tubing that would sleeve over it.

Only one little problem- I got my wires crossed as I placed the order (late at night), and the OD of the thin uni tubing is 0.380", whereas the ID of the thicker wall HM tubing is 0.375" 😭. I think what screwed me up was my "plan B", where I thought about sleeving the liners with the uni tubing, and then sleeving that with 3/8" stainless tubing that I have.

So now, if I chose to commit to "plan A", aka the lighter-weight double CF tubing option, I would need to bore out the HM just enough to sleeve the uni tube and some Loctite (maybe ~0.030").

I guess I'll just have to experiment with boring operations/ process with some of the HM tubing. I have spun some on my lathe before, and it was not a great experience (delamination, nasty airborne particles, etc).

[mtnGhost]

Dup (forum shenanigans)

[KnifeMaker]

We Knife Makers learned long ago if working with
 
CF to use a very good respirator. CF is air born when worked and puts tiny shards of very sharp particles in the air.
They damage lung tissue and never leave the lungs. think floating micro fish hooks here.


Very dangerous!  And sadly, or foolishly, I have gotten in a hurry several times now and flat forgot to put the mask on. GRRRRR!!!


Knife

[KnifeMaker]

Its funny Matt chose to call out Ernest here where Ernest doesn't post. (That i know of)

Why don't you post this stuff on AGN Matt?  See if you can get him to explain himself to you.

I think the answer  to that is rather obvious Glem. His remarks are safe here for the time being. (such antics got him banned here long ago) How he snuck back in is puzzling.


This is almost Anti Fx. Why I have no idea. But Earnest is not well known here, nor is his long and distinguished history. On AGN he is very well known and Matt's antics would, if worded the same, make him more enemies in one thread than you could imagine.


Yes, he is intelligent, but that in itself does not excuse his rudeness or arrogance.


There is one other member here that I will not have anything to do with due to his berating people he disagrees with. I find such rudeness inexcusable. I'm sure you know exactly who I am referring to Glem.


Knife 

[PikeP]

Its funny Matt chose to call out Ernest here where Ernest doesn't post. (That i know of)

Why don't you post this stuff on AGN Matt?  See if you can get him to explain himself to you. (That i know of)

Fixed your post. I have posted to the likes of this on AGN...I don't understand why you continue to add fuel to a fire that is already extinguished.

[mtnGhost]

We Knife Makers learned long ago if working with
 
CF to use a very good respirator. CF is air born when worked and puts tiny shards of very sharp particles in the air.
They damage lung tissue and never leave the lungs. think floating micro fish hooks here.


Very dangerous!  And sadly, or foolishly, I have gotten in a hurry several times now and flat forgot to put the mask on. GRRRRR!!!


Knife

Great point. I learned my lesson when I had a fiber splinter in the back of my throat. I quite literally HATE working with it for that and other reasons. You have to treat it like fiber insulation (or good ol' asbestos). Nasty, nasty stuff!

I'm using EF-120 / Hysol to bond this time FWIW

[mackeral5]

Hmmm, I figured that I would sleeve a couple of my 22 cal STX liners in an attempt to form solid units. I found some cheap uni-directional tubing that would slip comfortably over the liners, and some pricier high modulus (HM) tubing that would sleeve over it.

Only one little problem- I got my wires crossed as I placed the order (late at night), and the OD of the thin uni tubing is 0.380", whereas the ID of the thicker wall HM tubing is 0.375" 😭. I think what screwed me up was my "plan B", where I thought about sleeving the liners with the uni tubing, and then sleeving that with 3/8" stainless tubing that I have.

So now, if I chose to commit to "plan A", aka the lighter-weight double CF tubing option, I would need to bore out the HM just enough to sleeve the uni tube and some Loctite (maybe ~0.030").

I guess I'll just have to experiment with boring operations/ process with some of the HM tubing. I have spun some on my lathe before, and it was not a great experience (delamination, nasty airborne particles, etc).

Where did you find this .375 ID CF tubing?

[mtnGhost]

Hmmm, I figured that I would sleeve a couple of my 22 cal STX liners in an attempt to form solid units. I found some cheap uni-directional tubing that would slip comfortably over the liners, and some pricier high modulus (HM) tubing that would sleeve over it.

Only one little problem- I got my wires crossed as I placed the order (late at night), and the OD of the thin uni tubing is 0.380", whereas the ID of the thicker wall HM tubing is 0.375" 😭. I think what screwed me up was my "plan B", where I thought about sleeving the liners with the uni tubing, and then sleeving that with 3/8" stainless tubing that I have.

So now, if I chose to commit to "plan A", aka the lighter-weight double CF tubing option, I would need to bore out the HM just enough to sleeve the uni tube and some Loctite (maybe ~0.030").

I guess I'll just have to experiment with boring operations/ process with some of the HM tubing. I have spun some on my lathe before, and it was not a great experience (delamination, nasty airborne particles, etc).

Where did you find this .375 ID CF tubing?

Rockwest Composites. I meant to sdd that it fits around te .25 liners perfectly too.

[darkcharisma]

I love rockwest! price is just right too.

[mackeral5]

Thanks for that info.  Previously I relied solely upon Ebay vendors for my CF needs, nice to see additional items to choose from.  The .375 x .503 is very attractive should I decide to put the .25 liner in my B51.....Thanks again.

[mtnGhost]

Thanks for that info.  Previously I relied solely upon Ebay vendors for my CF needs, nice to see additional items to choose from.  The .375 x .503 is very attractive should I decide to put the .25 liner in my B51.....Thanks again.

No problem! I've had some of the ebay / Amazon / Chinese made tubes, and I can say that even this thin unidirectional tube is stronger than those "3K roll wrapped" tubes (that like to delaminate if I look at them wrong).

[YEMX]

It's been gone over before, but which would be best for our needs- Unidirectional?  High Modulus?  Filamet wound?  I think Unidirectional, but I'm not an engineer though.