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Posted: Fri Jan 11, 2008 8:52 am
by jackssmirkingrevenge
What's the minimum calibre you can rifle?

Posted: Fri Jan 11, 2008 8:54 am
by SpudGunGuy
Ragnarok wrote:Sounds impressive, but until someone successfully rifles copper pipe, I'm going to have to wait. I'm not too fussed about accuracy, if I can hit it reliably from a safe firing distance, that's more than good enough for me, but I wouldn't mind trying a rifled barrel some time and seeing how it improves things.

What I have to ask is... how do you think that Joel might have got 5 lands and 6 grooves in his rifling? Unless I'm greatly mistaken, that's completely impossible - the numbers have to be the same.

I also compliment you on your writing ability, I'm sure one day I'll be wandering around here and find the corpse of the murdered english language hidden behind one of the threads in the combustion showcase.
First off let me apologize for the obvious mistake; That should have read 6 lands and grooves, too many beers before writing a post I suppose :-).

As for copper barrels, I have been getting into these as well and have thought about how to rifle them. What size barrels do you typically use? Maybe I could make a prototype or two and you could "pay" for them by firing (and logging) hundreds of rounds to test accuracy differences.

P.S. Mech Assult Rules!!!
jackssmirkingrevenge wrote:What's the minimum calibre you can rifle?
I have done 1 inch barrels, but it is a real pain in the A@@! I prefer to go no smaller than 1.5 inches however, as I said before, if I make this a full time venture, I will most likely do barrels from 1 inch to however large someone wants.
SpudMonster wrote:omg wtf guys? its not liek were in englsh classs so shut the he11 up! y do u have to be so bithcy and shyt?/ your so stupid lol sorry if i dont spend 10 extra minutes checking spelling and grammar, i just type it and enter it, if it bothers u so much u shouldnt even be on this site. im annoyed bcuz instead of ppl answering my ?s they just go on about my spelling when i only mispelled 2 words
Damn. After typing that I feel like I need to scrub my brain with turpentine and a wire brush.

How do you make the rifling lands different profiles? Do you have to make a different cutting head for each profile? I regret not purchasing a rifled barrel from Joel way back when, so I might wind up purchasing one now.
In brief, I use a miniature router to cut the grooves. Please see my earlier post for more details.

Posted: Fri Jan 11, 2008 8:56 am
by SpudGunGuy
SpudMonster wrote:omg wtf guys? its not liek were in englsh classs so shut the he11 up! y do u have to be so bithcy and shyt?/ your so stupid lol sorry if i dont spend 10 extra minutes checking spelling and grammar, i just type it and enter it, if it bothers u so much u shouldnt even be on this site. im annoyed bcuz instead of ppl answering my ?s they just go on about my spelling when i only mispelled 2 words
Damn. After typing that I feel like I need to scrub my brain with turpentine and a wire brush.

How do you make the rifling lands different profiles? Do you have to make a different cutting head for each profile? I regret not purchasing a rifled barrel from Joel way back when, so I might wind up purchasing one now.
In brief, I use a miniature router to cut the grooves. Please see my earlier post for more details.

Posted: Fri Jan 11, 2008 9:00 am
by SpudGunGuy
jackssmirkingrevenge wrote:What's the minimum calibre you can rifle?
I have done 1 inch barrels, but it is a real pain in the A@@! I prefer to go no smaller than 1.5 inches however, as I said before, if I make this a full time venture, I will most likely do barrels from 1 inch to however large someone wants.

Posted: Fri Jan 11, 2008 9:41 am
by Ragnarok
Rifled 1" pipe would be a good thing. Rifling would be best on a low calibre launcher in the style of a rifle, and 1.5" is getting too large for that in my opinion. They have been done, but it seems too much to me.
As for copper barrels, I have been getting into these as well and have thought about how to rifle them.
Well, I think part of the difficulty lies in the thin walls, which you can't cut deep enough into. The best idea I currently have is some how creating some lands that sit inside the barrel, rather than cutting grooves.
What size barrels do you typically use? Maybe I could make a prototype or two and you could "pay" for them by firing (and logging) hundreds of rounds to test accuracy differences.
That sounds interesting, but the difficultly is that I live in the UK, and my launchers are created to fit UK metric copper sizes. That problem along with shipping means I'll have to regretfully decline your offer.

It would be nice to have a rifled launcher though, and you've swayed me towards trying to do it myself. I've still got the nearly impossible challenge I was "set" of trying to hit a 5" square target at 500 yards, and that's going to need rifling or stabilised darts (or both!), so I'd better get cracking.
P.S. Mech Assult Rules!!!
I would agree, but my username wasn't chosen after the Ragnarok mech from the game (my personal favourite mech is the Star Adder from Mechassault 2 - pity you only get to use it in the single player for less than half a level, and the Blood Asp simply isn't as good in my opinion). My username is just because I like Viking mythology.

Posted: Fri Jan 11, 2008 11:00 am
by SpudGunGuy
Ragnarok wrote:Rifled 1" pipe would be a good thing. Rifling would be best on a low calibre launcher in the style of a rifle, and 1.5" is getting too large for that in my opinion. They have been done, but it seems too much to me.
I agree.
SpudGunGuy wrote:As for copper barrels, I have been getting into these as well and have thought about how to rifle them.
Ragnarok wrote:Well, I think part of the difficulty lies in the thin walls, which you can't cut deep enough into. The best idea I currently have is some how creating some lands that sit inside the barrel, rather than cutting grooves.
Actually, you can buy brass tubing that fits very nicely inside a piece of copper pipe. The fit is not snug but not too loose either. My suggestion:

1 - Cut the Grooves first on the "inner" barrel. Thes could go all the way through.

2 - Coat the outside of the "inner barrel" with a fine layer of solder (this is called tinning).

3 - Slather the outside of the "inner barrel" with flux and slide it into the "outer barrel"

4 - Now heat the "outer barrel" so that the inner and outer barrels fuse together.

5 - Ta-da! A rifled copper (and brass) barrel!!!

Hmmm, maybe I'll try doing that myself this weekend. Nothing like mixing a hot torch, flux, solder and booze!!!
SpudGunGuy wrote:What size barrels do you typically use? Maybe I could make a prototype or two and you could "pay" for them by firing (and logging) hundreds of rounds to test accuracy differences.
Ragnarok wrote:That sounds interesting, but the difficultly is that I live in the UK, and my launchers are created to fit UK metric copper sizes. That problem along with shipping means I'll have to regretfully decline your offer.
Ragnarok wrote:It would be nice to have a rifled launcher though, and you've swayed me towards trying to do it myself. I've still got the nearly impossible challenge I was "set" of trying to hit a 5" square target at 500 yards, and that's going to need rifling or stabilised darts (or both!), so I'd better get cracking.
SpudGunGuy wrote:P.S. Mech Assult Rules!!!
Ragnarok wrote:I would agree, but my username wasn't chosen after the Ragnarok mech from the game (my personal favourite mech is the Star Adder from Mechassault 2 - pity you only get to use it in the single player for less than half a level, and the Blood Asp simply isn't as good in my opinion). My username is just because I like Viking mythology.
Ahhh, Gotterdammerung!

Posted: Fri Jan 11, 2008 11:39 am
by Novacastrian
That sounds like a very reasonable way to make a rifled copper barrel. Can you please post pics if you get around to making one!

Posted: Fri Jan 11, 2008 12:02 pm
by Carlman
yes can we have pictures of the final product, that is a picture looking down a rifled pvc pipe?

You couldn't post a picture of your machine could you?
There is probably no chance of that, but anywho lol

Posted: Fri Jan 11, 2008 3:03 pm
by jimmy101
SpudGunGuy wrote:Actually, you can buy brass tubing that fits very nicely inside a piece of copper pipe. The fit is not snug but not too loose either. My suggestion:

1 - Cut the Grooves first on the "inner" barrel. Thes could go all the way through.

2 - Coat the outside of the "inner barrel" with a fine layer of solder (this is called tinning).

3 - Slather the outside of the "inner barrel" with flux and slide it into the "outer barrel"

4 - Now heat the "outer barrel" so that the inner and outer barrels fuse together.

5 - Ta-da! A rifled copper (and brass) barrel!!!
I've wondered for a long time if you couldn't just fuse a slinky inside a PVC barrel to make rifling. :P

Or, for metal barrels you could skip the cutting of the inner barrel (to form the lands) and just use say 1/16" square copper stock. Wrap it in a coil, coat with flux and solder, insert in barrel, untwist to force the coil against the outer pipe wall, nuke the barrel with a torch to weld.

Posted: Fri Jan 11, 2008 3:35 pm
by MrCrowley
Ragnarok wrote:my launchers are created to fit UK metric copper sizes.
Ok Seriously for the last time, NPT works with BSP.

I myself have tried it many many times with fittings direct from America, and I know some Aussies also have tried it.

I do know brass and copper fittings all work with NPT as well.

I don't know how many times I need to tell people this, NPT and BSP are perfectly fine together.

Yes some pipe may have a different I.D but they all have the same O.D for their relative size and all the threads are perfectly compatable.

Posted: Fri Jan 11, 2008 4:18 pm
by DYI
The threads aren't "perfectly compatible". BSPT threads have a different angle, as well as rounded rather than square tops on the threads. They can be used together, but it isn't a good idea if you're planning on pressurising them. For a barrel, it probably doesn't matter.

And spudmonster, has it ever ocurred to you that if you were familiar enough with the English language, that you wouldn't have to check over your posts for ten minutes to find grammar and spelling mistakes? I've never used spellcheck on a post for months. My grammar is the way it is not because I go over and correct it afterwards, but because I naturally write like that. Reading is a probably a better way to improve your language skills than English class anyway.

Posted: Fri Jan 11, 2008 5:10 pm
by MrCrowley
DYI wrote:The threads aren't "perfectly compatible". BSPT threads have a different angle, as well as rounded rather than square tops on the threads. They can be used together, but it isn't a good idea if you're planning on pressurising them. For a barrel, it probably doesn't matter.

I'm talking BSP not BSP-Tapered threads.

You can see the difference <A HREF="http://www.newmantools.com/taps/bsp.htm">here</a> and <A HREF="http://en.wikipedia.org/wiki/ISO_228">here.</a>

I think you thought BSPT meant 'British Standard Pipe Thread'?
Well BSP Just means 'British Standard Pipe' and BSPT is 'British Standard Pipe Tapered'.

The only BSPT fittings i've ever seen are the ones for gas. Other then that i've never seen tapered threads on a fitting us spudders would use whether it's a NPT or BSP fitting.

Posted: Fri Jan 11, 2008 5:13 pm
by DYI
I know what BSPT stands for, and am rather confused: Almost any threaded fittings used for our purposes use tapered threads, at least in Canada. Straight threads in pressure applications are only commonly encountered on compression and flared fittings, and the CGA fittings on compressed gas cylinders. All of the normal hardware store fittings use tapered threads, to aid with sealing.

Posted: Fri Jan 11, 2008 5:18 pm
by MrCrowley
Ah I see what you mean
Image

I just realised it's the gas fittings that have straight threads and the other ones that are tapered. The gas fittings i'm talking about is the one in the bottom right corner.

Still i've used tapered threads in conjunction perfectly. Have a look at my SGP all metal gun:
http://www.spudfiles.com/forums/viewtop ... tml#123928

I explained somewhere what fittings are NPT and which ones are BSP, lemme find it hold on.

Edit:

Middle of the page, with the pictures of my gun, I explain which fittings are which.
http://www.spudfiles.com/forums/viewtop ... tml#143479

With pipe dope or teflon tape I haven't had any problems.

Posted: Fri Jan 11, 2008 5:39 pm
by ALIHISGREAT
Actually, you can buy brass tubing that fits very nicely inside a piece of copper pipe. The fit is not snug but not too loose either. My suggestion:

1 - Cut the Grooves first on the "inner" barrel. Thes could go all the way through.

2 - Coat the outside of the "inner barrel" with a fine layer of solder (this is called tinning).

3 - Slather the outside of the "inner barrel" with flux and slide it into the "outer barrel"

4 - Now heat the "outer barrel" so that the inner and outer barrels fuse together.

5 - Ta-da! A rifled copper (and brass) barrel!!!

Hmmm, maybe I'll try doing that myself this weekend. Nothing like mixing a hot torch, flux, solder and booze!!!
wouldn't tinning be a PITA i would get a really good fitting outer barrel and just use epoxy to secure it in there instead of tinning, or you could just solder it normally.

and as for the small caliber barrels someone should really make a rifling machine that can rifle copper down to 15mm... any volunteers :P

edit: @rag: if you wanted to rifle copper it would have to be lots of micro-grooves in my opinion, no faffing about with outer barrels and the micro grooves would look cool too 8)