Cutting an inner barrel

[KaRcop]

Hey guys,

I'm looking at buying a Tanio Koba barrel from one of the forum members on here. The only thing is that it's too long for my M4 (roughly 100mm too long!). Is it possible to cut it down to size and how should I go about doing it? Please bear in mind I only have simple everyday DIY tools here.

Thanks!

[the_firing_dutchman]

Re: Cutting an inner barrel

I wondered about this too... is it a simple hacksaw job?

[N_Scooby]

Re: Cutting an inner barrel

Buy a 100mm silencer?

You could just hacksaw it off but you would have to be very careful not to kink/bend it. Afterwards just de-burr the outside with a file and inside with a stanley knife (blade held and turn the tube).

If you can find a tube cutter that will cut 8mm* OD tube then that would be better. B&Q sell them but not sure how small an OD they will cut. Also they could crush brass if you are too brutal.

* never measured the OD of an inner barrel, guess at 1mm WT.

If you haven't guessed, I work with tube!
My tube cutter will cut all sorts of exotic metal and cost a fortune!!

[N_Scooby]

Re: Cutting an inner barrel

I wondered about this too... is it a simple hacksaw job?

If you could hold the tube in a vice with soft-jaws, with just a tiny bit + what you want to cut off, hanging out - then yes. Fine hacksaw blade and smooth strokes so you don't grab and bend the tube. Just tidy all burrs when finished, and blow any swarf away.

[KaRcop]

Re: Cutting an inner barrel

Haha that was what I had figured! It might have to be a gentle clamp + carefuly hacksawing, finished with a file to de-burr and then sand the end smooth.

What I was interested most in was whether you need to re-crown the end of the barrel (some people are big on getting that right) or whether just making it nice n rounded would do the trick?

[Arnie013]

Re: Cutting an inner barrel

Ive tried both personally and it i cant see any difference in crowning or not (crowned looks a bit tidier i suppose) Drill the end GENTLY (ideally with a pillar drill but a vice and hand drill will suffice if done carefully.)with a 12mm or so drill bit until it has a nice chamfer on it and then remove burrs as described above.

[No1_sonuk]

Re: Cutting an inner barrel

How about trying to reproduce the original end?

Never needed to do it myself, but then my method would be different as I have a lathe...

[richardy]

Re: Cutting an inner barrel

your going to have very little if any resale value if you cut it, your better off just buying the right size.

[KaRcop]

For me, being able to use something is of more importance than selling what I'm about to buy. Thanks for all of the valuable information guys! This is why I love this forum! :-D

[Evilllamas]

Re: Cutting an inner barrel

the largest accuracy deciding factor of a barrel, is the very tip where the bb comes out of-this is why in many real steal firearms the rifling stops an inch from the end.
you could get away with hacksawing of the end that the hop up feeds maybe, but I dont recoment it.

[N_Scooby]

Re: Cutting an inner barrel

Making the end look pretty makes no difference to performance but will make sure there are no internal burrs that would hinder performance. A large drill or 45 deg. countersink will do the job and leave a professional looking finish.

[richardy]

Re: Cutting an inner barrel

th hop unit ends has important cuts i wouldnt cut there, but he is right some barrels have porting, and you also dont know what they have done, maybe the radius edge at the end is vitaly important or maybe it doesnt mater. TK twists are tricky at the best of times with setups. Its just not worth it.

And you should always think about the resale value as no airsofter holds on to anything for ever! And if i brought a barrel, not that id buy second hand, but if i brought one and found it to be cut, it would go right back!

[hapi]

Re: Cutting an inner barrel

the largest accuracy deciding factor of a barrel, is the very tip where the bb comes out of-this is why in many real steal firearms the rifling stops an inch from the end.
you could get away with hacksawing of the end that the hop up feeds maybe, but I dont recoment it.

Really I've looked down hundreds of barrel types and never seen rifling that stops short of the muzzle!

As for cutting a barrel down using a lathe is the best option, I've done this a couple of times with no problems

[jagillham]

Re: Cutting an inner barrel

Every time I see one of these threads makes me want to hit my head against the monitor. :eek:

People spend a lot of money getting a barrel which is perfect to a 10th of a millimetre. But then to gain a few cm extra length, hack it off with a saw.

No matter how much you file it, you can't get that accuracy back - so might aswell have kept the bog standard barrel in.

[KaRcop]

Re: Cutting an inner barrel

Fair play Jag... Didn't realise it could have that kind detrimental effect. As I'm looking at a TK twist, it's probably not worth it then? I'm trying to decipher the very mixed messages I'm getting here!!