Cutting barrels?

[Sam Pascoe]

I am looking to R-Hop my CM16 srxl.

I am wanting to use the Prometheus tight bore barrel (6.03) but I can't seem to find one with the same barrel length (330mm).

 

Would it be okay to buy a longer barrel and cut it size? Obviously removing any burrs 

 

Any help is appreciated

 

Many thanks 

 

[Hangtight]

You can't just cut a barrel. The muzzle has a carefully and accurately cut profile known as the crown which is critical to accuracy. Unless you have access to a lathe then you won't get this right and you've just ruined a decent barrel.

Why not just get the next shortest one down so it fits completely in the outer barrel. Accuracy won't be affected, and as long as it's fairly close then the cylinder volume should be fine.

You could also practise the R hop on the G&G barrel. They're actually quite good, and unless the rest of your gun is maxed out you wouldn't tell the difference between that and the Prometheus. Save yourself fifty quid and spend it on decent 0.28g BBs.

[Sam Pascoe]

Okay thank you for the help, I think I'll get the shorter option, I'm new to teching and I'm looking forwards to the learning! 

 

Many thanks! 

[AshOnSnow]

It's not as simple as just going mental with hacksaw for the ultimate DIY CQB thrasher. Inner barrels are cut to very precise spec, and have a particular angle at the end which can only be done with a lathe. Just think - one of my pistols was getting BBs jamming up inside the barrel because there was a tiny speck of dirt on the inside that was stuck fast until I spent 15 minutes cleaning and polishing it. Imagine what trouble bits of metal shavings, a bent barrel and a splayed ends will do.

 

Just buy the shorter barrel and save yourself a whole lot of money and trouble.

[Samurai]

But if you have some DIY skills, you can do it with hand tools. I made cuts with an angle grinder using a metal cutting disc. Use a dremel or a bigger metal drill bit to give it a crown.

Get the metal and dirt out with a good hosing and cleaning and then wipe it dry with the cleaning rod.

Finally, use a scalpel / hobby knife to remove any leftover protruding brass. Look into the barrel from the other end towards a light and you will see a thin black line where there is still a protrusion. Insert the scalpel carefully, not touching any other part of the barrel, and turn the barrel around the scalpel so it cuts off the edge of the crown. Repeat until there is no visible black line at the crown looking at a light source.

[Sam Pascoe]

Would I sacrifice any range of accuracy by getting a shorter barrel? 

[Hangtight]

Nope, not unless you go really short, as in less than 200mm.

[Hangtight]

You can make a good job of cutting and crowning a brass barrel with a few basic tools. I've just done one by hacksawing it to length, then spinning it in a cordless drill so I could file the end square and use a countersink bit held in a pair of vice grips to cut the crown. After that it's just a case of using a couple of grades of wet n dry abrasive paper wrapped around a small stick to polish up the cut and the crown. That took about five minutes.

 

Not so easy with a stainless steel barrel!

[CARBr6]

On 08/08/2017 at 11:18 PM, Hangtight said:

You could also practise the R hop on the G&G barrel

 

This is probably answered somewhere (if not then perhaps a teching sticky could be created!), what is R-Hopping?

[warlord]

6 hours ago, CARBr6 said:

 

This is probably answered somewhere (if not then perhaps a teching sticky could be created!), what is R-Hopping?

 

A pirate after you steal his wooden leg?  I'll get me coat

[Prisce]

Use the search feature sir.

In short, it is a modification you do to a barrel, by placing a little bit of rubber/pipe/whatever you use over the window in the barrel, it helps with hop, and allows your gun to lift higher weight BBs easier.