Cutting down inner barrels

[Point_Man]

Is it possible to use a pipe cutter on inner barrels? If so, what other issues need to be addressed. Thanks.

[The Saint]

Yes, careful not to apply too much pressure while cutting. Remember to crown the barrel afterwards. Some barrels (such as MB) may have a special finish on their bore that might fray/chip/flake with sawing. Always better not to cute a barrel, if all possible.

[ILLusion]

Yes, just go very slow, and finish off the edges after you're finished.

I wouldn't recommend doing to any type of coated barrel, though. The coating will damage and flake off.

You may also want to crown the end as well, but if you have the tools (a lathe) to turn a crown in to it, then you'll also have the tool to properly turn the length down.

[Point_Man]

Right on. Thank you very much for the responses. I believe I can find the proper tools for the job.

[Buzzrexx]

IMHO, I would NEVER use a pipe cutter- the pressure that the cutter puts inward as it rotates and cuts will flare the barrel into itself, resulting in a smaller opening at the end.

I have the advantage of being able to use a steel lathe for the job; if you don't have this luxury, I'd use a hacksaw (very gently and patiently) to cut the length. Try to keep your cut as straight as possible. Then use sandpaper and a sharp X-acto knife to remove the burrs and smooth off the end.

[m102404]

I've seen more than a few barrels poorly done with a pipe cutter...the cutter bulges both the inside and the outside of the tip...you can correct it by deeply crowning the inside of the barrel and filing the outside, but it's more work than just cutting it properly in the first place.

Score a line with a pipe cutter...or even a knife blade...so you know where you want to finish to. A hacksaw will make short work of cutting through a barrel. Go slow and gentle, let the saw do the work. The cut won't be perfect...so finish with a file, again go slow and steady, key is to hold the barrel steady with a vice (or you can clamp it to a table and file up and down if you don't have a bench vice). I use the disc portion of my bench top sander...takes about 3seconds.

You can deburr the inside with a large drill bit...just spin/press the bit into the barrel by hand...it'll be enough to crown a brass barrel. Finish with a "cone" of fine wet/dry sandpaper (600-120grit). Straight and even is the key.

If you want to practice...cut it about and inch longer than your finished length, finish it off, inspect/shoot it and if it's all good, go for finished length.

Best of luck

Tys

[Point_Man]

Hey this is great. I really appreciate the different experiences in options. A practice barrel is a good idea. I do believe I have one lying around here that I don't need.

[Rabbit]

Necro.

Have there been any further discoveries of a good way to do this?

The HK416 inner barrels seem to have a length i've never delt with at like 283someodd mm.

I currently have a Prometheus 6.03 363mm that I have just sitting here and they have quite the rep of being the best and i'd really like to replace my stock one.

Airsoftparts.ca doesn't seem to carry a madbull in the 280s only 300mm which i'd rather not cover up with a silencer etc..I like my cqbs.

I'm considering just doing the clamp on the table with a hacksaw..thoughts?

[cetane]

Dremel tool with a cut off wheel. Then clean up & crown end.

[Renegade)]

Originally Posted by cetane

Dremel tool with a cut off wheel. Then clean up & crown end.

Yep! Cut on fast, and be precise. You dont want to go slow or youll risk chipping the inner surface. When your done, just sand or wire brush the edge, you can flare it if you wish.

[ArcticFox1984]

...

[coach]

plug the end of the barrel you are cutting with a bit of cloth to prevent filling it with filings. remove the plug from the end you just cut. the last thing you want to do is to mar up the barrel surface while cleaning it or dragging the plug with bits of metal along its length.

[Rabbit]

Shit thats a good idea plugging it up.

Luckily I have a dremel with the discs so we'll see how it goes tonight!

Theres some terms im not familiar with you guys used:

Crowning: Im assuming this is just sanding it after cutting is complete?

Flaring: I have no idea.

[turok_t]

When I crown my barrels, I don't use any dremel at all since I know it would be uneven. This is what I do....

I use a piece of masking tape and wrap the barrel to the approximate desired length. I use a marker and draw an outline on the masking tape to the exact length I want. I then use a hack saw and cut slightly more than my desired length since I know it will have to be grinded/sanded.

Following, I clamp the barrel vertically in my vise and use a filer to sand off the burs and rough edges. After sanding, the newly cut edge is still rough and crude.

I then clamp my inner barrel within a portable vise and place it underneath a drill press. HOWEVER, the inner barrel needs to be completely vertical or else the filing from the drill press will cause the edge to be slanted. I usually clamp the barrel right at the top to prevent any wobbling from the friction/sanding of the drill press.

I place a flat drill bit in the drill press to sand off the newly made cut and progress to a finer grid drill bit. Afterwards, I use a conical shape drill bit that just fits within the inner diameter of the barrel to chamber/crown the inner edge and again, i progress to a finer drill bit to crown the edges.

The final result is a cut to the inner barrel that is parallel to the length of the barrel with no slants, deformities, or uneveniness. The crowning is also very even within the inner ridge of the inner barrel. I don't need to use any sandpaper or dremel since I want to avoid the risk for human errors at all cost. Any slight imperfections or residual burs from the inner barrel can compromise the accuracy of the inner barrel, and as such, I avoid hands tools (except for the hack saw of course). I've used this approach 6 times, and achieved good results for all 6 attempts. Here is the what I did:

Marking the length of the inner barrel:


Cutting the inner barrel with hack saw


Drill pressing


Finished product

[Blackthorne]

DAMN!