Porting question

[Don@Tahoe]

I'm not a gunsmith just a home garage hobby guy with a lathe and mill, my question, is porting a rifle barrel as simple as indexing, drilling, and countersinking, or does the bore have to be enlarged and rifling removed? Also, can you run the bit through both sides of the barrel or do the holes have to be drilled one at a time?

[liber]

I'm not a gunsmith just a home garage hobby guy with a lathe and mill, my question, is porting a rifle barrel as simple as indexing, drilling, and countersinking, or does the bore have to be enlarged and rifling removed? Also, can you run the bit through both sides of the barrel or do the holes have to be drilled one at a time?

You are limited on the amount of rifling you can take away, so the caliber needs to be fairly close to what you start from.

Otherwise you will need to rifle the barrel again, and most people don't have the means to do so.

[Don@Tahoe]

I'm talking about drilling the end of the barrel, not adding a separate piece, so I don't touch the rifling except for the drill holes?

[kcstott]

I'm not a gunsmith just a home garage hobby guy with a lathe and mill, my question, is porting a rifle barrel as simple as indexing, drilling, and countersinking, or does the bore have to be enlarged and rifling removed? Also, can you run the bit through both sides of the barrel or do the holes have to be drilled one at a time?

It can be but I don't recommend it.

This is how i do it but I recommend against it and would rather see a muzzle break installed.

Lay out your holes, center drill, drill, and ream for a nice looking finish. counter sink the holes more or less depending on the look you want.
Then the barrel should be back bored about .050" larger then groove diameter. This requires a reamer of proper size and of odd number of flutes for best results. This also removes any burrs created during drilling. Chamfer the muzzle and call it good.

[Don@Tahoe]

You recommend a brake instead?

[kcstott]

You recommend a brake instead?

Yep. Far easier to install a brake and be able to install any brake you like in the future or remove all together. Threading a barrel is far easier.

[Don@Tahoe]

Thank you, I'll make a brake...