Hi:
As we probably all know in this forum, the biggest single challenge to manufacturing a barrel in the regular machine shop is the deep-hole drilling part. This usually requires specialized equipment or a highly modified lathe. After you get the hole drilled and finish reamed, the rifling part can be as simple as driving a carbide rifling button through the bore with a hydraulic jack.
Looking around on-line, I noted the existence of thick-walled mechanical tubing in alloys that are suited to making rifle barrels, like 4130 (suitable enough for many applications, as I understand it) or 4140 (one of the standard barrel steels).
The great majority of this tubing does not have anywhere near the appropriate bore diameter down the middle or correct wall thickness, but there are a FEW places in the catalog of a FEW vendors where you get some pretty good combinations of ID and OD...For my purposes, sourcing 4130 tubing with an OD of 1" and an ID of .250 is fairly easy...I am thinking that this should be about the perfect diameter to finish-ream out to around .264 for a 6.5mm barrel. 1" would be a little thinner than desired at the breech end, but I was thinking about a tightly fitted collar there to build up the ID around the chamber and for threading to match an action. There are other viable tubing/caliber combinations available, but this is the primary one I am interested in for the moment.
And before I get shouted down, allow me to stipulate the following:
Yes, this is not the way proper barrels are done.
Yes, we are talking about steel that is not rated for use as rifle barrels (though, for whatever it is worth, there are Chinese vendors selling 4140 tubing specifically to be used to make DIY rifle and pistol barrels).
Yes, I can buy a Green Mountain basic gunsmiths blank for the same money, already rifled and probably of better quality than I could ever manage to make.
Yes, I would have to be sure to end up with some very conservative thicknesses around the bore as a partial safeguard to a barrel bursting on ignition.
For all of that, I am still interested in doing this.
So, what say you?
Thanks in advance:
-Tom
As we probably all know in this forum, the biggest single challenge to manufacturing a barrel in the regular machine shop is the deep-hole drilling part. This usually requires specialized equipment or a highly modified lathe. After you get the hole drilled and finish reamed, the rifling part can be as simple as driving a carbide rifling button through the bore with a hydraulic jack.
Looking around on-line, I noted the existence of thick-walled mechanical tubing in alloys that are suited to making rifle barrels, like 4130 (suitable enough for many applications, as I understand it) or 4140 (one of the standard barrel steels).
The great majority of this tubing does not have anywhere near the appropriate bore diameter down the middle or correct wall thickness, but there are a FEW places in the catalog of a FEW vendors where you get some pretty good combinations of ID and OD...For my purposes, sourcing 4130 tubing with an OD of 1" and an ID of .250 is fairly easy...I am thinking that this should be about the perfect diameter to finish-ream out to around .264 for a 6.5mm barrel. 1" would be a little thinner than desired at the breech end, but I was thinking about a tightly fitted collar there to build up the ID around the chamber and for threading to match an action. There are other viable tubing/caliber combinations available, but this is the primary one I am interested in for the moment.
And before I get shouted down, allow me to stipulate the following:
Yes, this is not the way proper barrels are done.
Yes, we are talking about steel that is not rated for use as rifle barrels (though, for whatever it is worth, there are Chinese vendors selling 4140 tubing specifically to be used to make DIY rifle and pistol barrels).
Yes, I can buy a Green Mountain basic gunsmiths blank for the same money, already rifled and probably of better quality than I could ever manage to make.
Yes, I would have to be sure to end up with some very conservative thicknesses around the bore as a partial safeguard to a barrel bursting on ignition.
For all of that, I am still interested in doing this.
So, what say you?
Thanks in advance:
-Tom