Marlin Firearms Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
697 Posts
Discussion Starter · #1 ·
I would like to try my hand at reaming my own barrels to 30/30 Ai and 307. I have searched and read what has been previously posted on the subject. I kept up with William Iorg's posts on Beartooth when 30/30 Ai was being discussed and Taylor's. I would like to hear from any and all who have done their own work. Also, does anyone have either of these reamers they would be willing to loan or rent? If not, I may invest in a 308 Winchester Match pull through finish reamer from Midway to try and get the tightest tolerance for the 307. Opinions appreciated and thanks, Rick
 

·
Registered
Joined
·
230 Posts
Rick - I have done a number (3) of the .30-30AI re-chambers, two on Marlins and one on a TC Contender, they all came out well. As you might imagine caution and attention to detail are paramount.

On a Marlin, the first thing you need besides the reamer, is an extension rod that attaches to the rear of the reamer and a "T" handle to turn the reamer. Purchase some sulphur based cutting oil (Rigid brand works well) from a plumbing supply house. The reamer should be completely coated in the oil when inserting into the chamber and you must make sure you don't put radial pressure (side to side play) as you turn it in. After you cut approximately 1/16", withdraw the reamer, clean all chips from the reamer and the chamber. Use a 1/4" wooden dowel rod, split about 2" on one end with a saw and use an appropriate size piece of cloth slipped into the cut end of the dowel to wipe the chamber clean. Re-lube the reamer for each new cut. As the rim cutting portion of the reamer gets close to the breach face of the barrel, clean the breach face with solvent and paint it with a layout fluid like DiChem. Make very slight cuts until you see the faintest scratch (bright mark on the breach face. "STOP"

Clean the reamer and put it away. Clean the chamber thoroughly. Take the split dowel you used to clear the chamber of chips and put an appropriate size piece of emery cloth, about 200 grit, in the split end of the dowel. Put the dowel in a drill motor, soak it in kerosene or diesel fuel and slide it into the chamber. Turn the drill on and carefully polish the chamber making sure you don't push into the bore. You can use successively lighter grit cloth up to 320 but it isn't necessary for a smooth chamber. When your satisfied, clean everything up, wipe the bore and chamber clean and dry, re-assemble the rifle and test fire. If you begin to lose brass to splitting or case head separations, you either cut the chamber too deep (increased headspace) or the headspace was bad in the first place or your brass is too brittle (old). As long as the headspace isn't ridiculously off, you can compensate for this by buying .32 Winchester special brass and necking it down in stages until the lever will just close on it or by necking new .30-30 brass up to .32/8 M/M and necking it back down until it will just barely fit.

As for the .307, all of the above applies. You don't need to purchase/rent a .308 pull type reamer unless you think you will use it for other jobs.

Both reamers can be rented from Elk Ridge ( http://www.reamerrentals.com/chamber_reamers.htm ). They are good and have quick service and the rental price isn't very high. If you have any other questions, feel free to e-mail me.
 

·
Registered
Joined
·
2,220 Posts
Masterifleman, you the doctor here and I'm not questioning your expertise at all but a layperson's inclination is that 200 gr and even 320 is a bit rough for such a process. If you would explain why it is not necessary, or desirable to use 500+ for a polished serface. Just curious.

Thanks,

SS
 

·
Registered
Joined
·
230 Posts
The coarser grit cloth will wear as the polish procedure continues and a "glass smooth" chamber is not desirable. You don't want it to leave scratch marks on your cases but you do want a little adhesion at the time of firing to reduce backthrust on the bolt.

Fred Barnes once chambered a .375 H & H out to .375 Barnes Supreme for me and I believe he used coarser than 180 grit on the chamber. I questioned him on that and he told me essentially what I said in the first sentence. I ususally do go down to 200 grit but as you polish the grit on the cloth wears and leaves a very smooth chamber. I never get any scratch marks on a fired case. If it makes you feel more comfortable going to a smoother grit, it really won't hurt, especially with minimum taper cases like the AI cartridges.

Ackley in his two volumn set, "Handbook for Shooters and Reloaders",states in one chapter that he once chambered a '94 WIN to .30-30 AI, cleaned the chamber and a cartridge with acetone, loaded the rifle without using the locking straps and only held the bolt closed with the lever. On firing, the bolt never moved proving that with a super clean chamber and minimum taper that the chamber walls gripped the case sufficiently to keep it from opening the unlocked bolt. I wouldn't want to try that on a real high intensity cartridge. Again, as long as it doesn't leave marks on the case, the coarser grit cloth will do just fine.
 
1 - 4 of 4 Posts
Top