Guy I have a new 260 Rem built on a Arisaka action and the throat is very short. I have to seat even the middle weight bullets way into the powder capacity and the action has plenty enough room to handls a much longer cartridge. I want to rent a reamer and throat it out farther. Will be doing this by hand as I don't have a lathe. Anyone have experience doing this so they can give me some tips or advice? Especially concerned about keeping the reamer straight. Thanks in advance.
Joe, I happen to have in my possession a brand new Clymer throater. I bought it years ago to throat my .264WM. That cartridge actually has more case capacity than it needs and I came up with a good load and decided if it ain't broke don't fix it and never used it.
Anyway it is .266" diameter and probably has about a .256" pilot. I would have to measure to find out. I think I know where it is stashed and I would be happy to loan it to you. Just provide me with a mailing address.
I have a 6.5 Jap barreled action I have never played with. The bore is lightly pitted but seems to be in fair shape. They look worn out when they are new. One of these days!
As far as using the reamer, Clymer sells a T-handle to turn it by hand. I didn't get the handle but I am sure you can come up with a handle. Boolit casters are nothing if not resourceful! Reamers are said to be self centering so presumably all you have to do is be careful not to push it sideways as you turn it. I would have to measure to find the shank diameter.
Your first consideration is making sure that throater if large enough over your bore diameter for your needs.
.266" sounds like if your bore is .264, if your bore is actually .264 I think I would carefully slug it to make sure and measure the land top diamenter too before having a throater sent out.
The obvious is keeping that reamer going straight and starting it on center. If memory serves correct Clymer or ? also sold a centered device for various actions along with the handle. Probably as many methods to center the throater in the actions as there are smiths.
Posts: 57 | Location: Far North Western Mongolia | Registered: 07 September 2003
I have the piece of lead I slugged the bore with. I had done that when I first got the barrel to see what specs they had bored and rifled it too. The grooves are .2635 which is tight. I'll have to measure for the land to land. Thanks guys and NO BS you answered the one question I was concerned with and that was that apparently there is a centering device for the rear portion of the reamer set up to keep it straight.
Marc let me know what you come up for on the measurements on your reamer. I'll got remeasure the slug again.
Joe, the shank is a nominal .250" with a flat machined on one side to accept a set screw. The pilot is .2553" and the reamer body behind the flutes is .2658". So the flutes are no larger than .2658". I have an old Clymer catalog and they say the throat angle is 2-1/2 degrees. These are 5 flute reamers so they won't catch in the lands of a 4,6 or 8 groove barrel.
As for usage, the Clymer catalog I have does not show any bushings to align the handle. To use a bushing in the action would presume that the bore is concentric with the receiver. I think it is quite a stretch to expect the receiver to be concentric to the bore. I would be much more willing to gently turn the reamer and allow it to center itself. Maybe somebody who has actually done it will show up.
I've throated a couple of .25s by hand. Actually used a combined neck/throater. I just relied on the pilot and feel to keep them centered. First one was a .25-35 Imp that had an overly tight neck. Second one was a Bob that wasn't shooting quite right. I had the tool so I used it and got some improvement. Far as I could tell I didn't take any metal out of the neck of the Bob.
I dunno I would do this with $400 barrels, but I don't shoot no $400 barrels.
Posts: 1570 | Location: Base of the Blue Ridge | Registered: 04 November 2002
marc I was into clymer's website and looking at chamber reams of the 264 mag and the 260 rem. I was looking at the freebore throat diameter, which is the straigh part of the throat, and it is different between those two. The freebore throat and the 264 mag is .268 and the 260 rem is .266. Now I wonder if throaters are specific to caliber.
Okay I measure best I could my bore, which is land to land, and it appears to be .259. The groove diameter is .264. E.R. Shaw button rifles their barrels and I assume button rifling isn't as deep as cut rifling.
Your throat reamer seems more geared towards a 260 rem.
Just occured to me that a fired .444 Marlin case, slightly shortened and with the primer pocket drilled out to .25 and slid over the throater shaft down into the chamber would be better than no bushing. That lashup would get the rear of the reamer within a few thous of where it belongs.
It ain't perfect, but it sure Lord is easy. Email me a snail mail address and I'll do you one if you want it.
Posts: 1570 | Location: Base of the Blue Ridge | Registered: 04 November 2002
That's not a bad idea with that 444 case. I was thinking throating an already chambered barrel by hand can't be as bad to accuracy if it's not perfect as would chamber reaming by hand. I think the chamber not be perfect inline with the bore would be worse then if the throat was just a hair off.
Joe, the .264WM doesn't have a parallel section in the throat. Mine just has a tapered section that probably starts at .268" and tapers down to bore diameter. That is why I was going to throat it. Clymer just makes a single reamer for all 6.5's. You can also custom order.
Again I would not trust a case to keep the reamer concentric. I believe the throat is more important to accuracy than the chamber and there is no guarantee the chamber is concentric. I have a couple rifles and a Contender in which the throat is visibly off center and thus I have to assume the chambers are also off.
I think Buckshot may have mentioned throating one of his rifles. I don't know if he checks in here anymore. You might go over to the Cast Boolit site and ask there too.
Marc I posted on the site Buckshot hangs in. No reply from him yet. Anyways here is a cast bullet fired with just 2.0 grs of Bullseye into soft rags. Take in mind now that the nose of this bullet is .2555 and it shows no signs of grooves on it. I remeasured and the groove diameter is still at .2635 So this leads me to believe that the bore is indeed .259. Definately between .2555 and .259.
One way to apply torque without putting any side-load is to use two universal joints, from a socket set, one-behind-the-other. They "flop over" if you begin to get some side-load, or get out of alignment. Wrapping them both up, with a layer of electrician's tape makes things a little easier. You can drive the reamer with a speed-handle, or with a sliding T-handle. This is the way we were taught to torque the central shaft nut on a turbine fan, where it was VERY critical not to warp/bend the fragile output shaft. Haven't used this with a reamer, but that's the way I would do it, were I doing a rechamber by hand.>>>>>Bug.
Posts: 353 | Location: East Texas | Registered: 22 January 2003
Joe, I don't know what the best way to go is. With a .259 bore diameter the pilot is not going to offer any support. I do like Bug's idea a lot! If there is already a throat section the reamer will follow it. You might try a search on the gunsmithing board if you haven't already. I know there was a question about throat reamers there but I don't know if there were any helpful answers.
Another thought: you might want to read Mike Bellm's thoughts on throating. I don't have the url but if you do a search on his name you should find his web site. He specializes in correcting TC chambers and throats and has articles on the subject posted.
NO BS Well that was my thinking exactly to let a gunsmith do it after reviewing the facts. Guess what though? There's only one gunsmith in my near area and I called him and he said he wouldn't touch it. Reason being as he quote "then the liability would be on me". He compared it to getting engine work done on your car engine, only to find something wrong with it, and to bring it to another mechanic and expect him to make it right.
Wife says the damn thing is shooting pretty good so why not leave it alone? I believe she may be right.
