Chambering: indicate bore before threading and/or before reamer?

Back to my original question about indicating. Do most do on initial setup only or periodically indicate throughout?
 
Mram10 said:
Back to my original question about indicating. Do most do on initial setup only or periodically indicate throughout?
Click to expand...

I'll go out on a limb. Most just indicate and then turn the tenon to major diameter, thread, cut recess, and chamber. Those that are very particular about straight chambers and or have reason to suspect that the setup is prone to moving re indicate before pre boring the chamber.

If you want the answer that is right for you, just adopt the practice and see what happens. If you find yourself making adjustments on the second indicating, try other materials for your chuck contact. I agree with Al that aluminum wire is probably not the best choice. Another factor is just how much pressure your machining tool is applying to the tenon. For example: heavy cuts with a larger radius insert, using a parting tool to cut the end of the blank, dull insert, etc. all load the workpiece and might contribute to movement. Remember you have a very small contact area when you cushion the chuck jaws with wire.
 
Last edited:
Increased gripping surface is a laudable goal BUT...... in my case the ability to pivot is paramount.

OD is never concentric with ID

Holes are never bored straight.

Lathes are never straight.

Chucks are never straight.

((I've watched in awe these huge threads on the "Machinist" forums where guys balance and true and align bore and otherwise mutilate their chucks claiming to be making them "straight" ........ I am daily blown away with folks and their fixations on inconsequential details as being "important" all while thinking machines are "rigid" as if size eliminates flex..... it's nearly as stupid as those threads over on the Yukking It Up Around Ye Jollie Woodpile where guys go on and on about "press alignment" and "making straight reloads" because they spun their case 3-times widdershins in their massive align-bored Hollywood Double-Pumper ))

Large gripping surfaces tend to transmit their mis-alignments to the workpiece.

So, for ME, it's a delicate balance betwixt a stress-free swiveling action and adequate gripping force without distorting the squishy barrel. (When the pilot suddenly gets sticky, YOU'RE TOO TIGHT!! .... LOL)

I build an entire rifle around the 1 inch section of the bore that the bullet sees........ I simply don't CARE how far from center the barrel points, it's pointless to care. I do KNOW where it'll hit, just don't care how crooked it is. I use the crookedyness to my advantage, steering the rifle with it.....Yesterday I found out that a certain barrel I'd fitted to a Neuvo a month ago screwed right into another glued-in setup. I screwed 'er together, checked my notes concerning where that barrel pointed on the other gun, eyeballed my (new) index marks and HELD OFF 7 INCHES on my first shot to put the first bullet within an inch of my last group @ 100yds. Just because....."I Could"
 
A guy named Tubalcain

Mram10 said:
Definitely my weakness. I never had any training in a real machine shop. Just learned from watching old gunsmiths. I could use real machine shop training.
Click to expand...

sells a series of Machine Shop Training Videos for not much money. You can find him often on Youtube. He is a retired Shop Teacher and has a couple thousand Youtube videos available, some to buy and some for free. He isn't the only one. There are multiple Shop Practices Youtube videos available for the clicking.

Pete
 
Pete, thanks. I try to watch as many videos as I can when I’m on the road. Tubalcain is one of my favorites.

Jackie, I hear ya.... those years are flying by
 
There are plenty

Mram10 said:
Pete, thanks. I try to watch as many videos as I can when I’m on the road. Tubalcain is one of my favorites.

Jackie, I hear ya.... those years are flying by
Click to expand...

of chambering videos as well, The Viper for one and Gordie Gritters for another. Chambering barrels is really pretty easy stuff in the realm of machining, generally. I have done prolly ten now and all of them have shot a lot better than I can. I don't understand why the whole thing is so intimidating to folks and I'm somewhat ham fisted when it comes to machining.

Pete
 
Pete Wass said:
of chambering videos as well, The Viper for one and Gordie Gritters for another. Chambering barrels is really pretty easy stuff in the realm of machining, generally. I have done prolly ten now and all of them have shot a lot better than I can. I don't understand why the whole thing is so intimidating to folks and I'm somewhat ham fisted when it comes to machining.

Pete
Click to expand...

Thanks. Watched viper and Gordy videos numerous times. Always trying to learn from guys that do things a bit different. My buddy that retired and taught me said the same. He always laughed and said “I ain’t a machinist. Just know how to turn and thread barrels. It isn’t hard.” You guys are right
 
Talked to a guy named Alex Wheeler when I was just learning a few years back and he was nice enough to answer a bunch of questions over about an hour conversation. Great guy. Makes high end stuff and he told me, “don’t worry about most of the bs you hear on the forums. Some guys think they’re saving the effing world by chambering a rifle.” Made me laugh but he stressed simple machining practices.
 
You can put a dial indicator in the bore at any step after the initial indicating in of the bore. If nothing else, it will give you confidence in your setup. I’ve changed my procedure some since I wrote that article in Precision Shooting in the early 90’s. I still indicate in at the projected throat, drill and pre bore out most of the chamber. Whether you cut the tenon, thread and then chamber or chamber first, then cut the tenon and thread doesn’t make any difference as long as your setup is solid. Now I usually cut the tenon, thread and chamber in that order. Then check the finished neck and throat with a dial indicator and bore scope after the barrel is chambered and before I take it out of the lathe.
 
You must log in or register to reply here.
Back
Top