Barrel thread and chamber ???

Have you ever chambered a barrel? What would you suggest he do when he takes the barrel out of the lathe and checks it with your fired brass and it doesn't chamber?
I would do what I always do, I USE NEW BRASS IN EACH NEW CHAMBER JOB.
Butch
 
Going in deeper with the reamer will not make the base smaller if that is the problem.Do you check your chambers with your old brass or a headspace gage? How did you measure your old brass to compare it to the new chamber? If you are doing your chambering, I'm sure you do it correctly for yourself? I won't pass judgement on the gunsmiths that you are talking about, but if I so choose I could use the same brass in all my barrels. I do not do it though. It is false economy.
Butch
 
I use a good gunsmith....

Next week I'm getting a barreled action back from him.

The chamber is .003 short, tight neck and custom taper and a complete wildcat to boot. But two years ago this gunsmith chambered ANOTHER rifle for me, another brand of action..... completely different gun..... and so I sent him an action and a blank and said "do it like the last one...."

And he DID.....

And it WILL be like the last one......

And I've got 500 cases almost done AND I EXPECT THEM TO BE A CRUSH FIT IN THE NEW SETUP!!!!

I've never seen the new setup...and I'm scheduled to fireform brass with it the day it comes in.....

Wish me luck??????

To Quote Kavanaugh, "It ain't ABOUT luck..."

al
 
Alinwa
I use the same gunsmith as you and your post doesn't answer the original posters question.

In your example you had two guns built 2 years apart and I'm guessing he used the same reamer for both? Your reamer is 0.003 short and your expecting a crush fit? I would expect that as well.

Now for my question.What in the Heck does that have to do with chambering a second barrel for the same action but without the action actually being in the shop?
I only ask because I already have his answer on this very topic long before this thread ever existed.
Waterboy
 
This can be done quite easy but the Liability is the part most smart gunsmiths go by. In this day and time one mistake will close a shop. Why would you not want to send your action to your gunsmith?
 
I am still not sure what the hell the arguments are. When I chamber a barrel, I sometimes have the action in hand. I make a rough print of what measurements are needed, tenon length, c'bore, thread diameter, headspace, etc. My chambers are all done to minimum SAAMI specs as are all the reamers and headspce gauges I use. Often I will get a request, most recently, from a shooter in AZ for the winter, for a new barrel for his long range match gun. I go to my records, locate the print, and cut the barrel to those specs. I often do the threads, as was this one, for a trued action which the receiver threads have been single pointed and the action a glue-in, to the measurement of the drawing using the three wire method determined from the original barrel that was cut and recorded. Guess what, small wonder, it fit!!

What the hell is the big deal, you don't need the action in hand to do it?

Jim`
 
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I did .260 Match for a friend..

He wanted to know what the problem was.... All the once fired brass he had wouldn't fit the chamber!!!! But the new stuff would. He was pretty upset. He then wanted to know if I had the headspace correct. After drawing a picture of a standard factory chamber and then what he had, the light slowly came on.

One more thing. He bought once fired brass from a gunshow!!!!!!!!:eek:

He shot a 1/2" group at 100 yard in the prone position. So he change to a powder, that he had more of, which shoots 1 1/2". People are strange.

Myself, unless you are going to Africa. All my chambers are Minimum SAAMI or some sort of bastard like a .22/5.56 Johnson spitfire, their are six different versions.

I'm agree with Butch on everything he has said early.

Mark
 
A friend of mine has a 6BRX that I chambered for him. I recently set the barrel back a 1/4" to get it where he could get to the lands again. I used the same reamer as what had cut the chamber the first time and he's about the only one that I've used the reamer to chamber his barrel. It was headspaced originally to just close on a go gage and when it was set back it was headspaced to just close on a go gage. However, brass that he had fired before it was set back wouldn't work with the chamber as it was recut and reheadspaced. The brass was larger at the case head than what the chamber would allow. The original chamber wasn't cut oversize, but was a good fit on the reamer. There are no telling how many rounds he had on the barrel before setting it back. My best guess is that grit on his fired cases over time acted like a lap and lapped his chamber a little larger at the rear of the chamber where the brass entered the chamber and maybe pressure over time may have swelled the chamber slightly. Since it's such a problem making brass for a BRX, I polished out the back of his chamber to allow him to use his old brass. The simple solution would have been to start over with new brass. But, with a barrel that doesn't have much life left in it, there's not much point in that.

One of the biggest problems that I've seen with brass not fitting a new chamber is when people try to use their old brass that was fired in a different chamber and use it in a new barrel. Going with new brass in a new chamber always solves the problem.
 
Mike...Did you indicate the first chamber? Are you using a floating reamer holder? Sounds like the chamber was cut big on the first try. I seriously doubt the brass lapping the base bigger. Crooked chambers caused by floating reamer holders and out of line tail stocks is usually the culprit.

Your logic is mind boggling Butch. Did you learn all that here?

Cant wait to hear the KIA replays.
 
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It could be that the chamber cut a little oversize when it was cut. I don't think so, but it could have. I indicate in all chambers at the projected throat area of the barrel, drill and bore out most of the chamber. I indicated in the rechamber as best I could. It's a lot easier to indicate in a new barrel than one with a few thousand rounds on it. I've been running my reamers on a center since I changed lathes as I haven't seen it make any difference on the size of the chamber with this lathe whether it's run in with a center on the lathe that I have now or whether it's floated.

I have measured 6 PPC barrels that I installed originally and have seen the headspace grow on them a thousandth or two after being fired awhile. If you measure off the old barrel and run the reamer in for the same measurement on a new barrel, the headspace will be long when compared to the original dimensions that the barrel was chambered. What causes the chamber length to grow, I don't know, but suspect that it's wear whether at the bolt lugs or I figure in the softer barrel steel from the case working in the chamber and basically lapping the length. When I chamber a barrel for a glued in gun, I leave the chamber a few thousandths short and then run the reamer in by hand to finish the length of the chamber to just close on the go gage with the barrel tightened in the barrel vise.

Crooked chambers don't shoot like this barrel did originally. He was shooting one liter coke bottles with it at 1200 yards. I'm sure not every time, but enough to make it interesting. It could have been that the reamer cut a thousandth or two large on the first chambering. An oversize chamber and a crooked chamber aren't the same thing. The only thing that I can see mechanically would be that the pilot wouldn't have fit as well on the rechamber as it would have been looser on the rechamber and that may be why the first chamber was oversize compared to the rechambering. That would probably be the answer instead of wear on the chamber from firing, but I figure wear on the chamber happens as well whether in length or in diameter.
 
I have recently discovered

that brass from other chambers can be re-habbed with the use of the small base die for the parent case. I have done that to two different chamberings and so far, they work good.

I think dies are the bain of us all. Most of the dies we have available do not size our cases properly, including the very expensive custom dies. Somehow theory and actuality don't coincide.
 
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Pete Wass said:
that brass from other chambers can be re-habbed with the use of the small base die for the parent case. I have done that to two different chamberings and so far, they work good.

I think dies are the bain of us all. Most of the dies we have available do not size our cases properly, including the very expensive custom dies. Somehow theory and actuality don't coincide.
Click to expand...

Too true... :)

"I think dies are the bain of us all. "

But man, when they're RIGHT....... awesome!!

(the problem is finding someone who can get them RIGHT :( )

al
 
The answer to the original poster is that yes, if a gunsmith has action in hand and takes measurements (to include the thread index) then the barrel can be fitted without having the action when the job is done. I do that quite often for actions I have an indexer for (made an indexer that looks somewhat like Mike Bryants for 1 1/16 x 16 and 1 1/16x18 threads 20+ years ago). There are some threads I do not have an indexer for and the occasional job that requires them does not pay the time to make one for that thread pitch.

I normally agree with you Butch-you have real good common sense and good skills, but on this one I disagree. I, for one, do not do barrels for actions I have not had in hand-I have experienced situations where someone in the history of an action has made modifications to "improve" them and if I used the numbers that are common for that manufacturer, there would have been a problem. I have also had actions for manufacturers that are off by more than .005 on the accepted norm for headspace for that action model.
 
It's always better to have the action that the barrel is going on in the shop whether dimensions have been kept for that particular action or not. If the action is there, you can check your work. If it's not, then you can't check and make sure everything is correct with the barrell installed on the action. Making up a barrel for an action that you haven't barreled before and kept dimensions for it is just a guess and the barrel may or may not fit correctly with the correct headspace depending upon the tolerances of the action manufacturer. Most of the cnc made actions are pretty accurate on headspace dimensions, but even with the best thread size can vary a few thousandths. A gunsmith should be able to make up a barrel from dimensions that he has kept for that particular action and hit headspace as close as he wants. Its risky using generic measurements common to that action and probably not worth doing from the gunsmiths liability standpoint even if it is done for certain actions. Jim is correct in that just because an action leaves the manufacturer within his tolerances doesn't mean that it hasn't been modified later. Actions lugs can gall, lugs can be cleaned up and headspace dimensions will change. Also, let's say an action thread is 1 1/16 -18 x 1.062 as his standard thread. A customer orders an action set up for a 1 1/16-18 x 1.125" thread common to another makers actions. He winds up selling the action and someone orders a barrel without the gunsmith having the action in his hand. The gunsmith makes up a barrel for a 1 1/16-18 x1.062 thread common to that particular make of action. The barrel has excess clearance on the cone by .060". The case blows up at the head, the shooter is injured, sues the gunsmith and action manufacturer, putting them out of business or raising their liability insurance. All of this could have been prevented if the gunsmith had the action in his hand or glued into a stock to check his work.

It's best to have the action in the shop, 2nd to make up a barrel from dimensions that the gunsmith kept when he barreled that particular action the first time, feasible to make up a barrel from dimensions taken off an old barrel but you are taking a risk that the original barrel was set up properly, and too risky to make up a barrel for an action using generic thread specs.
 
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