What are your thoughts on this technique?

nksmfamjp

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Jan 5, 2004
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It is an explanation about why to use a separate chamber and barrel... I am interested in what folks who have reamed some chambers think when they see this, especially considering the number of "hummers" chambered by standard methods.
 
Maybe it works,,, dont know since I haven't tried one...

So far so good with the old school barrels I've been using...

A question though,,, why would any quality barrel maker start the chamber pilot hole 2 to 3 thousands off alinement...

All 3 of my custom barrels are less than 1 thou run out,,, good enough to get into National match competition...

I would think there would be less run out then doing the chamber to barrel thing,,, now you have 2 extra thread couplings that need to be trued...

Todays quality barrel makers are way ahead of the game,,, we know this from the groups we put on paper...

It must be working from what I see in my shooting sports...

Just asking since I don't know

Don
 
snake-oil.jpg
 
Dumb explanation about has Chambers are so crooked. If you dial in the bore using a range rod or a Gordy rod you are putting the chamber straight to the bore. The only way to get what he's talking about is to just Chuck your barrel up in a 3 jaw and start cutting. I don't know one gunsmith that would do this. So he came up with a complicated solution to a problem that doesn't exist. And like he said most custom rifles are off by .003 so how do my rifles shoot in the zeros and 1s consistently. All the best you could hope for according to him would be 3/8 moa if all was perfect. Just isn't so. I would put my 1800s method up against his any day of the week. If his way was better or if there was a problem with the 1800s method the benchrest crowd would already be doing it. I'm part of that crowd and we still use the 1800s method. I could show anybody how to dial a bore to turn within .0002 and that will give you a straight chamber. Magic. Voodoo. Nope just good machining skill.
Shep
 
Wow !!! what a load of crap.

The First thing to do is start with a "STRAIGHT" barrel bore. any good smith can determine this befor he even starts the barrel work.

The next thing to do is set the barrel bore in line with the center of the lathe spindle. then If the barrel has runout, it is on the outside where it can be fixed or rejected and sent back.

With the proper sized bushing/pilot and a proper setup the chamber will be straight and true and be an exact duplicate of the reamer.

As to the same methods of the 1800's tooling, process, and equipment has greatly improved and the evidence of improved accuracy is the results.

Adding another component/threaded connection to the process in the most critical area doesn't make sense and only adds more dimensional error and also makes the area that handles the most pressure weaker and more vulnerable to failure. also with thread clearance (Required to assemble)
expansion in this area will lead to excessive case expansion and bolt lift with loads that normal methods would handle. besides, who would want a seam in the chamber area !

Sorry, I just think that It is a very bad idea and would never buy into this process.
Good "Straight barrels" good barrel set up, and quality tooling plus a good smith would/should never run into the problems he describes. also if this were good we could have barrels in sections that could be screwed together to get different barrel lengths like some cleaning rods.:mad:

J E CUSTOM
 
Thanks for your time and energy in looking at this....I wanted to call bull poey on this, but lack the experience to do so. My engineering mind was thinking snake oil, but I had to ask.

Maybe on of you PA guys ought to call him and offer to teach him how to build a rifle! He has some folks on Snipers Hide bought in. Saw a rifle for sale here by one of his customers. I don't know his results. They don't all have bolt on chambers.
 
Snake Oil is right...been around for a couple of years now.

Dial in the throat area (direct or rod of your choosing) to zero runout.
Drill, then a light boring pass to true the hole precisely. Reamer will follow the bored hole, which is true to the throat...
That'll give you precise alignment to the throat.

Now let's talk about tolerance stacking/alignment of the threaded chamber section to the throat in the barrel...
 
I think he's been doing this a while....,12 years it says somewhere. I'm surprised he isn't on here, to be honest. Regardless, concepts and techniques are ok to discuss.

I would be sold, if he was shooting 0's and had some destructive testing to show the joint was solid.
 
Many in the PRS world go through barrels quickly and prefits are popular. Every time you get a new barrel, you have to adjust your dies or even get new ones to fit the new chamber. This would cure that issue. However, if your using a good smith every new barrel should have a chamber close enough that you can keep using your old brass and not touch the dies. In my opinion thats what it is good for, not an accuracy advancement. If a throat is off .0001-.0002 you can see it with a bore scope. Some chambering methods produce better results than others. But I think when he was talking about a throat being off center by xxx thousandths he was meaning to say ten thousandths.
 
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I may have been a little harsh. But there are ideas, and then there are "BAD" ideas. I like innovation and new ideas. but sometimes we tend to over think a problem and end up treating the symptoms instead of the illness/problem. the problem he describes starts before cutting any chamber and can be eliminated then.

There have been two (Or More) piece barrels and problems were dealt with to a degree and some success was achieved, but the fixes to having a connection in barrel bore were to extensive and not plausible for most and the results were no better.

I can see the attractiveness of having a replaceable barrel or chamber but every time you would have to change one or the other you would be essentially starting over.

The best method I have ever found is to start with a premium barrel that checks out straight, do a precision set up of the barrel, use quality reamers that fit the bore, And save that reamer if possible for the time that you may want to set the shoulder back and cut a new chamber, throat and lead with the same reamer. this returns the barrel to it's original quality and the rest of the barrel is already broke in/seasoned. this will almost double the life of a good barrel because the first .050 of the barrel wears the most and setting the shoulder back cuts a new chamber, throat and lead.

Note: after all work is centered to the bore, If the OD of the barrel has any reasonable runout (.0005 to .003) I like to re contour to .0000 runout so that the barrel wall is consistent end to end
with the bore. Barrels with more than .007 thousandths runout on the OD after the bore is trued in the lathe are rejected before I start any machining. I am not sure how much runout is bad, but I know zero is good.

I don't believe in solving one problem by creating another.

J E CUSTOM
 
Just a thought from a marketing standpoint:
I'm wondering if their target group would be more of the DIY self-assemblers... As stated above, the "1800's" method produces very true chambers and barrels if done correctly. But in today's times there are many who believe that a good Smith is overrated and they can get the same results themselves.
Just a thought.
 
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