The “ACE” Chamber System”......Anybody Tried It?

[jackieschmidt]

Over on Benchrest.com there is a rather lengthy thread discussing this.

http://benchrest.com/showthread.php?102909-Has-anyone-seen-this

I won’t go into everything discussed, but throughout the discussion no one who has actually used this system came forward.

I build one for myself, and discussed the results in the thread. Mine is a little different, but follows the basic principle.

This Site represents a wider range of shooters in different Shooting Disciplines, so I will ask. Who has used this and what are your opinions.

 

[TAJ45]

Never read of it so this should be another learning op.

 

[Dusty Stevens]

I cant see an advantage myself. I mean if you chamber one a year later and its within .001 of the last one who really cares? As you know we use the same reamer on hundreds of ppc barrels and the same die works on all of them- or any of the hundreds of dies made with the resize reamer companion. I just cant see it being necessary but applaud the out of the box thinking and skill there. Not sure why the reluctance to just chamber a barrel anymore. If you get one thats so far off from your last one you cant use your brass or dies you need to find another gunsmith- same reamer of course.

 

[300_whisper]

Im no machinist, Ive seen my gunsmith turn a barrel once, and of course watched youtube videos. That doesnt mean I know what I am talking about. In my opinion, very cool idea, thinking outside the box for sure, but it seems like a lot of work. How much more time will it take to create a chamber and then thread the barrel to fit in it? Also, weird question, but lets say you want a barrel length of 16 inches. If you use the ace chamber and then a ~13-14 inch barrel to get an overall length of 16 inches, does that make your rifle an SBR???

 

[Dusty Stevens]

Im no machinist, Ive seen my gunsmith turn a barrel once, and of course watched youtube videos. That doesnt mean I know what I am talking about. In my opinion, very cool idea, thinking outside the box for sure, but it seems like a lot of work. How much more time will it take to create a chamber and then thread the barrel to fit in it? Also, weird question, but lets say you want a barrel length of 16 inches. If you use the ace chamber and then a ~13-14 inch barrel to get an overall length of 16 inches, does that make your rifle an SBR???

Gotta be pinned and welded to be considered one piece

 

[Hohn]

The internal contradictions in the youtube video bother me. How do they know the ACE chamber is "perfectly straight and true"? True and straight relative to WHAT? He just said the bore is winding all over the place, so what is he taking as the "center" as a datum axis?

Yet he then says that the first few inches of the bore are straight so they use that as reference for the ACE system. OK, well guess what a reamer pilots from? Yup, the first few inches of the bore that are about perfectly straight.

In order to sell the merits of this ACE system, the presenter much convince you that the the existing techniques are a problem. But they aren't.

The reamer is piloting off a concentric portion of the bore and because of the way it is ground, it will cut a concentric chamber. Only if the machinist is WAY off in indicating the barrel could it be a problem.

Indicating should be done relative to the bore, not the OD. And since it's hard to get a test indicator in there with the rifling, I'd recommend the machinist move up in plug gauges in tenths until a perfect near-zero clearance is found. Then indicate from the plug gauge OD. Then can be confident that the bore immediately near where the chamber will be cut is as straight and true as you can make it.

Indicating off the barrel OD will add the concentricity error of the bore within the OD to your chamber error.

The ACE system creates problems that don't exist in order to market a solution.

 

[SG4247]

How do you keep the barrel bore exactly on center with the ACE chamber bore?

 

[Spook]

my conventional method of chambering works well enough that I cant be bothered ?

 

[coldboreshot]

How do you keep the barrel bore exactly on center with the ACE chamber bore?

Exactly. Wouldn't the rest of the rifle bore still be off center (bowed) according to the statements in the video???? I'm by no means a machinist or a physicist for that matter, but wouldn't be what the bullet does upon leaving the muzzle, be the determining factor. If a "bowed" bore allows the bullet to exit the muzzle the same way all the time and the internal rifling permit it to do so, that's where the accuracy would come in to play. If the bullet travels down a "bowed" barrel, I think it is still pointed in the same direction all the time. Anyone, please feel free to correct my ignorant self if it applies.

 

[paperpuncher]

I dont get this thing. Supposed to eliminate the chance of the throat/ chamber being misaligned. If you can figure out how to align the throating reamer for the ace then whats so hard about doing the same thing with the chamber reamer. He talks about misalignment of .003-.005 in custom barrels and up to .012" in factory tubes. Im not sure I could get .003" misalignment when chambering without making an effort to do so. I also see the potential for misalignment with this system by adding a joint and stacking tolerances although they may have some design features that mitigate this issue. Does it work... probably. Is it cool or innovative...ehhh? Is there an advantage to using this system, perhaps but curing chamber misalignment is not one in my opinion
The simple solution to all of the issues he has with the "1800s chambering technology" is to indicate the area in the barrel where the throat will be, drill the chamber undersize, bore out the chamber to give the reamer a true path to follow and finish with the reamer.

 

[INTJ]

The internal contradictions in the youtube video bother me. How do they know the ACE chamber is "perfectly straight and true"? True and straight relative to WHAT? He just said the bore is winding all over the place, so what is he taking as the "center" as a datum axis?

Yet he then says that the first few inches of the bore are straight so they use that as reference for the ACE system. OK, well guess what a reamer pilots from? Yup, the first few inches of the bore that are about perfectly straight.

In order to sell the merits of this ACE system, the presenter much convince you that the the existing techniques are a problem. But they aren't.

The reamer is piloting off a concentric portion of the bore and because of the way it is ground, it will cut a concentric chamber. Only if the machinist is WAY off in indicating the barrel could it be a problem.

Indicating should be done relative to the bore, not the OD. And since it's hard to get a test indicator in there with the rifling, I'd recommend the machinist move up in plug gauges in tenths until a perfect near-zero clearance is found. Then indicate from the plug gauge OD. Then can be confident that the bore immediately near where the chamber will be cut is as straight and true as you can make it.

Indicating off the barrel OD will add the concentricity error of the bore within the OD to your chamber error.

The ACE system creates problems that don't exist in order to market a solution.

That pretty much reflects my thinking on this. I have chambered a handful of barrels for my LR BR rifles. I cut an oversize chamber on the very first new barrel I chambered because I made a rookie mistake, had to put the barrel back in the lathe, and the floating reamer holder I used "hung up". I cleaned up the chamber as much as I could though it still had a small scratch.

Even with all that, because I carefully dialed the throat of the barrel in each time, this barrel shot well. It won for two-gun (6 targets) group agg the first match I shot it in (600 yds), it shot three consecutive sub 2" 3-shot groups at 1000 on a tuning day, and placed third in LG agg during the NBRSA 1000 yd NW Regionals.

My one example confirms what a lot of real gunsmiths have told me, that the important part of the chamber is the throat, not what is behind it. The only downside to my oversize chamber is that brass fired in it can't be used in any other of my barrels, and a portable press is really stressed trying to resize that brass in my custom die. My subsequent barrels have had very tight and consistent chambers. They shoot well too............

So improved accuracy is definitely NOT a feature of the ACE Chamber System vs current BR chambering methods. I would say that by having to machine three shoulders and having two sets of threads is a place for more error to be introduced. Since the goal of any chambering job is to have the throat area as straight as possible, the shoulder at the front of the ACE chamber and the shoulder on the barrel need to be prefect or else you will have misalignment. Add in the threads and there is potential for both angular misalignment as well as radial misalignment. Now good machining can greatly mitigate that, but why complicate the process at the most critical part of barrel?

 

[Alex Wheeler]

I think the disconnect here is that the system is intended for large companies like Remington from what I understand. I could see it improving mass production. But you should be able to use your brass in all your barrels without changing dies settings if your smith is doing his job, same goes for a coaxial throat.

 

[marazzi59]

Jamie is an awesome guy and I really enjoyed his podcasts, thats all I got

 

[riflewoman]

Like you said on BR Central, I think this Guy failed Machineshop 101. He cuts and threads a chamber to match the threads on an action, then cuts threads in the chamber extension, and then matching threads on a barrel “straight true and square” to the barrel? Note that the barrel a pond extension both “spin on with fingers”. This means there is clearance between the mating parts. How does this system remove the slight misalignments induced in these clearances?

Looks like a solution to a non existent problem....

 

[rardoin]

I think the disconnect here is that the system is intended for large companies like Remington from what I understand. I could see it improving mass production. But you should be able to use your brass in all your barrels without changing dies settings if your smith is doing his job, same goes for a coaxial throat.

Yup. I have my own reamers for each comp chambering and I use healthy brass across different barrels. My gunsmith ‘gnat azzes’ the headspace every time

 

[gme]

after indicating the throat to zero, I drill and bore the chamber prior to reaming, there's no issue with the reamer following the bore curvature

 

[Spook]

Like you said on BR Central, I think this Guy failed Machineshop 101. He cuts and threads a chamber to match the threads on an action, then cuts threads in the chamber extension, and then matching threads on a barrel “straight true and square” to the barrel? Note that the barrel a pond extension both “spin on with fingers”. This means there is clearance between the mating parts. How does this system remove the slight misalignments induced in these clearances?

Looks like a solution to a non existent problem....

dont worry, its like a floating bolthead

 

[jackieschmidt]

Like you said on BR Central, I think this Guy failed Machineshop 101. He cuts and threads a chamber to match the threads on an action, then cuts threads in the chamber extension, and then matching threads on a barrel “straight true and square” to the barrel? Note that the barrel a pond extension both “spin on with fingers”. This means there is clearance between the mating parts. How does this system remove the slight misalignments induced in these clearances?

Looks like a solution to a non existent problem....

If you look at my post #130 in that thread, you will see that I incorporated a male fit on the barrel to mate with a female fit in the adapter where it seats against the inside face.There is only .0005 clearance between the two. Plus, 1/3 of the neck is in the adapter, 2/3 in the barrel.

That is one reason I made mine from a piece of Chrome Moly at 38 RC, to give it a good anti-gall quality with close fits.

I made this thing just see if it would work. It did shoot quite well. But then, so do my usual barrels.

 

[INTJ]

I think the disconnect here is that the system is intended for large companies like Remington from what I understand. I could see it improving mass production. But you should be able to use your brass in all your barrels without changing dies settings if your smith is doing his job, same goes for a coaxial throat.

I could see it working for a large company perhaps, but the youtube seems aimed at the general shooting population.

 

[coldboreshot]

I'm still trying to wrap my head around this...help me understand why you would want an interruption in the structure of the barrel, i.e. seam, (in the area where the bullet leaves the case, where the highest pressure and explosive nature occur? I can see it where the barrel meets the action but at the throat? wouldn't this suggest a whole new erosion concern?