Stony Point Chamber-All

[Hawks Feather]

When I started, it was Stony Point's Chamber-All but Hornady has since bought out at least part of the Stony Point's products.  There are an assortment of tools and ways that can be used to find the length from the bolt face to the rifling in your firearm but this tool has been the simplest to use.

Well, what is this thing and what does it do?  First off, it is only going to help you if you reload and like to "tinker" with your reloading to see what you can do to get the best accuracy from your firearm.  The "system" is really pretty simple and easy to use.  You have the gauge (which has a movable center insert) and a modified shell case.  The shell case has had the primer pocket drilled out and it is then threaded so that it will screw onto the end of the gauge.  There are MANY different modified cases available, but obviously you only need them for the cases that you will be reloading.

Chamber-All Gauge and modified case.


A better look at the modification that is done to the case.

After seating the modified case on the gauge, you insert one of the bullets that you will be using into the neck of the case.  The neck has been enlarged and the bullet will literally fall into the end of the gauge.

Bullet in the gauge and ready to go.



The gauge is then inserted into the chamber of the firearm you will be reloading.

You will be able to tell when the modified case has seated into the chamber of the firearm you are checking.  When you reach that point, you gently slide the moveable insert forward which pushes the bullet forward until it touches the rifling.  You don't need to use lots of pressure, just gently slide the bullet forward until it touches the rifling.  At this point, there is a small nylon screw that will lock the insert at that point and you can remove the gauge from the chamber.  There is a VERY good chance that the bullet will remain in the barrel and you will need to lightly tap the butt stock on the floor or better yet, use a cleaning rod to touch the bullet.  It should NOT be difficult at all to remove.  Remember that when you are inserting the center that you just want the bullet to touch the rifling, not be driven into the rifling.  A couple of tries and you will get a feel for it.  I normally do this three or four times for each firearm that I am checking and then find an average measurement that I write down and use for that firearm.  For this measurement you should be using the bullet that was inserted into the chamber.

This is a measurement when the bullet was placed back into the modified case.

You can now use that measurement as a starting place for the length of your loaded round.  Normally it is suggested to start 0.010 off of the rifling – in this case 1.9600 – 0.010 or 1.9500 inches.  If I were using this measurement, I would start with the seating die well above the 1.9500 mark and slowly turn the die lower, insert the primed and powdered case with the bullet on top and check the length.  After checking I would again adjust the die a little lower and again recheck to see what the length of the LOADED round would be.  While this is not an "exact" a 90 degree turn of the seating die "should" lower the bullet by approximately 0.010.  With this as a "guide" if my initial length of the loaded round was 2.000, I would turn the die down about one full turn, which should give me an approximate length of 1.9600.  Again, this is not exact and will depend on the type of dies that you are using.  Assuming that I am looking for a loaded round of 1.9400 I would continue to adjust the die until I got that length.  For load testing, I usually start at 0.010 off the rifling and go down about 0.010 to 0.015 inches per set of shells.  I will load three to four sample rounds at each of these changes and usually load about five or six different overall lengths.  To keep from mixing them up, I will usually write the length on the outside of the case with a fine point felt tip marker.  At the range I shoot these different length rounds at different targets to see which works the best in "that particular" firearm.  Each firearm is different and usually likes a different length for a loaded round.


Now, lets assume that you want to try different bullets in the same gun that you just got all of the above set up correctly for or that you have found the best length for the ballistic tip bullets used, but you would like something a little more "fur friendly" than that ballistic tip.  You have two options.  The first is to repeat all of the above, but the second option is much easier – use a bullet comparator. 

Chamber-All with a bullet comparator attached.

The comparator will allow you to get a measurement from the base of the shell case to the curvature of the bullet.  This measurement will change with each new bullet weight or manufacturer used.  This means that when you change from 50 grain Nosler Ballistic Tips to 50 grain Sierra Ballistic Tips that the amount of distance between the bullet and your rifling will change.  In the following two pictures I have used two different bullets, but seated them both with the seating die set at the same place.  There is a difference and if your firearm likes one length better than the other, you will need to make an adjustment in your seating die.

Ballistic tip 1.5345 inches long.


Non-Ballistic Tip 1.5450 inches long when used with the above die seating depth.

Hopefully this will give you a brief overview of the Chamber-All gauge and what it can do to help improve your accuracy.  The one suggestion that I would make is to write down these measurements for each firearm checked and also after test firing, the length that that firearm likes the best.


Good shooting,

Jerry

[Ladobe]

Jerry,

Excellent write up and pictures pard.

I too have all the complete Stoney Point sets, the OAL gauges and many dozens of modified cases (including for all of my wildcats), their bullet comparator set and cartridge headspace set that I've used for many years.   However, I use a slightly different procedure for setting up my seater dies that might be worth noting here.

I jam the bullets in all of my firearms.    How much so is critical both for extreme precision shooting and on the hotter loads to keep pressures from going over the top.   So for setting up my seater dies, I use the bullet comparator gauges rather than the OAL gauge.   My reasoning... many bullets are not uniform at the tip and they can vary in OAL greatly in any lot or box, but mostly will have a very uniform ogive to measure off of.   Probably not critical to those who do not jam, but even a couple of thou can be to those of us who do.     

Getting the "feel" using the OAL comes with time and you can get quite consistent results eventually.   But as Jerry suggested, the more dry runs you do the closer the "average" will be, especially with bullets that vary in OAL.   There is almost no learning curve with the bullet comparator, or with the headspace gauges either when you know exactly how you want to headspace.

Larry