Stoney Point Chamber-All™ OAL Gauge

The question I would like answered is how does a oal gauge work when bullets have different shapes(ogives)? If there is a gauge that somehow goes off of this I will buy it.

Sorry if I butted in,I do not think I did.
 
If you want to measure to the ogive you use a bullet comparator, such as the Sinclair or Stoney point. If you want to measure what OAL hits the lands in your chamber you use an OAL gauge like the one RagnCagn sells.

Jack
 
First, the Stoney Point OAL gauge requires five things to give an accurate reading of each style of bullet. #1) Either the curve or straight gauge depending on which type of action you have. #2) A Stoney Point Modified Cartridge Case to match the chambering of your rifle. Example; 243 Win. vs 6 m/m Remington. #3) The Stoney Point Bullet Comparator. #4) A Stoney Point Caliber specific ( .172, .243, .338, etc. ) insert that fits onto the Comparator. And last but not least #5) An accurate Caliper.

The System is as accurate as the consistency of the bullets you are using (cast bullets come to mind here).

To use the system, you must screw the modified case onto the Gauge rod till it bottoms out on the bottom of the case. The Gauge has a sliding rod that will allow you to drop a bullet down the neck of the modified case, allowing the bullet to sit inside the case deeper than you would seat it if you were loading a live round. Here you would use the set screw to hold the sliding rod snug. At this point, you slide the rod, modified case and bullet into the chamber and hold the modified case tightly seated against the shoulder in the chamber, you loosen the set screw and very gently slide the rod forward, which will push the bullet GENTLY against the rifling. Do not push hard, you only want to touch the rifling, not seat into it. Re-tighten the set screw and remove Gauge/Modified Case from the chamber. At this point you should have the bullet sticking out from the case while the case is still attached to the Gauge. Attach the needed Comparator insert into the Comparator and set the set screw to hold the insert in place, then attach the Comparator onto your calipers (upper jaw) so that the Modified Case/bullet enters the Comparator straight (you will see two different ways to use the Comparator, the other way gives and off-set). Place the lower jaw of you calipers into the notch just below the case, hold straight and slide the caliper scale so that the bullet enters the Comparator Insert till it stops. AGAIN, DO NOT FORCE! Read the dial on your calipers and this will be the reading at the "OGIVE".

This system remove errors in measurements due to differences between two bullets of the same box not being the exact same length (damaged bullet tip, etc.). The reading will have been off the OGIVE and not the tip.

Hope this helps....JOHN
 
Yotehunter59 gave a darn good run down, "How To's" are extremly hard to write.

If I may---I think you could stop at the point where you've locked the sliding rod after just gently kissing the lands with the bullet. Remove the rod/case&bullet from the chamber and measure the overall length of the case and bullet. Then Subtract the amount of distance that you want your bullet from the lands, and set your seating die accordingly. (2.473-.003=2.470 or whatever)

If you want a measurement that you can use with other bullet designs (bt/sp/hp/rn) of the same caliber, or if you have bullets out of the same box that have different lengths, then the Comparitor can be used to measure off the bullet's oglive.

Yotehunter59's more cautious that I am, and he went directly to the Oglive Measurement because as he said--it reduces the chance of bullets being different lengths from the same box. I agree but usually it's spire points which seem to give the most difference in length.

Personnally---If you buy a box of spire points where the tips are all askew/damaged, the box will probably contain so many flyers that you should take it back to the dealer for an exchange. If you see a box of new slugs dropped to the floor, don't buy it. It will have more Flyers because of being dropped.
 
There are a couple of small steps I'd add to Yotehunter59's "How to" post. First I like to clean the chamber and throat of the barrel, it is amazing how difficut it is to get good consistent results with a dirty chamber. The next think I like to do is to take a number of readings, I like at least 5 then average them to get my final OAL. You will sometimes get some wild measurements, throw them out, sometimes you can work for a little while with a barrel before becomming comfortable with the readings you are getting.
 
Quote:
The next think I like to do is to take a number of readings, I like at least 5 then average them to get my final OAL. You will sometimes get some wild measurements, throw them out, sometimes you can work for a little while with a barrel before becomming comfortable with the readings you are getting.



Michael, if you will try one of mine, you can throw that step away.
 
Quote:
There are a couple of small steps I'd add to Yotehunter59's "How to" post. First I like to clean the chamber and throat of the barrel, it is amazing how difficut it is to get good consistent results with a dirty chamber. The next think I like to do is to take a number of readings, I like at least 5 then average them to get my final OAL. You will sometimes get some wild measurements, throw them out, sometimes you can work for a little while with a barrel before becomming comfortable with the readings you are getting.



Michael, this is very true, and I do the same with my rifles. The cleaning thing is REAL IMPORTANT, especially if you have any copper buildup at the throat...JOHN /ubbthreads/images/graemlins/grinning-smiley-003.gif
 
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