Stoney point gauge

[AtticusThraxx]

I don't know where my "lands" start, so from what I've read I need a Stoney Point gauge? Is that correct. Can't find one on Midway website. Anyone have a suggestion where to look? Gotta find my lands, lost without them.

Also on the Sierra load map for .308 I see an acronym C.O.A.L, can someone shed some light as to what that means? Thanks.

 

[tightneck]

JMHO but I think this tool is one of the most inconsistent tools I have used in reloading. The most consistent tool for finding your lands is your CHAMBER. Seat the bullet long and let the rifling finish the job when you chamber the round. Run the cartridge into the die and adjust the seater stem to this jam length. Now you have a OAL that can only be adjusted in one direction,deeper in the case). Find a powder charge to give you the best groups at jam length and then push the bullet in .005 at a time to find the sweet spot. I have a quite a few rifles that like full jam so no tweaking is necessary. And of course, always use a dummy round for this method.

 

[Forum Boss]

C.O.A.L.= Cartridge Overall Length.

The Stoney Pt. tool is also often called an OAL gauge. But more accurately it is a base to ogive gauge at the point of land contact.

Using a Stoney Point--
When I measure with a Stoney point gauge, I'll use three or four bullets and I'll measure each twice.

Normally, the two measurements of the same bullet will be within .002". For the set of all bullets, my spread might be .005" over 8 samples,4 bullets each measured twice). If I get one that's way long or short, I'll measure with that bullet again. If it's still way off I'll try another bullet from the box. Usually, you'll see one measurement really predominate over a large set of samples--that's what I'm working to find.

There is a technique to using the thing. You need to keep the rod straight. I've found it best to sort of tap-tap-tap on the end till you get solid contact. But if you push real hard you'll hard-jam the bullet in the rifling and that can alter your measurement by .010" or more.

But once you get used to the technique, I find the tool is very repeatable, once you understand that the measurement can vary up to .004" from one bullet to the next. I'll try to get at least 6-7 readings and then I'll choose the dominant reading and use that to set my dies. I generally seat .015" in from that position for a 6BR. This has proved very accurate. And, when I've recommended .015" in, as measured with a Stoney Point, the guys who've tried it have also had very good results. If the S-P tool was way off I don't think we'd be able to replicate a recommended seating depth from one gun to another and get consistent results.

The key is being patient, learning the technique, and taking multiple measurements.

 

[ballistic64]

Orders cant be placed direct to Stoney Point anymore as they were bought out by Hornady.
Since I started turning necks I got away from using the stoney point guages and just use my K&M expander mandrel.It gives enough tension to chamber the bullet in an empty case.

 

[AtticusThraxx]

Thanks guys, lots of good information. Apparently when I searched Midway I either misspelled it or made it all one word. Got to read these replies carefully and experiment a bit I think.

 

[halfmile]

I also use the empty case method, having resisted spending 35 or so dollars on a tool that I can live without.

I full resize the case and start a bullet just barely. then I put it in the gun and close it slowly. I make sure it extracts with ease and hold it to prevent sideways motion. then I measure the length. Sweet spot for me seems to come at 10-15 thousandths jump, usually I am speeding them right along at near max.

If I find a Stoney point tool for cheap, I will buy it. My pal makes his own dummy cases for the tool instead of buying them.

HM

 

[AndyW]

I also use a method like tightneck and halfmile. I like to use a fireformed brass that has been necksized, I start a bullet,dummy round)and close the bolt. Take the dummy round and set my seater to the lenght of the round. Theen I take 000 steel wool and scrub the land etch off of the bullet and seat the bullet a few thou in and keep repeating until the bullet has no mark from the lands. Voila, you will have the exact point of contact with the lands.

 

[chino1969]

C.O.A.L.= Cartridge Overall Length.

The Stoney Pt. tool is also often called an OAL gauge. But more accurately it is a base to ogive gauge at the point of land contact.

Using a Stoney Point--
When I measure with a Stoney point gauge, I'll use three or four bullets and I'll measure each twice.

Normally, the two measurements of the same bullet will be within .002". For the set of all bullets, my spread might be .005" over 8 samples,4 bullets each measured twice). If I get one that's way long or short, I'll measure with that bullet again. If it's still way off I'll try another bullet from the box. Usually, you'll see one measurement really predominate over a large set of samples--that's what I'm working to find.

There is a technique to using the thing. You need to keep the rod straight. I've found it best to sort of tap-tap-tap on the end till you get solid contact. But if you push real hard you'll hard-jam the bullet in the rifling and that can alter your measurement by .010" or more.

But once you get used to the technique, I find the tool is very repeatable, once you understand that the measurement can vary up to .004" from one bullet to the next. I'll try to get at least 6-7 readings and then I'll choose the dominant reading and use that to set my dies. I generally seat .015" in from that position for a 6BR. This has proved very accurate. And, when I've recommended .015" in, as measured with a Stoney Point, the guys who've tried it have also had very good results. If the S-P tool was way off I don't think we'd be able to replicate a recommended seating depth from one gun to another and get consistent results.

The key is being patient, learning the technique, and taking multiple measurements.

I agree that you can get pretty close by learning the technique and taking multiple measurements. The other trick is to send Stoney Point a fireformed case to be modified so that it is an exact fit to your chamber. The other method is to measure the headspace on your 2 to 3x fireformed case and measure the headspace on the standard case. Your fireformed case will be approx. .002 to .005 more than the Stoney Point standard case. Add this dimension to the dimension you've obtained with the standard case and you'll be within .001 of touching the lands.
Chino69

 

[Mikem]

Stony Point does make two types, one is curved and designed for gas guns, that its not easy to remove the bolt on, and a straight one for bolt actions.
There about $28. each, you also need a S.P. bullet comparator kit to go with it, which includes a set of caliber sensitive adapters, or I think you can just buy the one caliber you want. And you will also need a special brass case for every caliber you will want to test.
They do work well, and will give accurate readings, but I recommend taking several readings with the same weight bullet to get a good average length reading.
If you have both, gas guns and bolt actions, you can just use the curved one, I think its even easier to take reading on a bolt action with the curved one, in my opinion.
You can also measure throat erosion as time gos by.
For serious re loaders, I think there worth the money.
But for some, they have worked out other ways to measure this, but I cant advise on this, as I have never tried there method.
Mike..

 

[Dean]

All things being equal,I am probably the least experienced loader on this site,been loading about a year)but...the Stoney Point tool is just not that accurate.
When you use this tool you push the case as far up in the chamber as possible.
When you chamber your round using your bolt the bolt may or may not push the case in as far as you do with the Stoney Point tool.This will cause a difference of up to .015",in my chambers anyway).
I use whats called the cleaning rod method and this nails the distance to the lands right on the money.
A full set of directions is posted on savageshooters.com under reloading FAQ.
Give it a try and check it against the Stoney Point tool.
Just remember that as long as your rifle is shooting small groups it doesn't matter what your distance off the lands really is,if you think your bullet is .010 off the lands but it is actually .020 off...who cares???

Thanks for letting me ramble,
Dean