Hard jam -.02 and the stoney point oal gage

[Mr. B]

I have been experimenting with the stoney point oal gauge with numerous calibers and bullets. At the same time I have used the method described by Erik Cortina of seating a bullet long and using the bolt to seat the bullet on a case with .002 neck tension.

The results were interesting for my rifles and equipment. I use the stoney point gauge keeping hard pressure on the cartridge then pressing as firmly on the metal bullet rod as my finger will tolerate and then locking in place.

Comparing these 2 results is where it gets interesting the stoney point result is almost exactly equal to the number generated by Erik's hard jam -.02 (YMMV). This result has repeated for me so consistently that I now start load development at the number given by the stoney point guage when used as above and label it hard jam -.02 in my notebook. All of the rounds I have tried easily chamber and eject without the bullet getting stuck. I am interested to know if anyone else has compared these methods and their results.

 

[Ned Ludd]

Even though it is only made of plastic, pushing down hard on the Hornady OAL gauge (Stoney Point tool) rod will definitely move a bullet well into the lands. Exactly how far the bullet moves into the lands will depend on a number of factors. That is the same reason a little practice is necessary with such a tool to develop a feel for when the bullet just barely touches the lands. Nonetheless, once you have a good feel for its use, using a Hornady OAL gauge is a relatively simple, straightforward, and reliable way to find the distance to "touching", IMO. I have never been able to figure out why so many seem to struggle with learning its use.

 

[Mr. B]

Even though it is only made of plastic, pushing down hard on the Hornady OAL gauge (Stoney Point tool) rod will definitely move a bullet well into the lands. Exactly how far the bullet moves into the lands will depend on a number of factors. That is the same reason a little practice is necessary with such a tool to develop a feel for when the bullet just barely touches the lands. Nonetheless, once you have a good feel for its use, using a Hornady OAL gauge is a relatively simple, straightforward, and reliable way to find the distance to "touching", IMO. I have never been able to figure out why so many seem to struggle with learning its use.

Interesting to learn the new ones are plastic, I have a very old one with a metal rod for inserting the bullet. It doesn't sound like my method would work too well with one of the newer ones. I have gone so far as to lightly tap on the end of the rod with a soft rubber hammer to see how that compared to a hard jam.

 

[Big Mc]

I have been experimenting with the stoney point oal gauge with numerous calibers and bullets. At the same time I have used the method described by Erik Cortina of seating a bullet long and using the bolt to seat the bullet on a case with .002 neck tension.

The results were interesting for my rifles and equipment. I use the stoney point gauge keeping hard pressure on the cartridge then pressing as firmly on the metal bullet rod as my finger will tolerate and then locking in place.

Comparing these 2 results is where it gets interesting the stoney point result is almost exactly equal to the number generated by Erik's hard jam -.02 (YMMV). This result has repeated for me so consistently that I now start load development at the number given by the stoney point guage when used as above and label it hard jam -.02 in my notebook. All of the rounds I have tried easily chamber and eject without the bullet getting stuck. I am interested to know if anyone else has compared these methods and their results.

The tool you are using takes a LOT of practice. To get a true reading. Just my two cents Tommy Mc

 

[AlNyhus]

I've got the Stoney Point tool (early metal one) and another one I made myself, along with the tap to make modified cases . Both will give you useable info.

Honestly though, on any bolt gun, the best way is to strip the bolt, size a case, seat the bullet long and using 0000 steel wool to polish the rifling marks off the bullet....keep seating the bullet back until the rifling marks just disappear. Then record the seating stem length for each bullet for that barrel to the 'just touching' length. Makes quick work of going into or out of the lands as well as swapping bullets at the range.

Good shootin'. -Al

 

[JimSC]

I use the stoney point gauge keeping hard pressure on the cartridge then pressing as firmly on the metal bullet rod as my finger will tolerate and then locking in place.

That is exactly how I do it. I just call it touch and use it as a reference. I can measure using 5 bullets from the same lot and never have more than .001 or .002 difference

Mine is the 90 degree bent one with a brass push cable. I have been using it for years so I guess I do have a bit of practice

 

[dannyjbiggs]

I have been experimenting with the stoney point oal gauge with numerous calibers and bullets. At the same time I have used the method described by Erik Cortina of seating a bullet long and using the bolt to seat the bullet on a case with .002 neck tension.

The results were interesting for my rifles and equipment. I use the stoney point gauge keeping hard pressure on the cartridge then pressing as firmly on the metal bullet rod as my finger will tolerate and then locking in place.

Comparing these 2 results is where it gets interesting the stoney point result is almost exactly equal to the number generated by Erik's hard jam -.02 (YMMV). This result has repeated for me so consistently that I now start load development at the number given by the stoney point guage when used as above and label it hard jam -.02 in my notebook. All of the rounds I have tried easily chamber and eject without the bullet getting stuck. I am interested to know if anyone else has compared these methods and their results.

No idea. I've always used the "Cortina" method for the past 15 years or so as a base line to arrive at seating depth. I will admit to having a stoney point gauge somewhere down in the lower drawer, though...least I think that I ran across it a couple of years ago?? (It's been there for a little over 15 years.)

Dan

 

[milboltnut]

touching the lands and backing off .006 does it for me. Jamming? what for?

 

[Richard Coody]

touching the lands and backing off .006 does it for me. Jamming? what for?

Whatever works for.you. reality is it is just a datum to start seating depth test from. As long as it is repeatable and works for you does it really matter?

Touch has always been kind of an arbitrary point to me. Now hard jam with my stoney point is definitive.

 

[JEFFPPC]

The method you use and wether that result you get is actually the number you think it is , is of no consequence. As long as your result is totally repeatable you now have a reference point. It you think your jumping .003 but your really .003 into the lands it does not matter. If that's were it shoots you now have the ability to find that spot again.

 

[klamathsteel]

Using the Cortina method is'nt there a chance the bullet will pull out of the case some when you open the bolt ??

 

[M-61]

Using the Cortina method is'nt there a chance the bullet will pull out of the case some when you open the bolt ??

It's the method I use and I'd say every bullet was pulled from the case therefore when doing this my cleaning rod (minus brush) is right there so I can push the bullet out (obviously muzzle to breech direction)

 

[klamathsteel]

So then how do you get a measurement ?

 

[M-61]

Leave the cable locked. Place bullet back in case. Measure. Bullet pushed in until it bottoms on locked cable

 

[Ned Ludd]

Interesting to learn the new ones are plastic, I have a very old one with a metal rod for inserting the bullet. It doesn't sound like my method would work too well with one of the newer ones. I have gone so far as to lightly tap on the end of the rod with a soft rubber hammer to see how that compared to a hard jam.

I don't know how "new" the plastic rod is; I've had this one for years. I'm glad to hear that at some point, at least, they were made with metal. I think that is a much better design. My primary concern with the plastic rod isn't that the rod itself being plastic will dramatically affecting length measurements made using the use of the tool, per se. However, you have to be careful not to over-tighten the set screw, or it will leave a permanent indentation in the contact surface of the plastic rod that could adversely affect future measurements when re-tightening the set screw in that region of the rod.

 

[M-61]

over-tighten the set screw, or it will leave a permanent indentation in the contact surface of the plastic rod

I didn't know there was a plastic one made. I should have mentioned mine is metal with a metal cable that does the pushing. But because mine is the one that is angled and not straight the cable is like a tightly wound metal spring.
(spring is not the word I'm looking for)

 

[Ned Ludd]

I didn't know there was a plastic one made. I should have mentioned mine is metal with a metal cable that does the pushing. But because mine is the one that is angled and not straight the cable is like a tightly wound metal spring.
(spring is not the word I'm looking for)

I also have an angled Hornady OAL gauge with the cable for use with a Sig556 AR-type semi-automatic rifle. When I first bought it, the cable was extremely stiff and hard to move, making accurate measurements more challenging. However, it seems to be loosening up over time with use. Because of the interior design of the receiver, the straight Hornady OAL gauge cannot be used in that rifle, as it will not align properly with the bore. FWIW - the straight Hornady OAL gauge body is metal; only the the push rod is plastic. The outer body and fittings are the same as with the angled version. I looked into having someone machine a matching steel rod to replace the plastic one in the straight tool, specifically the longitudinal groove for the set screw, but ultimately that wasn't worth the effort, and I simply learned not to over-tighten the set screw. It would probably be possible just to use a round steel rod, but I haven't made the effort to find the appropriate rod stock to make one.

 

[milboltnut]

I accidentally jammed the whole tool in to seat the case and broke the threaded end... So I would be careful about jamming.

 

[Steve Blair]

I also have an angled Hornady OAL gauge with the cable for use with a Sig556 AR-type semi-automatic rifle. When I first bought it, the cable was extremely stiff and hard to move, making accurate measurements more challenging. However, it seems to be loosening up over time with use. Because of the interior design of the receiver, the straight Hornady OAL gauge cannot be used in that rifle, as it will not align properly with the bore. FWIW - the straight Hornady OAL gauge body is metal; only the the push rod is plastic. The outer body and fittings are the same as with the angled version. I looked into having someone machine a matching steel rod to replace the plastic one in the straight tool, specifically the longitudinal groove for the set screw, but ultimately that wasn't worth the effort, and I simply learned not to over-tighten the set screw. It would probably be possible just to use a round steel rod, but I haven't made the effort to find the appropriate rod stock to make one.

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