Hornady Modified Case/OAL guage issues

[morgantm16]

I'm using a Hornday OAL guage to measure my distance to the lands on a 6.5x284 Norma. Just recieved my Hornady modified today and when i insert a bullet in it, it has a much tighter fit than I imagined and does not allow me to push the bullet smoothly. It seems like there are two points where the bullet really binds up as well. So needless to say, I'm not sure that I'm getting an accurate measurement to the lands. I could be hitting the lands or the bullet may be binding up in the case and I think that I'm at the lands.

Should I get a .264 diameter brush and apply some polishing compound and hit the inside of the brass to try to smoothen it out?

I have tried with 140 VLDs and 156 EOL and get different distances to the lands. Both bullet would bind up in my modified case.

 

[Shawnba67]

You can sand out the neck a little. A 17/64 drill is .265 and a Letter H is .266. You might shove the shank end in and get the clearance you need. Tap it in with a rubber hammer?

 

[gunsandgunsmithing]

I'm using a Hornday OAL guage to measure my distance to the lands on a 6.5x284 Norma. Just recieved my Hornady modified today and when i insert a bullet in it, it has a much tighter fit than I imagined and does not allow me to push the bullet smoothly. It seems like there are two points where the bullet really binds up as well. So needless to say, I'm not sure that I'm getting an accurate measurement to the lands. I could be hitting the lands or the bullet may be binding up in the case and I think that I'm at the lands.

Should I get a .264 diameter brush and apply some polishing compound and hit the inside of the brass to try to smoothen it out?

I have tried with 140 VLDs and 156 EOL and get different distances to the lands. Both bullet would bind up in my modified case.

Finally, a use for an expander button...maybe!

 

[Dud]

I'm going to expand one of those but just because I need to turn it in to a 284 gauge.

Then I'm going to expand the rest of my brass.

 

[gunsandgunsmithing]

I'm going to expand one of those but just because I need to turn it in to a 284 gauge.

Then I'm going to expand the rest of my brass.

Some might make it too big but that's not likely.

 

[Fast14riot]

I've cut slots in the neck with a dremel. Sand and deburr the cuts inside and out.

 

[tmwinds]

I take a small piece of sand paper and roll it up tightly and chuck it up in a small cordless drill. Taper the end of the rolled sand paper and run it in and out of the case neck until the bullet slides in smoothly. Takes about 15 seconds.

 

[Dusty Stevens]

Not being able to use it just saved you some time- too bad you already bought the case. Just use one of your loaded rounds- free of charge and actually repeatable

 

[Texas10]

Go ahead and size the case like you normally would. Seat a bullet long, install it on the tool (forget the pushrod) and slide it up the chamber with a firm push, then retract. Any tendency to stick is an indication of the bullet in the lands. Seat the bullet a bit deeper and keep repeating until there is no tendency to stick upon withdrawal.

Might start with the case without a bullet first and check for any drag as sometimes the modified case is a poor fit to your particular chamber. Also make sure the chamber and the throat are clean first. Verify with a endoscope camera or borescope if you have one.

The whole process only takes a few minutes and will give repeatable results to within one or two thousandths.

If you want absolute accuracy, you'll need to account for the difference in case base to datum measurement (sometimes called headspace) between your fire formed brass and the Hornaday LNL brass.

 

[Scalloper]

Not being able to use it just saved you some time- too bad you already bought the case. Just use one of your loaded rounds- free of charge and actually repeatable

I agree. I bought the bits to drill and tap a fired round that way it fits the chamber tighter and gives a more accurate measurement.

 

[mike a]

Go ahead and size the case like you normally would. Seat a bullet long, install it on the tool (forget the pushrod) and slide it up the chamber with a firm push, then retract. Any tendency to stick is an indication of the bullet in the lands. Seat the bullet a bit deeper and keep repeating until there is no tendency to stick upon withdrawal.

Might start with the case without a bullet first and check for any drag as sometimes the modified case is a poor fit to your particular chamber. Also make sure the chamber and the throat are clean first. Verify with a endoscope camera or borescope if you have one.

The whole process only takes a few minutes and will give repeatable results to within one or two thousandths.

If you want absolute accuracy, you'll need to account for the difference in case base to datum measurement (sometimes called headspace) between your fire formed brass and the Hornaday LNL brass.

I'm sure your right about a fire piece and the LNL brass but I'm struggling to understand. If the case head is against the bolt face and the ojive is in contact with the lands what does headspace matter.

 

[tmwinds]

I'm sure your right about a fire piece and the LNL brass but I'm struggling to understand. If the case head is against the bolt face and the ojive is in contact with the lands what does headspace matter.

The case head won't be against the bolt face since there is no bolt in the rifle when using a Hornady LNL. It will headspace on the cartridge shoulder.

 

[mike a]

The case head won't be against the bolt face since there is no bolt in the rifle when using a Hornady LNL. It will headspace on the cartridge shoulder.

Duh! Do I feel dumb. I've always used the Wheeler method.

 

[tmwinds]

Duh! Do I feel dumb. I've always used the Wheeler method.

Not so dumb. You're doing it correctly in my opinion.

 

[Texas10]

The Wheeler method will work on pretty much any custom action, factory actions are not nearly as well made. I could not get my Savage action to work using this method, the bolt would not drop smoothly on an empty chamber. Without that "feel", IMOP the Wheeler method is useless. That is why I turned to the method I describe. The bolt is not even in the equation, and doesn't need to be as you are measuring the distance from the SHOULDER of the cartridge to the lands, not the distance from the bolt head.

We use another gage to measure the case base to ogive after establishing "touch" as a matter of convenience, and yet another to measure case base to shoulder for setting your full length sizing die, hence why you need to know the difference between your fully fire formed brass and the Hornaday LNL case.

It all may seem a bit confusing at first, which is why I encourage you to try the method I describe so that you understand just exactly what you are accomplishing with this measurement. You will know immediately what "in the lands" and "not touching" will feel like, and you don't have to disassemble your bolt to do it.