Hornady Threaded OAL/CBTO Case

[General RE LEE]

Howdy folks

My 6mm ARC threaded Hornady case has a tight neck making the bullet not flow smoothly through the neck to reach lands when taking a measurement.

Anyone had a similar issue and found a hack?

 

[Carlos88]

Flitz on a bronze brush chucked in a cordless drill. Get after it then clean the case. I've also done it with bore cleaner and the above.

 

[RegionRat]

Anyone had a similar issue and found a hack?

I have bought the tools on occasion, but for the most part drill and tap my own so that the tooling case is fire-formed and fits snug compared to a standard tool and gives less slop in the measurement.

When I start to modify the case, I run the mandrel diameter up in steps till the bullet will just slide. I am going to assume you don't have the mandrels or you would have already done so.

If you cannot borrow mandrels or don't want to invest in them, I would check the neck for dents and iron those out first. If the size is to blame and you don't mandrel, I would apply grit paste to a brass rod or sacrifice a bullet and spin inside that neck till it slides.

If you don't have the tight brass rod or a way to hold the bullet, a split cut into a dowel rod can hold sand paper or ScotchBrite media and be spun to help smooth and open the neck as a last resort. As a last resort, a tight fitting bronze bore brush with grit paste will also work. Start with rotation speed and then slow the rotations and make more plunges before you finish, and clean up well.

If you stay in this game long enough and you trust yourself with tapping threads, it isn't difficult to make the case modification and you will eventually want to learn to mandrel necks, so make sure you add the over-sized ones to your toolbox and you will be able to make your own tool. I realize everyone isn't a machinist, but maybe your friends are and if you own the drill and tap they can do this for you. YMMV

 

[Coyote Shadow Tracker]

Howdy folks

My 6mm ARC threaded Hornady case has a tight neck making the bullet not flow smoothly through the neck to reach lands when taking a measurement.

Anyone had a similar issue and found a hack?

We have made hundreds of Drilled & Tapped Brass Cases Hornady OAL Guage. We use a K&M "expand mandrel" to open the necks of the Brass. You can also use a Phillips Screw Driver with the shaft close to the size of the ID Neck and wiggle it around until the bullet freely fits in and out of the case.

 

[birddog 68]

If you stay in this game long enough and you trust yourself with tapping threads, it isn't difficult to make the case modification

Agreed. I'd like to know why did Hornady make this such an oddball size though?

 

[Coyote Shadow Tracker]

Howdy folks

My 6mm ARC threaded Hornady case has a tight neck making the bullet not flow smoothly through the neck to reach lands when taking a measurement.

Anyone had a similar issue and found a hack?

We have been making Modified Cases for members for a few years. We do the Drilling and Tapping from free and just pay for the ship/packing $6.50. We are making some Modified Cases for some other members right now so If you need another Modified Case from your chamber send us a PM.
Thanks
Len & Jill

 

[asd9055]

Howdy folks

My 6mm ARC threaded Hornady case has a tight neck making the bullet not flow smoothly through the neck to reach lands when taking a measurement.

Anyone had a similar issue and found a hack?

Use your expander either mandrel or depriming die

 

[EndersPrint]

I've used a collet bullet puller to cycle a bullet through the neck several times to reduce neck tension. Other suggestions are probably better but maybe this matches your tools on hand.

 

[Mikecr]

Or, dump the method all together.
Seems nothing but a problem for many here.

 

[Coyote Shadow Tracker]

^^^^^^
There are dozens of Threads and hundreds of Posts on how to get COAL (Case Over All Length) and CBTO (Cartridge Base To Ogive) the Hornady LnL OAL Modified Case Gauge Tool.
There are opinions from everyone on how to do it.
I am not going to say which method is better than the other of if you should even check for COAL CBTO. That is up to the induvial reloader.
I will state that if you are going to use the Hornady LnL OAL Modified Case Guage you first need to purchase The Lock-N-Load® O.A.L. Gauge, then Lock-N-Load® Bullet Comparators, A Caliper to measure and a Lock-N-Load® Modified Cases for the Cartridge of your rifles.

You can make your own Modified Case for your specific rifle by Drilling out the primer pocket and then tapping it. Hornady made an odd size Thread on their Tool so that Tap is not included in most Tap Sets. You can purchase the Drill Bit and Tap. The Drill is "L" size and Tap 5/16 36 tpi.
If you are going to do a DYI I suggest that you have a Drill Press and a jig to put the case in, in the vise. Better yet if you have a Mill or Lathe so that you drill straight and Tap straight.

We have Drilled & Tapped Modified Cases for Hundreds of LRH members along with several hundred cases for other Reloaders. We have never charged $$s for labor or machine work. We only asked for a small fee to cover shipping and over the years have lost $$$ when we even shipped free. We just ask to "Pay it Forward" and possibly help out a fellow Reloaded/Hunter/Shooter.

Whatever way you get to CBTO please do it so that your measurements are correct and safe.
If you need some assistance, feel free to PM us and we will try to help you out within our knowledge base.
Thanks
Len & Jill

 

[Seabeeken]

https://feeds.brownells.com/userdocs/learn/SinclairSeatingDepthGage.pdf