Someone on this forum last month mentioned that you could make your own modified cases for the Hornady/Stoney Pt OAL gauge with a 5/16 x 36 tap. Where can I buy this tap? It is an unusual size and not easily available.

Hornady will make a modified case for you for $11 if you send them 2 cases fired from your rifle. That's great, but I would like to make my own modified cases for different rifles on an ongoing basis. You really need a custom modified case - I noticed that the case body length (base to datum line) for my fired cases is about .005 greater than their modifed case, which of course is an unfired case.

Try Here....

http://www1.mscdirect.com/CGI/NNSRIT?PARTPG=NNSRAR2&PMPXNO=1735758

Thats where I ordered mine. Around $17.00

Thanks, Xsskeet. The tap is on order.

What do you think of the OAL gauge? Making repeatable measurements of the "to the lands" distance requires some practice, but this works better for me than other methods that I have tried.

A very respected bench rest shooter and gunsmith/barrel maker once showed me how to measure this distance by seating a bullet, then chambering the round so that the scuff marks on the bullet made by the lands were "square." This worked well for him with his bench rest rifle with custom barrel and action, but it did not work for me. The OAL gauge is the best method in my hands.

I have had mine for a few years. It takes a little practice, but once you figure out what you are doing it works well.

I use it quite a bit on my Contender and Encore barrels. With the information I get, I can play with different seating depths and have a good idea how far off the lands they are seated.

Good Luck...

What size drill do you need for that tap??

Any pointers to the same supplier as above?? Maybe he would have the right drill bit as well (saves on shipping...)??

- mike

This information was posted by "Pdpdad" last month, regarding drill bit size for the 5/16 x 36 tap:

"Proper size is .282-.286 diameter.
Best fit is 9/32 at .2812 or "K" at .2811 or
7.2mm at .2835.
I=.2720 not a problem in a soft metal."

[Credit goes to "Pdpdad" for this information - thanks.]

Thanks Mate!
- mike

I went to the MSC website to look for suitable drill bits. Not being a machinist or familiar with the overwhelming choice available, would a drill like this do the trick??

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1683600&PMT4NO=

If not, what attributes am I looking for?? At home, I would probably just look for a "metal" drill, and be pretty convinced it would do the job on the comparatively soft brass material... (OK, now you can laugh at my simple mind... ).

Thanks for any help in advance.

- mike

quote:

Originally posted by mho:
I went to the MSC website to look for suitable drill bits. Not being a machinist or familiar with the overwhelming choice available, would a drill like this do the trick??

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1683600&PMT4NO=

If not, what attributes am I looking for?? At home, I would probably just look for a "metal" drill, and be pretty convinced it would do the job on the comparatively soft brass material... (OK, now you can laugh at my simple mind... ).

Thanks for any help in advance.

- mike

Mike

I did my cases in 3 steps for drilling the hole for the tap.

Brass is a lot like women, it's soft but tough and resilient.

For the final hole take the bit and hold it against the tap end and insure there is enough space for the threads. Then tap the threads. You don't have to have a lot of torque to hold the cartridge case.

Bill

I found that a drill press and proper vise really make the process easier and you don't "tip" or cant the cartridge off center when in a locked up position- tried to drill and tap a few 300-221 Fireball(nee 300 Whisper) cases by hand holding the case and every one was off center.
Fixed problem by use of the vise.
Just a helpful hint.

Gary