Removing a .30 cal. g/c shank

[Ben]

I've had several people ask if I'd post my technique for removal of a gas check shank from a .30 cal. mould.

1st , let me say that if you've never done this kind of work before, you might want to start with a used Lee mould. In the event things don't go well you haven't lost a big pile of $$$.

I use a super sharp 5/16 HS drill bit ( .312" dia. ). ( I know ....everyone says this can't be done ! ! ). Well, it can be done under the right conditions. I'll admit that it is best done by a machinist with proper skills and equipment. Since I don't have access to that, I've learned how to do it with satisfactory results with my " low tech " approach.

I'll also say , if you're the least bit " ham handed " you my want to totally skip all this ! !

For me, the secret has been :

(1) Having your drill bit PERFECTLY perpendicular to the mould cavity.

(2) Having access to a drill press that has minimal run out.

(3) Using the drill stop on your drill press to insure the bit doesn't plunge too deep into the mould.

(4) Having a fixture to hold the mold securely ( see photos below )

Here are some photos :

50 yards, 5 shots, 30-06 , Ruger # 1 :

 

[Gary]

Beautiful Ben, thanks for the education. I really appreciate the info and quality pictorial guide.

 

[Ben]

You're very welcome ! !

If you decide to try the technique, share the results with us.

Ben

 

[Gary]

I just might do that, once the drill press gets put back together.

 

[Ben]

Check your bit for " run out ".

 

[waco]

I have access to a lot of nice milling machines at work. I haven't a clue as to how to run them but work with several very skill machinists that just happen to be gun guys as well.
I have an old Lee .30cal 180gr mold I should take into work and convert it to a PB mold.
My Savage 340 in 30-30 loves this bullet. I could do without the GC's for that load anyhow.

 

[Ben]

WACO ,

My Handi , 30-30 loves plain base bullets.

Be certain that you show your machinist friends where the bottom most lube groove is on the bullet and that you want their cut to go up to that point , but not beyond it.

Ben

 

[Brother_Love]

Ben,
Thank you for posting this.
Malcolm

 

[Ben]

Malcolm,

You are very welcome.
I hope it will be a benefit to some of you that are thinking about plain basing a mould.

Ben

 

[Centaur 1]

I have access to a lot of nice milling machines at work. I haven't a clue as to how to run them but work with several very skill machinists that just happen to be gun guys as well.
I have an old Lee .30cal 180gr mold I should take into work and convert it to a PB mold.
My Savage 340 in 30-30 loves this bullet. I could do without the GC's for that load anyhow.

Waco,

If you have a machine shop at work, It's almost a sure bet that they have the proper reamers available. Undersized reamers are a standard item, I've used a .3115" when removing a .30 cal gas check shank. While you're at it, ask the machinist to teach you how to float the reamer. It's a technique which produces an accurate hole and it can be done on a drill press.

Mike

 

[John]

Ben, My method is the same as yours though I have only done 4. My first, a Lee 113 gr 30 cal is slightly off by .001". A sizing die smoothes that out. I am glad I learned on a lee, but messing one up isn't the end of the world either.

 

[Ben]

Very True.

 

[KeithB]

Ben, don't take this as criticism at all, just as a comment dealing more with my own ham-handedness than with you and your techniques. I have never had any good results using a two flute drill to enlarge a precision hole, especially in steels and cast irons.. For a few extra dollars, especially if you plan to do more than one mold, I would invest in a multiflute machine reamer. Here is a link to a page with a selection of approximately .30 cal reamers for about $19 each.

https://drillsandcutters.com/hss-chucking-reamers-decimal/?sort=featured&page=10

Of course they also have reamers that cover the complete size range you might need to do different caliber molds.

 

[Ian]

That's how I've always done it, Keith. I also unplug the drill press, snug the quill tension to a firm drag, and rotate the chuck by hand. For aluminum moulds I use a chucking reamer that's the same size as what I want the final bullet dimension to be.

Chucking reamers are also very handy for reaming revolver cylinders on the cheap. Bush the flutes with tape to fit the chamber, making sure not to overlap the ends. It's bush league but works.

 

[Ben]

Ben, don't take this as criticism at all, just as a comment dealing more with my own ham-handedness than with you and your techniques. I have never had any good results using a two flute drill to enlarge a precision hole, especially in steels and cast irons.. For a few extra dollars, especially if you plan to do more than one mold, I would invest in a multiflute machine reamer. Here is a link to a page with a selection of approximately .30 cal reamers for about $19 each.

https://drillsandcutters.com/hss-chucking-reamers-decimal/?sort=featured&page=10

Of course they also have reamers that cover the complete size range you might need to do different caliber molds.

I certainly don't take your comments as a criticism .

I've been told the same identical thing you've just said by 20 people. Not the 1st time that I've been offered the suggestion.

Ben