5/16"x 36 tap

[300winmag]

Someone was looking for this tap. I cant remember who, bought mine here!
To modify cases for stoney point.
https://drillsandcutters.com/search.aspx?find=5%2f16%22+-36&log=false&category=1071

[mac60]

It wasn't me brother, but if you don't mind I'll make good use of the link. Much appreciated.

[Catshooter]

Winmag,

Good site. What did you want with that tap size?


Cat

[Pilgrim Sojourner]

300winmag,
Which tap is most appropriate for the Stoney Point modified cases (plug, taper, or bottoming)?

[Dutchman]

300winmag,
Which tap is most appropriate for the Stoney Point modified cases (plug, taper, or bottoming)?

The taper or plug tap would be fine. You wouldn't use the bottoming tap for such a job. I assume you're doing this in a lathe... which may be an incorrect assumption. Either one of these taps would be fine for use in a lathe to do this. If you were doing it by hand then the taper tap. But its really a job that requires very accurate alignment.

I used a 5/16" (.3125") reamer in the case mouth of the various .30 caliber cases: .30-40 Krag, .308 WCF, .30-06, 7.5x55 Swiss, 7.65x53 Argentine, etc. This makes the movement of the bullet easier when setting the gauge. Then I made sure those bullets that would be used were sized in a .311" die.

I've done business three times with this company. I also bought the 5/16-36 tap for my own shop-made Stoney Point gauge. And I bought a couple dies, one a 5/32-32 die to thread 1891 Mosin-Nagant rifle cleaning rods (29" length).

I ordered the high speed steel die but they sent a carbon steel die... an ancient carbon steel die. I wrote the company and they apologized saying the order puller stuck his hand in the wrong bin. They told me to keep the carbon steel die and they sent a new HSS die. Fact is, I've used the carbon steel die more as it's an excellent die. The thread series for 5/32-32 was NS (National Standard) which is a very old thread standard that was obsolete... I forget what year it was but it was pre-WW2.

I also bought the 5/16-36 die to thread the tube portion of the gauge.

http://images55.fotki.com/v585/photos/4/28344/9895637/DSCF2777s-vi.jpg
http://images61.fotki.com/v1609/photos/4/28344/9895637/DSCF2787s-vi.jpg
http://images108.fotki.com/v1623/photos/4/28344/9895637/DSCF2789s-vi.jpg

http://images43.fotki.com/v679/photos/2/28344/6456804/3124_Stoney_pointFirearm_tool1-vi.jpg

[W.R.Buchanan]

Too bad they didn't use 5/16-32 which is the common tire valve stem size.

McMaster has alot of bastard sized taps.

But MSC is the king of oddball sizes and has virtually every tap known to man, IN stock in any configuration you want. They never cease to amaze me with what they have in stock.

Very reasonably priced, and usually in several grades. You don't need a $30 tap to do one hole.
However you should always at least buy High Speed steel taps. Avoid the hi carbon steel taps as they tend to break at the worst possible moment.

Randy

[Catshooter]

Randy,

I wish that bold statement about MSC was true. I usually go here: http://www.victornet.com/ when I need a weird tap/die. But neither them or MSC has the 7/32x40 die that I'm looking for. The tap I have it's the die that is tough to find.


Cat

[3006guns]

Victor was the only company that carried a somewhat obscure metric size tap so I could repair my Japanese type 99.

[W.R.Buchanan]

Cat: I said taps, not dies. Bastard dies are indeed a problem. Even if someone had one they would want a bunch for it. Probably a deal breaker.

Most threads like that are turned on a CNC or some other kind of automated thread cutting machine.

I could get 7/32-40 chasers for my Geometric die head but at $120 a set it is not viable for anything but a production type setup. Also a PITA to set up for only one or two shots as it would probably take a few attempts just to get the pitch dia set right.

Last resort would be to make one using your tap , then driilling 3 or 4 holes for the relief. That's how they make them in the first place. Depending on what you're trying to cut and how many times you want to use it it might be a viable alternative.

Randy

[Catshooter]

You're right Randy, you did say tap and you're right a second time; dies are a whole 'nother animal, dang it.

Since I've got the tap making the die wouldn't be all that bad and it's probably what I should do.


Cat

[W.R.Buchanan]

CAt did you say you have a lathe? if so you could single point thread your part. Just do a few practice runs before you have at your good part.

Randy

[Catshooter]

Yep, got a tiny lathe and mill. The way this lathe is built it's actually pretty easy to thread, much easier than a big lathe (in my very limited experience). Makes a nice thread.


Cat