Author Topic: Stubbing (Read 5441 times)

D Humbarger · « **on:** March 08, 2010, 10:40:58 AM »

Thought that you guys might be interested in some stubbing photos of my 375 JDJ in progress.

Boring out the stub to be threaded. That slug barrel was pretty hard.
It rockwell tested out at 30. Good steel!

The stub bored out to .937 ( the minor diameter for 1"x14 thread).

The stub threaded to full depth.

The shilen 375 barrel turned & threaded to fit the stub.

Screwing the stub and barrel together.

Waiting on that custom reamer now.

cwlongshot · « **Reply #1 on:** March 08, 2010, 10:44:05 AM »

Looks GREAT!!

Thanks for sharing!!

CW

billy_56081 · « **Reply #2 on:** March 08, 2010, 10:50:22 AM »

Thank you very much for sharing, loved the pictures.

Spanky · « **Reply #3 on:** March 08, 2010, 10:50:50 AM »

Very nice work D.
Is the barrel blank tapered or is it full diameter to the muzzle?
What are you going to do for the forearm lug?
I can't wait to see the finished barrel.
Please keep us posted on your progress.

Spanky

Airsporter · « **Reply #4 on:** March 08, 2010, 10:59:38 AM »

What kind of lathe do you have? I see that old lantern style tool holder! I get by with an old-as-me Sears (Atlas) 12x36, but appears you have larger spindle bore.

D Humbarger · « **Reply #5 on:** March 08, 2010, 11:28:00 AM »

Spanky the barrel is a #5 Shilen. Straight taper 1.110 to .720 at the muzzle, 23" long. I will recontour it to a lighter contour probably about a 4 1/2 & bring the muzzle down to .685~.700. I might try to use the original forearm lug.

Air my lathe is a Jet1236 (1 3/8 spindle bore) that I bought new in 1984. Never could get used to the ratchet type tool holders.

I recontoured the underside of a one piece Leupold 7600 base to fit the 1.110 radius of the handi stub.

LaOtto222 · « **Reply #6 on:** March 08, 2010, 11:33:54 AM »

Nice work, thanks for sharing. Please keep us updated; with a range report to follow. I have a Handi stub with a Douglas barrel and it shoots great, but it is not a 375/444, it is a 22 KHornet

quickdtoo · « **Reply #7 on:** March 08, 2010, 11:35:11 AM »

Quote from: D Humbarger on March 08, 2010, 11:28:00 AM

I recontoured the underside of a one piece Leupold 7600 base to fit the 1.110 radius of the handi stub.

What did you use to contour it? I have a 1" ball end mill which is as close as I could find. Nice work, great pics and thanks for sharing.

Tim

D Humbarger · « **Reply #8 on:** March 08, 2010, 12:50:32 PM »

The recontouring was the ti-tech part.

Turned a mandrel to the diameter of the stub minus the thickness of the sandpaper & went to work by hand back & forth. I PROMISE you WILL have blisters
by the time you are done.

quickdtoo · « **Reply #9 on:** March 08, 2010, 01:02:45 PM »

My first attempt was even "higher" tech, I used a 1.1" diameter sanding drum working it back and forth on a stationary Weaver #62 after milling a shallow 5/16" groove down the middle to give me a head start, the base will fit good after is is epoxy bedded. I'm going to try the 1" ball end mill on a Weaver 417M which is flat on the bottom next.

Thanks,

Tim

trotterlg · « **Reply #10 on:** March 08, 2010, 01:05:32 PM »

Really looks nice. I have always wondered about threading at the front of the stub. Do you think that the .054 inch thickness of the stub wall at the threads is enough for the breach thrust the barrel will have? By my calculations that gives an area of about .17 square inch. Tensile strength of that much 413 stainless is about 14,000 pounds. A 308 sized cartridge head running book pressures (45,000 psi) makes a breach thrust of right about 8,000 pounds. What I worry about with the H&R Stubs is that I don't know what the tensile strength of the steel is, (or what it is) so the margin of 6,000 pounds is only a guess, may not be that much at all. Be safe, tie it to a tree for the first few rounds. If yours works out I may have to try one, let us know. Larry

Spanky · « **Reply #11 on:** March 08, 2010, 01:15:26 PM »

Could you please take a close up of where the stub and the barrel meet?

Spanky

mitchell · « **Reply #12 on:** March 08, 2010, 02:04:46 PM »

man i really need to try one of these dont look that hard hey larry do you thread the whole stub on just the first bit.

either way looks real good Humbarger how long is that barrel btw

D Humbarger · « **Reply #13 on:** March 08, 2010, 02:07:30 PM »

Quote from: trotterlg on March 08, 2010, 01:05:32 PM

I have always wondered about threading at the front of the stub. Do you think that the .054 inch thickness of the stub wall at the threads is enough for the breach thrust the barrel will have? By my calculations that gives an area of about .17 square inch. Tensile strength of that much 413 stainless is about 14,000 pounds. A 308 sized cartridge head running book pressures (45,000 psi) makes a breach thrust of right about 8,000 pounds. What I worry about with the H&R Stubs is that I don't know what the tensile strength of the steel is, (or what it is) so the margin of 6,000 pounds is only a guess, may not be that much at all.

I have been thinking about that very thing & am considering doing something on the back end, silver solder a ring in the 12 gauge groove, tig weld... don't know yet.

Machining the stub was a bitch because the OD & the ID wern't in the same axis ( they wern't parralell to one another). Maybe it was just the luck of the draw with the barrel I got.

Spanky which pic do you want a close up of?

trotterlg · « **Reply #14 on:** March 08, 2010, 02:13:35 PM »

The way I do it is to put a sholder on the barrel at the front of the stub and thread the rear of the barrel, Then I counter bore the stub at the breach end and put a nut in there. That keeps the stub loads all in compression. I usually thread about an inch at the breach, so there are plenty of threads to hold it in. I also go with 20 tpi which keeps the walls of the nut and barrel a little thicker. Not anything wrong with any of the stub methods I have seen except the one that was held in with super glue. OT, I saw a Savage 219 30-30 today for $125 and think I want it.

Larry

Airsporter · « **Reply #15 on:** March 08, 2010, 11:37:02 PM »

Quote from: trotterlg on March 08, 2010, 02:13:35 PM

OT, I saw a Savage 219 30-30 today for $125 and think I want it. Larry

think?

pvtschultz · « **Reply #16 on:** March 09, 2010, 04:27:03 AM »

Quote from: trotterlg on March 08, 2010, 01:05:32 PM

SNIP:
What I worry about with the H&R Stubs is that I don't know what the tensile strength of the steel is, (or what it is) so the margin of 6,000 pounds is only a guess, may not be that much at all. Be safe, tie it to a tree for the first few rounds. If yours works out I may have to try one, let us know. Larry

At 30 HRC, steel as an approximate tensile strength of 136 ksi (136,000 psi) which you should stay below half of in order to prevent fatigue failures.

OBTW: SAMMI spec for 308 WIN is 65 ksi, not 45 ksi

pondenck · « **Reply #17 on:** March 09, 2010, 04:29:13 AM »

Nice work. did you use shotgun or rifle barrel for the stub. hope it shoots as good as it looks. Jim

cowboyup453 · « **Reply #18 on:** March 09, 2010, 07:13:09 AM »

Quote from: pondenck on March 09, 2010, 04:29:13 AM

Nice work. did you use shotgun or rifle barrel for the stub. hope it shoots as good as it looks. Jim

Quote

That slug barrel was pretty hard.

You can see on the stub and in the first post. It was a 12 slug barrel.

blacksan · « **Reply #19 on:** March 09, 2010, 04:26:30 PM »

Hmmmmm, my dream of a 35 Rem BC just might happen some day with this inspiration/post.

D Humbarger · « **Reply #20 on:** March 10, 2010, 11:08:26 AM »

Did some deep thinking about the barrel flying out of the stub so I bored out the back end of the stub to .925 x 3/4" deep. Threaded the end of the barrel .750x 24tpi. The threaded bushing on the left is left long. I need something to hold on to to tighten the bushing. I will machine the excess off Now when everything is tightened down & sandwiched together nothing is coming loose.

...... Piece of mind.....priceless!

I contoured the barrel to a 4 1/2 contour 23 1/2" long.

Spanky · « **Reply #21 on:** March 10, 2010, 11:17:39 AM »

That's beautiful work D.

What are you planning on for a finish?

Spanky

D Humbarger · « **Reply #22 on:** March 10, 2010, 01:46:42 PM »

I will blue it next week.

Badnews Bob · « **Reply #23 on:** March 10, 2010, 01:49:58 PM »

Wonderful work friend. I really wish I had a lathe and knew how to use it.

trotterlg · « **Reply #24 on:** March 10, 2010, 01:55:22 PM »

That is one nice looking stub job! Larry

mitchell · « **Reply #25 on:** March 10, 2010, 03:24:51 PM »

Quote from: Badnews Bob on March 10, 2010, 01:49:58 PM

Wonderful work friend. I really wish I had a lathe and knew how to use it.

keep your eyes open for one they dont seam that hard i bought one when i got back from iraq and all ive done is read books and ask larry a bunch of questions, and its not really that hard.

polara426sh · « **Reply #26 on:** March 10, 2010, 03:51:14 PM »

Looking at your bushing, it might be a good idea to cut a couple of notches 180* out from each other on the breach end so you can use a spanner to tighten it. It would also make it easier to remove the barrel if you shoot it out.

dpe.ahoy · « **Reply #27 on:** March 10, 2010, 04:23:20 PM »

This stuff's better than lookin at Playboy, safer too if the wife walks in.

DP

briannmilewis · « **Reply #28 on:** March 10, 2010, 04:40:13 PM »

Dumb question...is there any advantage to Stubbing over Reboring? I know stubbing could be a do-it-yourself proposition whereas I doubt if the average Handiholic has equipment to rebore a new caliber. Just wondering...inquiring minds want to know!

trotterlg · « **Reply #29 on:** March 10, 2010, 04:47:55 PM »

It is easier to make a small hole bigger than the other way around, it would be a real task to make a 12 gauge into a 17 cal. without stubbing. Larry