Gunsmithing Machining practice

[Ritten]

Months ago I decided that I wanted to get the machinery to be able to work on my own rifles, and after reading much advice here on the subject decided to take a couple of mill/lathe classes at Murray St. College NRA summer program first. The reviews of that can be found in another thread, but I got to spend some time on the Grizzly G0509G and compare it to the South Bends and other American machinery at the school. After an exhausting month of trying to find a good American lathe within a day's drive I decided to go ahead and purchase the big Grizzly. Done...

The machine will be delivered in Mid-August so I figured I'd start getting the tooling/mandrels and the real expense of the trade together while waiting. I'd like to be able to practice "rebarreling" and cutting chambers before making my first attempt on a match barrel and was wondering if it would be nearly the same to just use some 1.25" mild bar stock? I have an (almost) unlimited supply of 24-36" pieces. I thought I remember someone mentioning that barrel companies may sell scrap/blemished barrels on the cheap for this purpose as well. I guess I'm just looking for validation that I'm taking the wisest next step toward learning how to build some of the one-hole-shooters that you guys are putting together.

At the same time as all of this I am keeping an eye out for a decent Bridgeport J-head mill to fill the corner of my home shop.

 

[lvcatfish]

Re: Machining practice

I started practicing on mild steel stock at first but it is harder to get the pretty looking threads you will see on a custom barrel. Best cutting/threading practice is on old shot out premium barrels. Talk to your friends and other competitive shooters. Stainless steel bar stock is another good choice and is still less expensive to learn on than a $300+ custom barrel blank.

Good luck, the first step is absolutely the most difficult one. Build your skills and confidence in running the machine on scrap then just decide to go for it. I was glad when I finally let go of my apprehensions and have been having fun learning and making stuff ever since.

 

[Bugholes]

Re: Machining practice

Why don't you offer to buy a bulk of takeoff barrels from a busy gunsmith. Give them scrap value and pay for shipping. Easy and cheap

 

[Adam B]

Re: Machining practice

I have a couple of take off barrels from TC Venture actions I would give you, just cover the shipping

 

[crumpmd]

Re: Machining practice

I practiced on some Dana axels. Some mild bar stock. Some take off remington barrels. The practice you do, make it as near perfect as you can every time. No distractions, just the work.
I crashed my threading tool a few weeks ago when my phone rang and diverted my attention a moment.

 

[eddybo]

Re: Machining practice

Just find a BR smith and ask if he has some old barrels you can have for practice. It is amazing how well some of those old barrels will shoot after you lop off the threads and rechamber them.
I see your in Houma. If your ever heading up I-55 just across the MS line send me a PM and I will meet you at the interstate near McComb or Summit and give you a couple of old benchrest barrels.

 

[Rafael]

Re: Machining practice

If you can't find an old barrel to work on, nice offer up above, try one of these:
Adams & Bennet
I got one a few years ago for $69.00.
It shoots well, still.
Cheap way to learn but not as cheap as using a salvaged barrel.

 

[koodbe]

Re: Machining practice

If you are near a water well\ pump shop, you might see if they have some old head shafts they are getting rid of. The shaft material is usually 416 stainless in various diameters standard being 1 15\16 and larger. They will have some wear on them but that doesnt matter because you are now an apprentice machinist..... food for thought!

 

[Ritten]

Re: Machining practice

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Adam B</div><div class="ubbcode-body">I have a couple of take off barrels from TC Venture actions I would give you, just cover the shipping</div></div>


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eddybo</div><div class="ubbcode-body">I see your in Houma. If your ever heading up I-55 just across the MS line send me a PM and I will meet you at the interstate near McComb or Summit and give you a couple of old benchrest barrels.</div></div>


Wow...thanks guys! I'll certainly take you up on these offers!!

 

[GasLight]

Re: Machining practice

My first practice threading and chambering was making some dies. This gave me good practice and was also practical.

Dave

 

[LRI]

Re: Machining practice

If it were me:


I'd order a stick of material from a vendor. Speedy metals in WI is a great source. Ask for Marty.

Get it in 1.250 OD and start practicing threading. I would order tooling from Sandvick as I've had excellent results with them. If you go insert carbide focus on learning to run the spindle at an rpm where the tool actually works right. That means your going to have to learn to thread above 1000 rpm. It CAN be done with diligent practice. Just learn to count a cadence while your doing it and you'll be fine when it comes to pulling the tool out and disengaging the half nut.

If you go with waterbase coolant I suggest CimCool Cimtech 320. Awesome stuff. Run it at 10% indicated (15.0% actual) and you'll be amazed how long your inserts last and how good the surface finish is. You'll have some issues trying to chamber with this stuff as it's not really meant for the tool pressures involved with form tooling (reamers). Many stand behind and advocate the sulpherized cutting oils. I personally prefer a 50/50 mix of Castrol Moly D tap fluid and AFT tranny fluid.

Aloris tool posts are the only way to go if you can swing it. They repeat better than just about anything.

Good luck and welcome!

C.

 

[Clark]

Re: Machining practice

I met the Wisners Saturday and they told me that CNC programming is not as hard as it used to be.

Now everyone will be programming like Chad, but me

I could make gun parts on the lathe and mill with no training.
I cannot learn foreign languages, music, or software syntax, even with a good looking female tutor.

Anyway, here is how I learned how to cut barrel threads, ON A MANUAL LATHE;
Make threads on a plastic pipe, until it fits the receiver.
Make threads on an Aluminum rod, until it fits the receiver.
Make threads on a steel rod, until it fits the receiver.
Make more steel threads until they look smooth and fit tight, but easy to turn.
Make threads on a cheap barrel blank.
Make a drawing/sketch of what the barrel threads, breach cut, shoulder ect should be.

OK, now after a couple hours of making chips, you are ready to work on that expensive barrel blank.

You have to fill in your own numbers.

 

[Ritten]

Re: Machining practice

Thanks Chad and Clark. That's pretty much my plan....to practice threading with scrap and get it within tight tolerances using familiar TPI's used in common actions then move up to better material and end up working on some actions/barrels I have laying around.

I've got some good Mitutoyo indicators and depth micrometers on the way. I have some used Chinese stuff, but wanted to make sure my measuring tools are good to go.

 

[x ring accuracy]

Re: Machining practice

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bugholes</div><div class="ubbcode-body">Why don't you offer to buy a bulk of takeoff barrels from a busy gunsmith. Give them scrap value and pay for shipping. Easy and cheap </div></div>
Excellent advice. I have given a few away for shipping costs only. Happy chip making.

 

[GlockandRoll]

Re: Machining practice

cant wait to see the delivered product, I'm thinking about getting one of the Grizzly combo mill/lathes, let me know what you think.

 

[crashandburn]

Re: Machining practice

I nabbed a peice of Cold rolled 1.25 bar stock for 32.00
Its a good way to practice contouring as well and making the marks on your tail stock for the next time you have to do it.

Glad to see another SH member getting after it. Good luck with all your work and I hope to see more posts.

 

[BBeyer]

Re: Machining practice

What size is your lathe, I recently moved from Mass. to Maine and had to get rid of a 14 inch Clausing. I still have a very few pieces of tooling if you are interested let me know.

 

[Ritten]

Re: Machining practice

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BBeyer</div><div class="ubbcode-body">What size is your lathe, I recently moved from Mass. to Maine and had to get rid of a 14 inch Clausing. I still have a very few pieces of tooling if you are interested let me know.</div></div>


Thanks! PM sent.

So I've started to assemble some of the measuring tools that I'll be needing. My little brother used to operate CNC's for an oilfield service company and gave me some cheap Chinese indicators. Still, I'd rather have measurement tools that I'm not second guessing. So far I've got:

Mitutoyo dial calipers, 0-1" micrometer, 0-6" depth micrometer, .0001 dial indicator.

My question is what other devices will I find myself needing? I know I'll eventually need another indicator. I've looked for a long needle horizontal indicator for dialing in chambers but can't seem to locate one.

 

[Ritten]

Lathe coming early

Just got a call from Grizzly that the G0509G that I ordered is now state side and will be shipping on Tuesday!! That 1.5 months ahead of schedule. Looks like I gotta get my ass in gear and have the shop ready for it!