Gunsmithing My first time cutting on a gun (barrel threading)

W

wtopace

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Full Member
Minuteman
Jul 30, 2009
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Wylie, TX
#1
Hey guys... first of all, know that I'm no Chad Dixon or anything (my camera skills suck and I am using an 8MP cellphone camera), but I figured I should take a few pictures of my first time cutting on an actual firearm and not making tooling, fixtures or other not-as-cool-stuff.

Yesterday I threaded a 10/22 as a test run and today I cut some threads on a heavy barrel .22-250 Remington 700. Both turned out really well! Just so you know, I endured the tedious process of thread wires and shallow cuts and was rewarded with some very nice class 3 threads with absolutely no play, but not tight either.

Ready to start dialing in the .22-250
20120428_181247.jpg


Idea shamelessly stolen from Chad - checked it with a long reach indicator afterwards, dead on to 0.0002 (best I could get this barrel to). Dialed the barrel in two spots moving the "ball-rod" with the tail-stock wheel (kinda like the Gordy Gritters method).
20120428_191208.jpg


Cutting away - I think my cell phone camera made the finish look worse than it really was...
20120428_201951.jpg


Test fit with a 30P-1 (after the thread wires of course)
20120428_202619.jpg


The 10/22 next to the .22-250, both wearing a can
20120428_212618.jpg


Final threads (because I forgot to take pics still in the lathe)
20120428_215659.jpg

20120428_215719.jpg


Once I finish my receiver truing jig I plan to chamber my first rifle - a .260 on a Remington 700 action.
 
#2
Re: My first time cutting on a gun (barrel threading)

looks like a great start. one question, did you make your four jaw chuck or did you buy it? i haven't seen one like that and it looks pretty rigid
 
#6
Re: My first time cutting on a gun (barrel threading)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Johny B</div><div class="ubbcode-body">looks like a great start. one question, did you make your four jaw chuck or did you buy it? i haven't seen one like that and it looks pretty rigid</div></div>

I copied some of the things that I liked from other guys here. The bolts on the front that make it look "rigid" probably need to be counter bored and replaced with socket head cap screws, but it seems to work pretty well so far.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Skullybones</div><div class="ubbcode-body">What did you cut the thread relief with?

Looks good by the way. </div></div>

Thanks! I used a part-off tool that probably needed to be re-ground (there is such a difference between cheap Chinese cutting tools and USA made cutting tools), although I didn't realize it until I had already made the cut, live and learn right?

Thanks for the compliments guys!!
 
#7
Re: My first time cutting on a gun (barrel threading)

It looks good.

On the relief, if you have more overhang then you need or if you are above center it can cause trouble. I use a cheap holder with my lifetime stash of USA made part off steel and it works stellar.

Does the end of your indicator rod snap into a wiggler or the chuck?
 
#8
Re: My first time cutting on a gun (barrel threading)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hero's machine</div><div class="ubbcode-body">
Does the end of your indicator rod snap into a wiggler or the chuck?</div></div>

Right now it is in the drill chuck (on the tailstock end), but I soldered a ball on both ends, so it pivots freely inside of the drill chuck. The plumb bob ensures that it doesn't rotate and is seated in the grooves at all times (except obviously when it crosses the lands).
 
#9
Re: My first time cutting on a gun (barrel threading)

I built a similar setup, but used a wiggler to hold the ball on the tailstock end.....that's why I asked. I too have had good results. Congrats, you just started down the road of endless costs and never-ending tool gathering.
 
#11
Re: My first time cutting on a gun (barrel threading)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dave Berryhill</div><div class="ubbcode-body">I like the brass tips on your screws. Nice work!</div></div>

I actually plan to drill out the bolts and swage in some copper wire, but I wanted to work on a real project this weekend.
 
#13
Re: My first time cutting on a gun (barrel threading)

Looks good but I did notice a bit of chatter on the thread relief.
Spindle speed a touch fast(gear down as slow as possible) and I would ditch the cutoff tool method-too much tool flex. Better to grind a HSS tool for doing reliefs. I ground a .060 wide tool for 1/2" threads and a .080" wide for above that.
Made a huge difference in finish.
I took an old chuck backplate and made my spider like yours, I use #6 Copper ground wire ring instead of brass tips on the screws. That allows a "Pivoting" point so the barrel is not stressed by conflicting pressure from the front and rear spiders.
 
#14
Re: My first time cutting on a gun (barrel threading)

Man, you're hurting my feelings here ;o) Great job.. my 1st attempt looked similar to that but I quickly realized I'd turned what my machinist buddy calls the "WTF" thread pattern. When asked, he said yeah, those "look" great and professional but I bet they don't match anything - he was right!!! ;o) ..

Seriously, if you find you can back this up and keep getting good results, you have truely been blessed by the threading gods.

Pics aren't bad either... good job all the way around.

Keep us informed and stay safe!

drez
 
#15
Re: My first time cutting on a gun (barrel threading)

Shot the 10/22 last weekend with the Sparrow on the end. I only have a 30 yard range in the backyard for .22lr (yes, in unincorporated county land, it is legal to shoot). By the 5th group, I was extremely impressed with the fresh crown on the rifle (it is still a factory 10/22 with a crappy trigger) and possibly even more impressed with the new Gemtech subsonic ammo!

PS - Real men shoot 10 round groups =)

Ruger_1022_Sparrowjpg-1.jpg
 
#16
Re: My first time cutting on a gun (barrel threading)

Thanks for the kind remarks.

Constructive criticism to offer if I may:

Thread chatter. It can be sourced back to speeds and feeds. No argument there. However if it were me I'd look first at your setup.

Your chuck has 4 very narrow/pointed contacts with the barrel. You can snug that bugger down till veins pop in your head and you still have four little tangent points holding onto your barrel.

Rule #1 with any machining operation is achieve as much surface contact with the part via work holding as possible. A collet is a fabulous way to do this. Trouble becomes figuring out how to indicate it in as most collet chucks don't allow for this.

Fortunately they do exist, you pay more, but I can promise you the chatter issue goes away due to work holding problems.

Just something to consider.

C.




 
#18
Re: My first time cutting on a gun (barrel threading)

I would also try to bring the barrel back in a little closer to the spider chuck. More rigid the closer you can work to the clamping point. Looks like your on the right track though.
 
#19
Re: My first time cutting on a gun (barrel threading)

Last:

Tooling. Are you certain its on center/pinch below center? A simple way to tell is with a 6" scale. Pinch it between your tool/part. If the top of the scale leans away your over, if it leans towards you its below. (Assumption made your not using a slant bed machine where the tool is on the back side of the spindle.)

Never hurts to check tool height.

C.
 
#20
Re: My first time cutting on a gun (barrel threading)

Thanks for the tips guys! My tool height was on dead center (I'll try slightly below next time).

I believe the chatter in the "in progress" picture is an artifact my cell phone image sensor with the fluorescent / halogen lighting. Unfortunately, this was the only picture I took during the process, so I decided to go ahead and post it. There was some chatter on the relief cut (this is my fault, and I wish I had fixed it while it was still in the machine), but the threads looked good the entire time.

I am looking at different point and shoot cameras for the next project so I can get some better pictures.

Thanks again for the kind words!
 
#22
Re: My first time cutting on a gun (barrel threading)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wtopace</div><div class="ubbcode-body">Thanks for the tips guys! My tool height was on dead center (I'll try slightly below next time).

I believe the chatter in the "in progress" picture is an artifact my cell phone image sensor with the fluorescent / halogen lighting. Unfortunately, this was the only picture I took during the process, so I decided to go ahead and post it. There was some chatter on the relief cut (this is my fault, and I wish I had fixed it while it was still in the machine), but the threads looked good the entire time.

I am looking at different point and shoot cameras for the next project so I can get some better pictures.

Thanks again for the kind words! </div></div>


Judging from the last photo, I don't think its the cell phone.

Look closely down along the flanks. It appears faceted. The facets (assuming the camera didn't goof) would be the chatter.

You could almost pass it off for a thread milled finish. With the old software I had for my cnc mill it would write the code for thread milling as splines instead of arcs. Splines are short segments of straight lines, where's arcs are smooth curves. The difference was immediately evident in surface finish. The code with splines would look exactly like this. Arc movements solved it. (required editing the post processor)

Not picking at you. Please don't take it like that. Just trying to help so you know next time.

Overall good job. We've had far, far worse come through into the shop.

A guy two weeks ago had just picked up his suppressor. Waited 9 months. Gets it, attaches it, and then discovers it won't come back off!

Two hours spent sawing off the end of his barrel, machining out the tennon inside the can, turning the barrel/threading, and assembling.

C.
 
#23
Re: My first time cutting on a gun (barrel threading)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">Not picking at you. Please don't take it like that. Just trying to help so you know next time.</div></div>

No worries, just checking to see if I goofed with the pictures or the cutting. The reason I posted pics here was for critiquing, so any and all feedback is definitely appreciated!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">
A guy two weeks ago had just picked up his suppressor. Waited 9 months. Gets it, attaches it, and then discovers it won't come back off!

Two hours spent sawing off the end of his barrel, machining out the tennon inside the can, turning the barrel/threading, and assembling.

C.</div></div>
Wow that really sucks. One thing I have found while getting my feet wet on the lathe since January is that very few machining jobs are ever the same and all of them are different enough that it takes time designing a solution before just cutting. It also seems like the more I work on it the better I get at fixing problems =)
 
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