Hey fellas I wanted to try my hand at redoing an old 22lr bolt of mine. It needs some tlc. My question, is there a way to re-crown the barrel with out having a long reach DTI? I been wanting to get one for awhile but I haven’t been able to. I am still building up my equipment for gunsmithing and a action truing jig and a long DTI is pretty much the last 2 things I need to get. However I am bored and wanna give something a try. I also plan on bedding it the action, not that it would really need it. I am just doing it for practice. Then I will move into rebuling and refinishing the stock. Like I said this is just for practice but I don’t want to ruin it either. However a expensive DTI just isn’t in the budget right now.
Marlin/Glenfield 780 22lr bolt project complete
- Thread starter Shooting in the wind...
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PTG makes piloted crowning tools that do not require a lathe or indicators. It is a pretty straight forward process.
Would hate to do that when I have a capable metal lathe.
Fast14riot
Gold $$ Contributor
Lapping compound and a round head brass screw has touched up plenty of rimfire crowns.
But, do you have gauge pins and any indicators? I've seen rimfire guns with crown visibly not square still shoot surprisingly well.
But, do you have gauge pins and any indicators? I've seen rimfire guns with crown visibly not square still shoot surprisingly well.
SSL
Gold $$ Contributor
We're talking real 'hick' gunsmithing here, but since you are going to get the proper tool anyway, I've removed dings in several rimfire muzzles using nothing more than an old Lyman chamfer tool for cartridge mouths. Obviously not for match quality rifles, but worked quite well on those older ones. Barrel steel isn't really all that hard on those old .22s.
Can a regular DTI be used? I also have a coax aswell, I know it’s not the ideal tool but might work? When I get more funds I plan on getting a long reach DTI but until then I gotta make do with what I have
For a crown, I would think that a regular DTI in about half the stem (to be sure it's good "meat" of the barrel) should be sufficient for the muzzle end. Assuming you have outboard adjustment (spider), dialing in the breech to under a thou and the muzzle within a half thou should be straight enough for a good re-crown in my humble opinion.
I seen some using a thick piece of copper in the jaws to act like a pivot point for the barrel. My lathe has a head stick to long to use an outboard spider. I do have a nice steady at my disposal.
I have a lathe and would not dismount a bbl and go thru all of the setup just to touch up a crown. There are 11/60/90 degree tools are piloted and hand driven.
When finishing a crown, I just use the 60 degree tool to make a nice clean finished crown.
there is a lot of “ Vodoo” associated with crowning, do a bit of experimenting to see what really affects the end result. It isn’t as much “ Rocket Science” as some think.
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I agree it isn’t rocket science, but I am willing to go through the setups because I want to practice so when I open my own gunsmithing shop I’ll have the experience of action truing, chambering, and crowning to name a few. I want to build a few guns for myself and get proficient with all the aspects of running a gunsmithing shop and repairing or customizing. That way I’m not learning on a customers firearms.
This is a marlin 780, does anyone know if the action “lug” in the pic comes off? I need to get it off to fit thru my spindle bore. I can’t find any information on the internet about it.
nicholst55
Brass Whore
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SGW Gunsmith
"Accipere non casus-Virga Bis"
It does, it just unscrews.
Does anyone know why the barrel appears to have a crack in it? I found 2 other spots further up the barrel. Also, it appears this one is going to need re-crowned aswell.Practice on an old military barrel or two . Going through unnecessary work on a firearm usually creates more problems or liability down the road .press fit barrels have a number of on , off cycles before the fit or receiver pin holes get sloppy any chasing problems that have been created will only give you experience on one specific firearm.
Find a copy of Precision shooting, the one where he buggered up the crown and interior of the barrel and it grouped better than the 2 other precision crowns . These were all on the same barrel . He was testing the theory of 11 deg crowns I think . Hes as we all were shocked . Stranger things happen .
SSL
Gold $$ Contributor
Maybe I'm dreaming this, but I seem to remember seeing an article once that said that some older inexpensive rimfires had the barrel and chambers manufactured as two pieces and then forged or welded together. Maybe that's what you see?
I have no clue, there is a few other spots that look very similar up the barrel. It’s an older one. It never shot under a 2” group at 50yrds. The sear and trigger was junk, someone tried filing it so I had to buy a new sear, trigger, and sear spring. I was bought used about 15 years ago.
redrockranger
Silver $$ Contributor
That's a scary thought.
What is? If your referring to learning on clients firearms then yea it’s real scary…
What you say looks like a crack in the barrel looks like a groove cutting tool got spun around one time cutting a sideways groove across the lands. Old barrels ( and some new mass produced ones too ) can have a variety of manufacturing defects. Most have little to no effect on performance. I have a couple of old Mossbergs that if you only looked at the bore scope pictures you'd swear couldn't hit a barn from the inside that are sub MOA.
You have to learn somehow and learning by doing is a great tradition. Go slow and be very careful in doing the set up. I'm no gunsmith but I've done a lot of machinist jobs and experience is a good teacher. A good mentor will get you there faster but if you don't have one patience and critical thinking will get you there eventually.
You have to learn somehow and learning by doing is a great tradition. Go slow and be very careful in doing the set up. I'm no gunsmith but I've done a lot of machinist jobs and experience is a good teacher. A good mentor will get you there faster but if you don't have one patience and critical thinking will get you there eventually.
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