My James River Armory AK 74 keyholes occasionally. Someone online

>>34615898
It isn't hard. Worth trying.

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>>34615898
Just put a little chamfer on it, a small center drill works great. Make sure the little tip of the center drill is a good .05" smaller than your bore

>>34615898
Maybe they pulled a Century and used a .223 caliber barrel rather than a .220 sized one?

>>34616106
I did the bullet test and apparently it's a 5.45 barrel.

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>crowning your own barrel
what the fuck nightmare did I stumble into?

>>34615898
I didn't even know uncrowned barrels were a thing. Yeah, they should definitely be crowned. The best way to do it is on a lathe with a steady rest and a crowning bit. Obviously, that option isn't possible for a lot of people. Brownells sells these hand crowning tools that are this bit with a T-shaped handle that you twist over the barrel. I've never used one but I've heard they're bullshit.

>>34616144
>I didn't even know uncrowned barrels were a thing. Yeah, they should definitely be crowned.
This. WTF.

Send that shit back to JRA and have them fix it since you're obviously inexperienced. Otherwise next week we'll see you on here crying about how you fucked up your rifle with the shit advice given on here.

>>34616128
The bullet test won't detect a small difference like this. My Carcano does well on the bullet test with .264 bullets but it slugs at .267. You really need to slug the bore and check if you think that is the issue

>>34616135
A lot of people that cut down barrels do that.

>>34615898
Muzzle brake should make up for barrel being uncrowned. What kind of brake do you have? Possibly your barrel may just be shit. Is it chrome lined? Sometimes poor chrome lining may be uneven and cause issues.

>>34616459
I've used a standard 74 brake and a Jet brake clone, both had similar results. I've read about the chrome issue and I've heard putting rounds through it will fix it. It does appear to be chrome lined.

>>34615898
are you sure its just not dirty? there is a crown its just covered in carbon and other crap

>>34616563
kek, I did clean my barrel and it got rid of the keyholing but I had only put about 200-300 rounds through it which I don't feel is very many.

>>34615898
Fuddlore.

>>34615898
>keyhole
Is a specially engineered outcome design for maximum damage. Projectiles should tumble through the air wildly. It's good. It will kill.

>>34616678
Barrels needing to be crowned is absolutely not fuddlore. That's science my nigga.

>>34616857
Or, you know, dont ding up the tip of your barrel...

>>34615898
>JRA
The issue isn't a lack of crown

>>34617445
I live in CA and my access to 74's is very limited, especially at the time I bought it.

>>34616135
>not paying someone to do everything for you

Oh no!

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>theres still people on /k/ who dont know 10 ways to do a simple crown with hand tools

>>34617590
Please post pictures of your 12" Monarch lathe, your nearest dial indicator or your favorite 60 degree threading insert.

>>34617575
Thats understandable. I very highly doubt that your issue lies in the barrel crown unless there was some severe damage. The issue could be related to your barrel or ammo. Try using different weight ammo and shooting at various ranges because your rounds might not be stabilizing.

>>34616144

Let's play spot the guy who's never used a lathe!

Fuck off guy, if you don't know what you're talking about just shut the fuck up

>>34617663

>12"
>he uses a massive tool for a small simple job, he must be super smart

>>34617663
or i can post a pic of a brass screw with a round head, a drill, and some fine jewlers compound

>>34617663
You wat m8, I don't know bout them fancy latheses or indicators, but I like to use 7 inch cutting wheels when they done been used down to around a hands width. I get the barrel tip real shiny and spray paint it to stop the rust for a while. I don't have no keyholeing after alot of rounds, pokes real good holes.

>>34617709
I was using WPA shit which I read some people had issues with key holing as well. I need to pick up 7n6 for testing.

>>34617859
Try different weights before doing anything these retards are recommending. Try them at different ranges as well, don't shoot them all at 25 yards, go further, if you were further try bringing it in more.

>>34617663
Why are trips almost always the most uninformed, clueless posters?

If you're going to continually embarrass yourself surely it should be done anonymously.

>>34618258
a trip is a huge red flag that a poster is a retard that should be ignored. its better that they label themselves.

>>34618258
>>34618312
Currently the only decent advice ITT has been given by a trip. You kids are apparently below that.

>>34618329
>try different ammo
>decent advice

That's the equivalent of telling someone with computer or phone problems to try a restart

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>>34617781
>>34617835
>>34617853
THIS IS MADNESS

>>34617424
So, is it fuddlore or "people who take a rifle outside" lore?

>>34617859
Still, keyholeing would be weird with steel case ammo made in a country with access would plenty of 5.45 projectiles. Unless they use the wrong bullet on purpose as a joke

>>34617747
What the fuck are you talking about? I'm a gunsmith and a machinist. That's how you fucking crown a barrel.

>>34618775
>he doesnt even gunsmith

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>>34619444
I do 90% of gunsmithing myself but I know what jobs not to fuck with in my garage and barrel chops, crowns and threading are such jobs nice trips

>>34619544
But cutting barrels and crowning is like the easiest shit ever dude. Especially if you have a lathe. I could understand not wanting to chamber and thread a barrel blank or something.

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>>34619567
Yeah maybe for 7 MOA milsurps you don't give a fuck about accuracy, consistency or concentricity sure. Not for ARs, not for precision and not when dealing with suppressors, you're going to cause hundreds of dollars of damage with garage-cut threads under a suppressor.

We come from different worlds I think, this is unthinkable blasphemy to me.

OP here. I've recrowned a Mosin and M57 Tokarev and improved the accuracy on both using the drill and brass screw trick.

>>34619610
Does your lathe suck? Are you a shitty machinist? I've only been doing this shit for two years and I do 11 degree target crowns on match grade custom rifles. It'll turn out perfectly concentric if you set it up properly before making the cut. Just dial that shit in with a dial indicator and use a steady rest. Threading is easy too, the machine basically does it for you. It's only difficult if your fuck up and end up having to chase the threads.

>>34619701
hes a fucking faggot retarded trip of course he doesn't know shit about shit. Anyone who needs to stand out on 4chan is literally the worst kind of cancer.

>>34619610
>We come from different worlds I think, this is unthinkable blasphemy to me.

Sure thing Burt, I come from the real world, and you come from planet dipshit.

Maybe because I live in Southeast Michigan, where every fifth male is a machinist or competent enough to fake their way through an extremely simple metalworking task.

Do you happen to live in Nevada? I just got back from the giga factory trying to teach those desert rats how to use a fucking screwdriver and ratchet without fucking up the fastening hardware.

>>34616857
Cite some scientific evidence that a rifle that comes from the factory without a "crown" is automatically inaccurate.

>>34619374
Maybe "people who use their rifles as tentstakes" lore

AK-74s are suppposed to have a brake on them, which would prevent the muzzle from getting damaged. And If you're worried about damage from cleaning rods, crowning isn't going to anything about that.

>>34619894
Nigga I don't have a peer-reviewed study on hand. Quit being a faggot. The expanding gas exits unevenly if the barrel isn't crowned. This has an adverse effect on accuracy. This is well established. You have no basis to argue against that.

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>>34619701
You have the equipment, that's my entire point. Do you think these scabs in this thread have lathes? Homeboy is talking about chucking a brass ball in a drill and going at the crown with some fucking jewler's compound.

>>34619744
Post your AR, berniebot

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>>34620140
>post your ar berniebot
>implying

>>34620168
>implying you have an ar
>or any guns
yeah that was kind of his point lol
>>>/b/

>>34620179
>gets called a shitter for not knowing shit about basic gunsmithing and claiming others cant/dont

>YOU'RE JUST A NO GUNS

>>34620209
>wants to bubba gunsmith is barrel and will most likely fuck up because he has no idea what he's doing
>"why do people think I'm nogunz?"

>>34620271
https://www.youtube.com/watch?v=9MOlxPdnbww

see>>34617615

This is easily the most retarded thread on /k/, due to literally another nigger tripfag.

Larry Potterfield shows in other videos like this one how to crown with a brass ball and lapping compound.
https://www.youtube.com/watch?v=gsg-Yt6t-HM

A 600 yard BR recordholder talks about his rifle and mentions his crown, being cut flat and square with no angles or anything. This guy's rifle, with "no crown" but hand-applied brass ball and lapping paste, literally shoots 0.18 MOA.
http://www.6mmbr.com/gunweek066.html

I could go on. Burt, find a large fire and kill yourself in it. Other anons should also consider suicide for posting shitty content, no content, or generally being dumb as shit.

>>34620345
this anon gets it. fuck all the other retards, and faggot fucking trips.

>>34620345
Go rub some balls on your shit and post groups son.

Can't wait to see.

>>34620510
Get filtered retard, I'll take the word of Larry Potterfield and a record bench rest shooter over your shitspewing faggot ass any day. I advise anyone else to ignore this literal imbecile.

>>34620540
I literally trip so angsty millennials like you can filter me, it's no skin off my back.

I would like to see the end results of your ball-barrel grinding in MOA though. Very much.

>>34620586
There's no angst, or anger here. You're spreading misinformation because of your own lack of experience. So no skin of MY back.

>I-I was only pretending to be retarded

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>>34620622
>There's no angst, or anger here
>you come from planet dipshit
>fucking faggot retarded trip of course he doesn't know shit about shit
>find a large fire and kill yourself in it
>get filtered retard
>implying none of these are you
Filtering is probably the best bet for you, Damien, if you don't want to schedule a therapist.

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>>34620689
>Doesn't know how to crown a muzzle

>>34620706
Thanks to anon I do!
>>34620345
>>34620280

>>34620689
How is your lightweight build going?

ITT: a bunch of autismos replying to a bait posting retard from arfcom

>>34620140
>Homeboy is talking about chucking a brass ball in a drill and going at the crown with some fucking jewler's compound.
whats the problem?

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>>34620714
Almost done, waiting on another batch of V Seven parts!

>>34620730
There's no harm in providing answers to troll posts, even if they are obvious. People who have the same question may stumble across it and find good information. But that's rare in these angsty, ironic-spiral dark days of 4chan.

>>34617445
JRA puts together really decent rifles, especially their M14 and M1 Carbine. They had some issues with their 47" kits back in 2012 but their CS solved all of it, and Ive had nothing but good experiences with my 74'

If you check the AK files, there is a guy that rents out all the crowning equipment for barrels. You basically pay him full price for everything and once you ship it back he sends you back the rest. I used him when I dinged the crown on my 74 barrel on accident and it works great. Takes about 10 minutes to do the actual crowning if you go slow. No power tools needed.

>>34616135
Dude it isn't that hard.

>>34621111
all you need is a cordless drill and a countersink bit

>>34621149
>>34616045
Dear fucking god no.

>>34615898
Please for the love of god don't use a fucking countersink bit.

Get a fucking dome head brass screw and some lapping compound, chuck the threaded end into the drill and coat the head of the screw with the compound.

Press spinning dome into crown of rifle.

Make circular motions with the back of the trill as you hold it in place.

You'll cut a target crown onto the muzzle and it'll perform damn well.

>>34620748
Dude you are the dumbest motherfucker

>>34621389
Why on Earth are you replying to me instead of filtering me? I can only assume you are a sadomasochist.

It's mind boggling.

>>34616045
Don't do this, it creates mustard gas

>>34617663
>threading insert.
Look at this fancy pants monopoly man, asking about disposable inserts.
You're not a real machinist unless you grind your own HSS blanks!

>>34622817
>grinding HSS to exactly 60 degrees
nigga...

>>34624596
58.5° nigga
>its almost like you don't want 100% interference fit

Dear god, what have I started with this thread.

>>34624596
>implying that can't be done.
The gunsmithing school I went to, everyone had to grind a 60 degree threading bit their first fucking semester.

>>34625365
It's not your fault that tripfags are the fucking worst.

>>34616744
They're supposed to keyhole after striking a solid target, not in midflight.

>>34619972
>The expanding gas exits unevenly if the barrel isn't crowned.
No, it doesn't. The gunwriter "theory" is that "crowning" (which isn't even well-defined--see beveling) protects the muzzle from damage. But even in such a case, there is only anecdotal evidence for its effect on dispersion.

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>>34625433
Literally prove it.

>>34619544

>dremel

The world would honestly be better if you killed yourself, consider it. Please.

>>34628107
>implying this entire thread isn't just you embarrassing yourself repeatedly.

>>34629700
>cant even produce evidence
Thank you for proving my point, anon.

>>34616135

PRECISION crowning isn't generally something the home gunsmith is capable of. Improving a barrel that is to the point of keyholing or putting a serviceable crown on a chopped down barrel that will be better than nothing? Not a big deal.

>>34616144
http://www.brownells.com/gunsmith-tools-supplies/barrel-tools/barrel-chamfering-tool-kits/precision-reamers-muzzle-crown-refacing-kit-prod7718.aspx
this one works gud enough if you don't have a lathe. it's just a pain in the ass having to sit there and crank it for an hour.

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just weld a circle on the inside side part of the barrel and then shoot the gun it will take off even amount all the way around very easy very natural it's how my Daddy used to do it