Gunsmithing Damaged crown on .22-250...

S

Sgt_Jamez

Sergeant
Full Member
Minuteman
Dec 24, 2009
265
0
Carmichael, CA
#1
Here are a few pics of what I think is causing the accuracy of my Ruger M77mkII Target to suffer. Is this fixable by hand? Or is this a gunsmith/lathe project?

IMG_6108.jpg


IMG_6109.jpg


IMG_6109-2.jpg


What do you guys think? How bad is this?

Sgt Jamez
 
#3
Re: Damaged crown on .22-250...

Yeah I kind of feared that. Any idea what could cause this? When I bought the rifle I was only a tad more dense than I am now. I didn't know to check for such things. The rifle, as I recall, has never been all that accurate. So I am wondering if this has been there all along or if I caused this myself somehow?
 
#4
Re: Damaged crown on .22-250...

Boy, you sure have a crappy lookin crown there. Even beyond the obvious big chunk it looks like the whole crown is beat all to hell. Maybe it is just the pic,but most of the crown looks chewed up. Just like Glen said "have a smith re cut the crown for you".
 
#5
Re: Damaged crown on .22-250...

Yes it looks like hell. The rifle has been babied the whole time it was in my care. Could this have been done in cleaning? If not, then it was purchased damaged. There are only two 'smiths in my local area. One is in the process of relocating and wont be taking new work until mid-Jan. And the other is closed 3 days a week. I'll be talking to him today though.
 
#6
Re: Damaged crown on .22-250...

I was able to cut a better crown on my rifle with one of these:

http://www.midwayusa.com/viewproduct/?productnumber=665761

Then you will need some valve grinding compound and one of these:

http://www.midwayusa.com/viewproduct/?productnumber=718110

You can turn it with a hand drill at a mediumm pace with some cutting oil on it and it does a very nice job.

You wouldn't have to wait for the gunsmith to get it done and it is about the same price. Then, the next time you pick up a gun with a crappy crown you can get it to shoot.

Josh
 
#7
Re: Damaged crown on .22-250...

Brownell's

One of the things I customarily have done with a new barrel is to have a 45 degree muzzle chamfer cut into the crown by a good friend who is also a master tool, die, and model maker. This 'hardens' the crown by making the rifling/muzzle interface less sharp/delicate. It has no effect on accuracy.

I think this might be a pretty good solution to your problem.

Greg
 
#8
Re: Damaged crown on .22-250...

Send it off, the crown is the last interface your rifle has with the bullet. you can do it yourself but, I think its worth the money to have a qualified smith do it.
 
#9
Re: Damaged crown on .22-250...

It almost looks like someone has tried to cut the crown with a 3 sides handheld "scraper".

I would have someone true the crown on a lathe. You get a lot of accuracy either good or bad at the crown.
 
#10
Re: Damaged crown on .22-250...

Here is an article where they intentionally damaged the crown and their results were it might have changed point of aim but the groups actually tightened up. I'm not sure if its in this article or not, but they used a pocket knife to ream the damage and it shot as good as ever.


http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/71410414/p/1

and another test they did on a .22 rifle

http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/429100685/p/1
 
#11
Re: Damaged crown on .22-250...

I dont know much about crowns. I know my brother just cut down a barrel and recrowned it himself with hand tools. I think the stuff listed above might be what he uses. Anyway, you can PM him.
He goes by Nashlaw on here.
 
#12
Re: Damaged crown on .22-250...

this happened to me before, i had my ruger m77 mark II in 22-250 in the back seat just chilling while i was hunting, the muzzle was down and i hit a big bump and it jolted it onto one of my seat mounting bolts, put a big ding in it, i was pissed, so i had an inch cut off and got a new crown done. send it to a smith
 
#13
Re: Damaged crown on .22-250...

you can do it yourself with the brownells/midway tools, just use PLENTY of CUTTING OIL !! very simple job, just remember to clean the tool every few turns and RE OIL
 
#14
Re: Damaged crown on .22-250...

I've decided 2 things... one is that I want this barrel done right so I will have it 'smithed. The other is that I have an AR barrel with a pinned on AK-style flash supressor that I've always hated. I will saw off the supressor and use the Brownell's facing cutter and 45-degree chamfer as a test of my ability to do this by hand on a barrel I don't really care about.

Two questions... how do I chamfer the outside edge? And how do I treat the bare metal? Just a blueing kit?
 
#15
Re: Damaged crown on .22-250...

I'm willing to bet that AR barrel you are talking about is a Bushmaster? Either way, DON'T saw off the flash hider. To remove that flashhider cut two vertical grooves on opposite sides of the flashhider with a small cut off disk, like on a Dremel. They should be running the same direction of the bore. You cut through the muzzle end of the FH, but just groove the part that is over the barrels threads. With the barrel secured, use a cold chisel and split the FH from the muzzle down. It will split into two halves and you will have an un-damaged barrel.
 
#17
Re: Damaged crown on .22-250...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sgt_Jamez</div><div class="ubbcode-body">I've decided 2 things... one is that I want this barrel done right so I will have it 'smithed. The other is that I have an AR barrel with a pinned on AK-style flash supressor that I've always hated. I will saw off the supressor and use the Brownell's facing cutter and 45-degree chamfer as a test of my ability to do this by hand on a barrel I don't really care about.

Two questions... how do I chamfer the outside edge? And how do I treat the bare metal? Just a blueing kit? </div></div>

Well if you are going to do it yourself on the AR, do it and see how it turns out. If it works, is easy to do, etc. - then you can use the tool on your .22/250 and save yourself some money. If it fails, then have the smith fix it.....

Kaiser Norton
 
#19
Re: Damaged crown on .22-250...

I misread your post, and I'm not familiar with a pinned on FH. I have seen Factory Bushmaster barrels that are secured with pins and welded over to be permanently attached. I hope that it works out for you.
 
#21
Re: Damaged crown on .22-250...

I have done about a half dozen crowns with the Brownell's hand cutters and lap. All have turned out well and shot excellent. I won the factory class in a Varmint For Score Benchrest match with a Savage 22-250 I recrowned. With the right load that rifle was/is pretty close to a consistent .25MOA shooter at 100 yards. It is definitely one of my most accurate rifles. No, not quite as good as my custom benchrest competition guns. But close. Having said that I will say it is usually better to get a crown cut on a lathe by a good smith if it is for a competition gun but otherwise I think you would be surprised just how well you can recrown by hand. I have not and do not plan to try it as part of a barrel cut off but for just recrowning it works fine.
 
#23
Re: Damaged crown on .22-250...

it looks like someone pulled a steel cleaning rod back through the bore and chipped the crown on both sides. make sure you use a good quality cleaning rod dont use steel section cleaning rods the joints are the best way to ruin a barrel. As for the AR have a gunsmith machine it off. i know you can buy the tools but add up the costs then the cold blue and it would have been within $20 to have it done profesionaly and you wont risk ruining anything.

We recrown barrels all the time we have had guys that cut 1/2" off the barrel every 2000 rounds with an angle grinder and keep shooting then they think they are benchrest shooters aswell.
 
You must log in or register to reply here.

Similar threads

StocknRock
Hunting calibers and barrel life: 223 vs 243 vs 22-250
Replies
39
Views
2K
Modoc
Modoc
C
.22 bullet performance at 200 yards
Replies
7
Views
656
cliffy110
C
hafejd30
I need some LMT MWS help…..
Replies
34
Views
685
hafejd30
hafejd30
XP1K
Gunsmithing My first rifle,
Replies
18
Views
812
lariat
L
T
Suppressed 22 LR for 13 Month Old Daughter
Replies
4
Views
450
nikonNUT
nikonNUT
Top Bottom
Back
Home
Forums
Merch
Alerts