Recrowning of Muzzle

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.338 lapua
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Re: Recrowning of Muzzle

Post by .338 lapua » Sun May 20, 2012 3:08 pm

Hi Mark,

I have posted a couple of images ,as i was at this guys workshop,kindly chk the images and hope you understand what i meant.I am sure you are a gun guru and are very much more experienced with guns ,however I after a struggle of almost three years was able top obtain my arms licence a couple of years ago.Initially was using a sxs indian shotgun,sold it and then purchased the new Indian ordinance factories .30.06 rifle.I am sorry as i used layman terms to
explain the issue.the rifle should be ready in the first week of june will post the pics then,

Regard's

Dhiraj
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Re: Recrowning of Muzzle

Post by mundaire » Sun May 20, 2012 11:31 pm

You are planning to recrown the IOF .30-06? Why? Is it not shooting accurately?

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Abhijeet
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Re: Recrowning of Muzzle

Post by .338 lapua » Tue May 22, 2012 9:39 pm

Hi Abhijeet,

Honestly I am not sure if i can comment on this as i haven't shot the rifle enough.The reason i had a question on crowning the muzzle is because the rifle is with the gunsmith and felt the crown should also be finished ,However the post by Mr Pritu has solved the query .Was quiet a silly query i agree ,it was more about aesthetics than technical.However this person who is working on the rifle has the equipment for jeweling the bolt that was gifted to him by a prominent person who many know has some very beautiful rifles,so has assured me that he will jewel the bolt on my rifle an also change the bolt handle,I also saw another IOF .30 which was customized by him i think he does a pretty decent job and is reasonably priced.I have also posted the pics of the walnut i brought from gill timbers after reading the posts on IFG and find the wood is better than what is available in the market .Thankyou.

Regard's

Dhiraj
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Re: Recrowning of Muzzle

Post by brihacharan » Wed May 30, 2012 5:50 pm

.338 lapua wrote:
The reason i had a question on crowning the muzzle is because the rifle is with the gunsmith and felt the crown should also be finished
Dhiraj
> Re: Crowning of the muzzle - I suggest that you Google "Larry Potterfield" Gun Smithing videos. There is one 3 minute clip on Muzzle Crowning - very informative.
Cheers
Briha

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Re: Recrowning of Muzzle

Post by Priyan » Fri Jun 01, 2012 9:41 am

brihacharan,

That's not a good way to crown a muzzle of a gun that's new. That is for guns that is shot out a little and just plinking gun. Proper crowning is done on a lathe using proper tools.
When I'll get to shoot a gun?

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Re: Recrowning of Muzzle

Post by xl_target » Fri Jun 01, 2012 10:43 am

Priyan wrote:brihacharan,

That's not a good way to crown a muzzle of a gun that's new. That is for guns that is shot out a little and just plinking gun. Proper crowning is done on a lathe using proper tools.
Right! If I had an expensive hunting rifle or a target gun, I would definitely take it to a gunsmith with the proper tools. If I accidentally nicked the crown on my .22, I would attempt the brass screw method and if it shot well, I would leave it at that.
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Re: Recrowning of Muzzle

Post by .338 lapua » Fri Jun 01, 2012 9:01 pm

Hi guys,

I found this link,this unit from brownells seems to be a nice tool if one would like to get the rifle crowned without using a lathe,the unit should cost approximately 85$.the muzzle crowning cutter ,brass guide and the cutter handle can be bought separately from brownells ,any idea if one can purchase the tool and import it.is it restricted in anyway.

http://riflestocks.tripod.com/targetcrown.html

Regard's
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Re: Recrowning of Muzzle

Post by Mark » Sat Jun 02, 2012 11:07 am

Dhiraj,

Since you seem set on re-crowning your barrel, and not only that but not using a lathe and a proper 4 jaw chuck, I will tell you how to do it by hand.

However, you need to understand that if you will need to be meticulous and pay attention to every detail, if you do this carelessly or simply make a mistake you most likely will have to find an experienced gunsmith with a lathe who has done this before and knows how to use a 4 jaw chuck with indicator rods and knows how to indicate off the bore.

So do you understand what I just said COMPLETELY? If you do, then read on-

First, you need to understand why the crown of a muzzle is so important. Someone earlier had mentioned burrs, but the main reason is this- The muzzle is the last thing that touches the bullet. After the bullet leaves the muzzle it is not supported by anything but it is still exposed to the expanding powder gasses. If the crown is not perfectly symmetrical, then there is a chance the gasses will exit at one angle on one side of the bullet base and a different angle on the other side of the bullet. The theory is that unequal angles can deflect the bullet slightly, which then affects the accuracy.

So what we do to the crown is mainly just make sure the angle around the bore of the muzzle is as even as possible.

You had mentioned an 11 degree crown, so I will show you how to do that by hand.

First, you need some engine valve grinding paste:
Image

Then you need to get an old computer mouse, the kind that uses a ball, and remove the ball. Now peel the rubber coating from the ball.

The last item you need, and this is the critical one, is a decent magnifying glass or jewelers loupe:
Image

Image


Now, what you do is simply rest the butt of the gun on the floor, then put a small dab (about the size of 1 or 2 lentils) on the muzzle, and set the ball on the muzzle on top of the grinding compound. Now slowly twist and rotate the ball. After a few minutes examine the muzzle under the magnifying glass to ensure you are doing it evenly all the way around. Continue until you have an even ring about 2mm or 1/8" .

When you are satisfied with the ring do a thorough and proper cleaning of the bore and you are finished.

The interesting bit of trivia is that a mouse ball has a radius that will give you an 11 degree crown.

Good luck!

Mark
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Re: Recrowning of Muzzle

Post by .338 lapua » Sat Jun 02, 2012 5:44 pm

Hi Mark,

really appreciate your effort to explain in such detail.The option to use the mouse ball seems very logical and If I plan to crown I will definately try this procedure if it does not work then I will work it up on a lathe . however I will be back at my farm on 2nd or 3rd week of june and try shooting at 80 yards open sights of a stable rest and see how the groups come up,until then I plan to keep the muzzle crowning part on hold.I think that will make sense.Thankyou once again Mark ,Brihacharan,Pritu,Xl for your valuable advice.Have a nice weekend !


And congatulation's Mark you will turn SIX years old tommorow on IFG :cheers:
"India is the cradle of the human race, the birthplace of human speech, the mother of history, the grandmother of legend, and the great grand mother of tradition. Our most valuable and most astrictive materials in the history of man are treasured up in India only!"
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