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Discussion Starter #1 (Edited)
Hello, i don't have found that info on HQ 416/417.

My thought is: "little" better than "nothing"

Ok it's not a bolt action rifle long range, but may increase a little more precision, i think it's not bad to chamfer the muzzle end. I have see the muzzle barrel of my old MR223 and my new MR223A1, they don't have the muzzle barrel worked.

like this
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finished example (i don't know if that is 45° or 60° worked, i suppose 45):


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What do you think? if agree with me, i have at home 60° tool (http://photoshare.shaw.ca/image/3/b/d/203599/60degreereamer-0.jpg) you think it's little bit better then 45° or not? reasons?

60° with custom rod the same diameter of barrel (handwork):

 

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When I did the barrel work on my MR556, prior to nitriding, I chucked up the barrel in the lathe and used a mill bit to do a slight counter-bore and a straight 90 degree crown. Zero chamfer.

After printing a 9/16ths inch, 7 shot group at 100 yards, and then a sub half inch 3 shot group moments later, I think a chamfer is not really necessary if the crown is machined correctly and is protected.
 

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90dgr is good crown for precision shooting. Some precision shooters prefer 79dgr crown, but it works better only with "boat tail" bullets. 90dgr is good both for boat tail and straight tail bullets. HK made good job on barrel crown on MR223. Leave it as it is.

45dgr chamfer, that protects crown from damage is not necessary, when rifle is equipped with muzzle device or protective nut is fitted (MR223 has this nut in stock config).
 

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Discussion Starter #4
90dgr is good crown for precision shooting. Some precision shooters prefer 79dgr crown, but it works better only with "boat tail" bullets. 90dgr is good both for boat tail and straight tail bullets. HK made good job on barrel crown on MR223. Leave it as it is.

45dgr chamfer, that protects crown from damage is not necessary, when rifle is equipped with muzzle device or protective nut is fitted (MR223 has this nut in stock config).

I thought that working of 60 ° on the muzzle barrel of MR prove more accurate with every kind of ball, but then even improves on the 300m? is therefore not advisable? because if it improves a little, I do
 

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I thought that working of 60 ° on the muzzle barrel of MR prove more accurate with every kind of ball, but then even improves on the 300m? is therefore not advisable? because if it improves a little, I do
I do not believe it will improve accuracy over factory 90dgr crown. Anyway, muzzle crown improvements have really little impact on accuracy (except from very badly made crown - this is not a case with HK). Interesting read here: http://www.precisionshooting.com/psm_2011_03_issue.pdf
 

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Discussion Starter #6 (Edited)
I do not believe it will improve accuracy over factory 90dgr crown. Anyway, muzzle crown improvements have really little impact on accuracy (except from very badly made crown - this is not a case with HK). Interesting read here: http://www.precisionshooting.com/psm_2011_03_issue.pdf
comparison

H&K MR223A1




Unknow



i want try to work 60° degrees into barrel for very few, like the last photo
 

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Discussion Starter #7 (Edited)
old:



now:


i don't have payed for that work, I think it's a good job and that my friend has not ruined the barrel doing this work
 

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Discussion Starter #9
How do you like your "new" muzzle crown right now? Does it improve on the accuracy?
honestly I could not compare, but my friend who did it on his rifle said it has increased the precision decreases bullet drop, he worked with an angle of 60 degrees
 
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