GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: Aerotulz on January 15, 2017, 03:52:14 PM
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Another open question to those of you with capabilities to crown your own Big bore barrels muzzle. Most of what I see on the pellet PCP's barrels look like 45* angle, as does my Sam Yang recluse, but I have not measured any of them. I am using an 11* crown angle on my .308 and it is performing good for me. Any thoughts or ideas are welcome.
John Hagan
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I prefer cutting the crown at 90* to the bore, and then either protecting it with a muzzle brake or LDC, or having a rebated muzzle, so that the edge of the barrel protrudes past the point where the bullet exits the bore.... There is nothing wrong with an 11* crown, PROVIDING than you index off the bore.... If you just chuck up the barrel to turn the crown and the bore is not centered, the point where the 11* taper meets the bore will not be at 90* to the bore, and the gasses will exit sooner on one side than the other, which is exactly what you don't want to happen.... The nice thing about a square face on the barrel, is that you don't have to worry about the bore being on center, you can just face it off at 90*.... However, it is easy to damage if you don't protect it as above....
Bob
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I mostly use 11deg on my builds, and as Bob pointed out its a bit more time consuming dialing the bore but nothing more.
On factory crowns I just lap them with a copper ball end bar and some lapping compound.
Marko
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Yep,
What Bob said ... "Rebated Target Crown".
And don't forget the 'Q-Tip' test when you're done. ;)
Cheers,
Smoketown