Does anyone use 11deg target crowns ?
- Thread starter Mram10
- Start date
jackie schmidt
New member
20 years ago they seemed to be the big fad. I did it for while, but honestly, I can’t remember the last time I cut one.
As Jackie stated they were very popular 20 or so years ago, hardly ever see them on BR rifles anymore.
I seem to remember reading or hearing that the theory was the 11* crown helped the gas flow turbulence around a BT bullet base.
Personally I only use a recessed straight crown on a competition barrel, I come out straight for .100 and recess it .025 for a little protection.
I use a dedicated HSS cutter that I keep very sharp.
And just for the record I don't worry about the angle I come off the straight section with (compound is usually sitting at 29.5*),
so God only knows what I'm doing to the gas flow turbulence.
Greg
I seem to remember reading or hearing that the theory was the 11* crown helped the gas flow turbulence around a BT bullet base.
Personally I only use a recessed straight crown on a competition barrel, I come out straight for .100 and recess it .025 for a little protection.
I use a dedicated HSS cutter that I keep very sharp.
And just for the record I don't worry about the angle I come off the straight section with (compound is usually sitting at 29.5*),
so God only knows what I'm doing to the gas flow turbulence.
Greg
MilGunsmith
Member
We still use the 11* crown on all the M2010 sniper rifles we build.
I shoot a black-powder cartridge rifle, Highwall, in 40-65, in the sport of BPCR Silhouette and I cut a straight crown on my barrel. No bevel even at the bore, same as some 1,000 yd bench-rest shooters use (I also chambered and threaded using their methods). Rifle is very accurate. I am careful with my rifle (to not strike the muzzle) and didn't want to add anything "extra" that might not be strictly needed and might also cause the slightest of issues..
Rubicon Prec.
New member
For threaded muzzles, I do a 158 degree included angle (11 degree?) with a 60 degree included angle at the end of the rifling. Not that I necessarily feel any accuracy is gained/lost with this method, I do know for field rifles, the crown is well protected, and I think it looks clean.
For non-threaded muzzles, I do my version of a M40 recessed crown, still with the 60 degree included angle rifling end. I’d have to dig for a picture of one since maybe 1 in a hundred barrrels I do doesn’t get threads these days.
For non-threaded muzzles, I do my version of a M40 recessed crown, still with the 60 degree included angle rifling end. I’d have to dig for a picture of one since maybe 1 in a hundred barrrels I do doesn’t get threads these days.
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Butch Lambert
Active member
inran, I cut a straight crown with a tool that Jackie made for me several years ago. Cemented carbide that I touch up on my diamond wheel, but not needed much at all.
Thank you for the helpful post. I need to shoot today and see how the “Jackie style” crowns work for me
Thanks. Never tried the 60deg part. Nice Proof
Butch Lambert
Active member
Flat in itself is not important, just make sure that you have a properly ground sharp too and indicated properly.
be sure
after 11 degree come out 100 th straight on muzzle lets bullet exit straight this emportint bill b
after 11 degree come out 100 th straight on muzzle lets bullet exit straight this emportint bill b
jackie schmidt
New member
Here is what I use. It's 883 carbide. The "chip breaker" is ground on my tool grinder. I used this for nothing but finishing the crown.
It's just a nice sharp positive rake cutting surface.
By the way, I cut off of the back side with the Lathe in reverse. Why? I accidently ground the tool on the wrong side when I did it.
http://benchrest.com/attachment.php?attachmentid=22182&stc=1&d=1553352190
http://benchrest.com/attachment.php?attachmentid=22183&stc=1&d=1553352235
