|
|
Joined: Jul 2001
Posts: 60,079
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,079 |
Without a doubt, Red Cornelison was one of Benchrest's true innovators and experimenters. And likely the first to bring that style of crown to 100-300 Benchrest. He was a true pioneer in the world of extreme accuracy rifles. According to Kevin Thomas, chief ballistician at Sierra from 1987 to 2007, AMU armorers began using an 11 degree crown to match the angle of the original version of the .30 cal. 168 Matchking. There's more than the angle involved. Google won't help there.  Yep--and Kevin Thomas got to experiment a LOT with various stuff, because it was his job, not a hobby. Learned many things from him, involving all sorts of stuff from the once-popular moly-coated bullets to other stuff.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
|
|
|
|
|
Joined: Jan 2003
Posts: 3,425
Campfire Tracker
|
Campfire Tracker
Joined: Jan 2003
Posts: 3,425 |
Yep--and Kevin Thomas got to experiment a LOT with various stuff, because it was his job, not a hobby. Learned many things from him, involving all sorts of stuff from the once-popular moly-coated bullets to other stuff. Kevin is a smart, smart guy with a huge dose of common sense. If he said something, there was no marketing involved....just the facts. The receivers he sent from Sierra's .30 cal. accuracy testing rigs for rebarreling were a story unto themselves. FWIW, I've found that any crown shape that's been done in an indicated fashion (and finished with the same final step) will give the same on-target performance. Some crowns have a very short life span, however. But it has nothing to do with the angle. I do prefer an 11 degree crown on my accuracy rigs. For a hunting rig, a recessed or floor board style crown gets the nod. On a factory gun, Remington's rounded crowns were pretty darn good. Hope all is well with you, John. 
Forbidden Zoner
|
|
|
|
|
Joined: Dec 2004
Posts: 10,344
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Dec 2004
Posts: 10,344 |
Yep--and Kevin Thomas got to experiment a LOT with various stuff, because it was his job, not a hobby. Learned many things from him, involving all sorts of stuff from the once-popular moly-coated bullets to other stuff. Kevin is a smart, smart guy with a huge dose of common sense. If he said something, there was no marketing involved....just the facts. The receivers he sent from Sierra's .30 cal. accuracy testing rigs for rebarreling were a story unto themselves. FWIW, I've found that any crown shape that's been done in an indicated fashion (and finished with the same final step) will give the same on-target performance. Some crowns have a very short life span, however. But it has nothing to do with the angle. I do prefer an 11 degree crown on my accuracy rigs. For a hunting rig, a recessed or floor board style crown gets the nod. On a factory gun, Remington's rounded crowns were pretty darn good. Hope all is well with you, John. Al has been around the turnip patch several times and hasn't fallen off the tractor.
|
|
|
|
|
Joined: Jan 2003
Posts: 3,425
Campfire Tracker
|
|
Campfire Tracker
Joined: Jan 2003
Posts: 3,425 |
No falls off a tractor, Butch....but I did have a couple of unintentional dismounts off a couple of my HD's in my early days. One of them, a real deal XR750 factory HD flat track bike tried to kill me a couple times. I modified a small front disc brake from a Bultaco to fit, added small lights and a wider rear tire. Even though the bikes were sold without a serial number and weren't intended to be titled, the engines had a job/serial number on them when they left the HD Race Shop. Using the engine number, I was able to get a title and plate. They were right at 300 lbs. dry weight...my mods added about 15 lbs. The engines made right at 100 hp with the slide valve Mikuni carbs. Questionably street legal, it was like no other 'street' HD around at that time.
Forbidden Zoner
|
|
|
|
|
Joined: Dec 2004
Posts: 10,344
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Dec 2004
Posts: 10,344 |
I'll bet that it was fun. I had a Pursang in the olden days.
|
|
|
|
|
Joined: Aug 2015
Posts: 859
Campfire Regular
|
|
Campfire Regular
Joined: Aug 2015
Posts: 859 |
No falls off a tractor, Butch....but I did have a couple of unintentional dismounts of my HD's in my early days. One of them, a real deal XR750 factory HD flat track bike tried to kill me a couple times. I modified a small front disc brake from a Bultaco to fit, added small lights and a wider rear tire. Even though the bikes were sold without a serial number and weren't intended to be titled, the engines had a job/serial number on them when they left the HD Race Shop. Using the engine number, I was able to get a title and plate. They were right at 300 lbs. dry weight...my mods added about 15 lbs. The engines made right at 100 hp with the slide valve Mikuni carbs. Questionably street legal, it was like no other 'street' HD around at that time. I always wanted to do that with a XR. Nowadays they are getting expensive!
|
|
|
|
|
Joined: Feb 2004
Posts: 19,161
Campfire Ranger
|
|
Campfire Ranger
Joined: Feb 2004
Posts: 19,161 |
If we started referring to those crowns as 79 degree...which is correct...people would really get confused. The 'reverse crown' I worked with was a true 11 degree. It's on a f-form barrel now....should dig it out for a few pics. Good shootin' -Al P.S. FWIW, the Sierra .30 cal 155 Palma Match King bullets I have here are a 9 degree boat tail. Brownells sells a 79* chamfer tool. It's commonly referred to as an 11* tool but they market it as a 79*. kwg 79 degree chamfer tool
Last edited by kwg020; 04/23/23.
For liberals and anarchists, power and control is opium, selling envy is the fastest and easiest way to get it. TRR. American conservative. Never trust a white liberal. Malcom X Current NRA member.
|
|
|
|
|
Joined: Jun 2004
Posts: 7,170
Campfire Tracker
|
|
Campfire Tracker
Joined: Jun 2004
Posts: 7,170 |
I cut a few 11 degree crowns, at the request of customers. but never bought into the idea that it did anything. I used the same recessed flat crown, with a 60 degree chamfer, from the day I started to shoot BR to the present.
Regarding the performance of flat base vs BT bullets for short range, it is difficult for me to give any definite opinion. I can only say that my best BR rifles shot better with boat tails. I have to admit, my aggregates, back in the day, were not nearly as small as are being shot today. Might be that BT bullets could not compete today. GD
|
|
|
|
|
612 members (17CalFan, 10gaugeman, 12344mag, 10ring1, 1337Fungi, 16penny, 53 invisible),
2,687
guests, and
1,111
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums81
Topics1,191,312
Posts18,468,225
Members73,928
| |
Most Online11,491
Jul 7th, 2023
|
|
|
|
