Opinions on crown angle?

[Lefty7mmstw]

I don't like radiuses on crowns like many factory rifles have. I am sure my 375 Weatherby gets some buffering from powder…

Cheers.

Yup, the old school Win. and Remmy crowns that were basically a round over were nothing special for sure. They worked though. The barrels shot fine. The thing people don't really think of is the bullet doesn't see the crown. It sees that the barrel has ended. As long as that ending is square to the bore axis there should be no imparted yaw.
There are a few ways to cut buffeting on the bullet. A muzzle device like a brake or suppressor can re-direct some gas away from the bullet's tail. Using a faster burning powder can help a bit by dropping the pressure as the bullet gets to the muzzle, therefore pushing less as it leaves. Some guys (like my Pops) prefer to use flat base bullets when they can, partly so the bullet has less inclination to yaw as it leaves.

 

[JuddL]

I like a recessed crown on barrels that isn't going to have a suppressor or brake on it. I like 11 degree on those. I've not seen one shoot better than the other, but that 11 degree is way easier to clean carbon off of.

 

[Lefty7mmstw]

Read the same article in Shooting Times, did I believe it, no, same writer then buggered up bullet noses and shot for accuracy no further than 200 saying it made no difference.

I am still on the fence with this, have used flat crowns, differing angles to cut recesses and haven't found the sweet spot yet.

Cheers.

Bullet noses really don't make a difference short range unless it's a drastic difference. Some of the crap the factories peddle for factory ammo shoots well but it looks like a toddler got ahold of it banging the daylights out of it. I wouldn't try benchrest with bullets like that, but minute of critter is possible at shorter ranges.
As far as crowns, I'm of the opinion that it doesn't matter as long as the bullet leaves clean. There are bigger fish to fry. Even things like how quickly a barrel gets filthy from a certain powder and how much residue a given primer leaves in the bore matter more to me than the crown. If the bore is filthy and accuracy is diminished because of that the jigs up anyway.

 

[stazmania]

If you can find accuracy using a muzzle brake or can, I don't think crown angle is going to be much of a factor.

 

[Taj]

G'day all,
For the past few years all of my builds I have moved to a 13° crown after using 11° crowns on everything 30 cal and larger.
So, what are your thoughts on this?
As I am only using specialty VLD style bullet heals, I feel this makes a difference to bullet release and buffering from powder gases.

Any discussion welcomed.

Cheers.

When Robby Barkman worked for McMillan they did a little testing on crown angles. he told me that they took a rifle of know accuracy and proceeded to put a bunch of different crown angles on it and shot it. They found that the angle made zero difference as long as it was done correctly. I've seen a bunch of different custom and commercial rifle crowns that claim to be either a 90 deg, 11 deg or what ever. When you take a close look you find that no matter what angel they made the face cut at, the very edge, transition area, was polished at some obscure, random angle that didn't match the machined area.

 

[eshell]

I'm having a re-barrel done by a well-regarded benchrest gunsmith that holds a few records of his own.

He asked "I usually do an 11 degree crown, is that OK?". I said "Sure." and that was that.

BTW: How do I get that "degree" symbol on my computer that I see some of you fancy fellas using?

 

[MagnumManiac]

When Robby Barkman worked for McMillan they did a little testing on crown angles. he told me that they took a rifle of know accuracy and proceeded to put a bunch of different crown angles on it and shot it. They found that the angle made zero difference as long as it was done correctly. I've seen a bunch of different custom and commercial rifle crowns that claim to be either a 90 deg, 11 deg or what ever. When you take a close look you find that no matter what angel they made the face cut at, the very edge, transition area, was polished at some obscure, random angle that didn't match the machined area.

This isn't exactly what I am talking about. I know that a concentric hole is best, and I use 30° to bevel the bore from the inside out.
What I am talking about is HOW the gas is ejected and directed AWAY from the bullet base as it leaves the bore. Looking at high speed videos has shed some light on the subject for me.
Also, a can is not really going to effect the outcome either way because of the air gap just in front of the muzzle.

Cheers.

 

[MagnumManiac]

I'm having a re-barrel done by a well-regarded benchrest gunsmith that holds a few records of his own.

He asked "I usually do an 11 degree crown, is that OK?". I said "Sure." and that was that.

BTW: How do I get that "degree" symbol on my computer that I see some of you fancy fellas using?

Depending on OS, you hold tab/shift and zero together. On an iPad or apple phone, you hold zero down and a box appears with degree symbol.

Cheers.

 

[dfanonymous]

This isn't exactly what I am talking about. I know that a concentric hole is best, and I use 30° to bevel the bore from the inside out.
What I am talking about is HOW the gas is ejected and directed AWAY from the bullet base as it leaves the bore. Looking at high speed videos has shed some light on the subject for me.
Also, a can is not really going to effect the outcome either way because of the air gap just in front of the muzzle.

Cheers.

Even if there was a difference, can you out shoot that difference.

If you could out shoot that difference…as long as it's consistent…would it matter? Since it's shooting the same way each time in theory.
…because you have precision….it should shoot as good as it's going to shoot…

So, the circular logic goes round and comes back to not mattering. No?

 

[stazmania]

I think as long as the bore is centered in the barrel and the crown is cut consistent angle should make no difference. The bullet is clear of the barrel so as long as the escaping gases following the bullet are distributed consistently/evenly they cannot affect the bullet. Logic would tell me that the steeper/deeper the angle of the crown the more likely it would be for gases to be unevenly distributed and affect the bullet, but even this is disproven by the use of muzzle devices. Just my thoughts

 

[eshell]

Depending on OS, you hold tab/shift and zero together. On an iPad or apple phone, you hold zero down and a box appears with degree symbol.

Cheers.

Thank you kind sir!

 

[Taj]

When Robby Barkman worked for McMillan they did a little testing on crown angles. he told me that they took a rifle of know accuracy and proceeded to put a bunch of different crown angles on it and shot it. They found that the angle made zero difference as long as it was done correctly. I've seen a bunch of different custom and commercial rifle crowns that claim to be either a 90 deg, 11 deg or what ever. When you take a close look you find that no matter what angel they made the face cut at, the very edge, transition area, was polished at some obscure, random angle that didn't match the machined area.

That being said, I've seen plenty of factory and some custom rifles that look like they were crowned with a pocket knife.