Barrel Crown

[Coyote Shadow Tracker]

I have heard different opinions on the Barrel Crown and what is better.
"Recessed Crown" - primary to prevent the Crown from being damaged. Alot of hunting rifle have these.
"Target Crown 11 Degrees Cut" - helps the gas escape evenly when the bullet exits the barrel.
"Straight Cut Crown" gases escape evenly after bullet exits barrel. Have heard "F" Class shooters and ELR use this Crown.

Anyone have verified results from these three cuts and or additional Crown Cuts with verified results?

Thanks
Len & Jill

 

[Varmint Hunter]

I get the recessed crown/muzzle which makes sense for all rifles (IMO) to actually protect the crown. But, what is a "straight crown"; no crown at all?

All of my rifles have a crown, but I couldn't say at what angle. Hmmmmm

 

[Justice1327]

I routinely take my factory rifles with a recessed crown and put an 11° crown on them. It always shows more consistency and better accuracy. however, I can't say if that's because the factory crown isn't as precise to begin with.

Additionally, IMO, The 11° that many people refer to is the actual angle at which the muzzle crown is cut too. So you could have a 9° target crown or even a 13° target crown. Or you could have the same angles with a flat or recessed as this is referring to the end of the barrel and not the actual crown.

 

[Coyote Shadow Tracker]

I get the recessed crown/muzzle which makes sense for all rifles (IMO) to actually protect the crown. But, what is a "straight crown"; no crown at all?

All of my rifles have a crown, but I couldn't say at what angle. Hmmmmm

Straight cut "Flat" across the end of the barrel with no recess or taper cut like in a 11 degree. "F" Class ELR have 1.25", 1.35" barrels and it would be difficult to damage the rifling at the muzzle. Having a "Flat" or No Crown lets the even release of gasses from behind the bullet.
My understanding is that recessed crown protects the rifling at the muzzle from damage. The thought behide the 11 degree target crown is the even release of the gasses when the bullet exits and also protects the rifling.
Justin 1327 has some good pictures.
Just want to get other opinions.

 

[Alex Wheeler]

If cut concentric, it does not matter.

 

[AZShooter]

The beauty of a "straight" crown is the lathe setup doesn't have to be perfect. The barrel can be chucked up in a any lathe and do the job. No need for getting the crown exactly centered. A tool bit run 90 degrees across the rotating metal will make that crown a true 90 degrees to bore.

Heck the chuck could be way out of true and the crown would still be perfect, but if a recess was included it would be not concentric to OD of barrel, but the crown would still work just fine.

 

[MLN1963]

I don't remember which gunsmith said it, but he said he'd cut whatever you want because there is no down range performance difference. Caveated with as long as the crown is done properly and concentric.

 

[epoletna]

A friend who was an amateur gunsmith cut crowns with a brass ball, about 1/2" diameter, dipped in lapping compound and spun against the muzzle. It worked on one rifle he did for me.

 

[Coyote Shadow Tracker]

I don't remember which gunsmith said it, but he said he'd cut whatever you want because there is no down range performance difference. Caveated with as long as the crown is done properly and concentric.

Like Alex said "If cut concentric, it does not matter."

I was just looking to see what everyone likes and if they had an opinion on it.

If I don't have a Threaded Barrel to wear a Brake or Suppressor on a hunting rifle I put a "Recessed"
Brake or Suppressed I put "Flat" or 11 degree.
Comp heavy Barrels - "Flat".
The main thing is having a clean edge where the rifling is on the muzzle. You want the bullet to exit "Clean" along with the gasses behind the base of the bullet.
Before saying the barrel is shot out due to diminished accuracy I will cut a new "Crown"
Thanks
Len

 

[biednick]

The beauty of a "straight" crown is the lathe setup doesn't have to be perfect. The barrel can be chucked up in a any lathe and do the job. No need for getting the crown exactly centered. A tool bit run 90 degrees across the rotating metal will make that crown a true 90 degrees to bore.

Heck the chuck could be way out of true and the crown would still be perfect, but if a recess was included it would be not concentric to OD of barrel, but the crown would still work just fine.

This assumes the bore is perfectly parallel to the axis of rotation. If it isn't, you'll end up with a crown cut at an angle to the bore which will cause issues. Dialing in a bore to be parallel is easiest if the bore is also centered, so it's not a real advantage. It also assumes the cross slide is perpendicular to the axis of rotation, which isn't always the case on cheap or clapped out lathes. If you're trying to get around a bad setup your best bet is using a piloted cutter in a floating tool holder. Brownells sells 11° and 90° piloted cutters that work well.

 

[Aoudad 101]

I use 11 degree. The powder residue from my silencers is easier to clean off .. only advantage I have seen

 

[ntsqd]

I prefer the looks of the 11° crown on purpose built target rifles. I even went as far as putting that crown on my 1.5" bore, 75" long spud gun barrel. Mostly because I could. Aoudad has a good point, 11° crowns are easy to clean.
However, I feel that the more traditional and vintage hunting rifles should have the radius crown that they were born with. An 11°crown would just look wrong on a Win M70 Featherweight or an M64.

I think that it would be interesting to learn at what diameter does the escaping gasses stop influencing the bullet. I.E. what is the minimum diameter for the recess of a recessed crown? Similarly, what is the max depth of the recess?
I would imagine that this is highly muzzle velocity dependent, but within reason it may be that an RoT can be established.
I would also expect that this at least somewhat dependent on the actual shape of the bullet's base (& not just whether a boat-tail or a flat base).
Beyond that minimum diameter the barrel can likely have any shape desired and not have any influence on the bullet.
It very well could be that with some experimentation that an RoT could be developed that says something like: Recess step depth equal to or less than 1/3 bore diameter with the recess step diameter equal to or greater than 2.5X bore diameter.

 

[Pat Byrne]

I shot competitive bench rest for 15 years and knew many of the better BR gunsmiths.. Most cut the crown straight across, 90' to the bore. I've been barreling rifles since '92 so 30 years and have tried many variations of crowning.. At the end of the day, I think Alex is correct.. If time is taken to indicate the bore in perfectly the angle of the cut is fairly irrelevant .. The 90' crown is proven.. BTW no spuds or brass screws/balls will ever be used on a barrel I do..

 

[chindits]

The Effects Of Crown Damage On A