Barrel Muzzle Crown

[truck driver]

I was reading on another forum that if a barrel prefers flat base bullets over boat tail bullets that the crown could be the source of the problem.
What are every ones thoughts on this?

 

[Dr. Vette]

I would have to see objective, repeatable evidence.

As with most internet chatter, I suspect it's more rumor than fact.

 

[Thebear_78]

A good crown is important no matter what bullet shape.

 

[DrMike]

A good crown is important no matter what bullet shape.

+1, A crown that is not square to the barrel, or a crown that is nicked, etc. will disrupt the direction of bullet travel. It is certainly not conducive to accuracy.

 

[Guy Miner]

There sure have been a lot of different crowns tried. I think just among my rifles I've got quite a few:

flat
concave
rounded
stepped down (for lack of a better description, maybe "recessed" ?)
coned

Sometimes I think it's whatever the machinist feels like doing to the barrel he's finishing up!

I've no idea if one type works better with a flat base or a boat tail bullet...

Guy

 

[Thebear_78]

Hard to go wrong with the 11 degree target crown. I like to recess the 11 degree crown just a touch to help protect it.

 

[IdahoCTD]

I've tried about all of them and it doesn't makes a difference in accuracy. A crown will not effect the way a rifle shoots a certain bullet. That is the barrel itself.

 

[HomerOz]

G'Day Fella's,

Truck Driver, IIRC the 11* target crown, was found to be the best crown for Bench Rest target shooting.
Given that the vast majority of BR shooters use Flat Base bullets, I have always assumed that 11* and Flat Base bullets go together!
This is not necessarily the case with Boat Tail bullets?

FYI, here is an image of what my standard (in this case .308 Win) muzzle crown looks like.

This, as was mentioned above by Guy M, is a recessed crown that is cut at 90* to the axis of the bore of the barrel.
Whilst I have given it a bit of a clean up, it still has carbon fouling on the muzzle and the thread still has Anti-Seize paste on it.

And here (in my experience), is a pretty typical target shot with this type of muzzle crown!

FYI, this is a Rem 700 MLR factory rifle, in .338 Lap Mag, 250grn Woodleigh Protected Point Hunting Bullets, and maximum recommended charge of ADI AR-2217 (aka H-1000) at 100 meters!
The only thing I did to this rifle, was remove the factory muzzle brake to re-crowned the barrel, and epoxy bedded the action into the factory (HS Precision) stock.

Homer is a Happy Camper!!!

Doh!
Homer

 

[DrMike]

And you have every reason to be a happy camper. Fine looking representative of what the rifle paired with a competent rifleman can do. I do like the recessed crown for my hunting rifles. The eleven degree crown was quite common in years gone by, and many of my older rifles still wear such a crown. They always performed well for me, but I was often concerned that they weren't as protected from the rough-and-tumble of the hunt.

 

[1Shot]

if a barrel prefers flat base bullets over boat tail bullets that the crown could be the source of the problem.

As has been stated a proper square cut crown is needed for good accuracy. I don't think that if a rifle that does not like boat tail bullets means that the crown is bad. I have a perfectly made 25-06 with a Shilen select match SS barrel that from day one does not like BT bullets. But it is bug hole accurate with flat base bullets.

 

[truck driver]

Actually I'm think it has more to do with barrel harmonics than the crown and was waiting to here what you guys thought.

 

[Darkhorse]

Actually I'm think it has more to do with barrel harmonics than the crown and was waiting to here what you guys thought.

Exactly what I was thinking truck driver.