WTF is the bullet test? And what is the crown of a barrel and how does it effect my accuracy?

WTF is the bullet test?


Thank GOD im not the only one.

The crown is the chamfer on the end of the muzzle, where it angles inwards. If the crown is messed up, it supposedly alters the way the gasses exit, and the way the bullet spins, causing accuracy problems.

I dunno about the bullet test, though.

great ? anyways,crown is the end of the barrel.if you look at the end you will see the rifling and it looks like the crown.if thr crown is not cut square with the bore it will cause the bullet to fly to one side or the other.thats why you should clean your barrel from back to front.you do not want to damage it in anyway.

If it is what I am thinking, it is used to see if a barrel is "shot out". For example, a 30.06 bullet, should be not drop through a 30.06 barrel. In order for the bullet to shoot accurately, the bullet has to be twisted through the lans and grooves of the barrel to create twist. Therefore the bullet must be a little larger than the barrels narrowest ID. I've mostly heard of this test on older military rifles.

The crown is the very end of the barrel. I don't know the specifics but certain shapes create good aerodynamics(?) as the bullet leaves the barrel. No wobble etc.

Something like that.

The only "bullet test" I can think of would be the ballistic fingerprinting crap that they do in Kalifornistan, the PRNJ, or PRM. The crown is as Dieselmh said. It looks like a dish cut into the muzzle.

There are lots of different tests. Usually they consist of firing a bullet into some sort of test media and then the amount of penetration and/or weight rententation are compaired with others.

The crown is the muzzle, and it is often overlooked. It can entirely change the accuracy of a rifle if the crown is damaged. I have a m1917 enfield that would sling bullets all over the place, after a DIY crown job that I did it tighted the groups up significantly

Like mentioned, the bullet test is basically trying to pass a bullet the wrong way through the muzzle end of the barrel. An excessively worn bore will allow the bullet to pass through with little or no effort. This indicates a worn bore, and accuracy will suffer. It's more or less a "tire kick" for checking out a rifle at a glance. It's a fairly common practice at gun shows where the guns being sold are "used" but in "great condition". This is a quick and easy way to tell at a glance, but of course is not scientific, and is one of many areas to be checked before buying a used rifle.

Crown is the end of the barrel where the rifling stops. You want this to be sharp and crisp. This basically means the rifling stops "gripping" the bullet at exactly the same spot all around the circumference of the bullet, and allows it to perfectly exit the barrel. If the rifling continues to "grip" the bullet on one side, as with a worn crown, it will cause the bullet to wobble, throwing off accuracy.

Look in my RPK thread and you can see what a "failed" bullet test looks like. Take any "new" rifle and pass a round through in the same manner, and it should be immediately obvious how the bullet test works.

Thanks. Kinda what I figured but I still learned something.

WTF is the bullet test? And what is the crown of a barrel and how does it effect my accuracy?

Bullet test:

Grab a bullet or loaded cartridge that matches the bore diameter being checked, ie. .223, .243/6mm, .284/7mm, .308, etc.
Try to insert the tip of bullet or cartridge into the muzzle end or the barrel.
You can get an idea how worn the bore is by how far the bullet fits into the barrel. If the bullet stops around the mid-point of the tapered end, the bore may be decent. If it goes in as far as the full diameter of the bullet, the bore is toast.

Barrel crown

The crown on the end of a barrel has everything to do with its accuracy. On most hunting arms they are rounded. Target rifles tend to have thier barrel crowns recessed or concave by a certian # of degrees, 11 being popular. This is done for accuracy as well as protection.

Ok I understand know. Thanks!

I'd seen pics of people with a cartridge sticking out the front of the barrel, but never understood what the point of it was.