Why are Barrel Contours Important?

Do contours affect the barrel weight?

Yes. There are heavier and lighter contours.

Do heavier contours shoot better than lighter contours?

Somewhat. If a barrel has a lot of residual stress in it (this is common in button made barrels) and as you shoot it the barrel gets hot and you make no adjustments to the scope/sights and what you see is the groups/shots wandering on the target. Usually stringing is what you see. A heavier contour barrel will help resist the barrel moving/wandering as it heats up.

 

Here at Bartlein Barrels, we only do single point cut rifling. This does not induce any stress into the barrel blank. Because of this, we tell people that the contour is not as important as it would be for button made barrels.

Does contour affect how a barrel shoots?

The short answer is yes. A heavier gun will typically shoot better because the extra weight involved with a heavier barrel/gun will help the shooter handle the recoil and experience less fatigue. The shooter will be able to shoot a greater amount of rounds over a longer period of time with a heavier gun.

 

However, we’ve seen plenty of lighter weight contours as good or even better than a heavier contour barrel. So we don’t think it as critical as some would believe.

Should suppressors be put on any barrel contour?

The short answer is yes. A heavier gun will typically shoot better because the extra weight involved with a heavier barrel/gun will help the shooter handle the recoil and experience less fatigue. The shooter will be able to shoot a greater amount of rounds over a longer period of time with a heavier gun.

 

No. If you are using a suppressor on a heavier barrel, it will typically shoot better. This is because you are hanging a heavy object on the end of the barrel and it affects the harmonic vibrations of the barrel. If you are using a suppressor we don’t like seeing it being put on anything smaller than a medium palma contour.

Why is single point cut rifling better than button rifling?

A lighter weight contour when the barrel gets button rifled (Bartlein Barrels only does single point cut rifling) the stress being put into the blank is much greater. As you turn the contour smaller and smaller in size this can have a negative effect on the bore sizes changing and opening up. When this happens you cannot make the bore size smaller. This is not an issue with single point cut rifling. We don’t see this happening at all. Same can be said about threading the muzzle of the barrel for a muzzle brake or suppressor attachment. On button rifled barrels, threading the muzzle this is a common problem with the bore opening up. The last place you want the bore to open up or go sour on you is right at the muzzle's crown edge. Anything going wrong here has a negative impact on accuracy.

 

The video link below shows this process happening. The point of the video isn’t to pick on other barrel makers but to suggest to people to make the muzzle threads as large as you can to prevent this from happening. The first barrels where all the bores open up are all button rifled barrels. The last barrels are Bartlein cut rifled barrels. Yes the threads are larger on our barrels but we have made barrels with muzzle threads that measured 5/8” and we turned these down from a blank that started out at 2.280” o.d. and have not scrapped/rejected a single barrel because of it.