Barrel Crown

[Don Sarkisian]

Owning several 1911's of various makes,I just could not stand it and recently purchased a PT1911 Taurus.I know, you would think I would know better. After getting it home I looked at the muzzle and found that the barrel is not cut square to the bushing.In addition the crown is not uniform or concentric to the bore.Knowing it would not shoot that way I sat down and ordered 90 and 45 degree cutters from Brownells to correct the situation.In the meantime I decided to go shoot it in spite of what I thought and after 150 rounds of hardball at 15 yards I found the gun to shoot dead on!! That, I do not understand.I will correct the issue anyway but can Tuner or someone offer and explanation why this gun would even shoot to POA prior correction of the muzzle issue? By the way the gun was 100% through the 150 rounds out of the box.

Thanks,
Don

[niemi24s]

Welcome to the forum, Don. All you need to know about the 1911 is available here.

The barrel slopes downward, toward the muzzle, 52 minutes of angle in the battery position. This may be what you are observing.

If the crown is mis-cut but shoots to POA, recrowning should theoretically throw the POI off. Are you dead certain it's mis-cut, or does it just look that way? Remember, the crown's that part of the muzzle that meets the grooves and lands.

A close up pic aligned with the bore axis taken with uniform lighting would help.

100% reliable, shoots to POA, but muzzle doesn't look right. Hmmmm. I'd not be too hasty in fiddling with it, myself. How does it group? Cheers

[Don Sarkisian]

Gripping the gun normally but with the muzzle help upward,the barrel is cut shorter on the left than on the right.Even with that condition one would tend to think that if the 45 deg. chamfer were cut to compensate that things would be correct.The chamfer on this gun is cut much heavier on the left side (short barrel side) than it is on the long side.Also thinking that the bushing may not seat square in the slide giving the appearance noted,calipers confirm barrel length dimensions to be offset as seen by eye when the gun is assembled.A stop at the gun shop to show them for comment,found them unpacking another PT1911 with a similar issue but not as pronounced as mine.Strange,I have never seen this before and it does not exist on my Springfield,Colt,S&W or Para.

Thanks for the reply.

Best,
Don

[hooks]

If you have a lathe, use that instead of cutters from Brownells (too easily deflected), a sturdy scallop tool in a tool post and the barrel bore indicated to .0005 TIR, with a gauge pin, over the last half inch, will do you much better. 40 degrees/80 included for the angle. JMHO....

[niemi24s]

Hi Don: Made the assumption you'd been fooled by the side view, in which the muzzle will naturally look a little cockeyed. Shouldn't look cockeyed from the top, however.

But, you still have a tough decision to make. If it's reliable, shoots to POA and (perhaps) has nice tight groups....

How does it shoot & group at 25 yards (compared to your other 1911's)?

[shovelwrench]

Even if the end of the barrel looks crooked, but the crown is square with the bore, the gun will shoot fine.
How the muzzle is cut does not effect accuracy near as much as the crown.

If the crown is true, and the muzzle is cut out of square, the crown will look off, but the gun will shoot (be accurate relatively speaking).

If the muzzle is square, but the crown is off, the gun won't shoot nearly as good.

Idealy you want: Square muzzle, square crown.


If the gun shoots better than you can hold it, leave it alone!!

[Don Sarkisian]

Well,ran another 100 hard ball rounds through it yesterday at 20 yards no rest.Still shoots to POA and seems to group as well as I my 71 year old eyes will allow and about as good as my other 1911's.You will note in reading my 2nd reply that I state that the muzzle chamfer is cut exactly opposite of what I would expect it to be to compensate for the non square barrel cut.My next move will be to sand bag test it against my other 1911's to develop the final story.At this point I am inclined to leave it as is but I still do not understand why it shoot with any degree of accuracy.

Best,
Don

[twin oaks]

ummm . . .shoots better than you do . . .100% reliable. . .hmmmm.
Yes, leave it alone, and just shoot the stuffin's out of it. Spend the $$ from the brownell's parts on ammo. Post pics.