Keyholes?

[Luckyforward]

Help, please!

I was reading a review of a handgun, and the author said the gun "keyholes."

What does "keyhole" mean?

Guess I was not enlightened somewhere along the way; thanks for the education!

[Guest bkelm18]

I always thought keyholes meant when the round tumbled in flight causing an oblong hole in the paper.

[Luckyforward]

What would cause a gun to do that?

[Mike.357]

Bk hit it.

The bullet tumbles and leaves a hole similar to the keyhole in old style door locks that accepted a skeleton type key.

My Ruger Single Action Six does it if I get a lead build up in the barrel. I have also read that a damaged barrel crown can cause that as well.

[Guest sling]

Hmm. I've heard different definitions. The first one is that stated above... and i've also heard the term used in place of 'clovers' when describing a very tight grouping. As in it could 'go through a keyhole.'

[glockster157]

Elongated holes in a paper target is caused by a bullet yawing in flight. Sometimes they will even start tumbling and this is when you see the keyhole type of bullet strikes on paper. The cause for a bullet losing stability and starting to tumble end over end is usually one of the following.

1. Not enough twist for the bullet being used. Such as, shooting a real long .224 bullet like a 77-90 grainer in a barrel with a 1-12" twist. The bullet will start tumbling within a 100 yards. A long 55 boattail in a 1-12 is what caused the M16 rep for tumbling bullets. It is actually bullet length not weight that causes the problem so boattails or solid copper, bullets w/o lead, will be longer and need more twist to be stable.

2. Bad crown. It would have to be pretty bad though to make one tumble. Usually just bad groups.

3. Damaged bullet base, if you are a reloader you don't have to worry too much about the nose, but pay close attention to the base. Of course the higher pressure, smaller, faster rounsd have more effect than the bigger slower bullets but it will be a group killer no matter like above.

4. Bullet slipping the rifling or being undersized. If it is too small it may not be engaging the rifling or if the rifling is filled with lead, then you have a musket. Long thin bullets will tumble immediately upon leaving the barrel.

I am sure there are other things but it is getting late and I cannot think of any right now.

[Luckyforward]

This is helpful . . . Thanks!

[Westwindmike]

Good explanation glockster. I had problems one time with the 550 gr FN bullets hitting the target sideways at 25 yards out of my Sharps. Those bullets were extremely long. Went back to the 405's and it shot great.