What are reasons for Key-Holeing??

Grunter

Grunter

New member
Just Wondering! Shot some different rounds through my 25-06 today and noticed some major key-holeing and horizontal stringing. /ubbthreads/images/graemlins/confused.gif The 117's I shot yesterday grouped well and the 115 Win. BST's I tried today were all over! /ubbthreads/images/graemlins/blush.gif

Thanks for any input, /ubbthreads/images/graemlins/grinning-smiley-003.gif Dave
 
Generally its a stabilization problem, but I shoot 115 CT from a browning 25-06 and I have never experienced key holeing. What was the weather conditions like between the two days you shot? Sorry I can't be of more help.
 
keyholing reasons

bullets longer than the twist of the rifle will shoot.
CURE: shoot shorter bullets (note different bullets may be of the same weight but shorter or longer, so the shorter bullets will work but the longer ones won't although they are the same wt)

velocity of long bullets marginal (meaning need a bit more speed, sometimes enough speed cannot be gained to stabilize bullet before pressure signs occur. Change powder and/or change bullets)
 
Destabilization of the projectile for some unknown reason.

Try looking for major barrel fouling and or bullet damage on unfired rounds.

Are these reloads or factory ammo?
 
Troy,

About the same today. 28 degree's with no wind. First shot right down the pipe and straight. Waited about 1 to 1.5 between shots and each seamed to get a little worse. Only thing I did since yesterday was a cleaning. Used factory ammo.

Dave
 
Major reason is damage to the muzzle through being hit or bumped, or poor cleaning habits, any changes the contours of the muzzle is enough to start the bullet tumbling as gas blows prematurely out of a nonconcentric muzzle. Have the barrel recrowned. Easy and cheap.
 
Quote:
keyholing reasons

bullets longer than the twist of the rifle will shoot.
CURE: shoot shorter bullets (note different bullets may be of the same weight but shorter or longer, so the shorter bullets will work but the longer ones won't although they are the same wt)

velocity of long bullets marginal (meaning need a bit more speed, sometimes enough speed cannot be gained to stabilize bullet before pressure signs occur. Change powder and/or change bullets)



From what I've read and understand blammer hit the nail on the head here. /ubbthreads/images/graemlins/grinning-smiley-003.gif Proud of that savage yesterday and frustrated today! /ubbthreads/images/graemlins/crazy.gif Sorry to hear that!
 
Bigdog,

The gun is brand new. Cleaning was done by wiping with a treated swab and patched out with a jag. No way has the muzzle crown been altered. Just hard to believe the diff between the two rounds. Tommorow I'll slap a few more of the Hornady's through it again and see what I get.

D-Popper,

Ya got that right!! Was really suprized. /ubbthreads/images/graemlins/shocked.gif

Dave
 
The quickest cure for keyholing is to try differnet bullets, the bullet and twist must be a good match, and it sounds like you have a mismatch between bullet weight and rate of twist.
 
I don't think it's a mismatch between weight and twist. 25 caliber's with 1-10 are made for a compromise between 100 through 117/120's. The stabilization problem occured when these heavier bullets weren't stabilizing in 1-12/14 barrels meant for the 87 grain bullet in the Savage 99 .250/3000.

(Thank you Jack O'Connor)
 
Few years back I found a NIB Kimber of Oregon chambered in the old fashioned 25-20 WCF. My original thought was to use lead bullets (85 gr.) at low velocities and have just a fun gun. Took it to the range and I had key-holing. Every other shot was tumbling. Went back and put the thinking cap on and I looked at twist, bullet length, velocity, etc. I wasn't getting stabilization. Needed a shorter bullet and more speed. Went to a 75 gr. Speer jacketed bullet, cranked up the velocity and guess what. A very good shooter.
 
take a tight patch and cleaning rod and find out what the twist rate is.

don't clean it, run it dirty see what happens.

take a loaded round of ammo and place it into the muzzle of the rifle. How far down does the bullet go? All the way to the case or farther or not all the bullet can go in? Let us know.

make sure you have the right ammo! Check to see what the chamber is labeled on the side of the gun. IF it's new something is a muck!
 
It's the rifling twist rate. Most 25's now days have 1-10 twist. The problem is that many modern bullets are longer than plain cup and core bullets of the past. This is a common problem with 25's. I'm not bashing 25's thay are probably my most favorite caliber. The factories have not wised up to the fact that a 1-9 or faster twist is needed. Heck, it's tough to find a custom barrel in 1-9.
 
I would try the Sweets or Montana Xtreme to see if it is coppering up. After that check to see if the bullets are correct using a caliper or mic. It could be the bullets are not correctly made.
 
Try the thorough cleaning like Jack and Steve suggested, if your copper fouled the rifling isn't getting a bite on the bullet. In this case decreasing your powder charge will usually show improvement.

I would also suggest you shoot groups at two and three hundred yards. If there is an improvement, you need to try different types of powders or bullets.
 


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