Author Topic: Key Hole Problem  (Read 881 times)

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Offline Fat NDN

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Key Hole Problem
« on: March 09, 2008, 04:50:03 PM »
I have been trying to work up loads for a new H&R .204 22" Bull Barrel Rifle, 1:12 twist.
I have been using Sierra 39gr blitzking bullets and Varget powder for 2 weeks now at different powder weights.
I could not hit the paper at 50 yds. Today I moved in to 25yds, ant hit paper, but the bullets are keyholing.
My velocity on the Chrono is an average of 3498 fps with 27.5 grs.
And what is odd is the velocity @ 28.0 grs. average was 3438 fps
Can anyone tell me what the problem could be. With 32 & 34 gr. bullets I get .50" groups @ 100 yds.


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Offline Paladin

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Re: Key Hole Problem
« Reply #1 on: March 09, 2008, 05:14:53 PM »
my best guess is your not spinning the bullet fast enough to make it stabilize at that velocity. ya might try a max load and see if that helps, but I think the twist in your barrel is to slow. Good Luck

Offline jhalcott

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Re: Key Hole Problem
« Reply #2 on: March 09, 2008, 05:30:34 PM »
  The bullets tumbling (key holing) can be caused by a few things. IF the twist is not correct for the LENGTH of the bullet is one. If there is poor burn of the powder,indicated by a very dirty bore is another. A third cause is often a problem induced by poor loading techniques. OR a bad barrel. IF you are scraping bits off the bullets while seating them this may be the problem. A poor powder to primer/bullet combination? The first thing to check is the bore. If there are any bad spots that could damage the bullet as it goes down the barrel or copper/powder fouling MUST be cleaned out. If you can borrow a bore scope look for any pitting. What does YOUR book say is a MAX load and velocity? You might have to go with a different primer to get a better burn.I'd also check the dia of the bore AND the bullets to make sure they are still correct.  Hope this helps!!

Offline Fat NDN

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Re: Key Hole Problem
« Reply #3 on: March 09, 2008, 05:39:28 PM »
 The bullets tumbling (key holing) can be caused by a few things. IF the twist is not correct for the LENGTH of the bullet is one. If there is poor burn of the powder,indicated by a very dirty bore is another. A third cause is often a problem induced by poor loading techniques. OR a bad barrel. IF you are scraping bits off the bullets while seating them this may be the problem. A poor powder to primer/bullet combination? The first thing to check is the bore. If there are any bad spots that could damage the bullet as it goes down the barrel or copper/powder fouling MUST be cleaned out. If you can borrow a bore scope look for any pitting. What does YOUR book say is a MAX load and velocity? You might have to go with a different primer to get a better burn.I'd also check the dia of the bore AND the bullets to make sure they are still correct.  Hope this helps!!
.

The gun is new. The only twist that I have seen for stock .204 Ruger is 1:12.  My 32 and 34 grain bullets shoot <.50 @ 100 yds. You did make me think about my primers,
they are old and I started using them with the Blitz kings.

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Offline swiss7.5

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Re: Key Hole Problem
« Reply #4 on: March 10, 2008, 04:39:22 AM »
had the same problem with a 30-30 and found it was just a bad batch of bullets. It really drove me nuts trying to figure it out. I wanted to throw the thing in the trash. bought a new box of bullets, same kind/weight and now she shoots great. :o

Offline KN

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Re: Key Hole Problem
« Reply #5 on: March 10, 2008, 01:10:14 PM »
Blitz Kings have a reputation for having a long "Oglive" (spelling?). Meaning you need to drop back on bullet weight or try a different brand. I have experienced this with 22cal's and BK's. A friend with a 225 winchester was shooting 55gr bullets for years, switched to BK's and started key holing. Changed to a 50gr BK and it became a tack driver.   KN

Offline henryb

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Re: Key Hole Problem
« Reply #6 on: March 12, 2008, 06:24:30 PM »
Bullets that are at the top end of the weight spectrum or longer bearing surface (long bullet) for the intended caliber have a general problem with stabilization. (in the 223, 222 and 22-250 that I have experience with). You can find a multitude of articles on the net about heavy / long for caliber bullets in the 223 with corresponding twist suggestions that indicate heavy(ier) bullets need a faster twist.

What I believe is happening is as has been discussed above, the heavier bullets are not being spun fast enough to stabilize them.  You would best be served by shooting closer to a "standard" weight / length bullet for the caliber.  If you have a sincere hankerin' to shoot heavies, you might think about replacing the bbl. with a faster twist.  I have never heard of over stabilizing a bullet.

Offline KN

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Re: Key Hole Problem
« Reply #7 on: March 13, 2008, 12:40:39 PM »
"Over stabilizing" or spinning them too fast could result in the bullet vaporizing before it reaches the target. Basically the jacket on light jacketed varmint bullets could fail to hold together from the centrifugal force and come apart. Personally I have never seen it but I have heard of it happening. I've heard it described as a puff of gray smoke and no holes in the target.    KN

Offline Fat NDN

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Re: Key Hole Problem
« Reply #8 on: March 13, 2008, 03:45:24 PM »
i MEASURED THE BULLETS AND THEY  MEASURE .203 WHILE MY SMALLER BULLETS MEASURE .204
THE BULLET BEING TOO SMALL MAY BE THE PROBLEM.

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Offline DDelle338

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Re: Key Hole Problem
« Reply #9 on: March 14, 2008, 02:49:53 AM »
  I think you found the problem. I had the exact same thing happen to me with my .223. I got my caliper out and started measuring the bullets. They were all .223, they were suposed to be .224. I called Hornady and they sent me a new box. Fixed the problem.
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Offline jlchucker

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Re: Key Hole Problem
« Reply #10 on: April 07, 2008, 11:09:31 AM »
I have never had a keyholing problem with anything until I got the H & R 38-55 Classic.  It was a "Classic" waste of money! I've handloaded jacketed as well as cast bullets for over 30 years now.  I've tried powders, bullets, alloys--and I even called H & R where I got some bimbo that sounded too dumb to chew gum and listen to the problem at the same time.  I now think that H & R's single shot rifles are nothing I ever want to fool with again. In spite of all of the conjecture over .001 of an inch, I think you've just bought a bad rifle made by an equally bad manufacturer!   >:( :(

Offline PartsMan

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Re: Key Hole Problem
« Reply #11 on: April 07, 2008, 11:38:16 AM »
With 32 & 34 gr. bullets I get .50" groups @ 100 yds.

Oh yea jlchucker I'm sure it's because the rifle is bad.
I wish some of my rifles were that bad.

Offline jlchucker

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Re: Key Hole Problem
« Reply #12 on: April 07, 2008, 01:05:07 PM »
Partsman, if you're not just being a young smartass, and really want a bad rifle, try the H & R 38-55 Classic Target.  Mine's in like-new shape, but not a cast-bullet shooter- and it's not the bullets or ammo. Those bullets, in various configurations, were made for an Army friend who does long-range BPCR match shooting in national competition. I was once a foreman at a Winchester Ammo plant and have a pretty good idea of how to handload ammo. Tomorrow I'm going to see about a trade or putting this 38-55 on consignment. Someone else can shell out money fiddling with a bad product.  From now on, I'll stick with Ruger, Remington, Marlin, Browning, Older Winchesters, CZ 22's, or Savage. I've never had these kind of problems with any of those rifles in any caliber. 
 

Offline PartsMan

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Re: Key Hole Problem
« Reply #13 on: April 08, 2008, 03:42:01 AM »
It is common knowledge on this site that the 38-55s have over sized bores.
Your 38-55 may be bad, because ist won't shoot anything you put in it,
but a 204 that shoots .5" at 100yds is a GOOD rifle.



Offline jlchucker

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Re: Key Hole Problem
« Reply #14 on: April 08, 2008, 07:18:22 AM »
If a rifle shoots that well it's a good rifle.  My 38-55 is not--I intend to try a couple of more powders and then if nothing else works, trade it off.  There is no reason why any company should produce a rifle in a caliber 120 years old, designed for cast bullets, and then require the customer to squander money on experimentation and/or modification to make it hold something less than a 6 inch group at 25 yards--not in this day and age.  Notice that H & R dropped the 38-55.  I don't intend to go to the expense and extent of buying custom oversize molds and sizers just because someone at H & R couldn't read a blueprint or make an accurate measurement. 

Offline PartsMan

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Re: Key Hole Problem
« Reply #15 on: April 08, 2008, 08:37:02 AM »
Your 38-55 does sound like a bad rifle.
Did you call H&R about it?

I think you've just bought a bad rifle made by an equally bad manufacturer!   >:( :(
This is all I was protesting.

The problems with your 38-55 have nothing to do with his 204.