Keyholing


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ClemsonAl
July 23, 2010, 10:59 AM
Can too light a powder charge cause keyholing?

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243winxb
July 23, 2010, 11:10 AM
More info is needed. Gun, caliber, powder, bullets, dies ?? Causes can be - undersize bullet dia. Oversize bore groove diameter. Muzzle crown bad. Wrong twist in the bbl. for the bullet- long bullet-slow twist-too light a powder charge.

USSR
July 23, 2010, 01:52 PM
Can too light a powder charge cause keyholing?

Short answer - Yes.

Don

loadedround
July 23, 2010, 03:42 PM
As 243winxb stated, more information is needed. However whatever parameter(s) is present, an unstablised bullet will certainly key hole.

ClemsonAl
July 23, 2010, 03:46 PM
I was loading some Berry's 200 gr Hp's for my XDM 45. I had to go with a 1.20 COL for a good fit. The bullet resembled an XTP, which called for 4.7 of Titegroup. My Lee pro auto disk threw from 4.4 t0 4.5. My emptys were only ejecting 2 or 3 ft. compared to 5 or 6 factory. I figured the low charge was causing the keyholing. Some settings on the auto disk throw right on, and others low. I don't know if it could be the bullets fault, but I know my CZ-75 likes everything except xtp's. I wish I would have had my Kimber with me, but it was too hot to shoot very long.........Al

rcmodel
July 23, 2010, 03:52 PM
According to Lyman #49, 4.7 Titegroup - 200 Gold Dot plated bullet is a Starting Load giving only 13,700 PSI & 845 FPS.

5.3 gives 925 FPS at 16,400 PSI.

SAAMI Max pressure spec for the .45 ACP is 21,000 PSI.

You need to bump it up to at least the Starting load to get it to do right.

rc

243winxb
July 23, 2010, 06:40 PM
Some target backers can make a hole look funny.

375shooter
July 23, 2010, 11:49 PM
Key keyholing is when the bullet strikes the target sideways.
In my experience a light powder charge will not cause keyholing by itself. At the minimum, it would have to be a very slow twist with a long and heavy bullet, plus a light powder charge, and even then a true keyhole would be unlikely, if within a reasonable distance. It would likely result in just an oval shaped hole in the target. If the range is far enough though, it could result in keyholing.

rcmodel
July 24, 2010, 11:57 AM
Still like to see him increase his powder charge to at least the minimum recommended starting load.

rc

Red Cent
July 24, 2010, 12:47 PM
Competition shooters that use heavy for caliber bullets in their pistols use slow burning powders. Fast burning powders causes them to keyhole/tumble. They use Solo 1000, Blue Dot, American Select, and others.

http://www.brianenos.com/forums/index.php?showtopic=109372

rodregier
July 24, 2010, 01:10 PM
Bullet seated too deep can also cause keyholing.

Sunray
July 24, 2010, 11:50 PM
"...resembled an XTP, which called for..." Plated bullets use cast bullet data. They're not jacketed.
"...increase his powder charge to at least the minimum..." Absolutely. And work up the load, not just pick one.
"...Lee pro auto disk threw from 4.4 to 4.5..." Lose it. It's throwing far below minimum. It's useless if it isn't consistent. 4.8 is minimum for a cast 200 on Hodgdon's site.

ClemsonAl
July 26, 2010, 11:23 AM
Actually, Berry's recommends using low-to-midrange jacketed data for their bullets instead of lead data. I bumped-up some loads to 5gr of Titegroup. I won't be able to get back to the range for a week or two. I'll report back then.......,Al

ClemsonAl
August 3, 2010, 11:06 AM
Went to the range yesterday with some new loads. The heavier charges stopped the keyholing. I used 5.2gr Titegroup and 5.7gr HP38. The HP38 actually grouped better.:)

ArchAngelCD
August 6, 2010, 09:41 PM
Glad to see you fixed the problem. You will find HP-38/W231 is a good powder for many handgun calibers. It's my favorite go-to powder and is usually very accurate in everything I load with it.

BulletTime
August 6, 2010, 11:57 PM
Barrel leading caused keyholing for me. A good cleaning took care of it.

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