HP 9mm keyholes

[hubcap52]

I've cast some Lyman #356637 9mm (356 Diameter) 124 Grain Devastator Hollow Point Bevel Base boolits and loaded them up with Unique. Took them to the range today and from a Glock (aftermarket bbl.) and an XD subcompact they tumbled at 25 yds. Some were completely sideways. Is this typical or am I missing something? http://castboolits.gunloads.com/images/smilies/confused. I am an experienced caster and reloader (30++ yrs.) and these were good looking bullets. Any help would be appreciated.

[JIMinPHX]

How fast were you pushing them? What was the twist rate of your barrel? What is the total length of the boolit (not the loaded cartridge, just the boolit)? Did you find lead smears at the muzzle? Did you recover any of the fired boolits to look at? Did you slug your barrel before casting? What diameter did you size to? Did you find any lead rings at the front of your chamber?

[hubcap52]

1. How fast were you pushing them?
2. What was the twist rate of your barrel?
3. What is the total length of the boolit (not the loaded cartridge, just the boolit)?
4. Did you recover any of the fired boolits to look at?
5. Did you slug your barrel before casting?
6. What diameter did you size to?
7. Did you find any lead rings at the front of your chamber?
8. Did you find lead smears at the muzzle?



1. Haven't chrono'ed them yet. It's about a 125 gr. bullet, so probably upper 1000's
2. I assume the standard ROT for any 9mm.
3. .614
4. No
5. No, but I've shot many other cast bullets out of those bbls. without problems.
6. IIRC, I didn't size them. Used as cast with Lee Liquid Alox.
7. Haven't looked yet. Don't expect to find any.
8. Nothing out of the ordinary

[JIMinPHX]

2. Please determine this by pulling a tight fitting patch through the barrel & counting how many inches per rotation you get. The ratio of boolit length to twist rate is one of the basic parameters of gyroscopic stability.

5. Were the boolits that shot well sized to the same diameter as the problematic boolits?

7. I have only seen them on new barrels with sharp edges where the chamber meets the throat. It's an unusual thing, but I have seen it before on a 9-iron.

New questions:
1A) Did the hollow points appear to be concentric?

2A) Did the points get mashed at all when you seated them?

3A) If you chamber a round & then eject it, does the nose of the boolit have a big dent in it?

4A) What alloy are you casting with?

[geargnasher]

Boolits are too small for your particular gun, either when cast, after seating, after crimping, or after passing through the throat. Recheck your processes, slug the barrel with a dead soft lead slug and compare it to a boolit pulled after seating/crimping per your normal routine.

Gear

[fredj338]

Measure them first, they may be undersized. Are you using a LFCD? Lyman molds recently have been coming up on the small side. You can Beagle the mold & get a bump or try changing alloy/temp.

[finishman2000]

356 is too small.

[Lloyd Smale]

Ive got two guesses. Either the need to be shot a bit faster to stabilize or your using to soft of an alloy and its stripping through the rifling and not allowing the rifling to impart enough spin. Id bet the latter if your sizing to 356 and are using a soft alloy. try 357 or even 358. Most 9mms ive owned will chamber and shoot 358s reliably and try an alloy thats at least 12bhn and preferably around 16 plus. I know that that is counter productive if your trying to get them to expand but it may be nessisary.

[Rangefinder]

In total agreement---SIZE is usually the big factor whenever I've seen keyholing. Even a thousandth or two undersized will cause it.Slug your barrel, and size accordingly. Off the top of my head, I'd guess you should be using something in the neighborhood of .358--but slugging will tell you for sure.

[MtGun44]

Check out the sticky in the handgun section on 'Setting up a new 9mm for boolits'

It'll save you a lot of time.

Many 9mms need .357 or .358 diam, not the commercial boolit seller's usuall .356 diam
that they provide.

Wish I had a dollar for every new thread that starts "my 9mm bullets are hitting
the target sideways . . . . . ."

Bill

[rintinglen]

Bill, I DO have a dollar for every thread that starts out like that and I've almost saved enough to buy that new gun I wanted!!

[MtGun44]

I need to figure out how you are getting these newbies to send you a dollar. I have
answered about 3 jillion of these and never got a red cent. :bigsmyl2:

Bill

[hubcap52]

2. Please determine this by pulling a tight fitting patch through the barrel & counting how many inches per rotation you get. The ratio of boolit length to twist rate is one of the basic parameters of gyroscopic stability.

5. Were the boolits that shot well sized to the same diameter as the problematic boolits?

7. I have only seen them on new barrels with sharp edges where the chamber meets the throat. It's an unusual thing, but I have seen it before on a 9-iron.

New questions:
1A) Did the hollow points appear to be concentric?

2A) Did the points get mashed at all when you seated them?

3A) If you chamber a round & then eject it, does the nose of the boolit have a big dent in it?

4A) What alloy are you casting with?


2. 1/10

5. Yes

1A) Yes

2A) No

3A) No

4A) WW air cooled

[JIMinPHX]

1/10 is plenty fast to stabilize that boolit. In fact, it is very fast for a pistol barrel. The only problem that I might expect from a very fast twist is that it might rip up the bearing surface of the boolit a little if the boolit is not tough enough. Your other answers sound good.

I would try water dropping a dozen or so boolits & see if the performance gets better or worse. That might tell you something.

I would also try dropping your powder charge down a bit & see if things improve. This could prove educational.

Like others here have already said, I would slug the barrel to see what dimensions you are actually dealing with.

You might try running your mold a little hotter & try using a little more tin in the mix, like 2% more by weight. If you were getting air pockets in the boolits, this may help to minimize that.

[Iron Mike Golf]

+1 on water dropping a few. It's a cheap experiment.

Are you sure you don't have significant lead fouling? It's been noted the twist rate is pretty fast. Too much pressure, too weak and alloy, too fast a twist can combine to strip instead of engraving rifling. That results in the boolit spinning lots slower than the twist rate.

Having said that, I don't think that may be happening. It doesn't sound like you have the leading that would result with a proper diameter boolit and stripping. That's why I ask if you are really sure you got a spic and span barrel.

You do need to slug your bore. That's step number 1 before getting a mold or sizing die. If your boolit is way undersized for your barrel, you can get stripping, too little spin, unstable flight, and not much leading.

[soldierbilly1]

Hubcap:
they usually say that "Fit is King."
My nine taught me "Fit is First."

everything fell into line after that. Also, my barrel was brand new, did not help things. not to mention the FCD and the taper crimp. OHHH NOOOOOOOO.

billy boy

[Balta]

I also have issue with keyholing with my CZ75 and G19....Loading a boolits from WW and sized at .356...Now i use unsized bullets .358 diamater and i manage to stabilaze bullet but leading is still a problem my reloading dies swage a bullet at .357-.3575 ...Geting nice groups also. Trying to get .358 diameter AFTER reloading and see is leading bee a less or...Gonna use harder alloy.i stop using Lee FCD.
CZ 75 barrel is .3565 and G19 is .355,,and G19 much less lead the barrel ...I use Lee tumble lube and bullet is TL356 125 2R...feed good.
and magTech primers sucks....(FTF 1 of 40)

My first post...so proud:)

[Shiloh]

Mine tumbled at less than 50' until I found one that would cast large enough.
Sized at .358 they work great.

Shiloh

[bpratl]

+2 on .358" for my 92FS Beretta which keyholes at .356"

[Cherokee]

Balta - thanks for your post.

[tenx]

A friend shooting a 39 S&W 9mm had key holing issues, I mean at least half of the bullets hit sideways at 50 ft. Finally found it was a Lee Factory Crimp die overly adjusted and sizing the bullets way undersized. Just a thought.

[MtGun44]

Another testimony to the "benefits" of the Lee pistol type Factory Crimp Die.

Bill

[Tar Heel]

Bill,

Referencing the comment about "wish I had a dollar for every post...", That's all I saw when attempting to diagnose a 9mm problem....hundreds and hundreds and hundreds of posts all about the same thing and usually with no beneficial solution to the problem. May I suggest a forum redesign with a "troubleshooting" section broken down by caliber and type of problem? Dare I say that there is too much content on the forum which is making searches too difficult?

[MtGun44]

Go to the stickie on "Setting up a new 9mm for boolits", lots of info there,
if you work thru it you have a substantial chance at solving it.

Bill