9mm keyholing [Archive] - Glock Talk

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jadedragon
04-25-2011, 00:00
Developed a great accurate load using Bear Creek TC 125 gr bullets for my 34 using a drop in KKM barrel. I was curious what this would do using the stock barrel and as the title states they are keyholing. I wasn't expecting that. So, what's up?

cole
04-25-2011, 00:25
Bullet is not being stabalized. The why of this may be more challenging.

Have you tried increasing the charge? What is your load data BTW? What's your load OAL and what the diameter and OAL of the bullet itself? The KKM barrel is likely tighter, which will increase pressure. You may just be at the lowend of this load and the bullet is not obturating with the barrel.

Again, more load data is needed.

Boxerglocker
04-25-2011, 00:51
Bullet is not being stabalized. The why of this may be more challenging.

Have you tried increasing the charge? What is your load data BTW? What's your load OAL and what the diameter and OAL of the bullet itself? The KKM barrel is likely tighter, which will increase pressure. You may just be at the lowend of this load and the bullet is not obturating with the barrel.

Again, more load data is needed.

:agree: I'll bet your pushing less than 130 PF. The KKM is tighter and standard rifling stabilizes that moly bullet much better than the polygon Glock barrel. I've tried it myself just recently with both my Spartan and G34 with BC 125 too BTW.
I choose to stay with FMJ's with my Glocks, I run a Bear Creek 135 RN with WST on the Spartan.

Would you mind sharing your load? What powder and OAL? When you say accurate have you bench tested out to 25 yards. My Spartan will hold 2 inches at 25 with the 135 BC / WST mention, average 133 PF.

jadedragon
04-25-2011, 01:18
Load specs:

Bear Creek 125gr TC 4.0gr Titegroup Wolf SP
OAL 1.10
bullet OAL .614
crimp .376
bullet pkg says .356 diameter but mike says .355
3-4 inches at 25yds.
Not yet been chronoed because it's a plinking load.

JML2365
04-25-2011, 01:26
I had the same thing happen to me with Bulletworks plated in my G17. Someone suggested I back off on the crimp a little. So I backed off until it would not fit in the barrel and then slowly increased crimp until it fit into a barrel easily. I took the barrel out of the gun and dropped the round into the barrel until it fit flush. No more keyholing.

shotgunred
04-25-2011, 05:08
Load specs:

Bear Creek 125gr TC 4.0gr Titegroup Wolf SP
that should be fine
OAL 1.10
That is to short. stretch it out to at least 1.125
bullet OAL .614
crimp .376
that should be fine
bullet pkg says .356 diameter but mike says .355
3-4 inches at 25yds.
Not yet been chronoed because it's a plinking load.
Off hand I will say you are running your bullets pretty short. But I have no experience with molly bullets.

unclebob
04-25-2011, 08:41
I would say start out with your c.o.l. But whatever you do only do one thing at a time. Unless you well never figure out what is causing it.
Is this a new batch of bullets?
Are you using an undersize die?

Boxerglocker
04-25-2011, 11:41
I would say start out with your c.o.l. But whatever you do only do one thing at a time. Unless you well never figure out what is causing it.
Is this a new batch of bullets?
Are you using an undersize die?

I highly doubt he will be able too adjust his COL any longer than it already is. That's the issue I had with BC 125 RN. It has a blunt round ogive your forced to run is short like a JHP or SWC.

He needs to chrono and should at least be in the mid-range for the powder he is using. Maybe back the crimp off slightly, I use .377, they do not case gauge in either bench gauges I have but do using my barrel. The other unmentioned is the dies he is using, LFCD maybe? :dunno:

fredj338
04-25-2011, 16:13
Load specs:

Bear Creek 125gr TC 4.0gr Titegroup Wolf SP
OAL 1.10
bullet OAL .614
crimp .376
bullet pkg says .356 diameter but mike says .355
3-4 inches at 25yds.
Not yet been chronoed because it's a plinking load.
Lead bullets in any 9mm bbl can be finicky. Your problem is likely the smaller 0.355" dia of the lead bullet. Most lead bullets want to be at least 0.001" larger than groove dia. I suspect if you slug your Glock bbl, it is 0.355" or slightly larger. That is almost always going to cause a key hole. Same issue if you are using a LFCD, they can resize the bullet, smaller bullets refuse to stabelize unless pushed @ higher vel & even then, they won't be as accurate as a properly sized bullet.

WiskyT
04-25-2011, 18:56
All of the above suggestions MIGHT help. What is almost guaranteed to work is to back your charge down a bit. Try 3.5 and see how they do. Also, a slower powder will make a big difference.

I can't go over 3.5 Bullseye with a 125 LTC in my stock barrel. It still gives me 950fps which is fine for a plinking load.

When I want a full power load, I use 5.0 or so of Unique.

This is all with a stock G17 barrel. FWIW, the longest I can seat my Lee TC in my stock barrel is 1.08" and much of the data I find for them shows LTC at 1.04"

chris in va
04-27-2011, 10:06
I had horrible lead bullet keyholing with my CZ until I went .003 over bore diameter. The standard 356 simply didn't work.

fredj338
04-27-2011, 13:23
I had horrible lead bullet keyholing with my CZ until I went .003 over bore diameter. The standard 356 simply didn't work.

It is a huge issue w/ lead bullets in the 9mm, too many diff bore dia. It seems US manuf have one & Eruo have another. So trying to get the 9mm to run 100% w/ lead bullets seems hard than a 40 or 45 IMO. Can be done for sure, just have to eliminate variables, bullets to groove dia is where you start.

WiskyT
04-28-2011, 15:17
Okay, so now loads that don't keyhole in my G17, DO in my LC9!!!

3.5 Bullseye keyholed. So much for my advice on lighter loads working better.

4.8 Unique shoots great in both guns.

Since 4.8 worked great, I tried 4.5 figuring it might save some wear and tear on the LC9. It ****ing keyholed. So now I'm going to try 5.2 just because I can and it also shoots great in my G17. MY old Lyman book shows 6.0 as max with a 125, The new books are around 4.8 or so. Go figyah.

I'm thinking the LC9 might have a bigger bore.

GioaJack
04-28-2011, 15:37
Okay, so now loads that don't keyhole in my G17, DO in my LC9!!!

3.5 Bullseye keyholed. So much for my advice on lighter loads working better.

4.8 Unique shoots great in both guns.

Since 4.8 worked great, I tried 4.5 figuring it might save some wear and tear on the LC9. It ****ing keyholed. So now I'm going to try 5.2 just because I can and it also shoots great in my G17. MY old Lyman book shows 6.0 as max with a 125, The new books are around 4.8 or so. Go figyah.

I'm thinking the LC9 might have a bigger bore.


SLUG... More than just a word that describes you. :whistling:


Jack

WiskyT
04-28-2011, 16:11
SLUG... More than just a word that describes you. :whistling:


Jack

Yeah, except I'm shooting these unsized at 0.357" out of the mold. I'll tinker with the loads to see what works best. The three inch barrel of which at least one inch is chamber might have something to do with it too. I have the 4.8 load that will work in both so I could just live with that.

I guess I could lap the mold to make it bigger. If I get lucky I could hit it on the nose at 0.358". If not, and it's a lrch bigger, I could just size them to 0.358".

The gun shoots well though, 350 rounds so far and not a single stoppage. I can keep them all on a paper plate at 25 yards as long as the load is keyholing.

GioaJack
04-28-2011, 16:15
Yeah, except I'm shooting these unsized at 0.357" out of the mold. I'll tinker with the loads to see what works best. The three inch barrel of which at least one inch is chamber might have something to do with it too. I have the 4.8 load that will work in both so I could just live with that.

I guess I could lap the mold to make it bigger. If I get lucky I could hit it on the nose at 0.358". If not, and it's a lrch bigger, I could just size them to 0.358".

The gun shoots well though, 350 rounds so far and not a single stoppage. I can keep them all on a paper plate at 25 yards as long as the load is keyholing.


UH-OH... are we gonna see another one of those fictitious paper plate targets again?

And just what type of stoppages are you expecting out of a revolver? :dunno:


Jack

WiskyT
04-28-2011, 16:23
UH-OH... are we gonna see another one of those fictitious paper plate targets again?

And just what type of stoppages are you expecting out of a revolver? :dunno:


Jack

No need to post pics, the plates look like any other paper plate with holes in it.

It's an LC9 The emphasis on what the German Girls told you when you were a member of the Air Scouts.

GioaJack
04-28-2011, 16:40
No need to post pics, the plates look like any other paper plate with holes in it.

It's an LC9 The emphasis on what the German Girls told you when you were a member of the Air Scouts.


Oh, that's right... you've got that little sissy gun. I guess if the keyholing is effecting accuracy that much you could just hit the bad guy with your purse... or have your wife defend you. :whistling:


Jack

WiskyT
04-28-2011, 16:46
Oh, that's right... you've got that little sissy gun. I guess if the keyholing is effecting accuracy that much you could just hit the bad guy with your purse... or have your wife defend you. :whistling:


Jack

I think in Jack's own cute, cuddly way, he is telling me he missed me not posting for the last couple of days.

WiskyT
04-28-2011, 20:30
Allright, just to humor Jack, and to allow C4W to accuse me of hypocracy, I measured something. I drove one of my soft 9mm pills down the barrel of my LC9. The soft lead and liquid alox coating made it pretty easy. The grooves were easy to measure since they were opposite each other. It fell between 0.355" and 0.356" on a mic. I guess that makes it 0.3555" and the bullets are 0.357" so I should be good in that respect.

ETA: I also loaded up some with 3.8 Bullseye before changing the measure over to Unique. I loaded up 100 with the known good load of 4.8.

GioaJack
04-28-2011, 21:01
Allright, just to humor Jack, and to allow C4W to accuse me of hypocracy, I measured something. I drove one of my soft 9mm pills down the barrel of my LC9. The soft lead and liquid alox coating made it pretty easy. The grooves were easy to measure since they were opposite each other. It fell between 0.355" and 0.356" on a mic. I guess that makes it 0.3555" and the bullets are 0.357" so I should be good in that respect.

ETA: I also loaded up some with 3.8 Bullseye before changing the measure over to Unique. I loaded up 100 with the known good load of 4.8.


There's your problem rookie... you're supposed to be measuring the lands. :whistling:


Jack

fredj338
04-29-2011, 00:10
Since 4.8 worked great, I tried 4.5 figuring it might save some wear and tear on the LC9. It ****ing keyholed. So now I'm going to try 5.2 just because I can and it also shoots great in my G17. MY old Lyman book shows 6.0 as max with a 125, The new books are around 4.8 or so. Go figyah.

I'm thinking the LC9 might have a bigger bore.
Maybe w/ a jacketed bullet, but I can assure you, 6gr of Unique under a 125gr lead bullet is going to be really hot. I run 5gr under a 12rgrLRN @ 1.130", good accurate loads, makes 1100fps in my G17/LW. Go to a 124grLTC @ 1.060"OAL & the vel/pressures jump to 1210fps. I've run 6gr under various 124grJHP, all go well over 1200fps, I consider 6gr a max. load w/ a jacketed bullet, I would approach anything higher than 5.5gr under a 124-125gr lead bullet w/ caution.:shocked:

WiskyT
04-29-2011, 14:38
Maybe w/ a jacketed bullet, but I can assure you, 6gr of Unique under a 125gr lead bullet is going to be really hot. I run 5gr under a 12rgrLRN @ 1.130", good accurate loads, makes 1100fps in my G17/LW. Go to a 124grLTC @ 1.060"OAL & the vel/pressures jump to 1210fps. I've run 6gr under various 124grJHP, all go well over 1200fps, I consider 6gr a max. load w/ a jacketed bullet, I would approach anything higher than 5.5gr under a 124-125gr lead bullet w/ caution.:shocked:

Agreed! I wouldn't do it. I just take comfort in my 5.2 load knowing that 6.0 is still within the limits set by a reputable lab at one point. 5.2 does 1150 or so out of my stock G17 which is all I could ask of a 125 using Unique. If I wanted more, and I don't, I'd use Blue Dot or something else.

Really, I want to go the opposite way. I want a load that will reliably cycle and shoot well, and that's it. I just find it odd that my attempts to load down are giving me keyholing when my previous experience is just the opposite.

WiskyT
04-29-2011, 14:39
There's your problem rookie... you're supposed to be measuring the lands. :whistling:


Jack

Good point. I screwed up the terminology and that could confuse someone. I did, in fact, measure the lands at 0.3555".

fredj338
04-29-2011, 16:33
Agreed! I wouldn't do it. I just take comfort in my 5.2 load knowing that 6.0 is still within the limits set by a reputable lab at one point. 5.2 does 1150 or so out of my stock G17 which is all I could ask of a 125 using Unique. If I wanted more, and I don't, I'd use Blue Dot or something else.

Really, I want to go the opposite way. I want a load that will reliably cycle and shoot well, and that's it. I just find it odd that my attempts to load down are giving me keyholing when my previous experience is just the opposite.

Could be alloy, maybe the bullet is skidding in the shallow rifling.:dunno:

WiskyT
04-29-2011, 17:34
Could be alloy, maybe the bullet is skidding in the shallow rifling.:dunno:

Normaly I would agree. But in this case it's the Ruger with it's fairly deep rifling that is giving me trouble and the Glock with it's shallow rifling that is pretty forgiving,