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Jamese35

Key holing

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So here's the deal I am tuning through all my 9mm guns a 160 grain polycoated bullet with 2.8 grains of tight group and a oal of 1.155 and a pritty heavy crimp on that bullet. The bullet is shooting out of my glock 35 beautiful and my 928 revolver I mean they will stack them one on top of the other with no isues. Now my dad runs the same thing out of his cz tacticalsport and even now and agen he is getting on key hole on him. It's the same set of reloads that I run in my guns and I never have a key hole. So why is he getting them but I'm not? All of the key holes were in heavy cardboard uspsa targets.  And they are traveling ate 820 fps at ten feat from the crono.

 Any advice would be great thank you

      Jimmy

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The short answer is his gun doesn’t like the load. Heavy bullets tend to tumble if everything isn’t perfect even in guns that tolerate them.

 “Heavy crimp” can also contribute to the problem. All you want to do is remove the flare. Nothing more.

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All I can add is I run a 165 RN with 2.85 TG out of an STI and have great grouping and accurate out to 50 Yds. Agree with the last post. Gun just don’t like it.


Sent from my iPhone using Tapatalk

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If I reduce the crimp much more it tends to shake the bullets out of the case when I shout them in the revolver.

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7 minutes ago, Jamese35 said:

If I reduce the crimp much more it tends to shake the bullets out of the case when I shout them in the revolver.

Load some for dad with less crimp?

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2 hours ago, Jamese35 said:

So here's the deal I am tuning through all my 9mm guns a 160 grain polycoated bullet with 2.8 grains of tight group and a oal of 1.155 and a pritty heavy crimp on that bullet. The bullet is shooting out of my glock 35 beautiful and my 928 revolver I mean they will stack them one on top of the other with no isues. Now my dad runs the same thing out of his cz tacticalsport and even now and agen he is getting on key hole on him. It's the same set of reloads that I run in my guns and I never have a key hole. So why is he getting them but I'm not? All of the key holes were in heavy cardboard uspsa targets.  And they are traveling ate 820 fps at ten feat from the crono.

 Any advice would be great thank you

      Jimmy

 

Jimmy, you mentioned that you are using a "heavy crimp".

I'm curious what the "back story" is on this. 

i.e. Did someone tell you that running a "heavy for caliber" bullet required a special crimp?

 

 

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8 hours ago, ddc said:

 

Jimmy, you mentioned that you are using a "heavy crimp".

I'm curious what the "back story" is on this. 

i.e. Did someone tell you that running a "heavy for caliber" bullet required a special crimp?

 

 

The back story is last year when I started shooting revolver I had a lighter crimp and I noticed the my bullets were shaking loos, then I tighten the crimp a bit, then in a mtch I had one shake completely out of the case locking the gun up, so I kept tightening it until that stopped and that's where I left it. When I shot with Bob vogel he also told me to put a heavy crimp on my bullets to. FYI my loads shot out of his gun great too.

 I really don't see it being crimp because it's only dad's gun the key holes the bullets and it's just the cz his xdm runs them good aswell, but I also don't know everything lol that's why I'm here.

6 hours ago, Talon75 said:

Bullet diameter? Did you slug all barrells?

Yes I slugged the chambers and they are almost identical. He also shoots some of my 124 grain bullets with 3.8 grains of tightgroup at the same oal of 1.155 and he has no key holes with them. And that runs the same crimp as the 160s. Both bullets are running at .356 in diameter. 

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Are you using a roll or taper crimp ?

 

Revolvers use heavy roll crimps but semi-auto's use light taper crimps.

 

In Revolvers, the heavy roll crimp keeps the bullets from popping out =

 

In semi-autos, it's really the sizing die that holds the bullet in place and NOT the crimp.    :) 

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1 minute ago, Hi-Power Jack said:

Are you using a roll or taper crimp ?

 

Revolvers use heavy roll crimps but semi-auto's use light taper crimps.

 

In Revolvers, the heavy roll crimp keeps the bullets from popping out =

 

In semi-autos, it's really the sizing die that holds the bullet in place and NOT the crimp.    :) 

I'm running a Lee press with a factory crimp die, so basically a taper crimp. It works varry well for the 929 when dropping in that moon clip, nothing g hangs up they slide right in. And my 929 is a 9mm so it doesn't use traditional revolver amo. 

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It's really the sizing die that holds the bullet in place - not the crimp    :) 

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59 minutes ago, Hi-Power Jack said:

It's really the sizing die that holds the bullet in place - not the crimp    :) 

If that's the case why does my 929 shake the bullets out of the brass with a lesser crimp? That being sade I'm going to back the crimp off some and see what happens. The other thing I don't understand is why do they not key hole on any of my other 9mm I shoot them out of? I'm at a loss.

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8 minutes ago, Jamese35 said:

If that's the case why does my 929 shake the bullets out of the brass with a lesser crimp? That being sade I'm going to back the crimp off some and see what happens. The other thing I don't understand is why do they not key hole on any of my other 9mm I shoot them out of? I'm at a loss.

As for crimp, conventional wisdom says over crimping can cause bullet to be compressed. When you he brass case springs back from crimping, the bullet stays same size. Therefore possibly allowing movement. As said, with straight wall cases, and without cannalure like 38 special etc, sizing retains bullets, not crimp.

  As for why one gun keyholes and another doesn’t, like I said, the gun doesn’t like the load. Many guns don’t like super heavy bullets, heavy crimp, Short oal, long oal etc, while others have no problem digesting them.

  

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3 hours ago, Sarge said:

As for crimp, conventional wisdom says over crimping can cause bullet to be compressed. When you he brass case springs back from crimping, the bullet stays same size. Therefore possibly allowing movement. As said, with straight wall cases, and without cannalure like 38 special etc, sizing retains bullets, not crimp.

  As for why one gun keyholes and another doesn’t, like I said, the gun doesn’t like the load. Many guns don’t like super heavy bullets, heavy crimp, Short oal, long oal etc, while others have no problem digesting them.

  

Thank you for your help. I will play with the crimp and see if that fixes it. And if it doesn't I'll drop down to 147s.

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Well guys I went and played with the crimp and it didn't help. So I started picking up brass as we shot and noticed it was doing it on Aguila brass. So I touch out every loaded Aguila and shot them, every one key holed. Then I took a hand full of anything but Aguila and they all shot beautiful not one key hole. So the problem was brass, and my guess is that Aguila might just be thicker.

 Thanks for all the hell guys

 Jimmy

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12 hours ago, Jamese35 said:

 

 Thanks for all the hell guys

 

You're damn welcome    ?

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11 hours ago, Hi-Power Jack said:

You're damn welcome    ?

Damn big fingers make it hard to type at times. Sorry lol 

 

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I was going to suggest twist.  Older 9 mm usually had a 1:16 twist and many newer ones have a 1:10 twist.  Heavy bullets at modest velocities may not stabilize with the slower twist.

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26 minutes ago, SteelCityShooter said:

I was going to suggest twist.  Older 9 mm usually had a 1:16 twist and many newer ones have a 1:10 twist.  Heavy bullets at modest velocities may not stabilize with the slower twist.

I thought that at first to but both my g34 and my dad tactical sport have a 1:10 twist. Even my xd mod 2 4inch shot the 160s good and that has a 1:16 twist. I'm glad it turned out to be just a brass isue, we both really like the 160 grain bullets, and when people ask what are you shooting their jaw drops when I tell them that they are 160s lol.

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On 6/26/2018 at 8:04 AM, Jamese35 said:

I'm running a Lee press with a factory crimp die, so basically a taper crimp.

 

 

That's your problem right there.  Don't use the FCD with coated lead.  The FCD sizes all the way down the case instead of just crimping (it is NOT basically a taper crimp die) and with lead will swage the bullet down, reducing it's diameter.  This is a notorious cause of key-holing.  You're using the cartridges in a couple of guns that are dealing with it, and one that is not.  Stop using the FCD with coated lead, and your problem should go away.

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2 hours ago, IDescribe said:

 

 

That's your problem right there.  Don't use the FCD with coated lead.  The FCD sizes all the way down the case instead of just crimping (it is NOT basically a taper crimp die) and with lead will swage the bullet down, reducing it's diameter.  This is a notorious cause of key-holing.  You're using the cartridges in a couple of guns that are dealing with it, and one that is not.  Stop using the FCD with coated lead, and your problem should go away.

It's not the crimp. It would only key hole in th tactical sport not any other gun. I took out all yhe Aguila brass and havent had a problem with them at all, and that's useing the same krimp as I had been. In fact it's putting them in a 1 inch group at 15 yards off hand. I took and backed the crimp off alot and no difference and then I started watching which brass it was doing it on and it was always Aguila, I took out all the Aguila and no more key holes at all.

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