Awesome Case of Keyholing

[fiver]

lube carrying powder fouling.
I would mention purges too but your alloy system is out of whack just enough that lube purges are not gonna show up like that.
I would try a harder alloy or water dropping just to see how things went.
diameter is important of course [I use 358 in all my 9mms] but some guns are really touchy about how they chamber some diameters.

 

[JonB]

SNIP...

Somewhere in my travels,

Reed, you wouldn't happen to be the Reed I know, who lived in south-central MN, a couple years ago, are you?
I see your profile says from Montana.

 

[Reed]

Reed, you wouldn't happen to be the Reed I know, who lived in south-central MN, a couple years ago, are you?
I see your profile says from Montana.

No, that's not me. Drove through MN a few times, though.

 

[Reed]

Update on Keyhole Issue

I heated that batch of bullets at 430 for 45 minutes and quenched. Fired them today. Problem is much improved. I still got 1 out of 8 that would keyhole. I think if I make these just a little harder yet and they'll be OK.

 

[Reed]

lube carrying powder fouling.
I would mention purges too but your alloy system is out of whack just enough that lube purges are not gonna show up like that.
I would try a harder alloy or water dropping just to see how things went.
diameter is important of course [I use 358 in all my 9mms] but some guns are really touchy about how they chamber some diameters.

Turns out mine is one of the touchy ones. I've loaded .358 in it, but I had to assist the slide about half the time to get it into battery. The front driving band would shave on the headspace shoulder leaving plenty of little bits of lead everywhere.

 

[Rick]

Update on Keyhole Issue

I heated that batch of bullets at 430 for 45 minutes and quenched. Fired them today. Problem is much improved. I still got 1 out of 8 that would keyhole. I think if I make these just a little harder yet and they'll be OK.

How much times from heat treat to firing? Plus time in heat treating is as much a factor as temperature. Should be 1 hour minimum.
.

 

[Brad]

Have the barrel throated. Stops the shaving, lets you use a slightly larger bullet.

 

[Ian]

What Brad and Fiver said. Take Freebullet up on his generous offer pronto!

 

[Pistolero]

Larger diameter is the usual solution, but that requires enough throat. Many 9m. ms have
oversized groove diameters, few will work with .355 or .356 diams which work fine with jbullets.

I have many 9mms and all will take the Lee TC120 conventional bullet at .358 with no probs at
all.

Bill

 

[quicksylver]

Maybe a different approach would shed some light on whether it was the ..1. bullet/load or 2. the gun/throat..

If there is some one else on the range with a 9 try them in their gun..seems to me if it's the load it should key hole as badly..if they don't then it's the gun..
course I could be wrong..Dan

 

[John]

I felt joy with the 9mm tl mold when I got rid of it. 356402 from the same alloy were accurate. I am South of Whitehall, in Madison County building a house across the river and retiring first part of April. I would be glad to help in person if you are anywhere close.

 

[Reed]

John, I think my brother and I met you at the range up your way. I was shooting the 94gr SWC in the 303B. I'll be coming to your shooting association banquet in March. I'm in Deer Lodge.
Reed

 

[John]

You did and sorry I did not recognize the name. I'll see what I can dig up for samples and either drop them off at your brothers work or PM you.

 

[Reed]

John, PM sent.

 

[popper]

Naw, this is keyholing - 401-175 TC Lee beagled to 190, 5gr 231 BLL. Barrel is shiny for the first half.
Soft alloy leaves a rectangular outline (started as a TC). G.S. really likes the BO I gave him.

 

[JWFilips]

The only Time I had Key-holing like that I was .003" undersize! Fat bullets made all the difference!

 

[quicksylver]

+1 on JW here...1917 US Enfield..bullets .311....needed
313

 

[Pistolero]

Yep, keyholing can get pretty ugly.

This is my first attempt with some gunshow 500gr RN in my 1873 Trapdoor. Too hard by a lot,
and that gun has a sloppy bore, too small. That is one shot, stopped after that.

 

[JonB]

The first time I seen keyholing was with handloaded saboted 55gr 224 bullets in a 30-06, it was before I was reloading for myself, and a friend was trying to replicate the Remington "Accelerator" ammo.
The second time I seen keyholing, was shooting some 50gr Barnes Varmint grenades in a CZ-527 in 223rem, which I recall was a 1:12 twist rate barrel.