Lee 358-105-SWC boolits keyholing in 9mm with 4.0gr of Unique, too little powder?

[worker]

As a title says, these wonderful, economical cast boolits are, unfortunately, keyholing out of 4 inch and 4.5 inch barrels (9mm semi autos).
Keyholing seems to be more pronounced out of the 4inch than 4.5 inch barrel

OAL is on the plus side of 1.023,. The boolit weight with Alox coating is about 108 grains.

I am thinking 4 grains of unique is not enough for this OAL, this bullet.
Should 4.5 grains of Unique be better, or go up to 5 grains, or relax the crimp even more (they are crimped with Lee factory taper crimp)?
What are the other possible reasons for keyholing for the above?

As a background, the goal for the above reloads, was to have an economical practice round for aiming/hole punching fun.
So lightest possible recoil, and the most economic boolit that works well with a full and commander-sized 9mm semi autos, was the goal.
Two constraints:
- the only two powder choices are Unique or HS-6
- Alox or tumble lube, no powder coating or other lubing or alloy enhancement.

[fredj338]

Bullet size is often the culprit. If that short of a bullet leaves the bbl it should fly straight, any vel. IMO, yes 4gr is to low for 105gr bullet. I use 5gr under a 125gr??

[BK7saum]

Get rid of the Lee Factory crimp die...

Pull a crimped bullet and check diameter. I bet it is now undersized from the FCD.

[Finster101]

What are you sizing them to? Sounds more like they are undersize than anything. That is the usual cause of keyholing.

[gwpercle]

I have a Walther P38 that shoots that bullet into one ragged hole groups .
I size them .357" and load them over 5.0 grs. Unique .

My minimum load for reliable cycling is the 105 gr. SWC - 4.7 grs Unique ...
but 5.0 grs. is the sweet spot accuracy wise .
Make sure your boolit is the correct diameter ... size makes a big difference .
Gary

[jsizemore]

Barrel leading?

[armoredman]

Lee FCD is the culprit - I never use it with lead boolits, jacketed only. Try it without it, only use a medium taper crimp from the seating die.

[steve urquell]

Get rid of the Lee Factory crimp die...

Pull a crimped bullet and check diameter. I bet it is now undersized from the FCD.


Lee FCD is the culprit - I never use it with lead boolits, jacketed only. Try it without it, only use a medium taper crimp from the seating die.

Yes and yes. If you are using the separate factory crimp die get rid of it. Disassemble a loaded round and measure a boolit. You will probably find it is undersized.

Use the bullet seater crimper die set to only take the flare out of the brass when seating. That is plenty enough neck tension. Then disassemble a loaded round and verify that you aren't swaging it down too far as well.

[oley55]

... or relax the crimp even more (they are crimped with Lee factory taper crimp)?

OP,

unless I am uninformed your description of the crimping die is confusing or misleading to more than a couple of us. Having just visited the LEE site they list just two 9mm Luger crimp dies; 9MM Luger Carbide Factory Crimp Die (90860) or 9MM LUGER / 38 SUPER / 38 ACP / 380 AUTO Taper Crimp Die (90780)

That said and assuming you are actually using the taper crimp die you only need enough taper die contact on the case mouth to just remove any case mouth belling/expanding you made for your boolit seating efforts. You don't actually want any crimp.

[243winxb]

Undersize bullets.

[JonB_in_Glencoe]

If your boolits are undersized (compared to your barrel's groove diameter), you will likely get keyholes and probably will Lead foul your barrel as well. You should measure your boolits (before and after being loaded) and slug your barrels...because 9mm guns are notorious for being oversized. Also, now would be a good time to inspect the throat as well. New 9mm guns are notorious for having short abrupt throats, which are fine for factory jacketed ammo, but can be troublesome for cast boolit loads.
Good Luck.

[reddog81]

Are you sure it's key holing? Slower moving bullets will tear paper more than faster bullets and can look kind of like keyholing.

I have been using that bullet for quite a bit of 9mm shooting recently in a variety of guns. The bullet has to be seated so deep in the case, so I usually start with 124 grain data and is usually works OK. Like others have mentioned making sure the bullet is sized correctly before and after being loaded is important for good accuracy. I size to .357 and use a Lyman M die to expand the case mouths.

[worker]

steve, BK7saum, armoredman - I think you are right, nice virtual troubleshooting !

Boolit before seating and crimping = 0.357
Boolit pulled after seating and crimping = 0.355

The case outer diameter near case mouse (after the bullet is pulled) = 0.377 (is this too narrow?)

The boolit was hard to pull out, took many blows, so it was crimped hard.

The EGW 4 caliber chamber checker was used to check the sizing
https://www.brownells.com/reloading/measuring-tools/case-length-gauges/4-caliber-chamber-checker/
Aiming for a totally free in-and-out test.
As well as a barrel to check the 'free no-resistance drop-plump'.

But I am thinking, now, with the cast boolit there should be at least slight resistance. I will still chamber ok, just the case flare has to be removed


And still, probably powder could be a bit more, that probably contributed.
I did not get a chance to get the info the barrel leading yet.




Yes and yes. If you are using the separate factory crimp die get rid of it. Disassemble a loaded round and measure a boolit. You will probably find it is undersized.

Use the bullet seater crimper die set to only take the flare out of the brass when seating. That is plenty enough neck tension. Then disassemble a loaded round and verify that you aren't swaging it down too far as well.

[steve urquell]

steve, BK7saum, armoredman - I think you are right, nice virtual troubleshooting !

Boolit before seating and crimping = 0.357
Boolit pulled after seating and crimping = 0.355

The case outer diameter near case mouse (after the bullet is pulled) = 0.377 (is this too narrow?)

The boolit was hard to pull out, took many blows, so it was crimped hard.

The EGW 4 caliber chamber checker was used to check the sizing
https://www.brownells.com/reloading/measuring-tools/case-length-gauges/4-caliber-chamber-checker/
Aiming for a totally free in-and-out test.
As well as a barrel to check the 'free no-resistance drop-plump'.

But I am thinking, now, with the cast boolit there should be at least slight resistance. I will still chamber ok, just the case flare has to be removed


And still, probably powder could be a bit more, that probably contributed.
I did not get a chance to get the info the barrel leading yet.

With cast and 9mm you have to stop thinking about the outside diameter of that case. If it will fit and cycle in your gun it does not matter. Different cases have different brass thickness. If you try to make a case smaller by crimping hard all you do is make your boolit smaller then the case springs away from it making your neck tension too loose.

I use the 3 die Lee set and seat/crimp on the same die. I set it just to remove the flare---no more than that. If it indents a boolit I back it off.

Just so you know I put my money where my (case) mouth is :lol:

3/4" 25 yard group with the Lee 358-158-RF.

https://i.imgur.com/lZDZr4W.jpg
https://i.imgur.com/abR1uNB.jpg

[armoredman]

Good to hear - I've been loading 9mm for a few years and unlike many, I keep mine at .356 minimum, since .355 is the size for jacketed bullets.. They work pretty well out of my CZ pistols. I tried the Lee FCD on cast once, and figured out what went wrong. Now, have you set up for the new seating yet? Waiting to see results sir! :)
BTW, I don't have a fancy pistol like Steve, but they seem to do all right by me.
https://i.imgur.com/FPodewy.jpg
https://i.imgur.com/flQc0HP.jpg
See in the notes where it says, "No FCD"? ;) Oh, that was 10 yards, standing unsupported, BTW. I am not a great shot.

[dmccord]

I had a problem when I first started casting. My problem was I needed to size the bullets .002 fatter. Have you slugged the barrel?

[Taterhead]

The first thing I would do is seat a few dummies and pull them. If the bullet swages down after seating, an expander with a wider shank diameter is called for. That's because the interior diameter is too narrow for the bullet diameter. Or a carbide factory crimp die might be wrecking the diameter.

[worker]

did not get a chance to get the info on the barrel size yet.
the crimping die came from Lee's 4-die for 9mm (number 90963) , seating die was from the same set.

Does anybody have a link/ or a book isbn for a referenceable load data for HS-6 and Unique (that would include OAL and other typical info) for this bullet (358-105-SWC , sized at .357, with alox lube weighting at 108 gr)?
I do not see the info in in Lee or Lyman (including the Lyman cast )books or HS-6 reference load data database at Hodgdon.

[243winxb]

Includes all types of bullets.


From Steves Pages for 115 gr bullets.

HS-6 From 5.5 grains to 7.5 grains

Unique From 4.4 grains to 7.0 grains



For 100 gr bullets.....

HS-6 From 6.0 grains to 7.5 grains.

Unique From 4.2 grains to 5.9 grains