Report on gas-check 9mm bullet......

[Harry O]

I have unsuccessfully tried to get cast 9mm x 19 (Luger) bullets to shoot for some time. I tried three different moulds. All were plain based. All were between 115 and 125gr. I tried several different hardnesses, several different diameters, and two types of lube. None of them gave acceptable accuracy in the three different guns I tried them in. Groups ran from twice as big as jacketed groups from the same guns, to larger than the entire target. Many of them keyholed. Keep in mind that even jacketed bullet groups were a good deal larger than my revolver groups. Doubling that (and more) was unacceptable.

The largest one (0.357" to 0.358" as cast) worked the best even though there was an unsightly bulge in the case at the bottom of the bullet. The larger the bullet diameter, the less keyholes there were. It did not have a problem feeding though. I "sized" it with a 0.358" and lubed it at the same time. Harder was better, but hardnesses above about Bhn 15 to 18 did not seem to help. I was about to give up on them.

I asked about the possibility of a gas-check 9mm bullet here and someone directed me to one (thanks). After all, the pressure in a full power 9mm is very close to the pressure of a .357 Magnum and I shoot a gas-check bullet in the Magnum all the time without problems.

I got the mould and cast up some with Bhn 15 lead. The diameter was a little smaller (0.356" to 0.357" as cast), so I sized them with a 0.357" die while crimping and lubing them. The accuracy is pretty darned close to jacketed bullets first time out (between 1-1/4 to 1-3/4 times the jacketed bullet groups). I am not sure where I will go from here to experiment, but it is pretty good right now.

The cost and time for a jacketed bullet is worth it to me. If anyone else is having a problem with their cast 9mm bullets, I recommend trying a gas-check.

[9.3X62AL]

I haven't (yet) tried a GC boolit in the 9mm, but it stands to reason that it should work for all the reasons you gave. As long as you don't mind the expense, it's a good short-cut to good results.

The 9mm, 40 S&W, and 10mm calibers can be challenging chamberings for the cast boolit shooter. The 45 ACP spoils us rotten.

[bowenrd]

I have been shooting cast in 9MM for several years with satisfactory results. I size to .357 with out using a gas check and run them at about 1100 FPS.

Suggestions:
Do not crimp 9MM. A crimp will size down the bullet. Only remove the bell.

Try a different powder. I have good luck with Blue Dot. Red Dot causes keyhole for me.

I use straight wheel weights. Water dropped.

Try a larger case expander. The internal case taper may be swaging bullet undersized. Pull a bullet from one of you loaded rounds and mic it.

Make one change at a time so you will know which change made a difference.

[primersp]

i have an 9-124 rn rcbs mold ,which is an g.c bullet
try with and without ,i have an another rcbs 9-124 tc the 3 bullets give same accuracy in an 5906,size at 357,speed level in the low 964 f/s just for target shooting ,white lube 2500

[Silvercreek Farmer]

What's the range and size of your groups in inches/feet? You use a lot of relative terms-2x jacketed ect, makes it hard to visualize...

[Harry O]

I think I am starting to see why I had problems and others report they don't. I would not have problems with plain base between 900 and 1,000fps either. That will not operate one of my guns. I shoot plain base .38's at that speed with no problems. My loads are closer to 1,200fps. I taper crimp the case, not roll crimp it. I have used several powders, without much observed difference when it came to accuracy.

I don't mind the expense of gas-checks. I bought a lot of them (and a lot more of primers) about 4-1/2 years ago when I the nominee for both parties became known -- before the prices skyrocketed. I still have most of my gas-checks, but have gone through about half of my primers. Unfortunately, I am not as good at my retirement investments.

As far as group size, I can shoot down to 2" groups with various revolvers from a rest at 25 yards. I cannot do that with my 9mm semi-autos. The best is about 3" and some won't do less than 4". With plain base 9mm bullets, it was double that or more, often being not able to keep them on a 9" x 12" piece of paper. The gas checks are better than that.

[jmsj]

#2 (quote)
9.3X62AL
I haven't (yet) tried a GC boolit in the 9mm, but it stands to reason that it should work for all the reasons you gave. As long as you don't mind the expense, it's a good short-cut to good results.

The 9mm, 40 S&W, and 10mm calibers can be challenging chamberings for the cast boolit shooter. The 45 ACP spoils us rotten.

I'll agree w/ 9.3.
Have you recovered any of your bullets and checked for skidding?
I have used plain base gas checks w/ good results.
Good luck, jmsj

[40Super]

I have 4 9mm autos, all of them can get down to 2"groups with lead,no gas checks. There are a lot of loads that won't, but just by experimenting with correct sized bullets(this means two different sizes of bullets for me),hardness wasn't as big a difference as long as all bullets are the same bhn.I like AA#5,WSF and HP-38 for lead(SR 7625 is also a great "lead"powder).All my guns also tend to favor 140-147gr bullets,so velocities aren't as high, though I do have some great 115lswc loads along with a Miha 130gr over AA#5.
I did make my own PTX's so the brass is opened up deep enough to not swage the bullets down from the inside taper, which is a common problem in the 9.

[Dannix]

I don't have any 1200fps boolit loads developed, but here are just a couple of quick thoughts:
Get a good expander plug. (Have Buckshot here make a m-die plug for you.) And as mentioned, don't taper crimp, just de-bell.
It seems some 9x19mm barrels like even as large as .359. .357 plus any sizing down from the brass or the crimp could explain why you are having PB issues but success with gas checks.

[DX250]

I have played the 9mm game and won in my case. I have found as you have larger is better, mine get sized to .358 and loaded with a mid to upper load (1200 fps) of power pistol with no leading. I do use a 38/357 expander and it solved my problems. I also load the same boolit in 357 sig to north of 1400 fps and all is well.

[Bomberman]

I taper crimp the case, not roll crimp it.


You don't roll crimp a 9MM Luger as it headspaces on the casing mouth. No crimp at all is a better option as long as the boolit doesn't get pushed into the casing when pushed up the loading ramp. Make a few dummy rounds and try them out to make sure. Good luck.

[AlabamaEd]

You seem to be casting your boolits much too hard and running them much too fastl. I cast of COWW +1% tin and do not water drop. Size to .001 over bore and use a M die to expand case with mild taper crimp. I have a Wolf barrel in my Glock. I have no problems with 2" groups at 25yds.

[leftiye]

I suspect the very tight crimp is sizing down your bullets, as is the taper crimping. And, yes 35,000 psi loads won't help bullet deformation much. Case mouth against front of lube groove, slight roll crimp if it won't bear to keep boolits from setting back, then back off on sizing tightness some so as to not deform, size down boolits.

[HDS]

I am having issues with the cases sizing down my bullets on 9mm as well. Once I get my new barrel I will see what I need and order a modified expander for my dillon 650 powder measure so it will expand the ID of the case to .001" below the bullet size I will need.

[captaint]

Harry - A kind member here voluntairily sent me a lot of plain base gas checks made from (I think) soda cans. To install them, I ran them through the Star upside down and avoided the pump stage at the bottom of the stroke. I had been having leading problems with boolits smaller than .358. Issue solved. Great accuracy, no lead. Cheap solution. enjoy Mike

[lotech]

Experiment with alloy hardness and use the largest diameter bullet that will allow the cartridge to chamber normally, usually .358" or .359". Many 9mm moulds are too small. Gas checks should not be necessary.