9mm reloading questions

[JudgeBAC]

I have run into some questions regarding loading 9mm. In the past 30 years, I have reloaded many different rounds including .45 ACP but no 9mm until now. My bullet is an LBT 124 truncated cone bullet sized to .356. It has an overall length of .587. To make it chamber in my barrel, which is a cut rifled barrel in a Glock 19, my overall length is only 1.026.

Is this too short? I.E. will this tend to cause unacceptable high pressures? Would it be satisfactory if I stuck with the starting load or whatever minimum load is necessary to operate the action?

Thanks for reading.

PS: I posted this in another section which probably was not the appropriate place to post this query. Sorry for the duplication.

[Bigjohn]

JudgeBAC
Speaking (writting) from experience with loading simular styles of Boolit in 9mm, I would suggest the following. The TC's I have loaded were seated to the junction of the driving bands and nose, Then crimped.

These loads were for IPSC Handgun and were required to exceed a minor power factor floor level. Hence the loadings were maximum recommended or slighty below. No problems were encountered with pressures.

The GLOCKs tend to have their own chambering gauge; providing a cartridge will fit into the chamber of the barrel (while it is out of the firearm) and not protrude back past the hood (or protrusion on the top at the rear of the chamber) without jamming in there; then it is ok.

I can not help you with loads as here in Oz we use mainly ADI powders.

I know these methods sound a bit rough but they worked for me when proper equipment is not available.

There are some commercially made chamber gauges available if you can find one or ask the maker of your barrel.

But PLEASE, OH PLEASE; if you use the barrel to check the chambering of your rounds; REMOVE it from your handgun. Drop the rounds into the chamber and tip the out.

Also it may pay you to slug the bore as I have found some manufacturers are using .357" bores in 9mm handguns; it helps to keep the pressures down.

John.

P.S. Where you first posted is the correct place but don't worry about it.

[9.3X62AL]

Judge--

Aftermarket barrels tend to run truer to nominal dimensional specs than some factory barrels. A factory barrel with .355" grooves would be a mild surprise in my experience.

I really like truncated cone designs for autopistol boolits. My usual practice is to seat boolits somewhere between the location you surmise (junction of ogive origin even with case mouth) to a point where .020" of the boolit's front drive band is exposed above the case mouth. This regimen has worked well with both SWC designs (with shoulder, like a Lyman #452460), or with shoulderless designs like the Lee TC.

With the 9mm and 40 S&W, start low and work up--ESPECIALLY with faster powders like Bullseye, HP-38, or WW-231.

[fecmech]

When loading similar bullet wts for the nine I'm less concerned with OAL than I am with how much of the bullet is in the case. Case capacity is what determines pressure of the load and how much bullet is in the case determines capacity. An example is the Lyman 356402 tc 121 gr bullet and the Lee 120 gr tc bullet. The lyman is longer and more tapered than the Lee tc. Lyman calls for an OAL of 1.110 when loading their bullet. If you load the Lee TC to 1.048 you have exactly the same amount of bullet in the case(.280") as the Lyman at 1.110. I don't have pressure testing equipment but I'd bet that since both bullets have the same weight and same bearing surface and depth in the case that pressures would be very close. My $.02

BTW the Lee bullet is .567 long with a bearing area of .280. Lyman 356402 is .625 long with a .280 bearing area. Hope this helps. Nick

[JudgeBAC]

Gentlemen: Thanks for the information. I will start low and keep a close watch on any pressure signs. This is new territory for me so your information is greatly appreciated.

[Lloyd Smale]

thats the right answer and you came up with it yourself! Ill give you two more tips for cast in a 9mm. First size a tad bigger. Most of my guns shoot 357s better and even better with a 358 if they will chamber. Hard lead will about allways shoot better even at low pressures in a 9mm. Also if your loading on a progressive, really pay attention to your bullet seating. Most seating plugs arent designed for round nosed bullets and for some reason the 9mm seems to be very touchy as to seating bullets without getting them crooked. Id bet that 90 percent of the trouble people have with cast in a 9mm is caused by this. its hard to tell sometimes with your naked eye. Just take your time when running your press and use your fingers on the bullet till it gets into the die.
Gentlemen: Thanks for the information. I will start low and keep a close watch on any pressure signs. This is new territory for me so your information is greatly appreciated.

[JudgeBAC]

Thanks Lloyd, I tried a bullet sized .357 but it would not chamber in my barrel so I am stuck with .356. We will have to see how it works.

For cast bullets in the glock, I am using a stainless storm lake replacement barrel.

[Ron]

JudgeBAC,
I am using a Storm Lake bbl in my GLOCK 34 and have no trouble shooting a CBE mold cast 125 grn trun/cone sized to .357 in it. I would slug the barrel and check its size.

[Lloyd Smale]

try seating your bullets a little deaper it could make the difference in a larger bullet chambering.

[JudgeBAC]

OK, I slugged the bore and it measures .3555. I think I will be Ok with sizing them .356. The darn .357's just wont chamber no matter how deep they are seated.

At any rate, I will try and get some loaded up to shoot this weekend and let you know how it does.

[9.3X62AL]

With the minimum-dimension grooves and chamber your barrel has, the potential is there for some accurate work.

[Lloyd Smale]

yup thats one tight 9mm. I dont think ive ever seen one cut so tight.

[JudgeBAC]

OK, here are the results. 5.2 gr. of W540 126.5 gr. .356 LBT truncated cone.

Function was perfect, accuracy was certainly acceptable, but the pressure concerned me since I had to seat the bullet so deep to allow it to chamber. I have concluded this bullet was really designed as a .38 .357 bullet rather than a 9mm. It has two lube grooves and when you seat it deep enough to chamber it causes higher pressure. The primers showed definate signs of pressure to the point I will use this mold for .38 and .357 and acquire a different mold for 9mm.

Ah shucks I have to get a new mold. Don't you hate it when that happens.

[9.3X62AL]

Ah shucks I have to get a new mold. Don't you hate it when that happens.

Simply tragic, Judge.

As I've stated previously, the Lee 122 grain truncated cone design has become one of my favorites in 9mm (and other stutter-gun calibers). LOTS of drive band on both sides of the lube groove to grab even fast-pitch rifling securely, and not a lot of boolit base in the case when you seat the boolit with about .020" of the front drive band protruding past the case mouth. That formula works in 40 S&W, 10mm, and 45 ACP with the Lee TCs that have conventional lube grooves.

[JudgeBAC]

I now have about 35 dummy rounds sitting on my reloading bench.

I discovered that if the LBT bullet is sized .355 I can seat it out to an overall length of 1.134. The bullet does not jam into the rifling and it feeds well through the magazine. All of the other bullets I tried sized to .356 required a much shorter overall length. They functioned fine except for the last round which would jam itself into the feed ramp. By sizing to .355 I can get more length and the last round will feed from the mag.

Unfortunately, I cannot get the Lyman 356420 to work well at any length. If I seat it short enough to keep the shoulder from causing chambering problems, then the last round will not feed out of the magazine.

Hopefully, I can take a trip to the range tommorow and try out some live rounds and see what happens.