Noob question about 9mm cast boolit weight

[Rp-]

It seems like all the molds and bullets I come across tend to be heavy. Specifically, it seems that a 115gr 9mm lead bullet is not common. Just curious why that is? I've even seem some molds for 130+gr 9mm. Never understood it.

[runfiverun]

well it's got a lot to do with just the weight difference between a copper wrapped and a solid lead bullet.
if they are the same size and shape the all lead boolit will weigh more.
if you want 115ish grs look at a 100gr mold.

I shoot one near 130grs [not for sure never weighed one of the 15-20 k I have made]
I specced it out for ww alloy at 124grs.
but I'm sure it weighs a tick more in my alloy.
anyway by the time I got the design correct for the fitment in the throat, and the drive band length/shape/diameter I wanted, that was the weight it come in.

[Rp-]

I see. I had another member PM me a longer explanation going into tremendous detain about meeting power factors, barrel friction effect on p.o.I., and the likes. Lots of good info.

I never took into account the physical bullet size I guess. Of course a lighter lead bullet will weight the same as an equally dimensioned jacketed bullet.

Well, that's what questions are for.

Thanks

[6622729]

I can give you a couple reasons. First of all, making a cavity for a 125gr boolit puts you in the middle of the 9mm weight range. That gives you complete freedom to work from a very soft alloy to a very hard alloy and still stay well within the typical 9mm weight range. A mold is many times setup to use Lyman #2 alloy to attain the published boolit weight. Change the alloy to more lead and the boolit gets heavier. Change to more tin and/or antimony and the boolit gets lighter.

Another reason I can think of it's a good compromise weight between recoil and delivered energy at the target.

[Bookworm]

Another reason I can think of it's a good compromise weight between recoil and delivered energy at the target.

I have often wondered why NATO chose the 115gr projectile.
I first purchased a "wonder-nine" back in the very late 80's (what the good Colonel called a "krunchen-ticker"), and quickly changed from shooting the 115gr to shooting the 124gr - and for the same reason.
I even toyed with the 147gr for a bit, but even now I'm shooting mostly around the 125-ish range.

[9.3X62AL]

The poor old 9mm Parabellum has been taken from pillar to post during its service life, all in pursuit of an enhancement of its primary purpose--to make it stop bad guys from continuing/completing whatever atrocity they were contemplating/conducting. Its original bullet weight was 123 grains, and it was driven at ~1250 FPS.....which in 1902 was honking right along for a 36 caliber sidearm. Dissatisfaction with this load's "stopping power" has caused bullet weights to span from 88 to 147 grains in commercial ammo offerings. For my part, I think the 125 grain-class bullets are just fine for general usage......just run them at full velocity potential AND HIT WHAT YOU AIM AT (use the sights, don't spray & pray) and things might work out better for all concerned......except the assailant, who had it coming anyway.

All of my 9mm shooting gets done these days with 125 grain-class bullets, all castings. I refuse to carry the "sub-sonic" 147 grain FBI-touted JHP loads for social interactions. I believe these loads to be a cynical and dishonest adoption of a 30% power down-load to allow low-performance shooters to qualify more readily, all the while trumpeting the "controlled expansion" construction of their ultra-modern wunderboolits. If an officer or agent or citizen can't hit things under a zero-stress paper target interlude, it bodes poorly for times in which the soil amendment hits the oscillating ventilator. Real guns, real ammo, real shooters. If a shooter can't hack it, get off the street with that sideiron. There are bears in the woods and snakes in the grass, and at such times we need bullets in the bad guys--not into the background or into uninvolved bystanders.

[tazman]

115 grain boolit molds are available from NOE. I had one and it worked fine. That said, like 9.3X62AL, I prefer the 124-125 grain loads for social uses.
I load and practice with some heavier boolits to see how they perform and in most of my 9mm guns they shoot a bit more accurately. Not enough so to make any practical difference to a bad guy though.
That's why the one that I carry is loaded with 124 grain hollow points.

[Beef15]

If you just want light you can load Lee's 105SWC in 9mm. I imagine most of the 120ish molds with hp pins would be close. I think the weight just tends to end up a less traditional profile cast.

120/124 has a long history of working though, I'm partial to truncated cones in the class.

I prefer heavies, PF with lower perceived recoil and most 147s have been very accurate. Waiting for the weather to cooperate to try my NOE 155s.

[6622729]

115 grain boolit molds are available from NOE. I had one and it worked fine. That said, like 9.3X62AL, I prefer the 124-125 grain loads for social uses.
I load and practice with some heavier boolits to see how they perform and in most of my 9mm guns they shoot a bit more accurately. Not enough so to make any practical difference to a bad guy though.
That's why the one that I carry is loaded with 124 grain hollow points.

That's what I carry too. 124 grain jacket hollow points. For target it's almost exclusively my cast 125 grain Lee truncated cone or round nose.

[mdi]

I've always tried to research what bullet design/weight a particular caliber/gun was designed for. My little research showed 9mm was built around "hot" 124-125 gr. jacketed round nose. So, my first 9mm mold was for a 125 gr. RNFP bullet. My 1911 was started out with a 230 gr LRN, but I have another mold for a 200gr LRN, original 45 ACP weight I believe (and my favorite is a H&G 68 clone). I fired 115 gr. bullets in my 9mm once, as Hornady factory load were on sale when I got my LC9s, but haven't shot anything less than the 124 gr. jacketed or 125 gr. cast...

[jmort]

I like the heavier 9mm bullets. Especially the 135 grain GC Ranch Dog. That seems to be the sweet spot for me. I have no doubt that what Michael said would prove to be true:


"When I went to design the bullet, something in the 147-grain lead just wasn't working and optimum was at 135-grains. I have no doubt in the ability of the bullet in self defense shooting. I have killed a number of "man" size feral hogs with shots through the rib cage, behind the shoulder and the bullet does what it was intended to do."

[Shiloh]

Mine weigh heavy by several grains. Everytime I use range lead, the weights very from the last time a little.
It has never been an issue.

SHiloh

[Handloader109]

I have 9mm molds from 95 gr up to the noe 148gr which drops at 150 for me. Usually shoot the 125range also, but the 150gr is quiet when going through my suppressor. And low recoil.

[wv109323]

Another factor in bullet weight is COAL. The COAL has to be within certain limits for the auto pistol to function reliably. The bullet nose must hit the feed ramp, be pushed up the feed ramp and started into the chamber, then the magazine lips release the bullet base so that the rear of the case can come up,slide under the extractor and be aligned into the chamber. There is also a max. COAL that limits a cartridge length so that it will fit into a magazine.
Of course the longer the bullet the heavier. Long heavy bullets seated with a certain COAL may take up more of the case capacity. Less case capacity(powder capacity) will drive up pressures especially with the longer heavier bullets to obtain higher velocities. And more powder is needed to drive the heavier bullets which compounds the problem even further.
The 1911 pistol and the .45 ACP cartridge were developed jointly to the desired parameters of pistol reliability and stopping power. Thus the weight limits of the bullets used fall within 185 to 230 grains for 99% of the rounds.
Since the 9MM round was designed long ago,modern firearm designers probably design around a "middle of the road" COAL/ bullet weight hence 124 grains.

[fredj338]

IMO, more diff to get a functional load with a 115gr bullet unless you are up over 1150fps. That is a vel threshold many cast bullet guys won't go w/o harder/expensive alloy or gc. So a 124-160gr bullet allows 100% functioning at lower vel, less recoil too. I have several 9mm molds, 115gr-150gr, they will all work to some degree, depends on what I want from the bullet.