9mm: Why pick one bullet weight instead of another?

[SLOPlinker]

I'll start off by admitting I'm completely new to reloading, so I apologize right up front for the dumb question. I've been reading all I can find and trying to absorb it all. One thing that isn't obvious to me: What goes into picking what bullet weight you use? Common factory loads for 9mm are 115, 124 or 147 grain. Aside from a little experimenting, I've only shot Winchester White Box (115 grain) because it is really cheap, readily availalbe and goes Bang every time.

I should say right here that my purpose for my reloading rounds are purely action pistol target loads -- Steel Challenge, USPSA, maybe IDPA. So my goal is an easy-to-make (hard to screw up), cheap round that is very reliable and minimum felt recoil while still meeting power factor and at least moderately accurate. This is not defensive ammo, so stopping power, penetration, etc. don't count.

Most of the suggested loading data for 9mm seem to land about the needed 125 power factor whether they are 115, 124 or 147 bullets -- just different muzzle velocities. For action pistol, do I care? A heavier, slower bullet vs. a lighter faster one? Difference is felt recoil for the same PF? One weight or the other harder to load in a safe, consistent fashion? If it matters, I shoot an XD-9 with a 5" barrel.

By the way, I'll probably use titegroup just because it is what everyone seems to recomend as a starting place for 9mm, but I'm open to other opinions.

THANKS for helping the new guy!

[45Marlin carbine]

I don't shoot competition so can only say that I shoot the Golden Sabre 124gr because it's the most accurate out of my S&W 5906 useing Power Pistol.

[Sevens]

I would think, theoretically, that a heavier bullet would do better/more reliable work on any target that needs to take a hit and fall. With a paper target or a metal plate, all you need is a loud clang and you have accomplished your task. Bowling pins are an entirely different story.

If you don't need knockdown power and you only need to make contact, and you are shooting competition, your best bet is whatever load gives you the least muzzle flip. Not necessarily the least felt recoil, but whichever load seems to work the best for YOU when it comes to delivering quick follow-up shots with a very short reset time back on target.

For folks who simply plink, whichever bullet weight is the cheapest is the best choice. Doesn't always mean the lightest weight-- it depends on what your supplier produces scads of and offers at a good price.

For folks who simply practice for defensive purposes, whichever weight best matches the expensive carry ammo is the best.

In your particular situation, the answer (IMO, anyway!) is a very easy answer. Pick out a few folks that you shoot against that seem to bring the right attitude to the game and that can seem to get it done in a way that you respect, and ask them what powder and bullet they use and ask them how they came to that conclusion.

Ask a few different guys and add their knowledge to your arsenal!

The other way to accomplish this, but it much more time consuming and difficult (but very personally rewarding!) is to buy yourself 500 rounds of each weight and style bullet you can reasonably get your hands on, then grab 4 or 5 different powders and start experimenting. No doubt, this is the l-o-n-g way, and probably not the best route for a guy who needs a batch of match ammo for next week!

I would love to drop a few recipes for you myself, but I don't shoot competition and even worse? I simply haven't mastered 9mm at my bench. I haven't had the range time and components to get the work done properly. I'm finding 9mm to be somewhat trickier to build fine ammo than many other calibers.

[D. Manley]

I think the truthful answer, 115 grain is more popular simply because, they cost a bit less. For the purposes you mention though, you will probably find that shooting a 147 grainer over the faster powders (Titegroup, WST, N-320, S-1000, etc.) will get you to minor power factor and shoot very soft.

[Keltyke]

Most ballistics tests show a lighter, faster bullet to be optimum for PD in 9mm. The 115 and 127 JHP seem to be the best round for the 9mm. Take a look at the weights of popular, successful commercial bullets like Corbon, Speer, Golden Sabre, etc. Check GoldenLoki's website for some good ballistics comparisons.

[Redneckrepairs]

I honestly dont pick such things as weight and speed of defensive ammo . My pistols do . As a rule i count faster is better with a couple of conditions , it must feed reliably , and it must shoot close to where the sights look . At 25 yards my HK p7 likes standard 124s , my Kahr p9 likes +p 124s , and my kahr pm9 likes 147s . My Browning hp likes 115s best of all . So my carry ammo locker for 9mm alone looks kinda like a wall mart shelf lol .

[Redneckrepairs]

I honestly dont pick such things as weight and speed of defensive ammo . My pistols do . As a rule i count faster is better with a couple of conditions , it must feed reliably , and it must shoot close to where the sights look . At 25 yards my HK p7 likes standard 124s , my Kahr p9 likes +p 124s , and my kahr pm9 likes 147s . My Browning hp likes 115s best of all . So my carry ammo locker for 9mm alone looks kinda like a wall mart shelf lol .

[Keltyke]

Good point, Redneck. I'll second what you said First, it MUST feed 100% reliably. Second, it MUST shoot where you aim it. That being given, then you start looking at ballistics. Corbon +p and Corbon DPX in 115 and 127 JHP have both worked well for me in 9mm and .40 s&w, my two main carry pieces. I haven't tried enough in my .38 spcl. to evaluate it.

[Sidetracked]

Like Redneck, my 9mms prefer different ammo.
So, for me - it is the pistol that decides what bullet weight I use.

If you're going to be using Titegroup for your first loads, just remember to be very consistent. A 0.1 grain variation can be 20-30% of the difference between starting and maximum loads.

[Keltyke]

For example:

My Keltec PF-9 likes and is 100% reliable with aluminum-cased ammo. The two Steyrs I've shot (S-9, M9-A1) both jam with it.

[rg1]

Might check here for match shooting loads and info:
http://www.brianenos.com/forums/
I load 124's mainly because they shoot to point of aim and are reliable in my pistol and carbine. I've only been reloading 9mm for less than a year. They also are a choice between most velocity and heaviest weight bullets and I understand that the 124gr is what 9mm originally was designed for?

[totalloser]

The weight of the bullet affects the "muzzle energy". A lighter bullet will have a higher velocity, but the muzzle energy is not a 1:1 ratio, so the muzzle energy released with the same blowback force from a lighter bullet will have more power.

However, a lighter bullet will have less real world knockdown power for defensive purposes. 115 grain is (or used to be) the most common load, but in the 80's police chose 124-125 grain for better knock down power, which made it gradually catch on.

As to the cost, it makes very little difference in my experience. Heavier bullet costs more, but requires less powder charge. Lighter bullet costs less but requires a heavier powder charge.

The best way to save money on 9mm other than cheap projectiles is to use a fast burning powder. It will require a smaller charge.

I load 9mm for defence loads for my wife's pm9. 124 grain with slow burning no5. I have to go hot to make it reliable, but she taps a 6" plate with this load consistently at 80 yards out of a 3" barrel!

[Crosshair]

Depending on the use, people either go for what is the most accurate or the cheapest. So if your gun likes 124 grain bullets accuracy wise, use those. I cast my own 9mm boolits so I use a 105 grain design because it uses the least amount of lead and it is accurate enough for plinking.

[wncchester]

"What goes into picking what bullet weight you use? Common factory loads for 9mm are 115, 124 or 147 grain. Aside from a little experimenting, I've only shot Winchester White Box (115 grain) because it is really cheap, readily availalbe and goes Bang every time."

For now, the 115 is perhaps all you need and the answer is to stick with what you are using. IF you ever get dissatisfied you will know why and know what you want to change too. So our opinions won't matter because our needs and desires may not match yours at all.

Basically, if you want more speed and/or less recoil, go light. If you want more penetration or impact energy, go heavy. But you already know that.

[DWARREN123]

Not just weight but types. You have to find the one that works best in your firearm. As for 9mm some, or most, in my opinion like 124/125gr or less. As to type it depends on use.

[BillCA]

As others have said, many pistols will favor a certain weight of ammo over others.

Redneckrepairs' Browning HP is probably an older gun made prior to the mid 1980's. Like my older S&W Model 39's, these older series guns seem to favor the 115-grain bullets. Using 124 grain ammo will work fine, but the accuracy is best with 115-grain.

My later 9mm guns - a Glock, Kahr K9, Beretta 92FS and a S&W 3914 were all built in the 80's or later. These guns tend to favor the 124-grain bullets for best accuracy.

Why is this? So far as I can tell, the twist rates haven't changed from 1:16, but it seems the 124's do work better in the newer guns.

I'd work up about 30 rounds each of 115g and 124g loads at the same velocities or similar energy levels and shoot them for accuracy. This way, you can determine which bullet is more accurate in YOUR gun.

[WESHOOT2]

I seem to notice the common 9x19 twist rate is 1:10......(except my Nowlin barrel....)