Why Load Lighter Bullets in 10mm?

[10mm-Admirer]

I'm new to 10mm and have been loading 165 and 180 gr bullets so far.  I also have some 155 gr XTPs.  Why do people load lighter bullets, like 135, 150 and 155 gr, in 10mm?  Seems like 180 and 200 gr bullets would be optimum.  Do the lighter bullets at higher velocities have an advantage?  Don't they offer shallower penetration and more snappy recoil?  I'm not criticizing, just trying to understand.

[tommac919]

I would think you pick your bullet for the needed use.

Some bullets need the speed to expand properly and transfer the energy in a fast dump, some like the heavy cast bullets are needed to penetrate and work well against bone.

I like the 155 gold dots for my reloading in the lighter range but stick mostly with 180s.

[The_Shadow]

It's hard to say exactly why...but the lighter bullets at screaming velocities are what some people want.  Here is one of the things that concerns me.  Most bullets in the 0.400" production are geared towards the 40 (short and weaker) even though the bullets are designed to operate at slower velocities they still perform fairly well at 10mm velocities depending on what your target is and what distance.  The rapid expanding and fragmenting may be what is needed in some scenarios.

Myself, I like the heavier 180 and 200 grain projectiles especially for hunting but I do like the 155-165 grain as well when used for self defense purposes depending on the environment.  Being a handloader I can tailor the loading of the particular projectile to accommodate my needs, especially as accuracy is concerned.  The heavier bullets are longer and that translates to better accuracy and stability for hunting.  In a close quarters defensive situation accuracy may not be an issue, but barrier penetration can be.

One of the best things about the 10mm is the wide variety of projectiles styles, weight and their construction to provide for any shooting scenario.

[445 supermag]

For me I got very good deal on the noslers 135 gr and load them to about 1600fps.   I have no problem taking a deer with this load up to about 45 yards.  But when my supply is gone I am going to stick with 180 and 200 gr.   I mean a 200gr nosler at 1250 fps or a 180 at 1350+ .  Makes me happy.

Some on Here dont think much about these 135 noslers but it's a pretty tuff little bullet.  I also wouldn't feel one bit nervous if I carried it. But i got them for a good price and use these for practice sessions.

pretty much shows the flexibility and greatness of the 10mm.

Brian

[Rojo27]

I'm new to 10mm and have been loading 165 and 180 gr bullets so far.  I also have some 155 gr XTPs.  Why do people load lighter bullets, like 135, 150 and 155 gr, in 10mm?  Seems like 180 and 200 gr bullets would be optimum.  Do the lighter bullets at higher velocities have an advantage?  Don't they offer shallower penetration and more snappy recoil?  I'm not criticizing, just trying to understand.

Well there's a topic that typically stirs a healthy debate. 

Not just the mass of the projectile to consider.  Several others critical variables like velocity (hot, midrange, weak .40 range), and design (JHP, Flat Nose, TMJ, Nosler, Bonded, XTP, Truncated, etc) that also heavily factor into the equation.
To echo what others have said; definitely not a one shoe fits all situation.  The intended application centrally influences best choice in bullet mass, velocity, design, etc.   

[Geeman]

Light Bullet Advantages:

Lower percieved recoil.
Lots of bullet energy and relatively explosive impact (small varmit plus)
Lower penetration, for when its desired.
Less ricochet potential with hollow point bullets.
The shorter the barrel, the more it favors lighter bullets.
Slightly less cost.
Handgun weight when loaded is less.

Heavy bullet advantages.
More penetration, when desired.
More down range retained enery
Better accuracy.
Better ability to shoot through obstructions if needed when engaging a bad guy.
Larger case capacity cartridges allows larger projectiles to perform.
Lower velocity leads to less leading with cast bullets.

I'm sure things are missing from the list too.

Greg

[10mm-Admirer]

Good information.  From what I've read about tests of different bullets and factory ammo on this forum, the lighter bullets don't penetrate nearly as well as heavier.

Interestingly, I killed an 11pt buck with my G22 and a 155gr Win Ranger factory load.  The bullet expanded perfectly and killed the deer with one shot to the chest.  The bullet was tangled up in the hair upon exit.

I wonder if the shallower penetration is due to driving the bullets too fast, causing very rapid expansion and shallower penetration.  I wonder if they were driven to more moderate 10mm velocities if they would penetrate deeper?

When I first got my G20SF, I was intrigued with the full powered factory loads but saw increased wear and less reliable cycling of the pistol.  I'm sticking to book loads now.

[denclaste]

Every hand loader has their own reason for light vs heavy bullets. I've never found anything a light bullet can do that a heavy can't do also. I use the 180 and 200gr in all my 10mm's and they have always done what I want them to. They recoil the same as the lighter ones do for me. To me the 180 gr is the best compromise I've found. I do use 175gr Win Silver tips as my carry ammo. The 200gr just seem a little to much for that job but if you are in a area where something might make you their lunch obviously 200gr FMJ/FP would be comforting to have or a 375 HH.

[Rojo27]

Interestingly, I killed an 11pt buck with my G22 and a 155gr Win Ranger factory load.  The bullet expanded perfectly and killed the deer with one shot to the chest.  The bullet was tangled up in the hair upon exit.

I wonder if the shallower penetration is due to driving the bullets too fast, causing very rapid expansion and shallower penetration.  I wonder if they were driven to more moderate 10mm velocities if they would penetrate deeper?

When I first got my G20SF, I was intrigued with the full powered factory loads but saw increased wear and less reliable cycling of the pistol.  I'm sticking to book loads now.

.40 cal Win Ranger factory fired from G22 humping along at about 1200 fps (more or less).  The same .40 cal projectile loaded by Underwood or Buffalo Bore fired from your G20 gonna be screaming along closer to 1500 fps (more or less).  If deep penetration was your primarily objective the 155 JHP loaded hot 10mm probably not going to yield result you seeking as the extra 300 fps well beyond .40 cal projectile original design envelope.  However it would produce one hell of a permanent cavity in 1st 10 inches of the deer. 

10mm 155 grain Barnes XTAC HP loaded by Buffalo Bore will yield incredible energy transfer and deep penetration due to its copper alloy construction.

If you have a G20 Gen 3; upgrade the 16lbs factory recoil spring with 20lbs-22lbs aftermarket recoil spring (possibly guild rod too) and have a blast with the hot stuff (light for caliber or not). 

[gandog56]

I suppose so people can get happy with warp speed velocities. Velocity has never been my desired end, I prefer accuracy. And I found a perfect little load using Precision Bullets 185 grainers.

[MikeS.]

I look at anything below 165g as being .40 S&W fodder. I load 180 and 200 grain bullets for my 10s.

[ShadeTreeVTX]

Thats the great thing about 10mm - you can load from mild to wild - it will cover just about anything you can think of. And the Glock being the most and easiest to change to other calibers of all other brands.
I still wouldn't mind a Glock 10mm in a single stack compact. If they ever make one I will buy it.

Doug

[Raggedyman]

I think that a large part of the reason is that 125gr bullets do really well in .357 mag at very similar velocities and many people don't understand sectional density, or don't consider it, anyway. 135gr 10mm projectiles don't behave anything like 125gr .357 mag projectiles, though.

135gr - 155gr JHPs would be good choices for small to medium game hunting. They would be ideally suited for javelina and small, Texan deer. The 8"-10" penetration would be adequate for those animals and the flatter trajectory gained by higher velocity would aid in accurate shooting at longer distance.

Geeman, generally speaking, shorter barrels are usually better suited to heavier bullets because the loss in velocity is less dramatic.

10mm-Admirer, that 155gr Ranger just didn't have the sectional density to drive deeper. Pushing it faster would likely result in LESS penetration. Increased velocity usually causes JHPs to expand more and therefore slow down more quickly.

ShadeTreeVTX, you nailed it. I've been saying for a while that the real advantage of the 10mm isn't any one thing; it's the versatility that it offers. EAA pistols also offer easy conversion to other calibers. One pistol can be 10mm, .40 S&W, .45 ACP, .38 Super, 9mm, or .22lr. Glock made your single stack compact in the models 42 (.380) and the G36 (.45). I do wish they would make an optimized, slim, single stack 9mm similar to the G42, though.

[10mm-Admirer]

I appreciate the replies. I still don't quite understand.  Seems like quite a few buy ammo with lighter bullets at high velocities or load their own even though they are known not to penetrate well.  If that's true it seems like everyone would be producing or buying 165gr bullets minimum.  Would the lighter bullets penetrate better at lower velocities?  I don't understand why a 155gr bullet in .40 or 10mm wouldn't be a better choice than 124 or 147gr in 9mm.

[10mm-Admirer]

I watched some penetration tests on YouTube last night and think I get it now. It is amazing how much of a difference 10-25 more grains of bullet weight can affect penetration depth! It doesn't seem like it would make that much of a difference but it does.