This is a discussion on Help me understand bullet weights vs recoil within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; I am trying to understand some things. I have a 9mm and someone I was with said to shoot 115 gr because it had less ...
Array
I am trying to understand some things. I have a 9mm and someone I was with said to shoot 115 gr because it had less recoil than a 147 gr. They also mentioned that a +P load had more recoil than a standard load. Now I didn't try any +P loads but my groups were better with the 147 gr than the 124 or 115. Was he wrong? I'm mostly concerned with the ability to return follow up shots. I am looking at Federal HST and EFMJ for SD. Bullet weights range from 105 to 147. Where should I start?
Array
A lighter bullet will have less recoil because there is less resistance to move the bullet forward (equal and opposite action law). Takes more force to move heavy stuff than light stuff.
+P (plus pressure) is loaded to higher pressure than standard ammo. Pushing something harder will increase the recoil.
The heavier the bullet or the more powder will increase the recoil.
I like heavy bullets in any gun. I suggest the most accurate, reliable bullet weight and type in your carry weapon.
07/02 FFL/SOT
Commercial ammunition reloader
I currently only serve local customers and do not ship ammunition. Thanks for understanding.
Array
Newton's third law of motion: For every action there is an equal and opposite reaction.
Combine this with Einstein's theory: e=mc˛
You can see the relationships.
Array
How light is your gun? Is it made of plastic or steel? What frame is it built on?
Bullet weight IS recoil, in any firearm. Shoot a slug, then shoot a turkey load. Shoot a 180 grain, then switch to the 150...Every firearm you'll notice a difference.
If you're looking for something to plink with, go with what's cheapest.
If you're looking for something to train with - stick with the weight you'll be using for defensive fire.
And if you're looking for something to defend the house with - consider the old hunting mindset: adreniline is pumping, you won't notice. It's your life v. hand being sore - go with what has the best stopping power + accuracy out of your particular firearm.
(I shoot 9mm, defense I use the 147 HP)
Some people don't deserve saving.
....the water is almost at a boil
Array
The firearm I am using is an M&P9. What you guys are saying is exactly what I thought. I guess my rookie flinch is compensated by the higher recoil of the heavier loads, becuase I am consistently low with the 115 and was right on target with the 147. I appreciate everyone's help.
Array
Use 115 gr for the range and 147gr for defense. 147gr has better stopping power and expansion.
Array
to elaborate on Ram's answer, remember that anything pushed pushes back with an equal amount of force. This is a good example of where Hollywood drops the ball as relates to the nature of firearms.
Knockdown power is a myth. Penetration and expansion are directly proportional to damage inflicted, but the idea that you're going to knock a BG off their feet with that 1911 is ridiculous. Basically, whatever you're shooting exerts the same forces upon the system it is released from, so if the BG is thrown backward, you will be, too. Equal and opposite reactions. Mel Gibson getting thrown through a window after being shot with 00 buck is ludicrous...unless the shooter were to be thrown an equal distance (or sustain an equal amount of impact energy from the inertia retained by the actual firearm after discharge).
Anyone see the Mythbusters dealing with this?
A man in the hands of his enemies is flesh, and shudderingly vulnerable. - author unknown
Array
I thought 147s were out of style for the 9mm, too slow to expand reliably. Then again, I remeber when they were the absolute rage back in the early 90s.
Array
The reasons listed by previous posters are the same reasons competitors in IPSC open division use .38 supers with lighter bullets; sure you get more muzzle blast, but less felt recoil.
"Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are inevitably ruined". - Patrick Henry
Array
You are shooting low with lighter bullets? I have heard that the way a barrel tips up in recoil is the cause of this. Lighter bullets can have enough velocity to exit the barrel completely before the barrel begins to tip up as the slide moves backwards. Heavier bullets are conversely slow enough to be aimed upwards -- the effect would seem to be most noticeable if the target is at the midpoint of the bullets trajectory. I think barrel length is also a factor.
Array
I just got back from the range shooting both 115gr FMJ's and 147gr Federal HST's in my XD9 subcompact. There was no noticable difference in recoil between the two rounds.
The XD is brand new and this was the first time I got some range time with it. I shot around 300 rounds, 100 HST 147's and 200 Magtech 115's. All were shot from 25 yards. While I wasn't 100% satisfied with my grouping, the gun and ammo performed well. You would not have wanted to be the target.
Get some of the different weights and try them for yourself. Then pick the weight that YOU can shoot most consistently. It doesn't matter what I or anyone thinks. It is how your gun and ammo works for you.
Ballistic tests show the 147gr penetrates about 2" deeper in ballistic gel than the 124gr. I think I will stick with the 147gr for SD/carry.
Your mileage may vary.
Array
Weight and velocity is "out" when considering bullet effectiveness these days for handgun rounds.
What matter is bullet design.
If you don't like heavy rounds look at 147 grain HST or Ranger Talon. Those heavy rounds work.
You have a thing against light rounds? Check out 115 grain DPX. That's a light round that goes deep.
Like I said: Design is the thing today, not weight or velocity.
Array
Very true, MitchellCT...I think bullet weight and velocity are major factors if you're only considering ball ammo. Beyond that, it's really a buffet of selections available, depending on what you're looking for in self-defense ammo.
-JT
Originally Posted by MitchellCT
Array
I respectfully disagree with my brethren regarding felt recoil. As for the "equal and opposite reaction" yes, this is the basis of the felt recoil measured by foot pounds of energy at the muzzle experienced by the shooter.
However, heavier bullets require a reduction to the powder charge to avoid over pressure issues and therefore a heavier bullet does not automatically mean more foot pounds at the muzzle and often means less than their lighter counterparts. The heavier bullets retain more energy further from the barrel than their lighter counterparts and that is the reason heavier bullets typically penetrate deeper all things being equal.
My experience is that the heavier the bullet, in typically commercially loaded ammunition within industry specs, the lighter the felt recoil, resulting in less muzzle flip.
Again using foot pounds of energy at the muzzle as the measure of felt recoil and Gold Dot .40 S&W as an example: 180 grains > 420 FP; 165 grains > 484 FP; 155 grains > 496 FP.
The 155 grain bullet has the most kick at the muzzle with 496 foot pounds compared to the 180 grain bullet's 420 foot pounds.
The light bullet kicks more (has more energy) and loses it energy faster than the heavier bullet. At 50 yards the 180 grain bullet has lost 13% of its energy resulting in 365 FP; 165 grain loses 18% resulting in 398 FP; and the 155 grain loses 22% resulting in 389 FP.
Between the 180 grain and the 155 grain Gold Dots by the time you get out to 100 yards, a mere foot pound separates the two loads (325 vs 326). The 165 grain actually wins the race with 342 foot pounds of energy at 100 yards.
In my personal experience shooting 165 grain vs 180 grain .40 S&W Gold Dots, I can feel the difference between the two loads with the 165 grain definitely being "snappier" than the 180 grain load- that is what an extra 64 foot pounds of energy can do when you are holding it in your hands.
The shooter must decided, based on their particular skill level, what is more important: maximum energy into the target with a higher degree of difficulty of placing each shot precisely as aimed vs maximum control of the firearm for each shot with a decrease in energy expended into the target.
Given the high adrenaline nature of most self defense shootings, I would opt of the increase in control over foot pounds. If you choose foot pounds I hope you also choose to practice a little more that the average bear.
Array
Simple solution: Read up on Issac Newton. What he wrote way back then still holds true today.
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote