Bullet weight vs. Recoil

[TonyDedo]

After 5 or so years of using moly coated lead 230 RN bullets in my XD45, I've finally exhausted my supply of components and I'm looking to restock. I want to get back into IDPA, and maybe even dabble in USPSA, so I need to take power factor into consideration when I work up my next load. For years I've had people (especially the IDPA guys) telling me I should shoot 200gr instead of 230gr bullets - conventional wisdom is that 200gr bullets will have less recoil, less muzzle rise, and I'll be quicker back on target.

Makes sense to me, at face value. Given that 200gr bullets are less expensive, it may even behoove me to switch to 200gr.

Then I start doing my research, and it seems this is actually a controversial topic - half of the internet thinks a heavier bullet will produce more recoil (less mass creates less force pushing back), the other half thinks it will produce less (slower speed, and some theory about the bullet pushing the gun back and not up).

So I start thinking about the physics involved. Now mind you, I'm an accounting and finance guy, the sciences were never my strong suit, but it seems to me that the force is the variable we should be concerned with, not mass. If I'm developing loads with the same power factor (a rough measurement of force), no matter the weight of the bullet, the force will be the same, thus recoil should be the same. Right?

I.E. a 230gr bullet with the muzzle velocity of 717fps should have the same recoil as a 200gr bullet at 825fps, because they're both have the same power factor.

Am I barking up the right tree here?

So really if I'm looking at this from an economic standpoint, my only concern should be how much more powder it takes to propel a 200gr bullet to 825fps vs a 230gr bullet to 717fps. If it's not significant, I can get the same power factor and same recoil using lighter bullets that cost about 1.5 cents a round less.

I have a few 200gr bullets kicking around, and I'm going to try to do a comparison based solely on perceived recoil, but I wanted to form a solid hypothesis first. Also I don't have a chrony yet (or enough 200gr rounds to build up a load to the right velocity), so I can't be sure both rounds are generating the same power factor.

Anyway, thanks for the help!

 

[Golddiggie]

I know, from personal experience shooting IPSC, that to make major power factor, heavier bullets are better. I was running 255 grain FMJ in my P14.45 pushing out at about 700-725fps to make major PF (fps x projectile weight / 1000 needs to be greater than 175, at least it was when I was shooting). Heavier, slower, rounds means less muzzle rise (once you tune the gun right). You get a recoil spring that's heavy enough to help with recoil, but light enough to get the action to cycle. For me, that was a variable recoil spring. I also found a load recipe that gave me the best results (for what I was looking for). That turned out to be standard primers, with 4.6 grains of Winchester 231 powder. I had maybe a 1-2" muzzle rise on the pistol, so fast recovery times.

People running lighter projectiles, faster, often have race guns. In those, you NEED to use lighter projectiles, moving faster, so that the comp does it's job. The goal is to get over 1000fps so that the comp does more good (other than being a weight on the end of the barrel).

 

[bill o]

At the same PF, the lighter bullet will feel a little snappier. 200's are fine for competition and you'll save money.

 

[EddieCoyle]

I can't speak to your exact parameters, but I can tell you unequivocally that heavier bullets cause more recoil.

If you'd like, we can meet at the range and you can shoot a 275gr .500 round at >2000 FPS and compare the recoil to a 700gr bullet at 1300 FPS (loaded with about 1/2 the powder charge of the 275gr bullet).

There is no comparison. The recoil of the 700gr bullet is so great that it shoots about a foot higher at 50 feet, and you can only single load them because the bullets in the rounds in the other chambers pull out of the cases during recoil - even with a maximum roll crimp.

 

[bill o]

I can't speak to your exact parameters, but I can tell you unequivocally that heavier bullets cause more recoil.

If you'd like, we can meet at the range and you can shoot a 275gr .500 round at >2000 FPS and compare the recoil to a 700gr bullet at 1300 FPS (loaded with about 1/2 the powder charge of the 275gr bullet).

There is no comparison. The recoil of the 700gr bullet is so great that it shoots about a foot higher at 50 feet, and you can only single load them because the bullets in the rounds in the other chambers pull out of the cases during recoil - even with a maximum roll crimp.

I would expect that the 900 PF load would have more recoil than the 550 PF load.

 

[Golddiggie]

That's not even close to a comparison. 275gr @ 2000 fps = 550,000 (550 pf). 700gr @ 1300 fps = 910,000 (910 pf). An increase of 1.65x in power factor. Maybe if you loaded the 700gr to move at 786 fps (550 pf) it would be a decent comparison. Then again the projectile weight being about 2.5x the smaller one also seriously skews things.

He's talking about going from 230gr to something larger, or smaller (200gr or 255gr are options). Going from 230gr to 255gr is NOT even close to what you put up. It's about a 10% increase in projectile weight. Going from 230 to 200 is about a 14% decrease in projectile weight.

It's VERY easy to 'tune' a pistol to make the increase in projectile weight reduce recoil. I've done it, it's not brain surgery. If you have the items on hand, it's a single range trip. If you want to use different projectile weights, you can even make up some different 'tune packs' to do that.

Tony, if you want to see what I'm talking about, let me know. I don't have any of the 255 projectiles on hand (right now) but I can order some up and make some rounds to show you. The cost of the projectiles isn't as bad as you might think. Current pricing is $64.11/500 round box. Oh, and that also includes $0 shipping.

I would expect that the 900 PF load would have more recoil than the 550 PF load.

I was busy writing up more, but exactly what I thought... It was a WTF EC moment when I read his post...

 

[Supermoto]

Generally a heavier bullet with a lighter charge and a light spring will have a better recoil impulse. The problem is if you go to heavy, it draws out the recoil impulse and while the gun feels softer, it is sluggish.

But getting a gun to quick return to point of aim has less to do with recoil and more to do with grip

 

[TonyDedo]

Of course a heavier bullet will create more recoil, if you don't take into consideration the change in velocity and subsequent change in force being generated. That's not what I'm saying. But if you go from a heavy bullet to a lighter bullet AND you increase muzzle velocity to maintain the same power factor, does the perceived recoil change?

FWIW, I'm shooting a Springfield XDM 5.25

 

[Supermoto]

Of course a heavier bullet will create more recoil, if you don't take into consideration the change in velocity and subsequent change in force being generated. That's not what I'm saying. But if you go from a heavy bullet to a lighter bullet AND you increase muzzle velocity to maintain the same power factor, does the perceived recoil change?

FWIW, I'm shooting a Springfield XDM 5.25

It generally will feel snappier. Which may or may not be a bad thing. Powder choice will play into how you perceive
the recoil too

You really aren't going to know if you like it, until you try it

 

[Gammon]

I have found that light bullets seem to produce more muzzle flip and felt recoil in major loads. My experience has been with 175 gr 45 swcs and 155gr .40 swcs. Using heavier bullets solves the problem, but I have also found that there is a limit to the advantage of a heavier bullet.

In 45 ACP I found that the 200 gr bullet produced less recoil and muzzle flip than the 175, but that heavier bullets didn't seem to offer any more improvement. This is not surprising because the 200 gr swc was the favorite bullet in IPSC competition when the 1911 was king and comps had yet to arrive on the scene.

In .40 I found that the standard 180 gr bullet produced less muzzle flip than the 155 and have been using this round for many years. Some experimentation with 200 gr bullets produced a softer load, but no real advantage. A friend and top shooter tried this bullet but said he preferred the 180 because the "snappier" 180 load seemed to get his gun back on target more quickly.

One thing to consider when using heavy bullets is trajectory. If you go too heavy, your loads will be running in the low 700 fps which means the bullet will drop a couple of inches at 50 yds. Bullets traveling 850 fps or so are pretty much flat out to to 50 yds.

In 45 I would go with the 200 gr bullet because it is cheaper, has a great track record, and the 850 fps velocity shoots flat out to 50 yds.