FN 5.7 vs. Glock 17

H

HighValleyRanch

New member
For any glock haters, just subsitute the glock for your favorite 9mm pistol for comparison.

I was watching Hickok45 on his review of an FN 5.7.
Light bullet weight, super high velocity and low recoi, right?
So the stats for some Amercian eagle 5.7 40 grain ammo is 1655 fps with 243 ft. pounds ME.

So that got me to wondering if you could get a 9mm pistol to act like that?
So Liberty Civil defense 9mm +P is 50 grains @ 2000 fps, and Double tap has a 77 grain at 1625 fps.
Or like this ammo:
https://www.sportsmansguide.com/product/index/magsafe-personal-defense-9mm-luger-defender-60-grain-10-rounds?a=1596238

So the question is, seeing that you could get a 50 grain bullet up to the same speeds as a FN 5.7, could you get the same low recoil effect with a comprable load? More a hypothetical question than why would you want to do that, or comparisons of actual defense use, etc.

So could you get a glock 17 to be like a FN 5.7?
 
Question becomes why. The main thrust, to my understanding, of the 5.7mm is to defeat soft body armor. If that's no longer the goal I don't see the point in very lightweight bullets at higher speeds. Handgun barrels are only so long and you can only build so much velocity in that time. I understand it more for rifles and the terminal effect you can have there, but for a pistol? I'd rather stick with a 124 gr bullet moving at 1100-1200 fps or so.
 
Same school of thought why we're (for the time being) using a 5.56 instead of a .30-something.

Fast light rounds tumble and cause serious destruction to soft targets(like soft tissue and organs). Granted it's much more effective out of a rifle length barrel a round as fast as the 5.7 can still do a lot of damage.

To answer the OP's post, IMO, we're comparing apples to oranges. 9mm defense loads(generally speaking) are designed to expand to cause damage, not really to tumble. If you take the typically heavier 9mm and make it go faster it'll likely just penetrate further, not tumble.

I think both are great options, the only reason I don't own an FN Five SeveN is because they're so damn expensive!

Everything above is my opinion so if someone proves me wrong with science...you win.
 
Mayber this will help.......

More a hypothetical question

1.than why would you want to do that,

or

2. comparisons of actual defense use, etc.

So the question is, seeing that you could get a 50 grain bullet up to the same speeds as a FN 5.7, could you get the same low recoil effect with a comprable load?
 
Sorry if I went down the wrong path...

I guess if the bullet weights, velocities, and firearms are similar then recoil should be similar?
 
Fast light rounds tumble and cause serious destruction to soft targets(like soft tissue and organs). Granted it's much more effective out of a rifle length barrel a round as fast as the 5.7 can still do a lot of damage.
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Could you point me to some ballistic tests showing 5.7 mm tumbling? My memory seems to think that until you get up to rifle velocities it doesn't really happen and instead you end up punching small holes.
 
Also, I am trying to understand why.....
Supposedly a 115 grain 9mm load gives more felt recoil due to its higher speed than a 147 grain going slower (according to many threads I've read.) I haven't noticed it myself that much, but haven't really given it much thought before).


But then if you go even lighter and faster, then the theoretical curve reverses and the super light bullet going at ultra high speed becomes LIGHTER FELT RECOIL?
 
Knockdown power is about as cringe worthy of a term as you can get in this industry. When I see someone use it, I lose all respect for that organization.
 
Their words:
"This ultra -soft shooting 9mm load has been customized to bring the greatest knock down power and keep your sights dead on target. We built this load for use in competitions that require you to knock down steel and transition between targets with improved accuracy."
The jeest of the conversation being that some others do claim that the 115 grain feels snappier than the 147 grain.

Knockdown power is about as cringe worthy of a term as you can get in this industry. When I see someone use it, I lose all respect for that organization.
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What's wrong with claiming that the 147 grain will knock over STEEL PLATES better than their own 115 grain ammo? It's not like they are claiming "knock down power" in defense ammo!
 
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I've never personally felt that 115 gr is snappier than 147 gr. To me that's somewhat subjective.

It's not like they are claiming "knock down power" in defense ammo!
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Fair enough that's my fault for not reading closely. I got "triggered", pun intended. I do think saying that something is ultra soft shooting but has the most knockdown power is a bit contradictory. Likely they mean the most power for a given recoil sensation, but there's no free lunch when it comes to physics.
 
HVR,

To answer your hypothetical, theoretically in firearms of equal weight, firing the same bullet weight at the same speed will produce similar felt recoil, pending gross differences in things like powder charge weight.

However, back to the points the other posters have made, at handgun speeds, the question is to what end? Handguns, even the 5.7, don't offer enough velocity to cause fragmentation, temporary cavitation, or dramatic bullet yaw. What you're ultimately left with is a long-range drill press that just pokes holes in things. And just like a drill press, a bigger bit (bullet) puts bigger holes in things.

As pointed out, the 5.7 is designed to defeat soft body armor as a military personal defense arm. Out of something like a P90, with controllable automatic fire capability, it would be quite useful in a close range situation. Though from what I've read, people who have USED the 5.7 out of the carbine suggest it's really only effective because you CAN put a bunch of bullets on target quickly. Reduce the velocity, take away the full auto capability and I'm not sure the real-world effectiveness is as impressive as the gel results.

Now if my choice is between the Five-seveN and a Glock 17, I'd take the Glock with 5-6 magazines, a case of ammo, a holster, and go shoot happy.
 
Look at ballistics gelatin results.

5.7 makes NO SENSE as a personal defense round when compared to 9mm.

9mm for the win.


Sent from my iPhone using Tapatalk
 
No such thing as "knockdown power". Bullets don't knock people over. Not off the big screen at least.
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LOL, I guess another poster that jumped the trigger.
Read the fifth post above.
" We built this load for use in competitions that require you to knock down steel ":D:D:D:D:D:

5.7 makes NO SENSE as a personal defense round when compared to 9mm.
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More a hypothetical question than......comparison of defense use

I guess people don't read carefully:confused:

THANK YOU P-990 for staying on topic and seeing that my question is hypothetical. I was wondering more for range practice for a low recoiling 9mm I could go with a very light bullet and higher velocity powder charge to get the same effect as a light snappy 5.7 round. No interest in the defense aspect of it. More for fun and shooting at steel.
 
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Do you find 9mm recoil to be particularly excessive? Considering the primary intent of range use, I wonder if a .22 might be more suitable.

The Five-Seven is curiously expensive. A better comparison might be a Five Seven vs two or three Glock 17's.

To answer your hypothetical, theoretically in firearms of equal weight, firing the same bullet weight at the same speed will produce similar felt recoil, pending gross differences in things like powder charge weight.

However, back to the points the other posters have made, at handgun speeds, the question is to what end?
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Yes and yes. Conservation of momentum and such.

The problem is that 50 grains is horrifically underweight for a 9mm load. To get there, you either need a prefragmented round (Magsafe), or some other silly gimmick (Liberty whatever).

In gel tests, such rounds tend to offer a very short, very messy wound channels. In more realistic tests, it's not unknown for these rounds to fail to expand and penetrate like a lightweight FMJ.

However, a paper target will never know the difference. In that case, does a cheap FMJ truly offer excessive recoil? Novelty rounds like Magsafes and such also tend to be prohibitively expensive for range use.

Without going as far as calculating impulse or free recoil energy, comparing the momentum of the rounds is a super fast calculation and can give you a fair idea of relative recoil.
 
On a dueling tree at 15 yards I had to shoot far fewer plates twice with a 230 grain .45 moving at about 750 fps than I did with a 115 grain 9mm moving at about 1100. I don't think you'll get what you are looking for out of a fast moving 9 at 50 grains.
 
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