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Best bullet weight for short barrel 5.56?

  • 55 gr

    Votes: 0 0.0%
  • 62 gr

    Votes: 1 20.0%
  • 68 gr

    Votes: 1 20.0%
  • 75-77 gr

    Votes: 3 60.0%
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Discussion Starter · #1 ·
I would like to have a discussion on ideal bullet weights for short barrel ar-15 pistol or sbr type 5.56 firearms.

I am trying to decide what ammo to zero for and stock up on. Ill always use 55 gr or 62gr fmj for practice and plinking just because i have a lot of it and its usually readily available.

So the question and debate here is, what bullet weight do i want for more of a defensive or stand off type round within 100 yards. This could be against a 2 legged assailant, mountain lion or even bear potentially, only as a last resort. I would like to focus on bullet weight here vs bullet design. I will probably be using BTHP or some sort of tipped rounds. I find the soft points aren't as accurate though they do perform well, for home defense Im using 50 gr HP/ polymer tipped bullets due to the limited risk of over penetration and explosive expansion. Im not really talking accuracy here as much as terminal performance.

my ar-15 pistol is a 1/7 twist, which should allow for up to 75-77 gr bullets. I'm tempted to try this as its maximizing bullet weight. velocity is going to be compromised already with a 10.5" barrel, so why not take advantage of as much weight as possible?

but on the other hand maybe it makes more sense to use 62 gr bullets since they would probably group closer to the 55-62 gr practice ammo and still have more velocity than the heavier bullets.Now we're talking an ar pistol with an rds, so not super precision here. I expect practical accuracy out to 100-200 yards. Consider that being able to put bullets in 6" or better group at 1-200. anything past that I should probably avoid contact and evade, or if hunting game get a bigger rifle.

I also considered 68 grain... somewhere in between. my thoughts come down to, whats better, slower and heavier, or faster and lighter?

thoughts?
 

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.223 Rem 64 gr GDHP. It is very accurate and works well in most everything I have. I got a bunch when on sale from PSA fairly cheap but it's harder to come by now.
 

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I know you would like a simple answer but when we are talking about defensive ammo and defensive ammo out of shorter barrels you can't just go by bullet weight.

You also have to go by bullet design and bullet composition and what you want to do with it.

Like do you want barrier blind rounds or not?



Even out of shorter barrels the

Barnes TSX 50 or 55 grain copper bonded hollowpoint rounds are very good.

The FBI uses the Federal XM556FBIT3 5.56 62gr TBBC round... (often times called the bear claw)... they make over runs you can buy sometimes and Federal from time to time makes equivalent loads to this and sells it on the commercial market.

Speer gold dots in 64 grain are good.

The Hornady LE TAP 5.56 75gr SBR is another good one...

So yea... those are examples ranging from 50 grain to 75 grain and they will all do very well out of short barrels.
 

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Discussion Starter · #6 ·
I've got 2 boxes of mk318, maybe that would be the best?

Here's an example. camping/hiking in the rockie mountains. I can open carry pistols. so im thinking of carrying my ar-pistol with a 20 round mag of some really good stuff, and a 30 round mag(or two) of m193 as back up.

I also have bear spray and a sidearm, but I like the idea of a compact and light rifle cal pistol, just for the added range and firepower. it can be carried slung over a shoulder, or strapped on a pack.
 

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......

The Hornady LE TAP 5.56 75gr SBR is another good one...
THIS ONE has my vote, especially when you are talking about using it for hikes in the woods.
 
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the majority of your problems will still have 2 legs.
anything threatening on 4 will need more than a 22 except you do have the spray and pray to fall back on and FMJ's or steel core stuff wouldn't be a bad idea in that frontal scenario.
 

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Yep I know this will sound vague but any good "bonded" bullet from 60-70grs will work. Although I'm partial to the heavier side of that range.
 

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the majority of your problems will still have 2 legs.
anything threatening on 4 will need more than a 22 except you do have the spray and pray to fall back on and FMJ's or steel core stuff wouldn't be a bad idea in that frontal scenario.
That reminds me I need to look into a .450Bushmaster pistol build. Or mostly an upper for my current pistol.
 

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Discussion Starter · #11 ·
So, been doing a little research, looking at energy and drop at different ranges.

bottom line, 75 grain wins out. its got more energy at every interval over both 62 and 68 gr.

now 68 gr has the best drop characteristics, less drop at all ranges over 62 and 75, but not as much as a difference as there is in energy against the 75.

I cant really see a reason to go with 62 gr. least energy, looses velocity fastest so its actually got more drop at longer ranges than either other heavier choices.

the debate is really 68 vs 75. i think the extra oomph that the 75 has is worth more than the slightly lower drop of the 68 grain especially considering that I would'ntplan on shooting this more than 200 yard max, at that point its about 6" of drop from either 68 or 75. from there it really starts dropping down to a foot at 250.. sheesh!

This chart is set using velocities for a 10.5" barrel. I looked at several YouTube vids where rounds of this variety were chrono'd and used those numbers. not perfect but its close enough for me.

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Discussion Starter · #12 ·
After some more thinking I dont think it really matters too much to be honest. with good shot placement and practical ranges they'll all do about the same.
 

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no problem just trying to be realistic about the rounds capabilities and effective range.
I shoot a lot of 223 for various small things.
300 yds is my observations for effectiveness and energy.
I can't even tip over the metal bowling pins at 300 yds with a full length barrel using 63gr bullets.
I can hit them no problem, they just don't tip over unless I hit them in the upper third which is pretty hard to do.
whereas something like the 204 ruger will push them right off the rack with a body hit.
a 165gr. 30 cal cast load going 1900 fps at the muzzle will spin them behind the rack 3 feet.
 

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no problem just trying to be realistic about the rounds capabilities and effective range.
I shoot a lot of 223 for various small things.
300 yds is my observations for effectiveness and energy.
I can't even tip over the metal bowling pins at 300 yds with a full length barrel using 63gr bullets.
I can hit them no problem, they just don't tip over unless I hit them in the upper third which is pretty hard to do.
whereas something like the 204 ruger will push them right off the rack with a body hit.
a 165gr. 30 cal cast load going 1900 fps at the muzzle will spin them behind the rack 3 feet.
Yup. It always tickles me when folks are surprised at how anemic a .223 round is past 300 yards.
 

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Discussion Starter · #17 ·
I stated multiple times im talking 1-200 yards here. I dont expect dmr results from a pistol.

from my first post:

"I expect practical accuracy out to 100-200 yards. Consider that being able to put bullets in 6" or better group at 1-200. anything past that I should probably avoid contact and evade, or if hunting game get a bigger rifle."
 

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Personally, I prefer the heavier bullets all around. If I could find 75gr plinkers for the same cost as 55gr, I'd swap 100%.
 
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100---300 it's pretty relative.
look at the muzzle numbers.
near 3-K for the long barrel...
 

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All of my 5.56/.223 get exactly the same cartridge, or at least as exact as I can make it. All of them, including the 24 inch barreled bolt gun are 1:7 twist. They get 77 Grain Nosler Custom Competition bullets over CFE223, CCI Small Rifle primers and Lake City cases. The AR pistols shoot sub-MOA off of a rest, 1.5 MOA off my shoulder. Everything with a barrel 16 inches or longer shoots sub MOA. Yes, it's expensive for plinking, but I train with what I will use in a bad situation. I have a bit of ammo made up and the components to make a bit more.
 
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