5.56 55gr, 69gr and 77gr ballistics.

[Podmonkey]

Specifically how big a difference is there between the three? Reason I ask is I want to get a Trijicon Accupower on my rifle and I like the segmented circle reticle the best but the BDC is regulated for the 55gr. I want to standardize on the 77gr and I also get 69gr when the former is not available. Most of my shooting will be up close but I do want to stretch my capability to 400 yards. There is a range around here that has steel plates out to 500 yards.

 

[dsdmmat]

That is really going to be tough to say without knowing what speeds your 69 and 77s are going.

For example my Nikon P223 scope is calibrated for 55 grain bullets traveling about 3000 FPS when I shoot my 53 grain loads the 100, 200 and 300 settings on the dial are dead on but, it is about 6 inches low at 400 so I have to turn it up a 5 clicks at to get it to strike the bull.

 

[Podmonkey]

Yes, that is a problem, I have no chrony. There's gotta be published data for a 16 inch barrel though. Man I hate maths!

 

[dsdmmat]

You got to come out to my range...... Lol

 

[Podmonkey]

I would love to but NY won't let me bring my naughty guns over. It really sucks too cause I really wanna hit the swamps with my new toys and old shooting buddies!

 

[dsdmmat]

What loads are you using? I may just be able to duplicate them and build a 16 inch upper to shoot them out of.

 

[Podmonkey]

This stuff mostly, it's nice quality an SG ammo has good deals on it.

 

[dsdmmat]

I'll see if I can find some at the gun show this weekend.

 

[Podmonkey]

If you're willing to do me this favor, I'd happy to send you some, how much would you need?

 

[dsdmmat]

Realistically 10 rounds of each would give a good average. I will have to build a 16 inch upper first. I don't have one laying around.

 

[Podmonkey]

Well I'm not gonna be home for awhile anyway. I could easily spare a 20 rnd box each.

 

[Aimtite]

There is a substantial difference from modern carbines to national match barrels.
There is also a big difference between ammo brands. A 55gr PMC bronce is 300fps slower (or more) than a LC nato XM193. Russian steel rounds are also pretty inconsistent.

At 100yards it is going to be a minor 1/2" and +2.5" at 200 but when you get to 500 yards is a 21" difference.
This equates to 1mill and almost 4MOA.
Wiht the quality 62 grain you will see a similar trajectory and with the 69 you will see lower impacts but consistent trajectory.
The real advantage of the 62 and even better the 69gr and 77-80gr will be the wind at 500 yards and beyond you will
start to see less wind deflection up to 1 to 2 mills less wind deflection depending on the starting speed and bullet.

This is why BDC reticles do not work well, even the ones in first focal plane. In theory they could work but they don't.
If one is going to take long shots either do the mean value in the turret or have a stadia in consistent units of measure to do
the holdover. Of if one can trace the shots and has the drop in inches one can hold on the target.

I have tested a substantial amount of 223/5.56 ammo over the years so if you tell me what ammo you are using I might have the spreads for it.

 

[Aimtite]

oh I forgot, this also changes a lot with the newest polymer tipped and vld bullets like the TMK and Amax lines.
IMO the 75gr amax is a great balance between bullet length, ballistic performance and terminal performance.
There is little point in the 77gr smk with all those around. The only exception being the berger VLD given the
firearm and chamber can take the COAL and has the proper twist. To be honest I don't have a lot of experience
with the TMK, speically with the amax value packs we got. But based on what others are getting either way
it is a substantial improvement to the already amazing 223 / 556 round.

 

[Podmonkey]

I wonder if its more trouble than its worth. Maybe I should just get red dot and rely on Kentucky windage. My problem is I want an optic that can two different things well, distance shots out too about 400 yards AND up close shots. A reticle good for the one sucks for the other. I wish Trijicon would offer their Triangle reticle on the accupower 1x4s. The ammo I like is the IMI stuff posted above. I like the 77gr for performance, the 55gr for bulk stock and I'll substitute the 69gr when the 77 is not available.
I'm not a precision target shooter, i just want to be able to reliably score hits on a man size target at 400 yards.

 

[Aimtite]

I don't see the trouble here. Red-dots are very limiting for fast, long reaching, high power rounds. There is nothing you want to do that it cannot be done with a number of scopes but there are some tradeoffs like always.
I went though some of the same dilemas a long time ago, tried many formulas and talked to people about this.
Ask yourself:
- What kind of shooting do I enjoy with this carbine? plinkin, 3gun/ defensive, target with large targets, target with small targets/varmints, etc...
- Do I have a spotter, want to spot the shots aside or I like enough magnification to be able to zoom in? 9 to x12 might be enough but quality of glass is more important I think.
- Do I want a massive FOV even w/o magnification?
- Do I want magnification range yet I wan to start low with a quick adquisition so the same glass can be use for close work as well as long distances? (This is my favorite)

for example: A friend of mine started with small CQB scopes but then he realized he is more likely to use the shotgun for home defense and discovered he enjoys the carbine to do slower precission
shooting from a bench seeking high scores. So we got him a modest yet good quality target scope. He is very happy now.

 

[Podmonkey]

Well I intend my AR as my SHTF rifle so that colors many of the considerations. I want versitility, good FOV and I still have good eyesight so I don't need massive magnification, 1x4 should do. I do like the Trijicon accupower for the clarity combined with the reasonable (for the clarity) price. My current range is an small indoor place with only 25 yards of distance but the range I want membership in has steel plates set up from 50 to 500 yards. My problem with the accupower is that I don't really like the mildot or moa reticles for close in work. That leaves the segmented circle with BDC reticle which is also less than Ideal. If I had a massive budget I'd just get an Elcan and call it done.

 

[Aimtite]

ACOG is the hdtv of practical scopes so one cannot go wrong with that. I like the variable magnification so a scope that will take both duties is preferred.
I think some of the 1-6 or 1-8 with large eyepiece adn 4 inch eye relief are hard to beat. On a tighter budget the 2-7 department has some very nice value offerings.
Not a problem for fast adquisition, two eyes opened, close range. Not the 1st option but a reasonable compromise.
I think a simple BDC will work if you stick to the same type of ammo and train a lot and pickup your reference holdover points for your ammo.
But in reality you can do the same with a simple mil-dot stadia and still have more and nicer options if you decide long shots even if it is not a first focal plane.
As soon as on has good glass with quality picture and light transmission and then conditioning.

 

[Podmonkey]

How effective would M193 spec 55gr be at 400 yards I wonder. Not very I'd imagine. It would be easier to stockpile in large quantities though.
A 3x Acog would do me well yes, particularly backed up with irons on a 45 offset (kinda mall ninja though). The Accupower can be had for around $750 though and I've looked through one, the clarity is crystal, like a $2k scope almost.

 

[Aimtite]

M193 is plentiful and affordable but it lacks at extended ranges. It is really Vietnam era technology designed for longer M2 barrels and slower twists.
The only 55gr fmj that is super consistent and does a number on soft targets is the norinco 55gr M193 equivalent that for whatever reason tumbles like crazy even in modern barrels. But
those are steel case and hard to find anyway. I have not seen them for years.
I would not mind picking up some M193 but also stock pile on the plentiful 62gr M855 or any green tip equivalent.
See if you can also find the MK318 (marines) that is a superior round terminally talking.
Also consider the 62gr FMJs from European brands but not sure the russians. The same fmj in 62gr is a better round than the 55gr.
Keep in mind the russian puffins are cheaper because they are also harder jackets so keep that in mind for ricochet and barrel life reduction. Barrels are cheaper than ammo anyway.

 

[Podmonkey]

I'm not terribly inclined to buy Russian steel case when I can get brass case for nearly the same price. And I had wlways thought the m193 55gr had better terminal performance than the M855 62gr. M855 does not have the greatest rep for accuracy either, it does offer some utility as a poor mans barrier blind round, but not as effective as the newer LE JHP stuff. But at $2 a round forget it. I am getting the IMI 77gr for .70 a round and it is supposed to be identical to the mk 262 mod 0 black hills stuff performance wise. Who is loading the the mk 318 commercially, and at what cost?

 

[Aimtite]

I have some steel for the AKM type but not a big fan of that garbage neither. I like consistency.
I got the MK318 at .70 or so a pop. and got a good amount for a rainy day. They had good discounts for 1,000 value packs. Federal makes it. Lake city plant.
http://palmettostatearmory.com/federal-5-56mm-mk318-mod-0.html

I am not sure who told you about the 55gr that is a nice round btw but there is absolutely no basis to put it ahead of any 62gr offering (at least the most popular ones)
One example the now retired M855 will penetrate a 3/8 hot role steel plate at 100 yards and wound or kill or wound the person at the other side.
The M193, 7.62x39, Blackout and a few others will fail at that. It has some shortcomings but it continues to be a better choice.
The 262 and any copies are great for soft targets but will strugle with intermediate barriers, vehicles, etc...
In the long range soft target also take a look at the Double Tap 80gr that is amazing. A superior long range round... I mean if you are going to pay
black hills better look into this one. I have tests on that one and I reload so I can reproduce the same thing with R15 or CFE even better.

 

[Podmonkey]

It was my understanding that the M855 , particularly at longer ranges after velocity has dropped, has a tendency to punch straight through soft targets with little disruption whereas the the M193 will violently fragment. At shorter range anyway. I've read that the mk318 is an excellent all purpose round that fits many roles, if I can get a stockpile of that going I may make it my go to round.

 

[Aimtite]

It was my understanding that the M855 , particularly at longer ranges after velocity has dropped, has a tendency to punch straight through soft targets with little disruption whereas the the M193 will violently fragment. At shorter range anyway. I've read that the mk318 is an excellent all purpose round that fits many roles, if I can get a stockpile of that going I may make it my go to round.

At extended ranges they all suck. At least the larger ones have more momentum and energy and the potential to catch somehing like a magazine, a bone or simply heavy clothing will make them destabilze and tumble.
The 55gr (other than the norinco) is not consistent and at 500 yards is going too slow and minimal momentum. And we want something that can do some hard barrier work so it is a bit of a tradeoff right.
For working with more authority then one needs to consider the 6.8 SPC or simply jump into the 308. Like always, trade offs.

 

[Aimtite]

BTW if one reloads take a alook at the barnes solids. The 62gr are amazing rounds for hunting and defense, includign barriers. But they are expensive. I think they are a great substitute
to the most current tactical ammo. They also sell ammo ready to go but they are way overpriced.

 

[Podmonkey]

By longer range I meant over 200 yards. I belive the "reliable" frag range of the m855 or m193 for that matter, out of a carbine is, what, 150 yards? From what I understand the newer rounds more than double the effective (meaning fragmentation) range over the older stuff. Am I correct in assuming the mk18 works more like the barrier blind LE rounds and thus not so dependant on velocity?
And no, one does not reload for one is a bit scatter brained and liable to double charge a case and blow up ones gun. Not to mention I have no time for it, I get 3-4 days off a month.

 

[Aimtite]

you will be fine.
It is 300 yards and no more than 400 for the M855. The ideal threshold is above 2100fps but never below 1800fps.
Now if you use a 55gr PMC bronze then it should not be more than 200 because as I said there is a difference of up to 300fps or more from
a LC nato load to the PMC bronze and others. Some carbines might not even cycle well with some 223R.

Speed is what kills and gets the job done same thing with barrirer penetration and that is why the AK47, Blackout and others fail in the hot roll test vs the M855.
That is the real differentiation over the popular fmjs including the 55gr.

Please take into account that all this is based on basic directives and a bullet can behave in a number of ways depending on where it strikes regardless off
the speed (real life). Just keep this in mind. Speed on the target is what matters and it is your best friend. That is why in long distances we go for
bullets that fly better, so although they might start slower they end faster. Also softer construction (match) for soft targets.
These will never be hunting rounds other than varmints. The 22 caliber is not the one for anything larger. For military the hope is to strike vitals or
wounding with those match bullets at long distances.

 

[Podmonkey]

Hey dsdmmat, did you still want me to send you that ammo? I will be home around the 5th.

 

[dsdmmat]

Hey dsdmmat, did you still want me to send you that ammo? I will be home around the 5th.

Nope, I haven't got the upper complete yet. What is your barrel chambered in? I was thinking about getting a 223 Wylde in 1-8 twist with a mid length gas system. I am looking for a stainless heavy barrel for the upper now.

 

[Podmonkey]

Its a 5.56 chamber, 16" 1 in 7 twist, gov't profile. Don't worry about, I'll just get the segmented circle reticle and use a little Kentucky Windage