My first post so point me in the right direction if this has already been asked.

I have two AR's a 5.56(1/7 twist)  and a 300 AAC Blackout (1/8) and I'm currently building a 16" 300 upper. I just got started reloading and I wanted to mess around with some longer range loads in the 223 to play with my scope turrets and show off to a few of my buddies. I'm surgical at long distance with my 300WSSM but I know both of these rounds can carry nicely on a windless day. My first question is what are the heaviest bullets I can load into the 223 while keeping the COL short enough to fit into standard mags. These loads are not intended for hunting so ethics and energy is not a factor. I just want a bullet that i can dial in and hit the gong for fun.
My second question is am I going at this ass backwards? I look at a round like the 220 swift and it's extreme velocity which gives almost dead on accuracy out to almost 400 yds and It makes me wonder if the heaviest bullet possible is the best one. Correct me if i'm wrong in my physics analogy but a pea thrown with all ones might probably lands in the same spot as the shot-put you threw next. Has anyone found a happy medium with weight/velocity? I currently shoot 62gn bullets and they stabilize well and group tight. Just wondering if a heavier bullet will be better as long as it fits in my mags.

Watched a guy hitting steel pretty consistently in the wind with an SPR build and M855 at 1000 yards.





So, there's a baseline for capability.

Regarding the longest bullet to load, Maybe an 80 grain, but 77 for sure. Velocity will be the issue. My strelok ap says my 77gr SMK traveling at 2550fps will drop almost 500 inches at a 1000 yards. You will need a bullet with a high BC, a hotter load and a lot of clicks in your scope adjustment.

Its more about bullet coefficient than bullet weight. Long bullets with a high sectional density will have a better BC. A good BC and velocity combo will get you there.

Regarding the pea and shot-put analogy: That is true if you are dropping them straight down, but if you are throwing them it is different. Two bullets shot horizontally will both fall at the same rate, but the bullet with the faster velocity will travel further before it hits the ground.

Keep the BS flag in GD - make an intelligent contribution or comment or move along. Eric802

Just keeping it on topic - Eric802

You are not looking at this the wrong way.  However, instead of focusing on weight, you should be looking at BC.  Generally, heavier bullets have higher BC and retain velocity better at range.  However, bullet shape plays a part as well.  A 70 grain VLD bullet might have a better BC than a different 77 grain bullet.  You will also be able to push the 70 grain bullet a little faster.

With that said, any of the 75 and 77 grain match bullets will work fine out to 1000 yards and most likely further.

http://looserounds.com/2013/08/05/what-will-the-m4-do-at-1000-yards/





An interesting write on using not long range ammo for long range shooting.

You're right. That WAS an interesting read.
His results with the M-855 really surprised me.

why?


the entire reason the SS109/M855 exist is to extend the range of the  556 machine guns etc.





77s are a good load for rounds that will feed through a magazine. but the 80s single fed are much better


the 75 AMAX are very finicky in my experience,  they require careful handlaoding and playing with seating depth to hit the sweet spot.  

I have seen the same thing with some of the lighter high BC  VLD type 70s and such.   yes they are great but you have to handlaod and spend a lot of time playing around with them to get the best performance from them


I stick to the seirra/nosler  77s.  seated to mag length with a warm load of 24.0 grains of varget, or N140. or RE15/.   if you can use LC cases with military crimped in primers you can even go a little more on the load. if you feel going that way is an option.   But be careful in a semi auto doing that


a good 77 grain load is very useable.

I do not find the TAP 75s  a really good 1,000 yard load though

Here is a test I did before the M4 at 1,000 yards


http://looserounds.com/2013/06/10/ar15-at-1000-yards-can-a-rack-grade-ar15-and-m855-make-1000-yard-hits/

Why not? It's cheap and plentiful and presents a challenge, plus bragging rights when you ring steel with the most plain jane of ammo.



To put it in perspective, it was m855 in IIRC a full value 15-17 mph gusting and dropping off wind.



I mean heck, what's more bad ass than rolling up with a mag of ball ammo hanging in with 80 grain single loads?



 

Ive liked the Nosler CC 77gr for distance, but mainly because I can get it cheaper than the SMK off SPS. I haven't tried 1000yd though. I also usually load over Varget as well. The lighter bullets do reach a higher velocity, but drift worse at distance. You can always adjust for drop, but its hard to judge downrange gusts.

Obviously if you are reloading the 300 you know plenty about the BC though. The accubond LR in 300 reports crazy numbers for an expanding bullet.

I guess you miss understood my comment


1st, I am the guy who shot the M4 and A2 to 1,000 yards and wrote those articles.  I am not against using M855


my "why"  was asking him why the results at 1000 yards surprised him.  not why do it.    

I am asking why he was so shocked the M855 can hit at 1000 yards so well when it was made for  extending the range

M855 is workable for long range.   and certainly worthy of working with

its not simply a matter of adjusting for drop at 1000 yards using light bullets



the lighter stuff goes subsonic a whole lot faster and that is a much worse problem to deal with than wind deflection and  adjusting for drop is not the only cure


and that higher muzzle velocity with lighter bullets  drops very very fast.  and is not a factor at extended range

I guess you miss understood my comment


1st, I am the guy who shot the M4 and A2 to 1,000 yards and wrote those articles. I am not against using M855


my "why" was asking him why the results at 1000 yards surprised him. not why do it.

I am asking why he was so shocked the M855 can hit at 1000 yards so well when it was made for extending the range

M855 is workable for long range. and certainly worthy of working with

the comments you hear about an AR being a '50 yd gun' or a '200 yd gun' are solely talking about the rounds fragmentation range.  shorter barrel ARs have a frag range of 50-75 yds while 20" ARs are a little under 200 yds.  this is with M855; Mk262 gets a little further out



i think people have confused this with the guns accuracy potential at long range, which as was shown, is not an issue

I guess I have not seen what you are describing. The ballistics that I have run out to 1000yd have still shown less drop on my lighter loads for 308 and the same for 6.8 at 600. And yes, they do drop speed faster BUT general have a significantly higher muzzle velocity which don't cross plains until VERY far out (900ish yards with 308) Both are far below subsonic at 1000 yards as well.

Oh, you're right I did misunderstand it.





I said the results of m855 surprised me... not the guy shooting it, he does it for a living.





 

when you say "The ballistics that I have run out to 1000yd have still shown less drop..."   do you mean on some ballistics program? or  by doing it and seeing it on paper?  because 20 years of long range shooting have shown me that past 800 yards,   light weight bullets are a pain in the ass


yes a 308 will stay close to super sonic until it almost gets to 1000. but the point is to hit at 1000 yards and its a lot easier to do it with a 175 than a 168

and its a lot easier to shoot a slower 77 grain 556 round at 1000 yards than it is to hit at 1,000 yards with a 50 grain bullet from a .22-250

there are a few examples of a ligh ( for caliber)t bullet doing ok.  The old 155 palma bullet is OK at 1,000 yards in a 308. but often plama shooters used 30 inch barrel.  




a lighter fast bullet will make for a flatter trajectory and simplified use at shorter ranges. for example the 53 grain flat base match bullet is very, very good in the 5.56 from 100-300 yards, but I damn sure do not use it to make hits at 900 plus.


I guess I should add a caveat or clarification  here.   When speaking about "light bullets"  I should really say  "light for caliber"  obviously a 77grain 556 round is llighter than a 175 grain 30 caliber.   But I guess at this point everyone discussing understand the reasons and difference  

OP:  to understand the effect of velocity, weight, wind and BC, play with a ballistic calculator like the one on Hornady's website or download the free version of software like Strelok.  It's all in the math.  Play with the numbers.  Generate some charts and it will start to make sense.

Because with my limited experience with M855, I could do no better than about 4" at 100 yds.
This was with a scoped 20" DPMS H-BAR.
I could not envision doing anything CLOSE to what you did at 1000.
Of course, I am NOT a long range marksman.

From the ninth paragraph of the quoted article, "The m-855 and it's ability SURPRISED me once again".
Why are you surprised that I was surprised, when you yourself was surprised?
Nice shooting, btw.

the range did not surprise, me . the accuracy did.  




and its not as hard to shoot that far as people think.


the fact people THINK they can not do it, is more of the problem than any failing of their skill.  

its a simple matter of understanding how to adjust your sights, then properly applying the fundamentals. it really is that simple  as long as the gun and ammo are decent.  dont sell your skills short.

convincing people they CAN do it, and that it is really not some great feat. was the entire point of that article.