Stretching the legs of a BCM AR

[Low_Speed_Notper8or]

So I have a 16" BCM AR and I have a 1x vortex prismatic on it and shoot mostly xm193 out of it. It runs and its good enough for 100 and in but eventually I would like to take advantage of the LPVO optics and 77 grain ammo and accuracy of the AR platform and see if I can push out farther.

So Im curious what ammo have you guys seen have good effects at 200-300 yards and with good quality ammo like mk262 or anything else out there what kinds of groups would be expected?

I'm not looking to do anything super long ranged but out to 300-400 doing something with a variable power scope with a BDC reticle and getting first round torso hits/hits on steel would be what I would be looking to do.

And also say if you have a 200 yard zero with 77 grain stuff what would the shift in POI be when switching to 55 grain ammo for training.

 

[Low_Speed_Notper8or]

Also is anything in the 60s grain weight good for 1/7 twist barrels?

 

[Mike_IA]

Are you just looking to ping steel or something else? 55-80gr with work out of a 16” 1/7 twist barrel. I have shot 55, 62, 64, 69, 70, and 77 out of my 16” BCM barrel and easily hit reduced B/C zone steel (Defense Targets RSTs) out to 475. 6” round steel get a bit more challenging 300 and beyond with 55s in windy conditions. I have one box of 70TSX that was a bit iffy on 6” round steel 300+ as well but that may have been my handloading and not the fault of those bullets, I have had 70TSX that did really well at distance too.

For sight offset, 0 to your preferred load and shoot 25-50 yard increments to see what it does in your barrel and conditions. 55gr ammo has a huge velocity spread and bullet design spread for the different brands so shooting and seeing is the best option in my opinion.

 

[Yondering]

First off, I'd say if you can't make consistent first round hits on torso-sized steel at 300 yards with your current setup and ammo, the problem is most likely your shooting technique, not the gun. (Unless you got some exceptionally bad ammo.)

With that said, sure, more magnification, a proper reticle, and some of the various 77gr ammo should make those hits easier. Skip the BDC reticles and go for a mil reticle of some sort (mil dot, hash, whatever); that's way more useful when you get off the square range and known distances.
There are several brands making decent 77gr ammo like Black Hills, IMI, etc. Personally I'd avoid anything with the Remington name on the box.

 

[Low_Speed_Notper8or]

First off, I'd say if you can't make consistent first round hits on torso-sized steel at 300 yards with your current setup and ammo, the problem is most likely your shooting technique, not the gun. (Unless you got some exceptionally bad ammo.)

With that said, sure, more magnification, a proper reticle, and some of the various 77gr ammo should make those hits easier. Skip the BDC reticles and go for a mil reticle of some sort (mil dot, hash, whatever); that's way more useful when you get off the square range and known distances.
There are several brands making decent 77gr ammo like Black Hills, IMI, etc. Personally I'd avoid anything with the Remington name on the box.

Well, I can make hits out to that distance on a square range in ideal conditions with no wind and a black/white target on a plain backdrop. I have shot out to 400-500 yards over open sights with a mauser and some modern production 8mm ammo and did my time in 3 postion smallbore. With my zero I know at 300 holding slightly low on the head should drop rounds in place upper torso

However, Im interested in the better ammo and optic to 1. Be able to identify what I am shooting at. 2. Cheat wind better and 3. Actually have more effect downrange then a .22 magnum like the 55 grain ammo does at range since it sheds velocity so fast and 4. have less ammo variability to magnify any issues with my shooting

I will look into mil dot type stuff. Any info on stuff about range estimation.

Is there anything developing with more compact 1-4x optics in the pipeline

 

[MojoNixon]

Well, I can make hits out to that distance on a square range in ideal conditions with no wind and a black/white target on a plain backdrop. I have shot out to 400-500 yards over open sights with a mauser and some modern production 8mm ammo and did my time in 3 postion smallbore. With my zero I know at 300 holding slightly low on the head should drop rounds in place upper torso

However, Im interested in the better ammo and optic to 1. Be able to identify what I am shooting at. 2. Cheat wind better and 3. Actually have more effect downrange then a .22 magnum like the 55 grain ammo does at range since it sheds velocity so fast and 4. have less ammo variability to magnify any issues with my shooting

I will look into mil dot type stuff. Any info on stuff about range estimation.

Is there anything developing with more compact 1-4x optics in the pipeline

Send me an e-mail to mws1508@yahoo.com. I have some range estimation info I can send you. I wont post it as I can't verify/recall the source. I don't want it to go un-attributed.

 

[Yondering]

There is a lot of info all over the internet about range estimation with mil reticles. If you're good with math, the key point is that one mil is an angle measurement that subtends 1/1,000 of the distance observed. I.e. if you're looking at a spot 1,000 yards away, 1 mil spans 1 yard, or 36 inches.

The standard ranging formula using distance in yards and target size in inches is:

Distance = target size * 27.76 / mils

For example, if our target size is 18" across, and looking through the scope shows us 0.8 mils across the target, the calculation is:

D = 18 * 27.76 / 0.8
D = 625 yards

Of course you can also use the same method at a known distance to estimate target size.

 

[Low_Speed_Notper8or]

There is a lot of info all over the internet about range estimation with mil reticles. If you're good with math, the key point is that one mil is an angle measurement that subtends 1/1,000 of the distance observed. I.e. if you're looking at a spot 1,000 yards away, 1 mil spans 1 yard, or 36 inches.

The standard ranging formula using distance in yards and target size in inches is:

Distance = target size * 27.76 / mils

For example, if our target size is 18" across, and looking through the scope shows us 0.8 mils across the target, the calculation is:

D = 18 * 27.76 / 0.8
D = 625 yards

Of course you can also use the same method at a known distance to estimate target size.

That.........Sounds nice if your posted up somewhere sitting behind a gun in a prepared position.

On the fly not so much.

Probably realistically I will print out my come-ups in mills at 300-350-400 and the adjustment for a full value wind at those distances and tape them to my stock, then memorize them.

On a different but related note do they have binoculars that are durable with a laser rangefinder that are not huge or expensive? Seems like if your joe civilian operating alone or in a small group just having binos to be able to see what is going around you is a good bet. Not to mention to be able to accurately measure range to use your limited ammo effectively. Being a regular guy your not gonna be able to let lose with a m240 and walk in rounds or have drones doing recon or call in firesupport or ammo resupply.

It seems like when people talk about "SHTF" people either think they will run around like rambo or do like they did in the military. But from what I see in reality anything going on here in the states will involve treading much more lightly looking and listening and trying to stay under the radar far more then people think, and being as accurate and quick as possible with any use of violence, and alot of breaking contact and running away.

 

[Yondering]

Range estimation with a mil reticle isn't something you do "on the fly" without a lot of practice. You're the one who asked about it.

Are you confusing range estimation with a dope chart? Those are completely different things. A dope chart lets you use a mil reticle as a BDC reticle, but you still need to know the range to the target to make it work. If you're one of those who's eyes glaze over at the first mention of math, range estimation with a reticle may not be for you.

The "SHTF" discussions get old quick. Maybe try to separate precision shooting from the prepping and SHTF stuff? The one really has very little to do with the other.

 

[Mike_IA]

Drops and wind holds on a 5.56 our to 400 aren’t bad. Those are closed distances where you will hold and go rather than dial. Get your 0- stick your info into JBMs free data set or just shoot the drop and know. Out to 400 if you hold on the head box you will drop rounds into the bottom of the Azone on a USPSA metric target with a 200 yard 0.

Here is a quick reference chart for 55gr out of my gun at moderate conditions:
50 - -0.2”
100 - +1.5”
200 - 0”
300 - -4.4”
400 - -17.7”
500 - -40.9”

1-4 is not what you are looking for there is a reason it wasn’t until good 1-6s came out that the LPVOs started to get popular. On a 16” AR as long as the scope is less than 20oz it won’t mess up the balance anD even if it is heavier like the Vortex Razor2 you can work around the different balance of the gun.

77s are great distance rounds for punching paper but less than ideal for other uses. And honestly learn with with 55gr ammo before spending money on 77s.

 

[Gypsy EDC]

I only reloading I do in 5.56 anymore is 77gr SMK or TMK with 24grs of Varget behind it. It's a home grown mk262 clone and it's got legs

 

[Wake27]

77s are great distance rounds for punching paper but less than ideal for other uses.

How so? The only complaint I’ve ever heard about a 77’s terminal ballistics is that it’s not the best at defeating barriers.


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[Mike_IA]

Exactly doesn’t work for barriers and is velocity dependent for fragmentation.

 

[Yondering]

Drops and wind holds on a 5.56 our to 400 aren’t bad. Those are closed distances where you will hold and go rather than dial. Get your 0- stick your info into JBMs free data set or just shoot the drop and know. Out to 400 if you hold on the head box you will drop rounds into the bottom of the Azone on a USPSA metric target with a 200 yard 0.

Here is a quick reference chart for 55gr out of my gun at moderate conditions:
50 - -0.2”
100 - +1.5”
200 - 0”
300 - -4.4”
400 - -17.7”
500 - -40.9”

Agreed, but I recommend taking it a step further and working in mils with a mil/mil scope; you don't need to know inches at all. With your dope charted in mils, if you have a mil reticle it's very easy to be precise in your wind and elevation holds, or depending on time and precision, dial the elevation with your mil turret.

The difference is that estimating inches on an object of unknown size can be iffy, but if you're working in mils, you've got a ruler built into the reticle. (Or, same for working in MOA with an MOA reticle.)

For example, with a lot of 5.56 loads and a 100 yard zero, at 300 yards the drop is 1.2 mils. We don't need to convert anything to inches, we don't even need to know or care what that correlates to in inches. All we need is that 1.2 mil value; hold high 1.2 mils on the reticle and you're on target. It doesn't need to be any more complex than that, if you're working at known distance.

 

[Mike_IA]

True just working in Mils or MOA is best practice. But for someone who hasn’t shot
distance or doesn’t know the drops it’s easier to give drops in inches because non-distance shooters don’t think in Mils. Heck even now it’s hard to think Mils unless I am ranging and shooting off my data cards in competition.

For work it’s more of “how far is that? Ehh 300. Self hold top of head to get impact in center of chest.”

 

[Ryan St.Jean]

Well, I can make hits out to that distance on a square range in ideal conditions with no wind and a black/white target on a plain backdrop. I have shot out to 400-500 yards over open sights with a mauser and some modern production 8mm ammo and did my time in 3 postion smallbore. With my zero I know at 300 holding slightly low on the head should drop rounds in place upper torso

However, Im interested in the better ammo and optic to 1. Be able to identify what I am shooting at. 2. Cheat wind better and 3. Actually have more effect downrange then a .22 magnum like the 55 grain ammo does at range since it sheds velocity so fast and 4. have less ammo variability to magnify any issues with my shooting

I will look into mil dot type stuff. Any info on stuff about range estimation.

Is there anything developing with more compact 1-4x optics in the pipeline

What do you want the ammo to do? At 200-300 m if you are putting holes in paper or ringing steel any decent 55-62 grain is just fine. The advantages of heavier ammo are largely about terminal ballistics.

Most low power variables have a BDC. I have used a Burris MTAC to good effect.

Unless you are trying to consistently shoot sub MOA any decent ammo and a optic that fits your budget will do fine at 200-300m.

As to shift in zero from this load to that one, you are going to have to shoot it with your rifle, in the given conditions, to really find out.