Lets talk urban prone (rifle canted 90 degrees)

kombayotch

kombayotch

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In some PRS-style matches, you have to shoot at targets that are hundreds of yards away in a modified prone position (rifle canted 90 degrees). I'm not going to get into why you should or shouldn't do this. Suffice it to say that its something that can show up in a match. To me, that is enough reason to know how to deal with it. But just for fun, here is a nice video about German sniper training. Have a look at 0.45 and 1:38.

[Youtube]HlLFkNV2YAM[/Youtube]

Urban prone is actually a very simple problem to solve. And it can be solved accurately If you know your scope height and how the zero changes when you can the rifle. It is fundamentally no different than having an offset sight like on a M1D Garand. First, understand what is happening:

scopecant_zps613e374b.jpg

Good ballistics calculators will have scope offset, in addition to scope height. In modified prone, you simply swap scope offset for scope height and account for the change in zero. Scope height becomes zero. Then trajectories can be calculated using the ballistics calculator. A good ballistics calculator will also have offsets for different ammo since those will also have shifts in zero. Some can also estimate the zero shift that you get when you cant the rifle, but it is usually off by a bit and is often different for a left cant than for a right one. I prefer to find my left and right cant zeros by testing. From here, I can calculate further distances or closer ones with the ballistic calculator. Or I can make a chart for different distances.

Here is a chart that shows what happens when I cant my 223 trainer 90 degrees left (in mils):



My 100 yard zero shifts 1 mil to the left and 0.9 mil down. So, now the elevation turret is the windage turret and the windage turret is the elevation turret. If I wanted to bring the POI back to the center, I would turn the windage dial 0.9 mils right and turn the elevation turret 1.0 mil down. Since my scope has a zero stop, I can't fully take out the horizontal shift. So, I adjust for elevation (using the windage turret) and then hold off using the horizontal crosshair (which is really the vertical one). Wind holds and mover leads get added to this (another reason why you want FFP)

As with most things shooting related, its best to deal with it in angular measurements. Like movers, trying to think about it inches instead of mils/MOA only complicates things.


First and second round hits at 200 (left), first round hit at 300 (right) with the rifle canted 90 degrees right. Settings calculated with AB Mobile using a separate rifle profile for this purpose.
 

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I came across that video when I first bought my AW so naturally I wanted to try and shoot it sideways like those Germans do their AWM (G22). I rotated the buttpad 90 degrees and used windage as elevation and elevation as windage.

Worked ok at 100 after a quick adjustment but at 300 I was way off left because of the 28 moa scope mount and what you describe above. It was fun to try though.
 
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Don't need infinite range time. Just a known zero offset, a scope height and a good ballistics calculator or a ready made chart. Then its no different than making a shot with the rifle upright as far as dialing in correct dope goes. Either read the dope from your table or your ballistics calculator, plug it in and go. If you practice it enough, you will know the values for different distances as you would shooting a lot normally.
 
This is how you would calculate a table in JBM:

The inputs for a normal data table would look like this with my trainer:


Now, there is a field there for Cant Angle. You could just enter 90 or -90 in that field and JBM would calculate the trajectory for you. But in my experience it is typically off around 0.2-0.3 mils at 100 yards in both directions. So, I prefer to check my zero and set things up manually.

I would enter this with a rifle canted 90 degrees left and my known zero of (-1.0, -0.9):



As a convention, left and down are negative. Scope height becomes zero, scope offset becomes the scope height value. We use the Zero Height and Zero Offset fields to enter our zero change when the rifle is canted. The real purpose of these are if you had some ammo that zeroed at a different location than your usual load and you didn't want to zero your turrets for that ammo. You would enter the offsets in and it would give you dope with the offsets rolled in.

A few critical things to get a good answer:
-Make sure Wind Speed is set to 0 (wind correction values and mover leads need to be added manually at firing time)
-Make sure "Elevation Correction for Zero Range" is checked
-Make sure "Windage Correction for Zero Range" is checked

I get a solution that looks like this:



If I wanted to shoot at 400 yards, I would turn the windage dial (now elevation) 3.4 mils R. And since I have a zero stop and can't zero out the horizontal offset, I would hold 1.5 mils right for a no wind condition. If there was wind, I would look at the value on my normal dope chart for a wind at that distance and I would add/subtract that value from 1.5 mils.

In AB mobile, an urban prone rifle profile can be programmed in a similar fashion.
 
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Based on the thread below I thought that prone was going the way of the dinosaur.

TBS I shoot with police and military in other countries and ALL of the rifle shooting is from prone ie. stay low and keep shooting.

Pistol Pete said:
No one goes prone anymore... too much work getting back up and with ballistic plates, you want them facing the threat. Also, in prone, your rear plate smashes you in the back of the skull and pushes your head down. In the snow, well prone just sucks... in the desert, the first round fired from the prone kicks up so much dust you can't see. Most guys just blaze away over or around walls and such while screaming "Ala Ackbar"!!! Plus... cool chest rigs are in the way!

Urban environment, and most of the planet is quickly becoming urban... prone is only used from rooftops... pavement makes those bullets and frag skim along the ground and you don't want to be laying down then.

Another fun thing is getting into a vehicle with plates on... and the front plate smashes you in the jaw and you bite your tongue... :(

As for the big pouch... first aid kit would be most useful, tourniquets and pressure bandages, a gas mask as noted already by lover of AK's or just extra kit like gloves, a toque, lunch, I phone what have you. I had two new "bren pouches" like that and I put grenades, smoke and frag, batteries and extra bandages in them. We didn't use a lot of grenades but we sure used a lot of bandages...

When I was a street cop, I carried two spare mags on my rear left hip in addition to the two up front... people asked me why I had them, my answer was when I went prone, I could still reach spare ammo... and when I was standing, if I went for one of them (mags 4 and 5), it was time to get the heck out of there...
Click to expand...

http://www.canadiangunnutz.com/foru...634-French-soldier-plate-carrier-pouch-layout
 
We have had "Side Prone" stages at our match going back to 1996.........
I practice this position every season in case that stage gets thrown in..........
This year it was changed to a 45 degree port you had to shoot through.
 
Thanks for this! Took a CQB clinic with Barney/Tactical Teacher last wknd in Petawawa. (Highly recommend!) Red dot battery conked out and went to my MBIS. When shooting modified prone had great groups but they were all to to the left. Initially thought my MBIS might have been off but later standing upright noted they were bang on. This post is super helpful in understanding what was going on with me and my sights in modified prone.
 
geologist said:
Based on the thread below I thought that prone was going the way of the dinosaur.

TBS I shoot with police and military in other countries and ALL of the rifle shooting is from prone ie. stay low and keep shooting.



http://www.canadiangunnutz.com/foru...634-French-soldier-plate-carrier-pouch-layout
Click to expand...

There are some fairly ignorant comments in that thread. Prone is most definitely still a viable and necessary fighting position. It's certainly been deminished to some degree. Due to development of close range fighting techniques (urban operations, room clearing, etc), plates make standing and kneeling slightly less dangerous and offers a sort of portable cover for much of your vitals (not to be confused with concealment), kind of a crap analogy, but you get my meaning. So prone certainly occurs less than it did a couple decades ago. But, are you going to stay standing when under indirect fire, setting an ambush, under the withering fire of a well executed enemy ambush, running a machine gun in any sort of support role, in a DM or sniper position? No. I'm sure you've noticed a lot of the differences being pointed out apply to conventional army operations, but there is definitely overlap. Especially in modern day policing, SOF, conventional war, and insurgency type conflict.

Just one mans opinion.
 
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