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Zeroing data sources etc

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    Posted: September 06 2014 at 11:08am
I'm having a strong urge to do some serious shooting with my No.4 Mk.2 but need some information first. I checked around the site but didn't locate what I was looking for. If I missed it or if anyone can point me to any other sources please speak up. The manual I have found is good fire material but nothing else. What's the point of having a rifle that requires an armorer to make sight corrections?

1. Trajectories for commonly found 303 loads fired from my rifle.
2. If trajectories aren't available near zero (NZO), maximum ordinate
    (ORD) and far zero (FZO) would be great to have.
3. MOA values per click for post war ladder sight (1,300 YDS).
4. Any guesstimates on values of front sight corrections at any given
    distances.
5. Off topic; any range estimation tricks using sights, etc.
6. I will be shooting 150gn FMJ S&B. I'm not good enough to have the   
    the ammo make a difference unless it's a horrible mismatch.
7. How can one determine the mechanical zero of the rifle> Which front sight post size provides mechanical Zero (MZO)?
I appreciate any information, tables or a point in the right direction. In the event this information is available here plz point me to it and accept my apologies.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Shamu Quote  Post ReplyReply Direct Link To This Post Posted: September 06 2014 at 10:02pm
What you need is a ladder target.
There are some on here you can print yourself.
You sight in @25 yds using the "tin hat" at the bottom as a POA & work everything else out there as well.
\Here you go just print this @ 8 1/2X11 & have at it. The measurements are ther so you can make your own if you need more.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lowspeed Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 12:55am
Shamu - I believe that will fit the bill. I'm assuming the NZO for the rifle is abt 25 yds and the FZO is at abt 200 yds.

It didn't occur to me to look for zero targets instead of written instruction.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Shamu Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 2:05am
This is with the MkVII ball a FB FMJ of 174 GR weight.
They are working it based on the  near zero @ 25 matching the Far @100yds.both should impact in the "tin hat". The trajectory is by having the bullet impact at the line corresponding to the desired distance line. Trajectory is actually the height of the lines marked on the side.

I usually go this way  Zero at 275 Yds. (pretty much where the MOD zeroed at 300) that gives me a Mean Point Blank Range of 50~350 yds with an 18" target diameter.

I think we're using slightly differing systems though.The MPBR gives the longest range that you can aim dead on for.

MPBR is where you have a dead on bull at a given distance & the trajectory is optimized so the bullet path never leaves the target area over the maximum possible range of distances. It starts at the bottom, rises up to the top & falls back down again once more passing through the center as it drops.

A milled rear sight should be about 1/2 MOA per click with a No4 rifle..
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 6:15am
The test target is useful and worked well for me using 174grain Sierra Match Kings.
To adjust the front sight error left or right I use the basic mathematical formula that works for all iron sighted rifles or pistols.
For example, I calculate the error and required adjustment for my No1 MkIII* today which was shooting 1,5" left of centre at 50 yards.
Multiply the error (1,5")times the distance between front and rear sight (19,5"), divided by the distance from the muzzel to the target (50 yards = 1800"inches). Make sure they are all in the same measurements, i.e. inches (or centimetres if your metric)

So 1,5"x 19,5" = 29,25
29,25 divided by 1800" =0,0162" or 16 thou'. So I need to move the front blade 16 thou to the left.
(Or rear sight windage 16 thou to the right if you have windage sights)

This also works for elevation so you can correct your front sight with the same calculations. I've used this to adjust My No8 rifles and 50 yards on the sight is POA =POI at 50 metres. 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 6:25am
Regarding use of the standard sights.
For the No4 or No8 rifles, I've found the trick for using the standard sights well is ensuring you have the same  centered picture of the front sight ears in the rear dioptre. As the rear sight hole is quite large, I've found that it helps to ensure the same reference points of the front sight ears are in view when the front sight pin is on target. It helps keeps the groups tight in my opinion.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lowspeed Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 11:28am
I can BZO AR's and FAL's all day long with no trouble. While I love the feel of my Enfield and lucky to have found this one however the moron that designed the front sight system must've been one of those communists in government in the UK all those years ago. I know this has likely been tried before but... Has anyone considered;

1. Set mechanical zero and post target at 25 yds. Fire 3 rounds. Move target accordingly until rounds are on paper OR striking backstop on the same plane as the target consistently. Finally measure distance from muzzle to target.

2. Firing from the previously established distance fire 3 round groups making windage adjustments until zero is established.

Once this zero has been confirmed the rifle should fire within the accepted variations in elevation until it falls through the far point of intersect. A table of NBZ, MAX ORD and FBZ. Having this info would likely cut the zero process down to 6 or 9 shots.

I know that not changing sight heights isn't proper procedure but my NPOA has never suffered from elevation changes. As long as I'm in the black from the bottom up I feel good about it and shoot accordingly.

Alright shooters :) please check this over and let me know if this has already crashed and burned. There must be a simple quick method to get a Battlefield Zero without bringing a pit crew to the range with you.

I can't wait to hear from you guys (esp if I'm getting ready to waste a bunch of ammo). In the event this is an unexplored subject (doubt it) I will prepare and submit a report on the matter.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lowspeed Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 12:12pm
Shamu!! you're correct; methods are pretty close.

The following is how I waste several rounds of 5.56 1x per year

Once I determine the distance at which the LOS and TRA intersect I zero at that distance. Once zeroed I record the MOA of the group and increase distance to the FZO and fire a group or two at that distance. I use this as reference for future shots since there's not a rifle in the world that isn't more accurate than I.

Before I retired I would fire 3 round groups at increments of 25 yds until reaching the far BZO. I would do sousing flip up irons, then unmagnified EOtech and finally magnified EOtech. I did this simply to keep myself aware of my limitations of which there were many.

This is why I was BOLO for basic ballistics, intersects and so forth for my rifle. I no longer have 24/7 365 access to the departmental range facilities which limits me to a range I made when I was 16 or 17 with a limited distance of 100 yards
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DairyFarmer Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 2:01pm
Before you start shooting any firearm that you do not know the point of aim, here is a trick we used on our PH course. What they did was take the rifle and mess with the scope or sights. You then had only 3 rounds in which to zero the rifle. We had to do it for both open sights and scopes. On most rifles the bullet will cross the line of sight at 25 meters and 100 meters.

Step 1: remove the bolt and bore sight the rifle. Basically get a friend to hold the rifle down on sand bags. First look down the bore and get it on target. Then adjust the scope or sights to also be on target.

Step 2: fire a shot and do adjustments to scope or sights. Your shot should be as close as damn it to zero. For sights use the formula. For scopes remember, half the distance double the clicks, double the distance, half the clicks. i.e. if the scope is 1 click = 1/4" @ 100m then at 25m 4 clicks = 1/4". The sights formula takes distance into account so no need to change it.

Step 3: Follow up shot. You will want to check that you have done everything right, or do a final adjustment.

To get more technical, use a program like PointBlank (free!!!). You are asked to enter data such as sight height, BC, SD and bullet speed. By entering these it will produce a graph that will show what distances the bullet crosses the sight line. Like mentioned earlier 25/100 meters is almost a dead sure thing. Some calibres will shoot a flatter trajectory between the two, some calibres will drop off very quickly after 150m, and some calibres have massive "climbs" followed by massive drops, much like a mortar. Sight height, calibre, velocity and bullet are what determines the flight path.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Shamu Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 9:05pm
Before you utterly condemn the sights remember that things were done differently back in Victorian army days. You didn't DARE zero your rifle yourself or the RSM would have you keel hauled & he'd find a ship to do it on as well.Confused

The factory set up the zero using ladder targets, buckets of assorted front sights & "Cramps" that had calibrated screw threads for windage adjustments.

Once you got it you shot it & you used a pull through to clean it, that's it! It was never "yours" to mess with, & RSM's had no problem explaining to you that Her Majesty The Queen had Graciously agreed to LEND you this fine rifle so you could serve the Empire!

It wasn't even allowed to use a cleaning rod! That chore was reserved for an Armourer who was specially trained.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DairyFarmer Quote  Post ReplyReply Direct Link To This Post Posted: September 07 2014 at 11:10pm
I remember basic training. We were all given R4's (basically a licensed version of an Israeli Galil ARM). They were completely packed in grease and issues in a sealed plastic bag. The only way to get the grease off was to have a nice hot shower with you new best friend (and I'm talking about the rifle not the guy who slept in the next bunk). Man did you get to know it intimately!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: September 09 2014 at 8:26pm
Not being from a military background I find this thread interesting, as I don't know much about ballistics and how to use the information when shooting. I would like to learn more about this subject. Any ideas were to read up on it would be welcome.
I tend to zero the rifle at 25 yards with the target as shown earlier; then reload my ammo for a velocity close to original at around 2440 feet per second and then just set the sights to the distance required. Then make minor elevation adjustments depending on the practice shots. As the windage is not adjustable I make sure its on the center line of the targets at 50 metres. When shooting at 200 metres I've not had much issue with wind etc so have not really mastered the art of aiming of to compensate yet. Lack of long range experience due to a lack of facilities.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote hoadie Quote  Post ReplyReply Direct Link To This Post Posted: September 09 2014 at 8:41pm
Great info, Shamu!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Shamu Quote  Post ReplyReply Direct Link To This Post Posted: September 09 2014 at 8:57pm
If you're interested in playing with ballistics there is a free (almost) ballistics simulator available called "Point Blank"
 Check it out it is free as long as you don't mind the short wait at the beginning or for a nominal fee you can become registered.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DairyFarmer Quote  Post ReplyReply Direct Link To This Post Posted: September 09 2014 at 9:21pm
Wind should not affect a bullet at 200m unless it is seriously windy, the bullet is travelling very slowly or the bullet is exceptionality light. And unless you are looking for 0.1 MOA I wouldn't worry about it. For very long shots, the pedantic shooter will even take the earth's rotation into account.

The main things that will affect the path of a bullet are: weight of the bullet, the speed it is travelling, the shape of the bullet and the distance it has to travel.

I'll try to get a few pics together and do a nice layman's explanation of how a bullet travels and what affects its travel
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: September 09 2014 at 11:26pm
Thank you Shamu and Dairy Farmer.
The first competition at 200 metres was a very windy day; as it was also the first ever time I'd shot at 200 metres I decided to just aim at centre and see what happened. Well basically, as you suggest; the wind had no real effect at that distance for the .303 and I ended up with a good result (4th place out of 40).
There are not many places to shoot longer distances in France; but there is a project underway for a new 600metre range at Chateauroux which will be a 4 hour drive (each way), it should open in 2015 so will have to organise a trip.
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