The Zero Range at Bisley

[ovenpaa]

DTA do you mean the difference in elevation from the black spot on the zero target to the 600 yard mark is 12MOA, or put a different way. From your indicated zero you need to wind up 12 minutes to be hitting the 660 line?

[hitchphil]

Lots of people shoot the black disc out thinking they have zeroed - er not quite........

This applies for a target rifle but can be adapted for a scope or service sight:

A weight on a string makes the target vertical set the scale under the string & pin in place- so DO NOT CANT the gun. a spirit level on the rear sight sets it as level, then you can level the foresight to that, so when you wind up to 1000 but for a bit of spin drift you will be in the black, if your foresight is not level with your rearsight or you cant, you will go out one side (right top for a RH shooter).

Dont zero on the black - Zero for 600yds (i.e. aim at the black hit at 600yds) & deliberately 2-4 moa windage out to one side (right) so you dont chop the scale up. All but 1 of our club guns are set at 13moa = 600yds (the other is 23moa!) slip the plates when at 600yds to 13moa or a multiple with 10. (or 3-rear +10-fore on an adjustable foresight) Then move the foresight / wind up to 900/1000 noting the settings & back to 600 then down to 500 / 300. That splits the difference of error so when you go to 1000 you have a good chance of being on the black vs if you start from zero/300 & just wind up cumulative errors can put you 1-2-3 moa out & the target is only ~4moa high / low.

Look at the pattern of shots up & down the card if not vertical then something on your gun is not level.
If vertical finally wind off the preset 2-4 moa & slip the windage to zero.

If you want to zero for 2 ammo types apply 2-4moa wind the other side (left) & repeat but keep the elevation for 600=13 moa for 155grain on a 308win. Just note the different settings.

Then refine those settings by recording your best elevation per ammo per butt per distance from your plot diagrams. (butt because at Bisley they aint level & you can gain lose an moa because of that). If your lucky on a dead calm day 300yds you can refine the windage or again take the best windage setting vs the flag indications & average them out. so e.g. a perfect 3oclock wind indicating at 2 moa flag - if your V centre on 2,5moa your out by ~0.5moa you can take a good bet & refine your windage by 1/4moa at least.

Once set try not to frig with them..............

Draw up a table e.g. 155 grain RG / (GGG) / Foresight Iris setting
& clip into your score book / weather writer (laminate it)

Distance..............Elevation...............Foresight..............Rearsight.......FS
1000.....................36..(34)................35.......................1...............2.8
900.......................27..(26)................25.......................2...............3.0
600 ......................13..(12)................10.......................3...............3.6
500 .....................7..(6) ..................5 .......................2 ..............3.8
300 .....................3.. (2)...................0 .......................3 ..............4.0

Note the rear sight hardly moves so you dont change you head position vs distance. & you close the foresight down as things get further away NB the black for 800/900 & 1000 at Bizzles is the same size so they get smaller as you fall back.

In TR you get 2 sighters the above makes sure the 1st is in the black & the 2nd can be converted to a V, remember VVVVVVVVVV or 5 VVVVVVVVVV beats 45 VVVVVVVVVV so converting sighters gives you an edge in ties.

Now spend the next 4-5-15 years learning to read the wind & winding the sights in predictive mode: Shot on 4, should have been 5 for a V when the flag is in 'that' position. & in 'that other' position 3 so now you have bracket. so now you look, wind on & shoot. Some people take every shot as a 1st sighter by setting their windage by what the flag says vs what the last shot did. If i lose the plot (i do that occasionally) I do same - wind to zero, & reset from the flags or if the wind is mad / variable.

NB the target centres at Sticks are 18moa so if its blowing a howler you can bung on say 5 & aim up wind on the adjacent target & you are shooting on 22 moa wind but it can work.

People with scopes can just aim off using their graduations to do that in a calibrated way so less messing about twiddling things.

[safetyfirst]

Crikey. A marksman. On here.

Thanks for the great post, it'll take some deciphering but it looks a well condensed couple of decades!

[IainWR]

NB the target centres at Sticks are 18moa

Only at one distance and one rearsight position. That looks to me like 1000 yards on your gun. At 900 the answer would be 18x10/9 = 20moa. Move the rearsight forward 1 1/2 inches and you change all the values by 4%, which at 1000 yards will put your first sighter well into the inner. Now that's unlikely to happen to you, but compare settings from one shooter (and rifle) to another and you can easily get enough difference to miss altogether at long range just because of differences in sight radius.

[Maggot]

Crikey. A marksman. On here.

Thanks for the great post, it'll take some deciphering but it looks a well condensed couple of decades!

Nope, just someone that collects data from his rifles and loads, understands and makes use of it.

It amazes me the number of people that go through half a box of 308 just to get on the bloody board at 300.

Once on, they wobble about the target, usually adjusting on every round until they either run out or shoot a V (more by luck than judgment) and then make sure the world knows it.

Not a plot sheet or notebook in sight.

"Look and learn" cried the club sniper with a bag supported F class rifle and bipod, the skill involved nailing an NRA V at 300 with a fully supported FTR rifle needs to be seen to be appreciated

Then mupped boy nails a string of the buggers with an old scoped target rifle using a sling.....hilarious and I can honestly say they were the luckiest 5 shots of my life, rubbed in by a mate saying to the club sniper "You see, you can either shoot or you cant"....all down to lady luck though

I grant you that not all will be moving between distances or even care about wind, but surely at £40 a box taking some notes and working out how they apply to your rifle makes sense? (It also saves money and is safer if you live near Bisley).

Its basic stuff....once you get the basics right you can start looking at stuff like the above, bracketing tactics etc, but if the basic observation or data is wrong you will find nasty ROs like me chasing you off to the Zero range.

OK, so I am in caustic mood this morning, but the moral of this bitching session is that propper plotting will give more info than you can imagine. Since I mostly shoot fixed service optics now I dont plot properly and my elevations are on some tape on the scope with the M67, but I still note conditions and plot the shots, it really helps, particularly with multi positional shooting where often the POA can be different for the same POI in different positions.

Happy shooting everyone....even the TR Nancies

[hitchphil]

NB the target centres at Sticks are 18moa

Only at one distance and one rearsight position. That looks to me like 1000 yards on your gun. At 900 the answer would be 18x10/9 = 20moa. Move the rearsight forward 1 1/2 inches and you change all the values by 4%, which at 1000 yards will put your first sighter well into the inner. Now that's unlikely to happen to you, but compare settings from one shooter (and rifle) to another and you can easily get enough difference to miss altogether at long range just because of differences in sight radius.

Iain is correct the scotch had kicked in by then & i forgot .......

Maggot said - It amazes me the number of people that go through half a box of 308 just to get on the bloody board at 300.

That infuriates some shooters! in TR if your 2nd shot is not on target you retire from the competition & bog off to the zero range with your tail between your legs. 0 score.

Please Beware Folks there are plenty of RCOs & shooters who shoot at Bisley that when they see this will now ask the offender to do the same or radio the Range Office to make sure they do. Its on the low tolerance list along with cardinal sins - closing the bolt with the gun pointing in the air & not clearing a rifle when coming off the FP.

Its not safe, rounds can bounce off the range floor & out of the danger area or over the top beyond it. I have made a bunch of Scouts hit the dirt behind the FP because of ricochets coming back over our heads from this & radioed the range office to contact the FP to stop shooting (& the butts to pull the targets down so they did!) exactly as we knew unzeroed rifle being zeroed at 600yds when we were at 300. Red card! Dont.

A zero range card costs ~£3 (~£4 high season) saves you money as well as sets you up safely. Its part of our clubs SSC drill: know how to zero a rifle to be safely on the target at any given distance (not as detailed as my post above but enough).

Having a Zero is the New Cool. Get one...............................

[Maggot]

Ah...now you see there's another one....

A while ago I was watching some sort of course going on while shooting on 300.

The chap next to me was shooting an NRA rifle I recognised (it was probably the rust patern) and I could not see any strike and he was not hitting the board....a round or two later I spotted the splash...about a foot off the top of the Century buttstop.

Polite words were had with him and his RO then it dawned on me.....we were probably the last people to use the thing on the NRA open day at 1000....Ahhh....

[dta europe]

for 600 yards you will need approximately

From a 100 yard zero
12 MOA 3.5 Mil

From a zero on the zero range (71feet 7 inches so just shy of 24 yards)
6 MOA 1.7 Mil

Sorry, don't get this. Can you expand a bit?

I will certainly try, although this was only to help a rifle get onto the target.

Firstly I had made the assumption (given this was a rented rifle) of using 155gr .308 ammo at approx 2950 fps.

I then (muddily) gave two come up examples from two different zero options. And probably confused further by giving two options of measurement.
The first was from a true 100 yard zero, in which case the elevation adjustment should be in region of 12 MOA in order to hit a 600 yard target.

The second was from a 24 yard zero (in effect a zero on the black dot on the zero range) and this would require an elevation adjustment of 6 MOA in order to hit a 600 yard target.

I hope this is a little clearer now.

Ewen

[safetyfirst]

PPPPPPP

[IainWR]

for 600 yards you will need approximately

From a 100 yard zero
12 MOA 3.5 Mil

From a zero on the zero range (71feet 7 inches so just shy of 24 yards)
6 MOA 1.7 Mil

Sorry, don't get this. Can you expand a bit?

I will certainly try, although this was only to help a rifle get onto the target.

Firstly I had made the assumption (given this was a rented rifle) of using 155gr .308 ammo at approx 2950 fps.

I then (muddily) gave two come up examples from two different zero options. And probably confused further by giving two options of measurement.
The first was from a true 100 yard zero, in which case the elevation adjustment should be in region of 12 MOA in order to hit a 600 yard target.

The second was from a 24 yard zero (in effect a zero on the black dot on the zero range) and this would require an elevation adjustment of 6 MOA in order to hit a 600 yard target.

I hope this is a little clearer now.

Ewen

Still puzzled. I can't see how it's down 6 minutes to go up from 24 to 100, which is what it looks to me is needed to make the numbers you quote coherent. What am I missing?

Iain