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Dougan wrote:Thank you for the PPs Heather - there're a crytal clear guide to plotting....now to work out how to interpret the plots :?

Cheers,

John.

Well, I never said they explained everything

Heather

HeatherW762 wrote:

Dougan wrote:Thank you for the PPs Heather - there're a crytal clear guide to plotting....now to work out how to interpret the plots :?

Cheers,

John.

Well, I never said they explained everything

Heather

I was going to use my old score cards to practice, but havn't recorded all the wind/elev changes - I've got a TR shoot in a month or so, and will record all changes so I can do the plot (after the shoot).....then, I will sit and stare at it, awaiting enlightenment :shock: :lol:

Thanks also Heather, I will try the new method out next week

Dougan wrote:

HeatherW762 wrote:

Dougan wrote:Thank you for the PPs Heather - there're a crytal clear guide to plotting....now to work out how to interpret the plots :?

Cheers,

John.

Well, I never said they explained everything

Heather

I was going to use my old score cards to practice, but havn't recorded all the wind/elev changes - I've got a TR shoot in a month or so, and will record all changes so I can do the plot (after the shoot).....then, I will sit and stare at it, awaiting enlightenment :shock: :lol:

When you do, take it step by step & make sure you completely understand the step before moving on. Otherwise you will confuse yourself - at least I did!

Any probs, let me know & I'll try to help.

Heather

I was very grateful for the packs that Heather provided because I'd never really grasped the process. The only problem is that I got to the stage of saying 'so what?'. Is the idea that it shows what the rifle and the ammo could have done if I wasn't such a poor shot

Watcher wrote:I was very grateful for the packs that Heather provided because I'd never really grasped the process. The only problem is that I got to the stage of saying 'so what?'. Is the idea that it shows what the rifle and the ammo could have done if I wasn't such a poor shot

The idea is not to make you shoot better, just to help you get more points from however well you *are* shooting.

For example:

• The elevation graph helps you to get your elevation group centered as quickly and accurately as possible.
• It helps you to identify shots that you should ignore (beacuse they are out of the group).
• It helps you to identify how the center of the group moves during the course of the shoot, and to keep track of the group center (e.g. due to light changes, or position changing or sling slipping, or barrel or ammo warming).
• It helps you to identify how your elevation changes as your barrel changes from clean though grubby to filthy, and therefore how to compensate-for or ignore these changes.

At any point during the shoot you should be able to look at the elevation graph and instantly answer the question "what elevation should I have on the gun *right now* in order to give me the best chance of being as close to the waterline as possible".

The wind graph is less directly applicable, but it can help you to identify the wind bracket to-date, trends, whether you are consistently under or over calling (which you may choose to do deliberately), and whether shots are significantly out of the group.

Both need to be considered with reference to your capabilities and group sizes. Actually, the time you shouldn't be worrying about an elevation graph is when your group is so tight that you can see everything you need to on the diagram, and you're better off watching wind and targets.

Ultimately, all the graphs are doing is splitting the x and y axes and removing the sight changes you make through the course of a shoot to give you a 'normalised' view of your group.

..

Cheers Rox - That's given me more understanding of the purpose of doing it - to fully understand, I'll have to wait until I put it into practice.

I can see how I'm going to be spending my lunch hour :roll:

Trevor Steele has produced some downloadable plotting cards which will help: http://www.mechengineer.freeserve.co.uk/targetrifle.htm

I've attempted to plot my card from last weekend - Not sure if I've done it right though :?

It was my first TR shoot for nearly 2 months, so was a little rusty - I forgot to put the windage adjustment on for the first sighter ( ), so have moved it, for the purposes of the plot, to where it should have been (see 'A' circled). Also, I think shot 1 was just a bad shot.

The elevation plot makes sense - It shows that the elevation 'creeps' up in the first half of the shoot, and then stabilises - which is normal for my rifle. However, normally my 'A' sighter is low by about 1 min, and then the creep starts after the 'B' sighter - this time though, my sighters were high...could be down to the fact that my rifle was out in the direct sun before the shoot?...normally (this being England) I'm used to starting with a cold barrel.

The wind plot though, just looks like random dots ( :? ). The wind was fairly constant up to shot 6, but then started to drop right off, and then gust again slightly - which caught me out, as you can see.

So, how do others interperate the plots (please feel free to be as critical as you like :P ) :?:

Dougan wrote:I've attempted to plot my card from last weekend - Not sure if I've done it right though :?

Some general comments:

1) Try to avoid negative elevations. Ideally don’t start with an elevation of less than 3 or so, then you’ve some room to come down without going negative. Plotting and reading elevation graphs with negative values just makes it a tiny bit harder to mentally juggle the numbers, taking longer and/or increasing the chance of making a mistake. You might adjust the vernier plates –maybe add 10 mins if there’s room – then your starting elevations are easily computed from your old settings.

2) Write the elevations that correspond to the grid lines on the elevation graph, with reducing elevations up the page (if the shot went high it needed a lower elevation to be on the waterline). Pick the nearest whole number to your starting elevation for the centre grid-line, i.e. don't put fractional minutes on the gridlines.

3) Label the center gridline of the wind graph with your initial wind call, to avoid running out of space (as you nearly did). I expect it was pretty clear that you were unlikely to need right-wind on that day, so you could have started with 2 or 3 left on the middle grid line (see my completed example). If you are really not sure of the wind bracket leave this until after the first shot, then fill in the grid line labels, but always make sure you have a good eraser with you just in case you need to redo the labels after your first shot.

As for the plots themselves, your wind graph looks to be spot-on, but not the elevation graph (maybe those negative elevations made it more confusing – usually the elevation graph is the easier one to complete).

I’ve plotted the graphs correctly in the attachment below; perhaps you might try again to see where you went wrong. There’s also a shot by shot evolution of the elevation graph,so you can see what the information you had available at the time – open it in a new tab, zoom to full size and view in conjunction with the comments below.

• A) The first sighter is over a minute from our initial elevation. If it was a good shot I would move down a 1/2' to increase my chances of getting a good second sighter for converting (this would have made shot B a V-Bull). I would commonly make a 50% or 75% correction after the first sighter unless it was called bad.
  B) Nicely grouped with the first sighter. No question that the centre of the group is at -1’. Get that on the gun.
  1) Nicely in the group centred at -1’.
  2) Low in the group. Hard to tell if this is out of the group, or if the group is falling. I would probably leave the elevation as it is, but watch the next shot and be ready to move if it were below the waterline.
  3) Come up to -3/4’. The first shot(s) are starting to become less relevant. There’s increasing evidence that the group is falling and the group centre of the last 4 shots is at -3/4’.
  4) Would probably stay at -3/4’ here, but watching out for the next shot again.
  5) Group centre is now -1/2’. Get that on the gun.
  6) Still low – centre of last four shots is at -1/4’. Come up another 1/4' to -1/4’.
  7) Stay put. I’m still concerned by all the earlier shots which plot to less than -3/4’, and don’t want to overdo it.
  8) Very tight group now formed at 0’. Up another 1/4' to zero.
  9) Significantly out of the group.
  10) All out

Summary:

The group was falling during the first 6 shots before stabilising at 0’. Check for things like sling slipping and position sagging, as well as consistent butt placement in the shoulder. It might help to spend more time before your sighters on dry shots, going through the full shot routine to work any looseness out of the sling and position, and check and adjust your natural alignment during and after these dry shots. I often see people take one dry shot then stuff a round in and start. I prefer to take four or five for the reasons above.


Hope this is useful.