Thanks for this, let me reply to some points:
- When you buy some Federal GM or Hornady match, you'll get a little table with deflections at every 100yds up to 300 (or 500, depending on brand). Here's an example:
http://www.federalpremium.com/products/details/rifle.aspx?id=150
- The factory ammo I use is 168gr BTHP Match
OK, that's standard Federal Gold Medal 168 match ammo. Very good stuff. The _only_ bad thing about it, is paying for it... ;-)
(And it really is good ammo. It is surprisingly difficult to make handloads for your rifle that will shoot as well as this factory ammo. Once you can, you can pat yourself on the back, knowing that your skills as a handloader have indeed "arrived")
Here are the two charts that they provide on that page that are relevant to us here - the drop:
and the drift:
- How accurate are those programs? I take it that the bigger challenge must be gauging the wind as opposed to memorizing the deflections at various distances.
- The math part is no problem (I've got a B.Eng
), although you'll have to convert all those MOA's to milliradians for me, because that's what my scope adjustments are!
Good! ;-)
In some ways milliradians can be more intuitive, being a "1 in 1000" unit of arc.
When you mix units and deal in yards of distance and inches on the target, MOA are pretty close (within 5%) of being a "1 in 100" unit of arc (1 MOA is about 1 inch at 100 yard, or 6 inches at 600 yards, or 10 inches at 1000 yards, or 8.5 inches at 850 yards, etc...). (if you care, an MOA is actually about 1.047 inches per hundred yards - but like I said, for most purposes "an inch" is a good enough description) And since meters are within ten percent of being the same thing as yards, an MOA is pretty close to "an inch per hundred meters" as well (if you care to be picky, a meter is a bit more than nine percent more than a yard - but that usually doesn't matter for this sort of thing).
What you need to do as a shooter, is not deal in "inches of wind drift" or bullet drop, but in units of angle (MOA or milliradians, at your convenience). This puts your drifts and drops into the same units as your scope (or iron sights) adjustments.
Also, you should convert (or express, or think of) your target's dimensions not in inches, but in the same units of angle. So if the "bull-5" ring is about 2MOA in diameter (as it is in Canadian, American, British, Australian etc fullbore targets), that is a much more useful fact to know than it is a particular number of inches. If a shot lands on the right edge of the bull line, that means it is 1 MOA from the centre of the target. So I immediately know that had I fired that shot with a sight setting 1MOA to the left of what I actually used, that shot would have been perfectly centred.
Or, if my shots are slightly low but still in the bull, I can see that I probably need to bring my group up by half a minute.
(What you don't want to do is this: "the 5-ring is twelve inches in diameter. So my shot is 6 inches from dead centre. So I need to move my bullet six inches left. Since I am at 600 yards, and once scope click is 1/4" at 100 yards, then I need to move (hmmmm...) 24 clicks left". Don't do that math up on the mound when you are shooting; do it before hand, express everything in minutes (or mils), and deal with consistent units!!)
I'll let you do the heavy lifting, but I'll give an example. If you read Federal's drop chart, I see that it indicates that at 500 yards the bullet will be about 52 inches lower that it would be at 200 yards. I will show you how to calculate how many MOA, and how many mils, you would have to move your scope from whatever it takes to shoot the bullet to your point of aim at 200 yards, in order to get it to hit your point of aim at 500 yards.
52" divided by 5(hundred yards) is 5.4 minutes. To the closest 1/4, this is "5.5" minutes. So, you add 5.5 minutes to your 200 yard elevation setting, and your bullet ought to hit where your reticle is pointing. If your scope has 1/4 minute clicks (this is most common), that would be 22 clicks "up". But try not to deal in big handfuls of "clicks", it's easy to get lost that way; it's much, much better to deal in "minutes" (and parts thereof).
In milliradians, you need to use the same units for both distance to the target, and transverse deflection. 52 inches is (52/36) = 1.44 yards. So 1.44 yards / 500 yards (times 1000 milliradians per radian) = 2.88 milliradians. If your scope has tenth-mil clicks, then 2.9 mils is what you should use.
- Where can I find a good coach in Qc?
There are two ways that I know of.
One is to pay for one, and hire a professional one. That'll cost hundreds of dollars a day though, so that is probably not practical.
The other way is to get a free coach. Which you can find in the form of a fellow competitor, if you become involved in competitive shooting. You'll pay for your "free" coaching, by spending hours (years in fact) on a rifle range. Which is only a good idea if you enjoy this....!
There are a number of very good fullbore shooters in Quebec, but I don't think any fullbore is being shot in the Montreal area any more (the 1000 yard range just east of Mtl. has been closed to shooting for several years now). There is fullbore shooting done in Quebec City at Valcartier (a nice 600 yard range), if it is practical for you to shoot there you should contact the PQRA /ATPQ (P.Q. Rifle Association) and ask them.
There is also some very good fullbore shooting done in the Ottawa area at the Connaught ranges (a 900m national facility, where our annual championships are fired) by the NCRRA (Natl. Capital Region Rifle Association).
Visit either of those, and look into fullbore shooting (either with iron sights and sling, which is known as "Target Rifle", or with a scope and rest, which is "F-Class"). You can spend a lifetime mastering it, if you are so inclined.
