Home Forums Hunting & Shooting Hunter's Campfire One Rifle, Three Scopes

Al Talbot's amazing QD mount has got me working enthusiastically on a new idea about scopes for a long-range prairie-dog rifle. This notion is based on a few fixed premises that I'll explain if you like but won't argue about.<P>� I don't like variable scopes. They're unreliable. I've tested dozens of 'em, probably hundreds, and found most of 'em changing zero too often, too easily, at each change in magnification. Anything inside that has to be free to move when you want it to move, will sooner or later move when you don't want it to move.<P>And Murphy's Law ("Whatever can go wrong will go wrong at the worst possible time") is not the worst of it. Howell's Law is more appropriate: Whatever can't possibly go wrong will go wrong sooner or later.<P>� The Talbot QD mount is outstanding in two regards.<BR>(a) It returns to zero every time you take the scope off and put it back on. Every time.<BR>(b) Once you get the knack of working this unique mount, you can change scopes in three to five seconds, easily.<P>� Usually, on a prairie-dog shoot, you get some "normal-range" shooting for a while; then all your shooting is farther out. Still later, all your shooting is 'WAY out there even farther.<P>� Using a single scope for all these ranges requires either<BR>(a) holding over, higher and higher, as the ranges get longer<BR>or<BR>(b) running the vertical-adjustment knob up and down as ranges change from near to far and later vice versa.<P>So on the high-quality .220 Howell varmint rifle that's in the works, I'm going to try using three fixed-power scopes, with three different magnifications for three discrete shooting ranges � an 8x to maybe a 10x, a 12x to maybe an 18x, and a 24x to maybe a 32x � depending on what's available that I can afford.<P>I've just been fumble-figgerin' trajectories with the QuickTARGET software, to see what I could work-out in theory first � using the 75-grain Hornady A-Max at a muzzle velocity of 3,550 ft/sec. This exercise has been most interesting.<P>If I zero Scope A at 257 yards, for example, the point-blank range for a two-inch vital height would reach clear out to 298 yards. Not bad for "normal range." The bullet shouldn't rise more than two inches at 153 yards.<P>A three-inch vital height would require zeroing at 296 yards to extend the point-blank range to 345 yards, and the bullet shouldn't rise more than three inches at 164 yards.<P>A four-inch height would require zeroing at 328 yards to extend the point-blank range to 384 yards, and the maximum height of trajectory (four inches) at 186 yards.<P>Listing all the options for all three scopes and all three heights of the kill zone would take too much space here, so let's jump to the figures for Scope C set for a vital or kill zone four inches high.<P>Zeroed at 517 yards, Scope C would allow me to hold for a four-inch height out to 548 yards, with the trajectory highest (within this range segment) at 480 yards.<P>If I settle on the four-inch-high kill zone as my standard, I can zero Scope A at 328 yards and use this one setting out to 384 yards with no more than four inches hold-under at 186 yards or four inches hold-over at 384 yards.<P>For shooting from 385 to 480 yards, I'd zero Scope B at 440 yards and not have to hold-over more than four inches at 480 yards.<P>For shooting from 480 yards to 548 yards, I'd zero Scope C at 517 yards, and the trajectory should be no more than four inches high at 480 yards, no more than four inches low at 548 yards.<P>The usually unacknowledged error in this kind of trajectory calculation is that while the theoretical trajectory is pretty much what the hard numbers say it is, the actual trajectory of each individual round is going to be somewhat different � and the differences are correspondingly larger as the range increases.<P>But this error is a matter of each individual trajectory itself, not the scopes' actual zeros and "pure" point-blank ranges.<P>This method just might make a better long-range hitter out of this ol' coot. Checking it out will most interesting, I think.

Have not seen or used the Talbot mounts but do have some modest experience with scopes and trying to precisely place projectiles at extended yardages. So hey, why let ignorance of one small facet prevent the posting of my somewhat educated opinion? <P>Anywho, it would seem that unless these mounts are held to tighter tolerances than internal scope adjustments that you'd be replacing one "variable" system with another.<BR>Even a half thousandth of looseness or eventual wear would wreak havoc with the POI way out yonder.<P>Also, I'm curious how many guys now use such extreme magnification on their scopes in the field? Isn't mirage a huge problem at 36X, especially on a hot day across a flat prairie? Benchresters use this much power on clearly defined targets, but even a 6.5-20X Leupold I had could barely make out little targets (ground squirrels) much over 250 yards at 20X when the heat waves were distorting everything. Generally kept it at 12X to 16X. Would need a 60mm objective or bigger and very good optics to get the exit pupil size and resolution necessary to effectively use more magnification than that on dull targets against a similar colored background. <P>Three scopes triples the scope budget. And even with "affordable" scopes, which is obviously a variable term defined differently for different income levels, you will need to spend at least a couple hundred bucks to get the optical quality necessary for good resolution. And the further out you go the more optical quality you need and therefore the more you must pay for the scope. Of course there is alway eBay and good optics can be had for well under $400 so I guess we are within everyman's definition of affordable, but still... But I digress.<P>Mainly I would be concerned with the inherent variability between any moving parts - scope adjustment rings or rings and bases.<P>The old fixed power Weaver T-10 was much praised by the silhouette shooter's for it's repeatability of adjustments. Would it not be better to stick with a fixed power of say 16X or 20x at most and good target knobs? According to your scenario one would not be cranking the elevation adjustment back and forth, but rather shooting close in, adjusting POI and shooting midway out there, then one more adjustment for long range shooting, then head back to the barn at day's end.<P>Further, I've been leaning more and more back toward a fixed power scope for hunting for one reason in particular. I can learn small hold-offs quite well at one power by using the duplex feature. I know that at the 4X setting, at 200 yards the bullet impact is right at halfway between the crosshair and the top duplex. At 400 the impact will be right at the point of the bottom duplex. Crank the power up or down and this changes. Kind of hard to remember this for 7 or 10 or 15 different power settings without a chart, but becomes almost intuitive through repetition at one power setting. The practical value of this was demonstrated last week when I hit two ground squirrels at 330 yards with two shots using a .30-06 and 180 grain Nosler Partitions sighted in for game animals, i.e. 3" high at 100. I knew exactly where to hold that duplex to connect. I know a .30-06 varminter is an extreme example, but I submit this to show the precision capable from a calibrated eyeball. The "tactical" shooters with their mil-dot scopes use this very technique taken to the next level. Obviously one needs to know the range fairly precisely. <P>Switching scopes is the same in principle as cranking up a power ring. The one scope/one power setup seems simpler and therefore more reliable, if one believes that simplicity is the arch enemy of Mr. Murphy.<P>You said you would not argue about this topic so while the above does kind of pick at your idea I hope it will not be seen as a call to battle. Just my opinion based on my experiences, but keeping an open mind on it. Unlike the economist who says, "Sure, it works in practice, but does it work in THEORY?" .<P>I am curious to see how the scope switching actually works in the field. Plese keep us informed of the results.<P>P.S. I think you may have explained how the Talbot mount works in a previous post, but I'd appreciate a review of what distinguishes these from the Warne, Talley and other QD mounts held in high regard for their return to zero ability.<p>[This message has been edited by Jim in Idaho (edited April 26, 2001).]

Jim,<P>I have to agree with your logic. Changing 3 scopes (sounds) like more movement then having one "good" scope on the rifle all the time. Another thing that would bother me is that if your POI is 2" high at a certain distance and 2" low at another your not leaving much room for error on a 3" target. <P>I have used and seen scopes that change POI when adjusting the elevation adjustment knob thats why I purchased a Swarovski 6 to 24 X 50 scope for my varmint rifle. I mounted that scope 3 years ago and check the POI at 100 yards several times a year. In fact I checked it last weekend and guess what no POI change at all. In scopes, you get what you pay for and the lessor scopes may not return to POI. I move the elevation knob up and down all the time for various ranges. Generally I leave the scope set at 6 power to get on the woodchuck, then once located I adjust the power higher. <P>I would suggest buying one "good" scope versus 3 cheaper ones. Then again, thats just me. The results of your tests will be interesting, if nothing else.<P>Don

"Progress" [?] report:<P>Been having enough fun playing around with QuickTARGET and other software to make this idea worth something even if it goes no further.<P>Granted, all this stuff is computer estimates so far, and field results will certainly be somewhat different, as far as precise, hard numbers are concerned. But the concept certainly shows promise for this aged prairie-dog shooter-misser. (Grade-A misser!)<P>First, I played around with hit zones of the same set height at all ranges (two inches high, four inches high). Then I wondered about the practicality and effects of using a variable-height hit zone -- (a) two inches above the line of sight (LoS) to four inches below LoS for the first range (8x or 12x Scope A) -- (b) four inches above LoS to six inches below it for the second range (24x Scope B) -- (c) six inches above LoS to eight inches below it for the third range (36x Scope C). The 8x (Leupold), 12x (Redfield), and 24x (Sightron) are loose scopes that I already have on hand. The 36x Weaver is what I'm looking at for Scope C. (Anybody wanna trade a quality fixed 12x for a new-in-the-box Leupold M8-8x?)<P>COMPUTER SEZ<BR>-- Zero 8x or 12x Scope A at 257 yards. Trajectory two inches high at 153 yards, four inches low at 330 yards<BR>-- Zero 24x Scope B at 395 yards. Trajectory four inches high at 330 yards, six inches low at 460 yards<BR>-- Zero 36x Scope C at 518 yards. Trajectory six inches high at 460 yards, eight inches low at 575 yards<P>Shots beyond 575 yards would simply require more than eight inches of hold-over with Scope C -- still worlds better than the 37 or more inches of hold-over or scope adjustment with Scope A zeroed at 257 yards! Also, holding into the wind would remain as usual-traditional with all three scopes. So what else isn't new?<P>The usually unacknowledged error in this kind of trajectory calculation is that while the theoretical trajectory is pretty much what the hard numbers say it is, the actual trajectory of each individual round is going to be somewhat different -- and these differences are correspondingly larger as the range increases. (I know YOU know that -- just letting you know I know that!) ;o<P>"mirage as a factor" � keep hearing this and been wondering why it's never bothered me. Then comes the dawn! (eventually) � I've been shooting in steady and worse breezes, with mirage being wafted off out of the way. Nice to see those *&^%$#@! winds good for something besides putting dust down your collar and stealing your hat.<P>"review of Talbot mount" � <A HREF="http://www.snipersparadise.com" TARGET=_blank>www.snipersparadise.com</A> under New Products<BR>(Sorry � under Product Reviews)<P>"3-inch target" � don't see why this would be any more of a problem with my plan than it already is, in spades, with any single scope, any zero, any range, any shooter.<P>"variables recommended" � had enough trouble with 'em to be dang near terminally leery of 'em.<P>All the other comments? Time and trials will tell. Then I'll tell � whatever the results prove to be (which of course I expect to be SOME different, somehow). Why should this plan be perfect on the drawing board?<p>[This message has been edited by Ken Howell (edited April 26, 2001).]