Q; How Much Accuracy Is Really Needed? A; All You Can Get!

[George]

FWIW.

I have come to my own conclusion regarding sub MOA performance in an IPSC rifle/ammo combo. It is not just desired; it is required! Sure, you can accomplish everything in 3gun using factory ball ammo. You do not need a tack driver to do well either. But you can do it all a little faster with a sub MOA rifle/ammo system when the shooting is at real rifle distances. I believe (1) MOA is the absolute minimum you should accept from your rifle/ammo combo, and closer to 1/2 MOA is better.

I think of the reticle in my scope as the center point of a cone of certainty (COC) that radiates out from the muzzle. The COC is the maximum distance from the crosshair aim-point, at the time of firing, in any direction, that a round will impact (this assumes shooting a zeroed rifle at the zero distance). For a 1 MOA rifle the COC is 1” @ 100yds, 2” @ 200yds, 3” @ 300yds etc. With a sub MOA rifle/ammo combo you will be able to take long shots faster. Why? Because you can spend less time refining the sight picture and still get a guaranteed hit.

Example based on 10” MGM flasher target at 300yds.

A 1.5 MOA rifle/ammo combo has a COC of 4.5” at 300yds. Divide the COC by two and subtract from target diameter. In effect you are now shooting at a 7.75” diameter target, because that is the diameter you have to hold to guarantee a hit. If you hold closer than 2.25” to the edge of the target, you have a reasonable probability of a miss due to random round variances. Therefore a more refined sight picture is required, and that translates to added time (an extra shot is even more time if it becomes necessary). The same scenario plays out with points on upper A/B areas at moderate distance (50-75yds), and full paper targets at long distances (100yds plus)

A 1/2 MOA rifle/ammo combo has a COC of 1.5” at 300yds. That means that the 1/2 MOA system only has to hold inside 9.25” to guarantee a hit. That is a measurable advantage in anyone’s book.

This means a little more than squat at the distances most rifle stages are testing our skills at (I hope that will change sometime soon). But, when those paper targets get out beyond 100yds, and the steel is getting real hard to see without optics, it can mean a very great deal.

Here is a scanned image of a group shot earlier today. It was fired from my open rifle (20" lightweight JP 1:8 bbl), prone with a bipod at 100 yds.

<img src=http://glinder.home.netcom.com/salejpeg/s77at100yds.jpg height="287" width="314" border="0">

The load is a Sierra 77 HPBT (not moly coated) over 24.0 of Varget. Kelly is going to wince, but I do (taper) crimp with a Dillon, die and it does not hurt accuracy in the slightest. In fact, my tests without crimp had the groups opening up a little vertically at 200 yards. I get a 16-18 fps average variance over a chrono with the crimped rounds. The un-crimped rounds gave an 20-24 fps average variance with a few 30+ out. That would seem to account for the increased vertical spread (about 3/8”).

Last diatribe. In retail there are three rules. Location, Location & Location. In competition, it becomes Function, Function & Function. Take my advice and get an ammo gauge that meets, or beats your chamber specifications and check everything in it. I use an L.E Wilson SAAMI spec .223 gauge (Not 5.56mm Nato) for most of my rifles. I use the custom cut gauge that JP Enterprises makes for my JP rifle. Basically, if it doesn’t gravity drop into, and out of the gauge, it doesn’t go into the rifle. You would be surprised at how many factory rounds don’t pass this test.

This is not as simple a subject as I am making it out to be. There are many variances in chamber dimensions and one size does not fit all. But a SAAMI spec gauge is still a good idea. All of my AR’s are various versions of SAAMI .223 specs (the JP rifle I have brings new meaning to the term “tight chamber”). AR’s, keep em clean,, gauge your ammo, and function will follow you wherever you go.

Regards,

(Edited by George at 8:37 pm on Nov. 29, 2002)

[kellyn]

Good post George, except that part about deforming innocent Sierra Matchkings. Accurate rifles build confidence.  My first Accuracy Speaks open upper really was a 1/2 MOA gun and when you called a shot as good, you knew it hit right where you called it.  Still even with a 1.5 MOA rifle, I've found that when I call a hit at 300, it's a hit.  IPSC rifle shooting is not as accuracy intensive as most other rifle sports but you still need an accurate rifle.

I like the Sierra 77 MK but I've never competed with it.  They sure are accurate and retain a lot of down range energy but the Hornady 75s have a better BC.

I use small base dies to guarantee fit and function in tighter chambers like the AS or JP.

[tightloop]

Townsend Whelen said it best, "...only accurate rifles are interesting."

[George]

"except that part about deforming innocent Sierra Matchkings"

Hey Kelly, I am actually a little bit kinder to the MatchKings than it would seem. After case prep (trim, etc), I use a Lyman VLD reamer to put a real shallow lead in the case mouth for the bullet The crimp is just enough to flatten the reamed portion against the bullet. I checked by pulling a couple after the crimp and comparing against a couple of uncrimped, and there was no visible difference. The shallow ream lets the case flatten against the jacket instead of turning into it. This method gives me just slightly better accuracy (by a rats ass) than the uncrimped version, and the crimp makes me feel just a tad better (mojo/juju stuff I guess).

BTW, I won the long distance rifle stage at the Area 1 3Gun with a real old "shavetop" AR that held about 1.5 MOA with 55gr ball (Hadn't gotten the JP yet). So yeah, 1.5 MOA works just fine, but I do feel a good bit more confident shooting a 1/2 MOA rifle. Just gotta watch out for overconfidence ;~)

[kurtm]

A11141:

Cone of certainty?? On a windless, same temp, same humidity, same elevation type of day? A barrle not lovingly resting on a part of a prop you didn't see kind of day? 3" instead of 4 1/2" at 300 yds?!

The quanitative part is that it makes you feel better there for YOU WILL SHOOT BETTER!!! If you want to deal in cones, go to Dairy Queen. You won't shoot better but they taste great! As both of you mentioned 1.5 M.O.A. has won for you. In reality a 2 M.O.A. rifle is just great for the stuff we do with them. What they all need though is a REALY good trigger. A 1/2 M.O.A. rifle with a 7 lb. trigger would turn into a 6 M.O.A. rifle in all but the most skilled hands when shot from field positions and unsupported jacka** positions. Yes a 1/2 M.O.A rifle is a confidence builder and almost all come with a good trigger; but a stock barrled AR with a good trigger will serve all but the most talented shoters just as well. By the way the rifle I shot at Mesa for the last 2 Years is a shot out ( over 9 cases of assorted factory ammo and quite a few reloads *) Colt flat top That holds just under 33/4" at 200yds in ideal conditions. The trigger is great!!

As a side note Kelly: I shoot only 55gr Nosler or Sierra balistic tips in .223, and sometimes PMC if I'm lazy. I've never shot heavier. On the othere side of the coin I've never shot lighter than 168s in .308. The world is truely a strange and majical place!                                       KURT

* using a Stoney point chamber gage, the bullet nearly falls out of the case befor contacting the lands. Needless to say when I reload, the powder charge keeps going up to compensat for the velocity decrease due to such a large jump, but I also don't feel bad when I shoot a 60+ round barrle melter stage!

[George]

1/2 MOA is 1.5" @ 300yds.

No rifle is 1/2 MOA without a decent trigger & TIM (Trigger Input Module).

Heavy .223 bullets don't wander round much nowadays at 200-300yds until the wind is real fierce. I used to shoot hi-power with S69's at 2750fps and didn't see wind up to 15-20 mph having much say at 200yds. The 77's fly like they are gyro stabilized out to about 300yds.

I have become a real convert to what a heavy bullet in .223 can do. Check out Glenn Zedickers book The Competitive AR-15 (The Mouse That Roared) http://www.zedicker.com/

In the end it all really depends on the TIM (see above).

First shot is last shot with a rifle if you are doing your job.

[kurtm]

A11141:

Believe it or not, I was triing to point out, in a tounge in cheek sort of way, that in order to be competitive in 3-gun one need not spend mega bucks on a 1/2 M.O.A. rifle. Yeah the cone comment was a little over the edge, but they really are yummy.

As for light versus heavy bullets for the .223, out to 300yds in light to moderate (10-20M.P.H.) wind, there is just not much difference; on the order of a couple of inches at most. I know alot of guys use heavies, but they aren't requiered to win.

I love the T.I.M.  concept. It is much friendlier than my N.B.T.S. ( nut behind the stock), and in the end of course this is the most important part of shooting.

The first shot, last shot satement is great, as long as the rifle has enough power for the job at hand, but in the context of .223, with a heavy or light bullet, unless we are talking dog sized targets and smaller, it is pehapse a bit optimistic. However this debate might stray far from the intent of this forum. Yes I am aware that .223 has indeed worked on larger targets, and so has .25 auto; but neither wold be my first choice. And now I'm sure I've steped in IT!     KURT

[George]

Somehow I am getting this picture in my head of Maxwell Smart (Old TV character from the sixties) getting whacked on the head with the "Cone Of Silence :-)

The right tool for the job is indeed the thing here. If i'm gonna be punching paper & clanging steel at under 400yds, I want a semi-auto .223. Further out than that, or with something other than paper & steel, I'll take my .270 with a 135-150 grain projectile doing about 2800fps.

In high tech circles, the TIM is referred to as the BIM (Biological Input Module) and most malfunctions are traceable to it. In motorcycle racing we used to refer to it as the "Shifter Activator" and once again it is where most problems start (and end).

BTW, I stepped in it first, as is my usual way ;~)

Regards, George

[kurtm]

A11141:

For some strange reason all I'm getting is a picture of agent 99's cones, although in the context of shooting paper out to 300 yds the "second shot is the last shot ",as we tend to think along the lines of two hits per target to score. Silly for major, about right for .223                                KURT

[kurtm]

A11141:

For some strange reason all I'm getting is a picture of agent 99's cones, although in the context of shooting paper out to 300 yds the "second shot is the last shot ",as we tend to think along the lines of two hits per target to score. Silly for major, about right for .223                                KURT

[George]

"in the context of shooting paper" "we tend to think along the lines of two hits per target to score"

(Pardon the edit, Kurt)

This brings to mind a couple of questions.

A:

How does everyone feel about the Multi Gun Association scoring method of "any two hits", or "one A hit" on paper to "neutralize" a target.

B:

Is "neutralizing" a target as opposed to "shooting" it PC, and who gives a damn about PC anyway?

I have shot a couple of matches scored that way recently and I think I am starting to like the method.

I see noticeable improvements in ease of scoring for the RO's and match staff.

It also seems to allow for some new ways to scr#*% up, and reward yourself, and anyone who knows me knows that I'm always looking for new ways to lose points :~)

Any thoughts out there?

(Yeah, I know this is a bit of a thread drift, but I started the whole mess anyway!)

[kurtm]

A11141, George:

The any two hit rule or one A is indeed much easier to score. The variation we used when we put on the S.O.F. shoot at Whittington was a variation of it; C,D major and at least 2 C,s minor, an A neutralizes in either case. This is also cool for the shooter as he can really crank up the speed. It is always fun to shoot Mesa's 3 gun because of this type of scoring.

With that in mind I personally like the way Mike Waidalich scores in W.C.3-G. 10 points for every A and fewer points for cs and ds with a split for major and minor. No penalties for a miss. One can not skip targets as they will call you back to engage them. ( you are probable already versed in their system). This form of scoring seems to reward accuracy much more than other systems, as two As are 20 points not the 10 from U.S.P.S.A. I believe accuracy should be rewarded, especially in  concideration of what we have discussed in our previous posts. I like both systems and both have their good points.

I don't like most scoring systems when it comes to rifles( major ), double tapping with a .308 is goofy all the time (and probable goofy for the little black CARBINE at ranges up to 150yds) as long as it is a c zone hit or better, same for shotgun slugs. Also the A,B zones in the head are just plain weird when it comes to rifle and carbine fire, but once again I guess it comes back to rewarding accuracy.                           KURT

P.S. edit away George A. I surely don't care!!

[George]

Upon review, I recognized that the truth to this issue required a little more definition to prevent misrepresentation of the underlying concept.

The accompanying illustration (borrowed respectfully from Glen Zediker?s Handloading For Competition, making the target bigger. Available @ http://www.zediker.com/ ) is the missing link that I was lacking when I attempted to delineate this concept earlier. However eloquently I tried to convey my thoughts on this subject, Glen does it better.

The main point to be made here is that the more accurate a rifle/ammo combination is, the looser a hold can be and still guarantee a hit (assuming the rifle/ammo combo are zeroed for the shooting conditions). The benefit here is speed. Anyone can get a 4.5 minute hold a good bit faster than they can get a 3 minute hold, anywhere, anytime, in any position, period. BTW. assuming that the target is 5 MOA, or 10" at 200yds, 4.5 to 3 is the relationship of a 1/2 MOA system to a 1 MOA system for required hold. Go figure out the disparity when you compare the 1.5 MOA system to the 1/2 MOA system, and see what you get then.

The math behind the concept of a "cone of accuracy" works like the illustration depicts. A half minute rifle/ammo combo will always get a 10 with the sight picture shown. A one minute rifle/ammo combo will NOT ALWAYS get the 10 with the same sight picture. I want the 10 if I held for it, thank you! This applies to any type of target, in any shooting competition. If I hold a good hit, I should ALWAYS get a good hit. I should be the variable here (out to about 300 yards anyway).

Regards,

[kurtm]

George:

The less accurate rifle will sometimes put one in the 10 even with a worse hold!! Just another way to look at it!! NOT A GOOD WAY, but a way. I now see that you are talking about the mechanical cone of dispertion, without out side influence such as me yanking the trigger because I spent all last month shooting sporting clays. I agree that a accurate rifle is better in this reguard. I was just hoping to point out that for 3 gun matches you don't need a sub M.O.A. rifle. All that aside you are CORRECT!!! great illustration!!!!        KURT

[George]

Thanks Kurt,

I came across the illustration today, and realized how perfect it was, wish I had seen it sooner.

And yeah, any reasonably accurate rifle will do quite fine. I didn't realize the benefits of an ultra accurate system until I got my hands on one. The benefits are all small gains in specific areas. But they do add up nicely in certain circumstances (warp speed steel shooting at a decent distance is the best example I can think of).

Regards,