Home Forums Hunting & Shooting Hunting Rifles 3 round, 5 round, or 10 round groups? An experiment.....

So in the spirit of the Terminal Ballistics thread (grin), I thought I would share a theory/observation about accuracy and groups and the results of a small test I shot today. To begin, with before someone says it- buy a gun, shoot decent bullets, practice, and go kill something. The rest is just gack. However, I like to operate on facts and reality more than emotion and "feeling".


Like the "which bullet to use" threads, one that is often cussed and discussed is how many rounds and groups does it take to know what a guns accuracy is. Well I test everything. One thing that is obvious is that people way over estimate how accurate their rifles are. We see it almost every thread on this site alone: everyone says their gun is a 1/2 MOA/sub MOA/etc rifle.......... "if I do my part." Or even better "my _______ (insert rifle/load here) shoots to .633 MOA at _______ (insert distance here)." Between teaching, competition and work I see several hundred thousand rounds a year fired. Everything from Military issued sniper rifles and M4's, to long range competition guns, to Pre 64 Model 70's in 270Win. In all those rounds fired I have yet to see a hunting weight rifle chambered in 24 caliber (6mm) or larger average, for multiple groups, under .5 of an inch at 100 yards on demand on the spot. For sure there has been some that will average 3x 3 round groups shot back to back with no called fliers under 1 inch (truly only a few at that), but not one that would do 5x 3 round groups, 3x 5 round groups, or 1x 10 round group averaged at .5 inch or under. The only guns I see that will do it are purpose built LR competition rifles.

I've had a running $100 bet in my classes and at training for anyone that can shoot 5x 3 round groups, 3x 5 round groups, or one 10 round group under .5 inch at 100 yards on demand, back to back with no called fliers, no excuses, and no bs with a hunting rifle. Not once has anyone been able to take the money even though fully 50% swore up and down they had a 1/2 MOA rifle......... "if I do my part".... If the rifle is sandbagged there should be no fliers. There should be no- "if I do my part". If you can't do your part sandbagged, stop referencing how accurate your gun could be and learn to press a trigger and stop flinching.


Of course it is human nature to remember the good and forget the bad, and so it goes with grouping. Forgetting the human part of it and only speaking to the mechanical part I have had a long standing theory (and I'm sure someone else has thought it before me) that 1x 10 round group will show what that gun/bullet system is going to do day in and day out on demand. And really what good is anything if it cannot be repeated on demand? Likewise 3x 5 round groups averaged with all rounds counting (i.e. no called "fliers") will do it and give you nearly identical results to the 10 round group. Now everyones favorite- the 3 round group. The stated reasons for using 3 rounds for a group is because, in no particular order- "it's a hunting rifle, it will never shoot more than 3 rounds at an animal" , "it has a thin barrel that walks when it gets hot", "3 rounds wastes less ammo" , "5 and 10 round groups test the shooter more than the rifle", etc, etc....

And that all may be true. Unfortunately 3 rounds does not tell us anything about what that rifle will statistically do on any given shot fired. Even a couple of 3 round groups isn't enough. It's just not a big enough sample size. Especially when shooters start not counting bad shots/groups because of "fliers" or because "I pulled it". Shooting sandbagged, unless that round is 8 inches away from my half inch group, it counts! I have seen time and time again guns that the owner said shot .5moa/1 moa/ etc groups mechanically consistently miss targets that they shouldn't have.




Today I setup a small test during relays in a military class. I shot 5x 3 round groups on individual targets with a backer containing the composite of all 3rnd groups for a total of 15 rounds. Then I shot 1x 10 round group with a backer catching all 10 rounds and the previous 15 rounds from the 3 round groups for a total of 25 rounds. Then I shot 3x 5 round groups with the backer containing all 40 rounds fired. This lets us measure each individual group and also see where the crossover point is that the groups get no larger.



The rifle used is my Recce/designated marksmen rifle. Chambered in 223 with a 16 inch stainless match free floated barrel cut with a Wilde chamber, and a JP Duty trigger at 3 pounds. Scope is a Leupold Mark4 6x40. Ammo was contract issued 60gr V-Max loaded to 5.56 spec.


Here is the rifle with the targets from all groups-




Having shot dozens of groups with this rifle I know it will go 1.5 to 2 inches for 10 rounds with this particular ammo. For sure it will shoot a bunch of 3 and 5 rounds groups under an inch but it will also "throw" one every now and then. It averages 1-1.25 MOA for 10 rounds with match ammo. The size of the groups doesn't matter only their relation to each other. This gun was perfect because it is just accurate enough for you to expect most 3 and 5 round groups to be about an inch just like most hunting rifles.

The range to the targets was 100 yards with 20 foot high berms on three sides. The rifle was sandbagged on a bench.


The pictures of each group will be posted below with the size of the group in inches written in marker to the right of the black bull. Group #2 of the 3 round groups was accidentally tacked over and isn't shown, however I do have the size recorded and you can see the shots in the 3x 3 round composite target. Also the composite 3x5 round backer was thrown away or shot, but again I do have the group size recorded.

BSA,

I said it before but that is one reason I enjoy seeing your posts; you actually show 5+ round groups generally sighted in with very few, to no, excuses and no taped up holes. I always think to myself- why show a group that isn't even close to being zeroed, and has tape all around it...?


Btw- that gun shoots very well and I would use it just about anywhere.

The following targets are all 308Win/155gr Scenar. Shot from Remington 700 varmint barrels.

I've found in general a 3-shot group will identify a bad load, but may not tell the whole story on a decent load.


5-shot groups keep everybody pretty honest, good or bad.


10-shot groups give me full confidence in a load, and that my zero is well centered.




Getting out to 300yds or so is also a good test.

10-shot at 100, and 350 yards, wind was working.