The effect of rifle and ammo on group size and score.

[in2anity]

Outside of fully-supported, time-unlimited shooting, I've long argued that F-class level accuracy is a rapidly diminishing return on expenditure and effort. Furthermore, it's a bit naive to come to conclusions based on small sample sizes. In the club circles, it takes weeks if not months to conclude whether a tiny variable tweak ultimately yields a better group.

https://youtu.be/wBIligz1NlU

Give me match-quantity, consistency over tiny 3-shot clovers any day. To me that's the appeal of a match rifle.

[bladeracer]

Quite a good job of mathematically explaining a concept that most of us know exists. A great shooter can shoot great with weak equipment, but a weak shooter still shoots weak with great equipment, and 1MoA is all anybody needs from a rifle.

[Larry]

His method of determining group size is a very old method called Berdan String. I dont agree totally with the premise. I try to get the equipment down to 1/4 MOA I measure this and keep track of it at 150 yrds. If I cant get this consistency then any adjustments made through a competition are really inconsequential. why make a 1/8 adjustment if the gun may throw the next shot 1 MOA in any direction. If you dont have the confidence in your equipment then making any decisions and adjustments through out the range irrelevant.

[in2anity]

Our very best shooters (all of which are also exceptional TR shooters out to 800m) can put ten rounds into under 2moa, during the slow course of fire (either deliberate or application) from prone at 300m, using a factory front blade sight and a rear peep, and a service sling like the m1907 sling or USGI web sling. Obviously they do slightly better with a front tunnel for Palma matches, but only slightly.

Everyone has completed the slow course after approx 2 minutes of shooting. Sub 2moa can yield a perfect integer score, aka a possible. With such skill, it should be possible to also group into the V, and get a perfect decimal score, alas take windage into consideration, and almost certainly decimals are dropped. That's essentially the same outcome as the top High Power shooters in the US, like Konrad. if you clean every course during a multi-stage, without dropping an integer, you will go close to winning overall.

A scope will bring the group in a bit, more importantly make it more circular. As analysed here:

https://youtu.be/ffuGpz1ZsD8?list=TLPQM ... ctXfkBeFEA

So in our context, the difference between a sub-moa gun and say a 1.5 moa gun is fairly insignificant, so long as the rifle is consistent. Consistency is king.

From standing offhand (distances), you are above average if you can put all your shots into sub 4moa. I mean all your shots, under match pressures, consistently. The best shooters are going sub 3moa, and will go close to shooting a perfect score if they can hold that.

I've heard high-power MS shooters claim they are "sub-moa accurate" from standing offhand, but if they somehow recorded all 40 shots from their match, particularly including the 500m rams, I bet their group would be significantly larger than 1moa. Granted they have the luxury of taking the weight off their arms, which would help. Personally, I think a 1.5moa grouper is perfectly competitive for HP-MS.

[in2anity]

His method of determining group size is a very old method called Berdan String. I dont agree totally with the premise. I try to get the equipment down to 1/4 MOA I measure this and keep track of it at 150 yrds. If I cant get this consistency then any adjustments made through a competition are really inconsequential. why make a 1/8 adjustment if the gun may throw the next shot 1 MOA in any direction. If you dont have the confidence in your equipment then making any decisions and adjustments through out the range irrelevant.

Definitely agree you need utmost confidence in your gear. So chasing the optimal load is a cog in that wheel. Nevertheless I agree with Konrad's analysis (of service rifle accuracy). Larry are you shooting F by chance?

[Larry]

Yes I shoot F class. I have also shot it with a factory rem 700 that could only hold 1 MOA at best and it is very frustrating. Was it the wind that moved those last two shots or just the gun. In the end with that gun making adjustments was often counter productive. You may make the adjustment and then the gun goes and puts the shot further out the other side than you just made adjustments from.
I think it is important to be able to identify what component of your shooting is causing any offset and whether that offset is variable or consistent.

[in2anity]

Yes I shoot F class. I have also shot it with a factory rem 700 that could only hold 1 MOA at best and it is very frustrating. Was it the wind that moved those last two shots or just the gun. In the end with that gun making adjustments was often counter productive. You may make the adjustment and then the gun goes and puts the shot further out the other side than you just made adjustments from.
I think it is important to be able to identify what component of your shooting is causing any offset and whether that offset is variable or consistent.

As I alluded to in my opening words, F-class is a different ball game. In that world, I agree you really need to be pushing the accuracy envelope to expect to take home the gongs. I've made some visitor appearances in F-class and believe me, with wind, I can totally see how you need to be pushing 1/2moa loads. That X ring does not leave much room for error.

[bladeracer]

The Berdan method measures from your point of aim, which is worthless to me when I'm testing a rifle/ammo combo, but I do think extreme-spread is a very poor way of measuring accuracy, we use it just because it's very easy, thus we are able to make quick and simple comparisons of groups by measuring across the outliers while ignoring all other shots.

I would prefer to measure a group according to mean deviation from the centre of the group, but I've always struggled to precisely determine where the centre is. And I've been unable to find a way of doing so.

[JohnV]

Top shooting rifles are produced in the machine shop / workshop . Then tested on the range . Top shooting ammo is produced by hand loading quality components with precision made projectiles that compliment that rifle and then tested on the range . If said outfit ends up in the hands of a top shooter then it will tend to give good results . I will go for the gun that shoots tight clover leaf groups every time .

[Larry]

Not so sure about the point of aim part you mentioned BR. Unless you assume that the point of aim was the center of the target. I have always understood it to be the distance of each shot from the center of the target originally measured with a piece of string. Each measurement is then added to each other to come up with a total.

[bladeracer]

Not so sure about the point of aim part you mentioned BR. Unless you assume that the point of aim was the center of the target. I have always understood it to be the distance of each shot from the center of the target originally measured with a piece of string. Each measurement is then added to each other to come up with a total.

Yes, I understand that method, but it's only relevant after you've developed a load, up til then your groups could be hitting anywhere relative to point of aim. Using the Berdan method to measure groups that are minutes away from point of aim tells me nothing at all.

But the author of the video did respond with a good suggestion.

I place twenty (or fifty, or more) holes on a target. I measure the distance from each hole horizontally and vertically (two measurements per hole) to the point of aim, then average them, it gives me the average distance from point of aim in both axis, which should indeed be the precise centre of the group. From there I can then measure the distance each hole is from the centre, and average those, then double it to give me a theoretical "group" size that includes every shot, rather than just the two outliers. Knowing the precise centre of the group also gives more precision when zeroing.

[Larry]

As I alluded to in my opening words, F-class is a different ball game. In that world, I agree you really need to be pushing the accuracy envelope to expect to take home the gongs. I've made some visitor appearances in F-class and believe me, with wind, I can totally see how you need to be pushing 1/2moa loads. That X ring does not leave much room for error.

Yes the X ring at the 500 yrd target is 65mm or 1/2 MOA 0.5118 and the 6 ring is 130 mm or 1.02 MOA.

So a gun that only gives you a 1 MOA consistent grouping is really making things hard as there are so many other variables in getting a shot down range. Just the way you place your hand on the stock will influence the position of the shots.

This is one of my better targets shot at 500 yrds

target1.jpg (96.82 KiB) Viewed 2412 times

[Bugman]

Just off the subject a bit. These are terrific targets. I see them in use at my local range.

[in2anity]

Just off the subject a bit. These are terrific targets. I see them in use at my local range.

As in the digital system? What is that Larry - Hexta? Nice shootin btw - so close my friend, sooo close...

[Larry]

Yes the target system is a Hexta. We are fortunate in Australia that a lot of the clubs have gone with these systems. They are the best in the electronic target systems out there. Expensive though again fortunately despite what a lot of people think about our government and there stance on Gun policy they do give a lot of grants to sporting clubs making these competition grade targets obtainable.

[in2anity]

We have the old kongsberg. Simple and robust, but highly antiquated.