I would like to know what are the parameters for grouping? I'm new to accuracy shooting, and I don't want to sound like a fool when I talk about how my rifle groups. How many shots does one need to take at a group to say a rifle is accurate 3,5,10? I was assuming 3 since I thought that was what the factory claimed their 1" at 100yrds addvertising with, is this correct or does their need to be more rounds then 3? How much time is taken between each round, is it click click boom, or do you wait a minute or two for the gun to cool down? When refering to groups past 3 rounds, could one assume that the accuracy will always suffer due to fouling and an unclean barrel? To some these questions may sound dumb, but please bear with me. I guess if one is looking for a factory rifle and the claims are that it shoots 3 rounds under an inch at 100yrds, could this be false advertising for a rifle they claim to have out of the box accuracy with since we don't know where that 4th and 5th etc. round ends up at? Just give me your thoughts, not looking for any brand name rifle explaination or put downs, just looking for a general definition of "grouping", and if you can please be technical meaning trying to stay away from general opinions and such. Thanks guys.
Grouping explaination
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Some manufacturers of the higher priced rifles/handguns will send along a proof target with the item to demonstrate it's accuracy potential WITH THE CARTRIDGES USED FOR THE TEST. This doesn't mean you can grab up another makers cartridges or your own reloads and shoot the same results. Also, they have sophisticated setups to test the firearms in. Its just like trying to duplicate the results printed in the reloading manuals without benefit of the same testing apparatus and equipment.
Now, as to how many shots need be fired for a group. Most manufacturers, rag writers and informal target shooters feel 3 shots constitute a group, and they are perfectly correct in that statement. Heck, even 2 shots could be called a group! Most serious shooters (benchrest and competition) feel 5 shots are more appropriate to properly define a group and then there's diehards that feel nothing less than 10 will be sufficient. My personal inclination is that 5 shots should prove the capability of the firearm's grouping, with that individual tweaked load combination.
Most firearms aren't going to do squat in the grouping department when using rapid firing. You should allow the barrel to stay below a temperature that would make holding your hand on it uncomfortable. Taking a bit between shots certainly helps and then, you have to factor in ambient temps, also. Hotter days, longer cooling off periods.
Again, MOST firearms perform best grouping after a few fouling shots have been fired. Clean, dry bores shooting to the same POI (Point of Impact) are a rarity, but they can be found occasionally. As to how many shots are fired before the fouling buildup caused a decline in accuracy depends on how well conditioned the bore is and how much carbon is left over with the type of powder being used, plus how much guilding metal gets stripped off the particular type of bullet being used. Soft all copper jackets tend to foul the most.
Sub-MOA and MOA are bragging points and some shooters won't be satisfied with a firearm that won't shoot that tight of groups. Actually, for the hunter and infrequent target shooter, 1 1/2" to 2 1/2" groups are perfectly fine to cleanly take game at the ranges most are shot at.
Now, as to how many shots need be fired for a group. Most manufacturers, rag writers and informal target shooters feel 3 shots constitute a group, and they are perfectly correct in that statement. Heck, even 2 shots could be called a group! Most serious shooters (benchrest and competition) feel 5 shots are more appropriate to properly define a group and then there's diehards that feel nothing less than 10 will be sufficient. My personal inclination is that 5 shots should prove the capability of the firearm's grouping, with that individual tweaked load combination.
Most firearms aren't going to do squat in the grouping department when using rapid firing. You should allow the barrel to stay below a temperature that would make holding your hand on it uncomfortable. Taking a bit between shots certainly helps and then, you have to factor in ambient temps, also. Hotter days, longer cooling off periods.
Again, MOST firearms perform best grouping after a few fouling shots have been fired. Clean, dry bores shooting to the same POI (Point of Impact) are a rarity, but they can be found occasionally. As to how many shots are fired before the fouling buildup caused a decline in accuracy depends on how well conditioned the bore is and how much carbon is left over with the type of powder being used, plus how much guilding metal gets stripped off the particular type of bullet being used. Soft all copper jackets tend to foul the most.
Sub-MOA and MOA are bragging points and some shooters won't be satisfied with a firearm that won't shoot that tight of groups. Actually, for the hunter and infrequent target shooter, 1 1/2" to 2 1/2" groups are perfectly fine to cleanly take game at the ranges most are shot at.
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5-shot groups. Some people still want 10shot, and a whole lot like 3 shot. 10 shots are a tough test, so only the hard core serious shooters bother. 3-shot groups are always smaller, but like fast food French fries, don’t really give a lot of ballistic nutrition.
3-shot groups...esp. if you shoot a bunch of them and ignore all but the smallest...are great advertizing. 10-shot aren't real meaningful to any but competition shooters. 5-shot is pretty much the standard, although a very good argument can be made for 7-shot.
Usually I find statistics about as friendly as a rattlesnake in my boot, but this one might be worth reading:
http://www.castpics.net/memberarticles/GroupSizesandStatsbyJB.htm
The real “meat” of the matter is in the charts.
Translating the charts:
If you want to be 90% sure of being within 10% of average accuracy, would take 23 5-shot groups. IF you could live with being within 20%, would take only 5 5 shot groups. Now in "stastitic-ish". 90% sure of being in 20% of average is usually good enough for most shooters.
3-shot groups...esp. if you shoot a bunch of them and ignore all but the smallest...are great advertizing. 10-shot aren't real meaningful to any but competition shooters. 5-shot is pretty much the standard, although a very good argument can be made for 7-shot.
Usually I find statistics about as friendly as a rattlesnake in my boot, but this one might be worth reading:
http://www.castpics.net/memberarticles/GroupSizesandStatsbyJB.htm
The real “meat” of the matter is in the charts.
Translating the charts:
If you want to be 90% sure of being within 10% of average accuracy, would take 23 5-shot groups. IF you could live with being within 20%, would take only 5 5 shot groups. Now in "stastitic-ish". 90% sure of being in 20% of average is usually good enough for most shooters.
Three shot groups are commonly used because they make factory barrels/rifles look better. Most standard production factory barrels are not stress relieved. When you take a standard, sporter weight barrel that has not been stress relieved, they have a tendency to start walking the bullets as they warm up. They can usually do ok with the first three shots, but by the time the fifth shot comes out, it could be an inch of more off from where the third shot hit. Doesn't give the shoot much to bragg about. Typicially, the heavier varmint style barrels will hold their shape better because they have a lot more metal mass to help assorb the heat, so they can usually do pretty good for five shots. When you start trying to get good groups beyound five shots, that's when the custom barrel makers come into play. Most of them stress relieve and lapp the bore of the barrel. You will always get the real shooters, the average shooters and the junkers when buying factory guns. Just depends on how the stars are aligned the day you happen to buy your's. Some factories do better than others but none are always going to make a rifle that shoots bug holes, even in three shot groups.
Reloading is going to be you're best bet if you want a rifle to shoot small groups. That will allow you to develope a load you're rifles likes rather than having to try and finding something close with factory loads. However, then you have a whole new learning curve to get around before you start making accurate reloads. There are also some rifles that even the best reload in the world won't help them shoot little bitty groups.
Reloading is going to be you're best bet if you want a rifle to shoot small groups. That will allow you to develope a load you're rifles likes rather than having to try and finding something close with factory loads. However, then you have a whole new learning curve to get around before you start making accurate reloads. There are also some rifles that even the best reload in the world won't help them shoot little bitty groups.
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674 Posts
Short answer is it depends on what use the gun. Target shooting, competition shooting, prairie dog shooting you are looking for a gun that will hold tight over a long period of time with fairly rapid shooting. You don''t have time to cool off your barrel in the middle of a rapid fire string on the firing line.
Woods gun, going after deer or squirrel or that pesky long shot at the goat who refuses to let you get closer than 600 yards then be happy with a tight 3 shot group. You won't get a 4th shot at that kind of game and you won't be shooting so many shots that your gun will get hot enough to change point of impact.
That is why I go out with a clean barrel when I hit the woods. I sighted in my gun with a clean barrel. I cleaned the barrel and shot again the next day and cleaned it again, a week later did it again. If I get a good first shot with a clean barrel then a so called fouling shot is not necessary. 3 shot group is sufficient because if you haven't hit your quarry by then he will be out of sight anyway.
Woods gun, going after deer or squirrel or that pesky long shot at the goat who refuses to let you get closer than 600 yards then be happy with a tight 3 shot group. You won't get a 4th shot at that kind of game and you won't be shooting so many shots that your gun will get hot enough to change point of impact.
That is why I go out with a clean barrel when I hit the woods. I sighted in my gun with a clean barrel. I cleaned the barrel and shot again the next day and cleaned it again, a week later did it again. If I get a good first shot with a clean barrel then a so called fouling shot is not necessary. 3 shot group is sufficient because if you haven't hit your quarry by then he will be out of sight anyway.
3, 5, 10? I use all with various rifles. If a deer rifle can put its first shot where I want it to go, I almost don't care where the next shot will go. But, just so I can have an idea, I will usually fire 3-shot groups. I rarely do any varmint shooting, particularly the high-volume prariedog-type shooting (no prairies, no dogs!), but with varmint rifles I shoot 5-shot groups. I have a .22 target rifle I usually will shoot 10-shot groups with -- just because they are SOOO tiny!
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I like to shoot a bunch of 5 shot groups at targets I print on regular printer paper. After I shoot a bunch of groups, I can stack up the paper so the targets all line up, hold it to a strong light, and I can see simulated 10, 15, or even 20 shot groups. One day I was testing three different hand loads, with quite varying powder charges, and the stacked groups were within a 2" circle at 100 yards. That made me feel really good; not only were the groups small, but the rifle was very forgiving of variations in the ammo. (Of course, the bullets and powder type were the same. No way it would put a 120 gr bullet to the same spot as a 140 gr.)
One other thing: if someone claims a certain size 3 shot group, that should be only three shots at the target. It's not shooting 5 shots and measuring the best three. If the best three are shots 1,3, and 5, that's cheating.
One other thing: if someone claims a certain size 3 shot group, that should be only three shots at the target. It's not shooting 5 shots and measuring the best three. If the best three are shots 1,3, and 5, that's cheating.
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Yup. Tennessee's "3-does-a-day" limit can really ruin a weekend!3 shots for hunting rifles. The few times I've connected beyond the first shot, I've generally regretted it as it just meant more animals to field dress....
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