3 or 5 shot groups

[stork]

When testing loads how many shot groups do you use.  What caliber and what kind of gun are you shooting?

[Leftoverdj]

I don't trust anything less than three five shot groups to identify a good load. (Much easier to spot a bad load) On rare occasions, with a light barreled hunting rifle, I use five three shot groups.

Any one group can be a fluke, even if you shoot ten shot groups.

[KN]

If I'm testing loads then its five shot groups. That will give you a better understanding of the loads characteristics. If I already have a good load and am shooting for accuracy then I'll shoot three shot groups. That helps minimize shooter error in you group size. It makes you look better too.   KN

[Catfish]

For big game hunting rifles 3 shot groups is good enough, but for varmint or target rifles 5 shot groups are the minimum.

[TNrifleman]

Both my big game rifles are Winchester Model 70 featherweights. For them, I use 5 or 6 three shot groups to give me a good idea of what a given load will do. My varmit / target rifle is a heavy barrel Remington 700. I tend to use 4 five shot groups as the standard from it.

[Lloyd Smale]

Rifles 5 shot handguns 10-12 two cyl full or two clips. Ive shot to many one inch 3 shot handgun groups that opened up to 3 inch when reality set in. I usually shoot 3 sets of groups with a load and average the bunch I allow for one flyer per set.

[longgun]

I tried to post this earlier but my server went down.   If it posted twice, sorry.

When working up new loads and trying various bullets and powders,  I shoot three shot groups.   If the three shot group looks good, then I do a couple of five shot groups.   Depending on wind conditions, I will try the same load on a different day and see how it repeats.  This keeps down unnecessary loading cost.  I am fortunate that where I live that I can load up a few rounds and step out of my shop door and test fire them.  Not like having to go to the range......Don

[Redhawk1]

I like 3 shot groups, 5 shots and the barrel is hot and may throw off your bullet. JMHO.

[ricciardelli]

5, unless it is a wheelgun, then one from each chamber...

[longwinters]

No matter what I am doing, new loads or just practicing, I shoot 3 shot groups.  For me it is more of a mental/concentration thing.  

Long

[Rick Teal]

I don't shoot groups.

[Iowegan]

Remember the reason for shooting groups is to provide a "sample" of the rifle's accuracy. The sample is then use to predict where the next bullet will strike. The higher the sample rate (more shots fired) the more predictable your next shot will be. statistically, a 10 round group gives you a 90% prediction, a 5 shot group gives 45% prediction, and a 3 shot group gives a 27% prediction.

Rifle barrels heat up quickly and that heat change will cause the groups to spread. You will get false samples if you allow the barrel to get too hot. I like to shoot 3 shots, spaced a couple minutes apart, then let the gun cool down for 15 minutes and repeat 3 more shots. I fire a total of 9 rounds per load.  I measure each group then average the three. From that data, I can predict with 81% confidence, the next shot will be within the average group size. I shoot each group at a different target and try to "call flyers". That way I can eliminate most of the human error and just deal with the rifle's accuracy.

No matter how many shots you fire, the key is to let the barrel cool down between rounds. The chamber heat will transfer to your cartridge and heat up the powder. All powder burns faster the hotter it gets. This will corrupt your groups because the muzzle velocity will change. I wait to chamber a round until just before I'm ready to shoot.

[fffffg]

a five shot group will tell you what your gun will shoot well. a three shot group will tell you what it dont shoot well..  another way of saying what already has been said..  try  all the powders, bullets, primers  crimps  etc you have with three shots,, then go to five with the ones that look  very good... 5 shots can  tell you if you have gun problems with that load.. ..  dave.

[PaulS]

I shoot four groups of five shots each. I use five targets to do this. One target gets taped to the target board and one gets taped over it. I fire the first five shot group. I remove the top target leaving the bottom target in place I tape another target over it and shoot the next five shots. I continue to do this until the four groups have been fired and then I take the "aggregate" target down and use it to measure the group. I compare that to the average group of the other four targets and the best and worst groups. I will shoot the "aggregate" target and four other targets on several occasions to measure an overall average aggregate and the best and worst group size and any patterns that immerge.

I do this for all the loads and when I find the three best I drag out the Chronograph(s) and test for velocities, S.D., and extreme spread. The ones that have the best accuracy is tuned to get as good a S.D. as it can without making groups grow and then I select the best one for accuracy. This is based on several days of shooting each load as described above.

PaulS

[rpseven]

I always shoot a 5 shot group when testing new loads, I myself can tell more about wether it is going to be a good load with a 5 shot group.