Wasnt sure where to post this....

I just shot a killer 3 round group at 100 yards and would like to know how to properly measure this group. I can get a micrometer and obviously measure the longest distance, but ive heard of people compensating for bullet diameter?? If someone could explain that more or post links to "how-to"'s that would be great!

Thanks!

Wasnt sure where to post this....

I just shot a killer 3 round group at 100 yards and would like to know how to properly measure this group. I can get a micrometer and obviously measure the longest distance, but ive heard of people compensating for bullet diameter?? If someone could explain that more or post links to "how-to"'s that would be great!

Thanks!

Supose to be measured center to center; center of the two farthest bullet holes.

Measuring the ouside edge of one bullet hole to the INSIDE edge of the farthest should do it...but paper often shows a smaller hole than the actualy bullet size (if you use brown traget paper, and tost it in the oven or other wise make sure it is dead-dry, it tends to show nice round full diameter holes).


Or measure the outside edge to the farthest outside edge and subtract the bulle diameter.

Most of us are pretty good at eyeballing the center of the bullet hole when there is some space between the shots on a target...I'll often lay a sheet of clean paper under the target, eyeball the center, and place a ink dot on the clean paler at that center....then do it for the fasrthest bullet hole...then measuer the distance between dots. If you want to be exsact, there are magnifcation eye loops that have gradiant scales (things were made for measuring things like quartz grains in geology, or tree growth rings, amoung other uses).


Often print my targets on old style graph paper...say the stuff with 1/10th inch grids...then I can just eyeball the target, count the grid squares, anc come very close to a real measure without any tools.
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One 3-shot group can be a freak....better to count the rifle's average of 5 or 10 3-shot groups.. or 5 50shot groups. But we all like a "bragger" group.

When checking overall accuracy, I prefer shooting at least one 20 round group. This accounts for the possibility of any fliers or whatever else may be going on that won't readily show on a 3 or 5 round group or may be discounted as operator error.

I started doing this after building up a load for my .222 rem. using three shot groups. Found a powder/bullet combo that shot an excellent three round group and went on to load another 80 or so of these. Upon missing a few woodchucks at ranges I knew I should have nailed them at, I went back to the paper. I shot the remaining 70 or rounds into a single target finding that well over 50% printed not even close to where they should have. Eventually tarced the problem back to the seating pin that had a slight high spot on it causing just a slight amount of cock to the bullet when entering the case. Wasn't readily seen until I really started looking for the cause of the accuracy problem but it made a huge difference. Had I loaded and printed 20 after finding the initial 3 shot test group, I would not have wasted so much time and money burning off the screwed up ammo.

The more you shoot, the better your chances of finding any other problems with rifle or ammo too.

I'll second ribbonstone's comment on using graph paper, sure makes things easier. I like gluing mine to a piece of thick cardboard backer with glue stick adheasive. Easier to handle and helps give a more accurate indication on center of hole. You can make it easier by placing the graph paper behind a standard target too, this way you don't have to work around any bullseye on the graph paper itself.

Your both right in that the three shot groups can be freak. I agree totally!! But its true, everyone needs a bragging group.

This rifle, using remington core-lokt ultra 150gr rounds puts together consistant(90% of the time) 5 shot sub-MOA groups, most of them at .5 MOA. These are eyed or measured using the .5" squares on my target when shot at 100yds. This particular 3 round group is basically one hole....it looks like 1.25 of a normal hole...I thought even for a 3 round group this is pritty good. I didnt realize how good the group was untill i got to the target. Ill get pics up when i can.

Anyway, thank you both for input! Its greatly appreciated.

Always like to see pictures of small groups.

Allright guys, here are the pics, some of my M77, some of my 10/22, and all the targets are three shot groups out of the M77. My one hole freak is in there somewhere. :D

...targets...

...more targets...the last one another of my best with comparison

I'll toast the paper in an oven...don't set fire to it, just "crisp" it up enough that it will show a good round sharp edged hole. Brown targets that have been stored for a long time often show this...so I just speeded up the aging process.

Usually shoot 5 round grous, but have been know to shoot 10 rounders for final decisions. When testing loads, may shoot as few as 3 rounds....after all, if the first 3 are a foot apart, the next two aren't going to make that load a "keeper" so why waste the time?

So I'll post five targets...he cener one is the sighter. Can waste as may rounds on the sighter as you want any time you want. But each of the other four has to count each and every round fired..has to be 20 rounds fired and counted, no "whoops" or fliers excluded (that's what the sighter is for).

Doesn't make for many braging groups, but does give a pretty good idea of how that load and shooter is performing.

I'll toast the paper in an oven...don't set fire to it, just "crisp" it up enough that it will show a good round sharp edged hole. Brown targets that have been stored for a long time often show this...so I just speeded up the aging process.

Usually shoot 5 round grous, but have been know to shoot 10 rounders for final decisions. When testing loads, may shoot as few as 3 rounds....after all, if the first 3 are a foot apart, the next two aren't going to make that load a "keeper" so why waste the time?

So I'll post five targets...he cener one is the sighter. Can waste as may rounds on the sighter as you want any time you want. But each of the other four has to count each and every round fired..has to be 20 rounds fired and counted, no "whoops" or fliers excluded (that's what the sighter is for).

Doesn't make for many braging groups, but does give a pretty good idea of how that load and shooter is performing.
Ill have to try that, see how im really doing

These are the targets so far that ive shot with the new rifle...besides the fouling shots....

Ill shoot some 5 or 10 groups and post those as well!

But it seems to me, that not ALL of those 3 roung groups can be fluke groups....

I go Ribbonstone one better. I may shoot as many sighter, adjusters, foulers, etc. as I want, but, when I start on the ones that count, it's 20 consecutive shots (4, 5-shot groups) out of that rifle. I developed that policy before I knew enough to know Benchresters allow for sighters anytime during the match.

I go Ribbonstone one better. I may shoot as many sighter, adjusters, foulers, etc. as I want, but, when I start on the ones that count, it's 20 consecutive shots (4, 5-shot groups) out of that rifle. I developed that policy before I knew enough to know Benchresters allow for sighters anytime during the match.
benchrest?? all im doing with this rifle is hunting deer...

i think this is a dang straight shooting hunting rifle, considering that these group are shot without the help of a rest....just prone position

i was very suprised with the accuracy and thoughti would share some of them

benchrest?? all im doing with this rifle is hunting deer...

i think this is a dang straight shooting hunting rifle, considering that these group are shot without the help of a rest....just prone position

i was very suprised with the accuracy and thoughti would share some of them

Guess it comes from impatience. Use to be the type to sit and observe the wind and light conditons for maybe 30-45 minutes before firing a single shot...looking for whatever combination was the most commonly encountered combination. Would only fire a round when that combination rolled around..maybe a 5 min. wait, sometimes 15min. IF the condition held, would rapid fire a second round while it held.

But as you noticed, this is a total waste of time for a hunting rifle...you have to take that shot now, not 15min. from now.

But if the truth is told, doing most of your practice from a benchrest is also a waste of time for a hunting rifle...unless you hit the deer firelds with a concete bench.

benchrest?? all im doing with this rifle is hunting deer...

i think this is a dang straight shooting hunting rifle, considering that these group are shot without the help of a rest....just prone position

i was very suprised with the accuracy and thoughti would share some of them
You and your rifle did a fine job eclarke! Those are some very nice groups. Like you said, if this is a hunting rifle, there's no need for 20 round, 4-5shot groups.

Congrats on your shooting and finding a great rifle.

BTW, I just measure outside to outside of the two furtherest bullet holes, then subtract the caliber diameter.

ribbonstone- I respect your patients...i could never sit there and wait to shoot my rifle. I guess that comes from a hunting backround...like you said, in hunting you have to take that shot now, not when the conditions are right.

Alyska338- Thanks. I just bought the rifle, and couldnt believe the groups that it put together. Even with a cheap 4x32 weaver scope on it, and weaver mounts, but those and the rifle work well with eachother. The only thing i think i would like to do is lighten the trigger pull just a tad, but why mess with a good thing?

The important point was that they are 20 consecutive shots, with no adjustments between shots. I usually shoot them in the span of 15 minutes or so. The 4 5-shot groups seems to be a widely accepted standard for average shot groups. So we are all on the same page. I'd be thrilled to get a new rifle that shoots as well as yours does. I wasn't belittling yours.

In a hunting rifle, I would think it of much more importance where that first shot hits, every time, from a cold barrel. I have a T-C Contender carbine in .223 that absolutely puts that first shot within 1/2" of the aiming point everytime. The second shot is also pretty close to the first, but from then on they start opening up considerably. But who cares? It IS a single shot rifle!

I didnt take it as belittling...no worries man!

I just thought maybe i mislead some people by not telling them it was a hunting rifle, not a range rifle or something i was really trying ot put groups together with. We started talking benchrest(of which i know nothing about btw) and i was like whoa....im not anywhere near that skill level(or money level for that matter)

I do like shooting my rifle and seeing how well it can group but im in no way trying to compete with you guys that accually know how to shoot!!

Either way good times eh?!?!

And btw, im taking u guys advice about the 4 5shot groups,a nd im going to try it! I hope i can still group 5 like i can group 3....i hope...lol

be careful with small group shooting, it is HIGHLY addictive, next thing you know, if all of your rifles don't shoot tiny you will be on a quest to get them all that way, just don't say I didn't warn you

be careful with small group shooting, it is HIGHLY addictive, next thing you know, if all of your rifles don't shoot tiny you will be on a quest to get them all that way, just don't say I didn't warn you
Great....another expensive hobby....

I allready know what you mean...deer hunting where i am, and where i do most of my deer hunting is all shotgun, and we all know how slugs fly out of even a rifled shotgun barrel....and the kick is terrible throwing 3" magnum slugs about 40 of them and ur shoulder is about gone. This shoots better, longer, and with less recoil than my slug gun, i may never go back!!!