Realistic 10-shot groups

[khart1988]

My Tikka will keep good ammo within 1.5MOA on a good front/rear bag setup, no matter how many shots (no rest or cooldown time, but the barrel also doesn't wander when got.). 3MOA with cheap bulk ammo.

Also, stating that a 1.5 MOA gun is good to 400 on a 6" killzone is not nearly as important as shooter ability. Dabbling into longer range rifle shooting, I see a lot of talk about group size being a 1:1 factor for determining max range and it's not quite so simple.

1.5MOA means it will put any bullet into that group size during any shot, and is typically similar to your wobble zone on target. But if you shoot 10 shots, your crosshair spends far more time comparatively within a much smaller area as it dances around, and any given round will most likely shoot far closer to center than your max group size if you breaks it properly.

Coming from archery we say to "accept the pin float and let the shot break" as 9/10 times a well-executed shot will place the arrow far closer to center than trying to force the shot to break on the bullseye. Your pin can be dancing all over the chest of an animal, or the X on a target, but if you hold it together and execute properly then you'll almost always center punch what you're aiming at.

So going back to the example, a 1.5MOA gun will hit a 6" target far more often than not at, say, 600 yards, and misses are statistically far more attributed to a poor shot or bad wind call than would ever be noticed if one had a legit 1MOA gun.

 

[Mickp7]

I spend my first hundred rounds through a new barrel fire-forming brass, breaking in the barrel, and getting an idea of what the rifle likes in terms of speed and seating depth. I start with 100 pieces of brass accordingly. Similar to the suggestions above, I'll start with 3 shot groups, then go to 5 shots once I have something promising, adjusting the charge up and down slightly to make sure the "window" of charge weight isn't too small (hoping this will also translate to different temperatures). This is done at the maximum distance my home range goes, 420 yards, and my goal is to consistently get 1/2 moa or better groups. Regardless, I know I am putting 100 rounds through the barrel before taking it to the field, so I have time to explore. On the 2nd brass firing, I shoot as many as I need to confirm the load is holding true, then load the remainder of the 100 for hunting or longer range practice.

If you google "Your groups are too small", you'll find some Hornady podcasts that talk about this subject.

 

[GSRetrievers]

A 10 shot group waiting 3 minutes between each shot is 30 minutes. In 30 minutes I could have fired 10 shots at varying distance in the wind and actually learned something, what the bullet is doing in those conditions. To me since I'll never be taking 10 shots on an animal at 100 yards, and I'm pretty confident taking a 100 yard shot, is not only a waste of components and barrel life but a wasted training opportunity as well.

 

[Starbuck]

What's the point of a ten shot group? If your shooting half moa 5 shot groups, that's better then 95% of the people on this forum. 10 shot groups proves nothing and is just wasting components and barrel life. If it's taking you 10 shots in the field to be successful in the field, you should probably find a new hobby.

Keep in mind the .223 with match bullets is gaining popularity as a big game set up. Form what I'm reading, multiple shots at one animal is pretty standard, or at least not uncommon. This is certainly due to faster time in getting on target between shots with a low recoiling rig, but just the same, I can see why some of these guys are so concerned with how close to original POI shots 5-8 in quick succession are landing.

 

[BALLISTICJESUS]

Ignore the internet clowns. . When it comes to a light weight hunting rifle. All I give a S@^T about is the first 3 three shots from a cold bore. We aren't talking about my 20+ pound 6mm Dasher here.

 

[richhymas]

I've been doing 5-shot groups for load development. Once I get a 1/2 MOA 5-shot group, I call it good. However, I'm finding that the same load opens up to 1 moa when I do 10-shot groups. I allow several minutes between shots to cool down.

Wondering:

1. Do others experience the same sort of thing?

2. I'm shooting with custom barrels (proof and fierce). But these are lightweight, high-recoil hunting rifles. Should I be demanding a 1/2MOA 10-shot group, or am I chasing a rainbow trying to make that happen?

I see guys at my range shooting 20-shot 1/2 MOA groups, but they are shooting huge bull barrel .223's literally ratcheted down to an enormous rest. I can see how that would be pretty consistent . What's a realistic expectation for the rest of us?

If this is a hunting rifle to be used for a hunting rifle, you are good. I would shoot a 5 shot group at 600 yards to make sure you are not opening up at distance.

If you wanted to be super picky you could shoot 5 consecutive cold bore shots. That first shot is the most importsnt. Make sure that shot is what you use to set your zero for hunting.

 

[Tommy T]

I've been doing 5-shot groups for load development. Once I get a 1/2 MOA 5-shot group, I call it good. However, I'm finding that the same load opens up to 1 moa when I do 10-shot groups. I allow several minutes between shots to cool down.

Wondering:

1. Do others experience the same sort of thing?

2. I'm shooting with custom barrels (proof and fierce). But these are lightweight, high-recoil hunting rifles. Should I be demanding a 1/2MOA 10-shot group, or am I chasing a rainbow trying to make that happen?

I see guys at my range shooting 20-shot 1/2 MOA groups, but they are shooting huge bull barrel .223's literally ratcheted down to an enormous rest. I can see how that would be pretty consistent . What's a realistic expectation for the rest of us?

Stick with your 5 shot groups I don't think you would have to worry about 10 shots out hunting

 

[Quinncannon]

There are plenty of opinions on this matter, each of us have our own standards, I suggest sticking to the one that works for you. I wouldn't call anyone a clown who has high standards and have put those standards to the test through testing and even competition.

For hunting, no doubt, the first round out is the one you should have the most confidence in. I have witnessed through competition, more good trigger time through training and practice are the most important.

 

[Rick Richard]

As mentioned your requirements may be different when hunting or competition. Just do what YOU do.

 

[Greyfox]

My psychology between my hunting rifles and my competition/Varmint rifle as different as the rifle configurations and weight. They are each tested for the conditions of use. Once a load work up with each, testing for consistent sub .5MOA precision/accuracy 3-5 shot groups on multiple session is complete, the practical criteria/testing for each rifle is different….With the exception of generally starting a shooting/hunting session with a 2-5 shot fouled bore.
Similar to Feenix, I can only recall a couple of situations over decades with my hunting rifles where more then one shot was fired. Once I have established a load which I am confident of its performance for 3-5 shots out to my max distance, I will test for a cold bore and follow-up spread over multiple days at varied conditions that are comparable to my typical hunting conditions. My criteria is <.5MOA POI. Once this is established, I will do an abbreviated check at the start of each hunting season, usually at 200 yards. My go-to rifle for 15 years has 1200 rounds fired with no material change in performance.


My competition/Varmint rifles use the same process until 3-5 shot confidence loads is developed. Since the typical demand is 10 shots in <2minutes at <.5MOA…They are tested as such…..During the warmer months .
I am lucky to make it through one season before replacing my barrel….But they will hold their performance for this duration. Setting my zero…10 shots/1.5minutes.

.

 

[BrentM]

I've been doing 5-shot groups for load development. Once I get a 1/2 MOA 5-shot group, I call it good. However, I'm finding that the same load opens up to 1 moa when I do 10-shot groups. I allow several minutes between shots to cool down.

Wondering:

1. Do others experience the same sort of thing?

2. I'm shooting with custom barrels (proof and fierce). But these are lightweight, high-recoil hunting rifles. Should I be demanding a 1/2MOA 10-shot group, or am I chasing a rainbow trying to make that happen?

I see guys at my range shooting 20-shot 1/2 MOA groups, but they are shooting huge bull barrel .223's literally ratcheted down to an enormous rest. I can see how that would be pretty consistent . What's a realistic expectation for the rest of us?

No one shoots 10 shot strings with a hunter. Literally a wast of time. If you want data do the 5 shots over and over and record the data for sd etc and repeatable accuracy over a wider temp range or conditions. If you a building a comp rifle, like prs, then yes you need tighter groups shooting longer strings.

 

[Hondo64d]

I've been doing 5-shot groups for load development. Once I get a 1/2 MOA 5-shot group, I call it good. However, I'm finding that the same load opens up to 1 moa when I do 10-shot groups. I allow several minutes between shots to cool down.

Wondering:

1. Do others experience the same sort of thing?

2. I'm shooting with custom barrels (proof and fierce). But these are lightweight, high-recoil hunting rifles. Should I be demanding a 1/2MOA 10-shot group, or am I chasing a rainbow trying to make that happen?

I see guys at my range shooting 20-shot 1/2 MOA groups, but they are shooting huge bull barrel .223's literally ratcheted down to an enormous rest. I can see how that would be pretty consistent . What's a realistic expectation for the rest of us?

The increase in group size with an increasing number of rounds is normal. Five shots is actually a very small sample size and if you truly want to have a very firm idea of where your rifle is going to place the next bullet, it takes a 20-30 round group to do it. FWIW, MOA 10-shot groups from a lightweight hunting rifle is very good.

Many years ago, I used 3-shot groups because conventional wisdom stated "I'll never take more than three shots at an animal." But, I noticed that when shooting another group with the same load, the point of impact might be slightly different, or maybe the group would open up, having two shots touching, and one a little out. Why? So, I started shooting multiple groups at the same POA and saw that the composite group showed me a much truer picture of what that rifle/load combo was truly capable of.

Providing the whole system is sound, a rifle will fire all of its bullets in a cone. With the 6PPC benchrest rigs, this cone will be very small, with others, bigger, but still a cone. The more rounds you fire, the bigger this cone will get until the sample size is big enough to represent a high level of confidence in statistical variation. What we, as hunters want, is to put enough rounds in a group to have a reasonable idea of where the next round is going. We're this not so, we wouldn't shoot groups at all, but just a single shot. In order to preserve barrel life, I do this by firing three, or maybe five, let the barrel cool, then fire three or five more at the same POA until I have a composite group of the sample size I want. The more shots in the group, the higher your confidence level can be. Most of the time now, I use a 10-shot composite. While not absolute, it provides a much higher level of confidence than the typical 3 or 5-shot group. 20 shots is better.

For those that say 3 is enough, I challenge you to do as I did years ago, and stack a couple of more groups on top of the first one, letting the barrel cool between groups, and see how big the composite is. It will absolutely be bigger than the single group and it is very likely that your "1/2 MOA all day" rifle really isn't.

A larger sample size doesn't just apply to group size either. The same principle applies to zeroing and load development. If you shoot enough rounds, you will discover that your .3gr increase in powder charge doesn't make nearly the difference you thought it did. I wanted to find max for a particular rifle once, so loaded 10 rounds, increasing by .4gr per round, figuring the first time I saw excessive pressure signs, I'd back off .5gr and call that max. The composite 10 round group with 10 different charges went into one ragged hole, well under MOA. I could have picked any one of those powder charges and expected similar results.

Actually, group size is no longer my preferred indicator of how well my rifle is shooting. Extreme spread only takes into account the data provided by two rounds, the two that make the widest spread. Average distance from center is better and you really don't have to measure it, you can see it. If during load development, I have a charge where the extreme spread of two different charges is similar but one of them has 8 of the ten wadded into a tiny little hole and the other is randomly scattered, I'm going to pick the first.

John

 

[mrjashu]

The increase in group size with an increasing number of rounds is normal. Five shots is actually a very small sample size and if you truly want to have a very firm idea of where your rifle is going to place the next bullet, it takes a 20-30 round group to do it. FWIW, MOA 10-shot groups from a lightweight hunting rifle is very good.

Many years ago, I used 3-shot groups because conventional wisdom stated "I'll never take more than three shots at an animal." But, I noticed that when shooting another group with the same load, the point of impact might be slightly different, or maybe the group would open up, having two shots touching, and one a little out. Why? So, I started shooting multiple groups at the same POA and saw that the composite group showed me a much truer picture of what that rifle/load combo was truly capable of.

Providing the whole system is sound, a rifle will fire all of its bullets in a cone. With the 6PPC benchrest rigs, this cone will be very small, with others, bigger, but still a cone. The more rounds you fire, the bigger this cone will get until the sample size is big enough to represent a high level of confidence in statistical variation. What we, as hunters want, is to put enough rounds in a group to have a reasonable idea of where the next round is going. We're this not so, we wouldn't shoot groups at all, but just a single shot. In order to preserve barrel life, I do this by firing three, or maybe five, let the barrel cool, then fire three or five more at the same POA until I have a composite group of the sample size I want. The more shots in the group, the higher your confidence level can be. Most of the time now, I use a 10-shot composite. While not absolute, it provides a much higher level of confidence than the typical 3 or 5-shot group. 20 shots is better.

For those that say 3 is enough, I challenge you to do as I did years ago, and stack a couple of more groups on top of the first one, letting the barrel cool between groups, and see how big the composite is. It will absolutely be bigger than the single group and it is very likely that your "1/2 MOA all day" rifle really isn't.

A larger sample size doesn't just apply to group size either. The same principle applies to zeroing and load development. If you shoot enough rounds, you will discover that your .3gr increase in powder charge doesn't make nearly the difference you thought it did. I wanted to find max for a particular rifle once, so loaded 10 rounds, increasing by .4gr per round, figuring the first time I saw excessive pressure signs, I'd back off .5gr and call that max. The composite 10 round group with 10 different charges went into one ragged hole, well under MOA. I could have picked any one of those powder charges and expected similar results.

Actually, group size is no longer my preferred indicator of how well my rifle is shooting. Extreme spread only takes into account the data provided by two rounds, the two that make the widest spread. Average distance from center is better and you really don't have to measure it, you can see it. If during load development, I have a charge where the extreme spread of two different charges is similar but one of them has 8 of the ten wadded into a tiny little hole and the other is randomly scattered, I'm going to pick the first.

John

+100
This is the way

 

[Mike6158]

Here, let me make this perfectly clear (not at all) with an example I shot a few days ago. Total rounds shot - 50 (sighter velocity was recorded in the Garmin but not on the first sheet).

The test was a ladder for my .338 Edge, 300gr OTM, 300 yards. 100 yard sight in check first. 5 shot groups. .5 MOA - .75 MOA was typical, but, by the time I got down to shooting the "fire forming" rounds, I was feeling a bit "assaulted" and not on my best shooting game. Along with good groups I was looking for best SD. I shot a total of 20 rounds at the same powder charge. That's where sheet 2 comes in.

Ladder Test. By the way - Fire Forming wasn't "fire forming". This was all brass I had shot before and set the shoulder back .005" when I loaded them (changed press and didn't check before I got 15 rounds in) instead of the normal .002". Based on the target (I took notes and tossed the target for some reason. Battle fatigue I guess), group 4 was the best (smallest at .38 MOA, 300 yards, and a little vertical). I'm pretty sure that the vertical problems I was having at 300 was me.

Shoot 5, let the barrel cool, shoot 5, etc. I use a little 3D printed fan from Echelon Rifles. It runs off of USB and for its size it works pretty good.

Group 4 SD was 7.1. But wait you say... Group 6 has the best SD at 5.6. It should have the best group. The 5 shot group (6) wasn't bad. 1/2 MOA at 300. Also no vertical. But let's see what happens when I put all of the 89 gr charges together.

Looking for the number of rounds shot that makes SD useful. Invariably, when the topic of SD comes up, if you've shot 3 rounds you need to shoot more, 5? 10? you need to shoot more. How many is enough? All of them? I call it Tootsie Roll Owl syndrome. You have to look at this right to left. Ok... you don't HAVE TO look right to left. It's the internet. I'll never know. Or care.

The first 4 on the right are the 4 individual 5 round groups of 89gr of H1000. Next is the first two groups combined and second two groups combined to make a 10 shot string. I combined them in order of when they were shot. That matters because it worked out that the two 5 shot groups with the lowest SD were combined and the two with the highest SD were combined to make the 10 shot strings. The 20 shot string is the more useful between 10 and 20 shots.

How do I use SD? I shoot 5 of each charge. If the SD isn't single digit I don't mess with it. IN THEORY, that lot of powder and that charge isn't going to improve in that rifle if the SD is high. It shows up on the targets too. If I just go off of target, what worked last time doesn't necessarily work the next time if the SD isn't single digit. I did this test with 3 shot groups and the same applies. If SD isn't single digit it usually doesn't shoot as well (shooter error is a bigger deal than numbers on a spreadsheet imho) as the single digit SD loads. So I can cull it with 3 shots but I can't count on 3 shot single digit SD's to be there the next time I shoot. 5 shots seems to be the minimum for this rifle.

Of course the last part of all of this is - Hunting rifle. Not Long Range hunting rifle... shoot 3 at 100 and if you like what you see go hunting. Both ranges I shoot at won't let me hunt there. I think most ranges are like that

20 round group of 89gr SD was 10.13. That's not horrible. The best 5 shot SD of the 20 was 4.58. Comparing 10 shot to 5 shot groups... I'm sticking with 5 shot groups but without the other 5 shot groups at the same charge I might've trusted those last two if the targets hadn't been a lot worse than the group 4 and 6. Just numbers doesn't tell the tale. You gotta shoot for groups if you're tracking down consistency. I'll shoot 4 and 6 again (5) shots. Just to see what it does.

Do I normally do this kind of test? H e double toothpicks no. I just started shooting at a new range that has 1,000 yards but you have to "qualify" to shoot there, otherwise I wouldn't have done any of this.