10 Shot groups......

[Mystic Precision]

As Boomer illustrated, the key is testing in a way that reflects the application of the rifle.

Never said, just shoot 1 shot with a random load and call it good.

No, if cold bore shot is critical to your application, then working up a load per normal methods has to also include 'cold bore testing'. but load testing in very large sample sizes doesn't reflect how the rifle will be used.

for my hunting rifle, a load that shoots as needed for 3 to 4 rds is plenty accurate enough. Testing to 10rds will not garner any added info as I will never use the rifle in this way.

I actually did the cold bore work up with one of my hunting rifle. took a silly amount of time but it showed me which load actually did work from a cold bore.

AND how to keep the condition of the bore so that first shot would go where I was expecting.

I tested the hunting rifle after sitting in sub zero weather to see what would happen on a real cold bore shot. To find out how the ammo would react to the cold and if my drop tables were correct. Left the rifle out on rainy fall days to see if the stock would change the POI - certainly not something any BR shooter would bother testing.

For my F class rifles, testing up to 20rds was necessary to see how the barrel would react to heat. Testing in 5 or even 10rds groups is great for testing the load but what if the barrel starts to head north at rd 12 and shots start launching into the 3 ring?

Testing my f class rig in the middle of summer also revealed some interesting results mostly in load tuning.

so the method of testing has to reflect the application and hopefully, the conditions that the rifle will be used.

Jerry

 

[DEZ]

I think cal plays into it as well I shoot 3 rnd groups out of my sendero in 300ultra because #1 IT gets too dam hot after that and its my long range hunting rig usually 1 shot in a cold barrel perhaps folled up by one more(hopefully not). So I tend to agree with mystic if its a target rifle that will see 10 rnd groups then thats how you shoot it.

 

[rnbra-shooter]

for my hunting rifle, a load that shoots as needed for 3 to 4 rds is plenty accurate enough. Testing to 10rds will not garner any added info as I will never use the rifle in this way.

I know you won't shoot 10 shots out of your hunting rifle in the field. But shooting 10 shot groups out of it during testing (allowing time for it to cool, so that each shot is being fired in an "as-in-the-field" state), will tell you much more about the grouping ability of the rifle than 3-shot or 4-shot groups will. There is a lot of "noise" in the size of a 3-shot group; it very likely that two 3-shot groups of the same ammo will differ in size much more than two 10-shot groups of the same ammo.

If it is useful for you to know how big a group your hunting rifle will shoot in the field (say, so that you can estimate a maximum sensible range for it to be used at), then firing 10 rounds will tell you more about its grouping abilities than 3 or 4 rounds will.

 

[notsorichguy]

Ok guys...... I was out at the range yesterday again.

I shot this same rifle and I didn't quite get the results I expected.

When I shot the 10rnd group in the first post (see pic in post 1) I had just finished shooting a 3rnd group to confirm zero, let it sit for 1 or 2 min while I grabbed ammo and made ready for my 10 rnd group, I then fired the 10 rnd group from post 1.

I noticed yesterday (10 degrees less warm and wind from a slightly different direction) that on a stone cold barrel the first shot is about 1 1/4" higher than the rest of a 5 rnd group @ 100y, the rest of the holes are touching..... So just to double check I immediatley fired another 5 shot group and all 5 are touching...... I then wait about a half hour and then re-shoot a 5 shot group and voila, same result as the first group..... 1 round about an inch high.

So what do I have to tweak..... Any ideas as to the cause?

CHeers!

 

[Ganderite]

here is a 10 shot group I shot yesterday in a 223 Norico BushRanger at 300 yards. It is a minute and half high. This gives me a real good idea of the accuracy potential of this rifle. A random selction of 3 shots or 5 shots form this same group might give me a distorted impression of its accuracy.

The exception would be if repeatably the first 3 or first 5 are always much closer and the group opens with heat during 10.

 

[rnbra-shooter]

notsorichguy, it seems that you are getting just over half-minute sized groups at 200 yards, for ten shots, from a factory rifle. This is wonderful performance; it is on par with what my purpose-built target rifle delivers.

Your rifle may or may not be "throwing" its first cold bore shot by an inch and a quarter. So far you think you have seen this happen twice, out of two times looking, and you have seen a warm-bore shot not do this, once out of one time looking. In order to really know one way or another, you're going to have to do a fair bit of careful and probably boring testing (unless the problem appeals to you and it ends up being a fun project).

A perfectly reasonable thing to do is to ignore the possibility of this "problem", even if it is really there. If your rifle is delivering 10-shot, approx. 0.6 MOA groups at 200 yards, _including_ the cold-bore "flyer", you are getting a performance from your factory rifle then that is not only wonderful, but perfectly adequate for the vast majority of shooting applications (including many kinds of pretty serious target shooting!).


BTW Ganderite that looks like pretty decent performance; is that the cheapie rifle you showed me a year and a half ago?

 

[redshooter]

I don't see a prob with three shot groups being posted. If your being honest with yourself about what your rifle can reproduce. If I post a 0.25 moa group when it's the only one out of twenty that shot under 1 moa is likely meaningless. If I'm firing five three round groups on one target that has five bulls on a 1"X1" grid I can extrapolate and say that nine of fifteen shots are under 0.50 moa and seven are approx 0.25 moa. If one three round group is 0.20" I think I could claim better than 0.50 moa with that load. I wish I had the time to do more reloading. If I did five shot groups would be the norm. I think I waste less doing load development with three shot groups. Who am I kidding a three shot 0.25 moa just looks better than a ten shot group with seven at 0.25 moa...I'm a fraud.

 

[Mystic Precision]

I know you won't shoot 10 shots out of your hunting rifle in the field. But shooting 10 shot groups out of it during testing (allowing time for it to cool, so that each shot is being fired in an "as-in-the-field" state), will tell you much more about the grouping ability of the rifle than 3-shot or 4-shot groups will. There is a lot of "noise" in the size of a 3-shot group; it very likely that two 3-shot groups of the same ammo will differ in size much more than two 10-shot groups of the same ammo.

If it is useful for you to know how big a group your hunting rifle will shoot in the field (say, so that you can estimate a maximum sensible range for it to be used at), then firing 10 rounds will tell you more about its grouping abilities than 3 or 4 rounds will.

I much prefer to do 3 or 4 - 3 to 4rds groups for a hunting rifle. total shots fired 12rds over a few range sessions.

That way I can confirm consistency and repeatability. If the rifle behaves in a predictable manner, the load and rifle will work. gives me a chance to confirm cold bore shot too.

with many shooting factory barrels, the likelihood of any degree of consistency is directly related to how badly the barrel warps under the heat of shooting.

Jerry

 

[Mystic Precision]

Ok guys...... I was out at the range yesterday again.

I shot this same rifle and I didn't quite get the results I expected.

When I shot the 10rnd group in the first post (see pic in post 1) I had just finished shooting a 3rnd group to confirm zero, let it sit for 1 or 2 min while I grabbed ammo and made ready for my 10 rnd group, I then fired the 10 rnd group from post 1.

I noticed yesterday (10 degrees less warm and wind from a slightly different direction) that on a stone cold barrel the first shot is about 1 1/4" higher than the rest of a 5 rnd group @ 100y, the rest of the holes are touching..... So just to double check I immediatley fired another 5 shot group and all 5 are touching...... I then wait about a half hour and then re-shoot a 5 shot group and voila, same result as the first group..... 1 round about an inch high.

So what do I have to tweak..... Any ideas as to the cause?

CHeers!

Unfortunately, this is a common problem with factory barrels. The barrel steel is not properly stressed relieved and may move as it warms up.

If that first rd repeats to be high, then that is something you have to accept and aim low until the barrel reaches the temp it needs to hold the rds in the group.

that is why for a hunting rifle, I tested the rig in the same/similar ambient temp and weather as I would hunt. alot can change from 25C to -5C.

solution B (more PITA factor) - develop a cold bore load that will put the rds in the same group as the warm barrel load.

solution C (best but $$$) - spin on a quality match barrel and live happily ever after.

Jerry

 

[carbonrod]

I disagree.

How you test your rifle should be relevant to how the rifle is to be used. But that is not at all the same thing as the testing being the same "course of fire".

Say a cold bore shot is important to you. The thing is, one cold bore shot by itself tells you nothing at all about the grouping ability of the rifle - it can't, it will always have a group size of zero. In fact testing the cold bore grouping ability of a rifle is a very demanding test regime - you need to get several cold bore shots made, so that you have a group to analyze. To get five or ten shots might take you hours or even days. So even though your use of the rifle might involve a single shot fired from a cold bore, the testing behind setting up your rifle to do that job well will be something quite different from going out and firing one single shot from a cold bore.

Yeah, that is about my opinion as well.

When comparing equipment performance though it is a good idea to have a common group that reduces flukes IMO. This is both when sharing performance data with others, and among your own variations.

Most of my shooting is from unsupported positions. I only put a bipod on if I have changed a rifle/load, or injured part of me and I want to be sure that the equiptment still appreciably outperforms me. This is where I will put a bipod on a semiauto, or hunting rifle, or add sandbags to a tac rifle to increase position stability beyond what is normally practical. Then it is time to shoot a couple 10 rnd groups to be sure there is no oddity that creeps in once in a blue moon. When I see a flier, called or not, I try to fix the flier.

Small round groups are too easy to post call fliers(especially with optics that let you see impact), or dismiss wandering accuracy while only measuring the precision of the group.

Either way, I think the OP did a good job in illustrating the capability of the example of this rifle he has. Great to hear the setup, and conditions that were used as well. --"all I had sitting around was a cheapo Tasco 2.5 to 10 rimfire scope" -- sweet! Should be only room to improve there.