The 'ART' of accuracy

[Someoldguy]

There seems to be a 'quantum leap' between 'hunting accuracy', which for the sole purpose of discussion, I shall establish as 1 MOA, and bug hole accuracy, which I'd like to establish as under 1/4MOA. We can argue for pages upon end as to the necessity of this, but let's just say this is a reference, please.

Now. To say such a level of accuracy is difficult to attain unaided is . . . an understatement, to be sure. So. I'd like to contribute an item I've discovered by hard-won perseverance to be of importance toward this goal of 1/4 MOA. If any of you have an area of 'expertise' you would like to interject as of significant importance, PLEASE, post your finding. And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are.

My contribution is to find a method to measure your chamber length. There are several options out there. I am currently using a Hornady comparator. Might not be the best, but until I find something better, It'll do. Now, why is this important, you may ask? IF you are adjusting your resizing die according to the manufacture's instructions, then you have NO IDEA how much difference there is between your chamber length, or headspace, and your resized cases. I have found this to be of paramount importance to accurate reloading.

I expect some of you will find this to be elementary information. But it was information I spent 3 years discovering. Perhaps I was not asking the right people, or looking in the right places. But it happened, none the less.

Anyone care to add a hint for the 'new to accuracy' shooter?

Thanks for your time.

 

[KMart]

If you are saying that for really good accuracy, you must have the case shoulder really close to the chamber shoulder, I don't think that is necessarily true. I have had instances where when fire forming 6br to 6 dasher, that the rifle has shot very good groups. When doing this, the case and chambers are quite a distance from each others.
I have seen others post here about how well their loads shoot when fire forming. Well enough that some will fire form during a match.

 

[Mozella]

I would say that in order to to talk about "accuracy" you should first define what you mean. Accuracy, i.e. the ability to hit a particular target, is important for hunters and most target shooters as well. Sometimes the match winner is decided by group size in which case it's all about "precision". When it comes to good scores in a discipline like F-Class, it's nice to have a precision load recipe which will make small groups along with a good caliber/bullet choice featuring high MV's and high B.C.'s. But if you're looking for the kind of "accuracy" required to shoot a bunch of X's in a match, then you have to talk about properly reading the wind. Wind skills are the most important component in winning many contests and are also the most difficult to master.

Guys who are really good at reloading and shooting small groups in dead calm conditions are called technicians. Those who can read the wind better than the rest are called champions.

So if I read the tone of your post to mean you're talking about the technical aspects of reloading separately from other factors such as wind reading skills and if we're going to consider accuracy and precision to mean essentially the same thing for purposes of this discussion, then I'm OK with that idea.

I have another question to pose.

You correctly point out achieving a 1/4 MOA result is difficult. Nearly everyone on this forum has the equipment and skills to shoot a 1 MOA group. Getting to 1/2 MOA doesn't require much more than careful use of low end reloading equipment and a little experience. Getting from 1/2 MOA to 1/4 MOA is WAY more difficult, but a lot depends on how you define shooting 1/4 MOA.

Anyone, given a little time, can shoot a three-shot group at 100 yards which is 1/4 MOA or less, especially if they fire five rounds and call two of them "flyers" just because they don't like them. Half serious shooters who attend local low-key F-class matches can show you countless 5-shot groups at 100 yards which are below 1/4 MOA. But does that make them 1/4 MOA shooters? No is the short answer.

Should your precision be based on the average of your 5 shot groups? Not really because that includes load development testing where you know that some groups are going to bad and some good. Sorting out the good charge weights and seating depths from the bad ones is the whole idea of load testing. In other words, during load testing you hope some groups are really good and that means some aren't so good and some might be down right bad. Averaging in the bad ones doesn't tell the whole story. So which groups should be considered?

I would say that your ability should be defined as the NEXT group you shoot using your "good stuff". There is no standard, but I like the idea of 5 shot groups at 100 yards as a comparison point. If that is the standard, then few hunters would pay you ten bucks if their next group isn't better than 1/2 MOA. However, many half serious F-Open shooters would be willing to make that offer and a lot of short range BR shooters would be happy to do so. However, when it comes to guaranteeing the next group to be below 1/4 MOA only a tiny handful of people in the world would qualify. Keep in mind that I have countless sub 1/4 MOA groups in my files and so do all of the guys I compete against. But nobody I know thinks they and their equipment can guarantee 1/4 MOA under normal circumstances the next time they make a 5 shot group. Sometimes the bullets just happen to fall into the same hole, but most times they don't.

So what makes a 1/4 MOA shooter, or 1/2 MOA for that matter? I don't know. Is it performing to that level of precision half the time, a quarter of the time, or just once-in-a-while?

One web site has a "One MOA All Day Long" challenge. The rules say you must show them a target with five 5-shot groups all on one page with no other holes. If all five shot groups are better than One MOA, you qualify as "MOA ALL DAY". I kinda' like that idea, but given enough time it shouldn't be hard to do. What really matters is if you can perform NOW........ no mulligans. Of course, that's why shooting matches is different from hanging out at the local range shooting group after group.

Bottom line: It's really hard to define precision and accuracy in such a way that I can compare my apples with your oranges. Ill let someone else decide that. All I really know is this. Although my goal is to put ten bucks on my shooting bench and invite you to pick it up if my next 5-shot group isn't better than 1/4 MOA. Unfortunately, I'm a long way from that. But, under no-wind conditions I'll risk ten bucks at the 1/2 MOA level of precision.

 

[dolek]

There seems to be a 'quantum leap' between 'hunting accuracy', which for the sole purpose of discussion, I shall establish as 1 MOA, and bug hole accuracy, which I'd like to establish as under 1/4MOA. We can argue for pages upon end as to the necessity of this, but let's just say this is a reference, please.

Now. To say such a level of accuracy is difficult to attain unaided is . . . an understatement, to be sure. So. I'd like to contribute an item I've discovered by hard-won perseverance to be of importance toward this goal of 1/4 MOA. If any of you have an area of 'expertise' you would like to interject as of significant importance, PLEASE, post your finding. And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are.

My contribution is to find a method to measure your chamber length. There are several options out there. I am currently using a Hornady comparator. Might not be the best, but until I find something better, It'll do. Now, why is this important, you may ask? IF you are adjusting your resizing die according to the manufacture's instructions, then you have NO IDEA how much difference there is between your chamber length, or headspace, and your resized cases. I have found this to be of paramount importance to accurate reloading.

I expect some of you will find this to be elementary information. But it was information I spent 3 years discovering. Perhaps I was not asking the right people, or looking in the right places. But it happened, none the less.

Anyone care to add a hint for the 'new to accuracy' shooter?

Thanks for your time.

This should get interesting,good luck.

 

[LHSmith]

If you are saying that for really good accuracy, you must have the case shoulder really close to the chamber shoulder, I don't think that is necessarily true. I have had instances where when fire forming 6br to 6 dasher, that the rifle has shot very good groups. When doing this, the case and chambers are quite a distance from each others.
I have seen others post here about how well their loads shoot when fire forming. Well enough that some will fire form during a match.

When fireforming it is paramount to get the case head against the bolt face to get consistent results (usually done by loading into the lands). Yes, many (including myself) will FF during a match to maximize barrel life......but usually these rounds are used for the throw-away (foulers, warm-up) shots and very seldom for record targets during a sanctioned match by a serious competitor. To FF rounds during matches goes against the #1 tenet in BR......minimize as many variables as possible......and pre-FF rounds "can" inject a lot of variables into the equation.
Since the OP is talking extreme accuracy of the spectrum, variations of distance from shoulder datum to case head WILL show itself on target in a well tuned rifle.

 

[LHSmith]

There seems to be a 'quantum leap' between 'hunting accuracy', which for the sole purpose of discussion, I shall establish as 1 MOA, and bug hole accuracy, which I'd like to establish as under 1/4MOA. We can argue for pages upon end as to the necessity of this, but let's just say this is a reference, please.

Now. To say such a level of accuracy is difficult to attain unaided is . . . an understatement, to be sure. So. I'd like to contribute an item I've discovered by hard-won perseverance to be of importance toward this goal of 1/4 MOA. If any of you have an area of 'expertise' you would like to interject as of significant importance, PLEASE, post your finding. And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are.

My contribution is to find a method to measure your chamber length. There are several options out there. I am currently using a Hornady comparator. Might not be the best, but until I find something better, It'll do. Now, why is this important, you may ask? IF you are adjusting your resizing die according to the manufacture's instructions, then you have NO IDEA how much difference there is between your chamber length, or headspace, and your resized cases. I have found this to be of paramount importance to accurate reloading.

I expect some of you will find this to be elementary information. But it was information I spent 3 years discovering. Perhaps I was not asking the right people, or looking in the right places. But it happened, none the less.

Anyone care to add a hint for the 'new to accuracy' shooter?

Thanks for your time.

Effective chamber length will change if one does not constantly address carbon build-up in the "unused" portion of the chamber neck. AKA carbon ring. Here, a routine regimen of IOSSO is your friend.

 

[Richard Coody]

There seems to be a 'quantum leap' between 'hunting accuracy', which for the sole purpose of discussion, I shall establish as 1 MOA, and bug hole accuracy, which I'd like to establish as under 1/4MOA. We can argue for pages upon end as to the necessity of this, but let's just say this is a reference, please.

Now. To say such a level of accuracy is difficult to attain unaided is . . . an understatement, to be sure. So. I'd like to contribute an item I've discovered by hard-won perseverance to be of importance toward this goal of 1/4 MOA. If any of you have an area of 'expertise' you would like to interject as of significant importance, PLEASE, post your finding. And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are.

My contribution is to find a method to measure your chamber length. There are several options out there. I am currently using a Hornady comparator. Might not be the best, but until I find something better, It'll do. Now, why is this important, you may ask? IF you are adjusting your resizing die according to the manufacture's instructions, then you have NO IDEA how much difference there is between your chamber length, or headspace, and your resized cases. I have found this to be of paramount importance to accurate reloading.

I expect some of you will find this to be elementary information. But it was information I spent 3 years discovering. Perhaps I was not asking the right people, or looking in the right places. But it happened, none the less.

Anyone care to add a hint for the 'new to accuracy' shooter?

Thanks for your time.

well you are heading down the right path. now what to do with that information?

first i don't really care about my chamber dimensions. i care about my fired brass and only after it has been fired at least 3 times with minimal resizing. when that shoulder is consistent after firing brass is ready. then send 3 pieces of that fired and not resized brass to the die builder of your choice to make a die to match your chamber. that would be a very positive step toward quarter inch or better precision.

now that is assuming you have a rifle capable of consistent 1/4" precision. not likely to happen if the rifle isn't built for it.

 

[msinc]

I have always found it interesting the number of shooter/reloaders that not only do not know how their rifle is headspaced, but don't know how the ammo they produce is headspaced either. Many don't have the first clue what headspace even is. I see people on here that when you read some of their posts, seem like they have a good grasp on things, then they post something about headspace and start talking about over all length!!!
Since I barrel all my own actions I know exactly where my chambers are. I have also played around with ammo length {in regards to headspace} as far as accuracy is concerned and I find that it can make a big difference if it is right, but not always. Seems like there are some cartridges that are way more "picky" about this than others.
I have had to correct several factory belted magnum rifles in which the accuracy issues were directly related to the shoulder being not where it was supposed to be in the rifles chamber. Even though the belt was okay and headspace was correct, the shoulder of the chamber was way long and all of these rifles shot very poorly. Some of these were so bad that I have to wonder if the factory chambers belted magnums with a two step process and two different reamers....hard to believe they repeatedly missed that bad, I mean grinding a reamer is not rocket science.

 

[Richard Coody]

I have always found it interesting the number of shooter/reloaders that not only do not know how their rifle is headspaced, but don't know how the ammo they produce is headspaced either. Many don't have the first clue what headspace even is. I see people on here that when you read some of their posts, seem like they have a good grasp on things, then they post something about headspace and start talking about over all length!!!
Since I barrel all my own actions I know exactly where my chambers are. I have also played around with ammo length {in regards to headspace} as far as accuracy is concerned and I find that it can make a big difference if it is right, but not always. Seems like there are some cartridges that are way more "picky" about this than others.
I have had to correct several factory belted magnum rifles in which the accuracy issues were directly related to the shoulder being not where it was supposed to be in the rifles chamber. Even though the belt was okay and headspace was correct, the shoulder of the chamber was way long and all of these rifles shot very poorly. Some of these were so bad that I have to wonder if the factory chambers belted magnums with a two step process and two different reamers....hard to believe they repeatedly missed that bad, I mean grinding a reamer is not rocket science.

question for you about the belted magnums. they were designed to headspace off the belt. With a factory round headspacing off the belt most find the shoulder of the fired brass moves forward quite a bit. many then when reloading these cases use the shoulder to headspace with and ignore the belt.

are you a belt headspacer or a shoulder headspacer?

what problems are associated with using the shoulder to headspace a belted magnum?

 

[Eddie Harren]

"And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are."

Loosely translates to: Keep your opinions to yourself!

 

[dolek]

"And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are."

Loosely translates to: Keep your opinions to yourself!

Wrong.

 

[JBT47]

Effective chamber length will change if one does not constantly address carbon build-up in the "unused" portion of the chamber neck. AKA carbon ring. Here, a routine regimen of IOSSO is your friend.

Great point here. I see a lot of guys that run into problems after about 500 rounds without any throat maintenance (Iosso, KG2, JB’s, etc.). I used to be in that camp as well. Now, I use an abrasive in the throat are at least every 100 rounds. Doing so take that variable out of the equation.

 

[Someoldguy]

"And if you feel the need to 'snicker' and post 'jibes', please feel free to move along. I trust we all know who these types are."

Loosely translates to: Keep your opinions to yourself!

I'm not sure how you read that into what I wrote, but it is not what I meant.
What I meant is, if all you have to add to the discussion are disparaging remarks, then please keep them to yourself. As such remarks benefit no one.

 

[Richard Coody]

Great point here. I see a lot of guys that run into problems after about 500 rounds without any throat maintenance (Iosso, KG2, JB’s, etc.). I used to be in that camp as well. Now, I use an abrasive in the throat are at least every 100 rounds. Doing so take that variable out of the equation.

yep and a cheap lyman borescope allows you to really see what is going on.

boretech C4 for regular use and a parker hale jag with C4 and a little losso on a patch for short stroking that throat when needed.

 

[Eddie Harren]

I'm not sure how you read that into what I wrote, but it is not what I meant.
What I meant is, if all you have to add to the discussion are disparaging remarks, then please keep them to yourself. As such remarks benefit no one.

You have a PM.

 

[Someoldguy]

I would say that in order to to talk about "accuracy" you should first define what you mean. Accuracy, i.e. the ability to hit a particular target, is important for hunters and most target shooters as well. Sometimes the match winner is decided by group size in which case it's all about "precision". When it comes to good scores in a discipline like F-Class, it's nice to have a precision load recipe which will make small groups along with a good caliber/bullet choice featuring high MV's and high B.C.'s. But if you're looking for the kind of "accuracy" required to shoot a bunch of X's in a match, then you have to talk about properly reading the wind. Wind skills are the most important component in winning many contests and are also the most difficult to master.

Guys who are really good at reloading and shooting small groups in dead calm conditions are called technicians. Those who can read the wind better than the rest are called champions.

So if I read the tone of your post to mean you're talking about the technical aspects of reloading separately from other factors such as wind reading skills and if we're going to consider accuracy and precision to mean essentially the same thing for purposes of this discussion, then I'm OK with that idea.

I have another question to pose.

You correctly point out achieving a 1/4 MOA result is difficult. Nearly everyone on this forum has the equipment and skills to shoot a 1 MOA group. Getting to 1/2 MOA doesn't require much more than careful use of low end reloading equipment and a little experience. Getting from 1/2 MOA to 1/4 MOA is WAY more difficult, but a lot depends on how you define shooting 1/4 MOA.

Anyone, given a little time, can shoot a three-shot group at 100 yards which is 1/4 MOA or less, especially if they fire five rounds and call two of them "flyers" just because they don't like them. Half serious shooters who attend local low-key F-class matches can show you countless 5-shot groups at 100 yards which are below 1/4 MOA. But does that make them 1/4 MOA shooters? No is the short answer.

Should your precision be based on the average of your 5 shot groups? Not really because that includes load development testing where you know that some groups are going to bad and some good. Sorting out the good charge weights and seating depths from the bad ones is the whole idea of load testing. In other words, during load testing you hope some groups are really good and that means some aren't so good and some might be down right bad. Averaging in the bad ones doesn't tell the whole story. So which groups should be considered?

I would say that your ability should be defined as the NEXT group you shoot using your "good stuff". There is no standard, but I like the idea of 5 shot groups at 100 yards as a comparison point. If that is the standard, then few hunters would pay you ten bucks if their next group isn't better than 1/2 MOA. However, many half serious F-Open shooters would be willing to make that offer and a lot of short range BR shooters would be happy to do so. However, when it comes to guaranteeing the next group to be below 1/4 MOA only a tiny handful of people in the world would qualify. Keep in mind that I have countless sub 1/4 MOA groups in my files and so do all of the guys I compete against. But nobody I know thinks they and their equipment can guarantee 1/4 MOA under normal circumstances the next time they make a 5 shot group. Sometimes the bullets just happen to fall into the same hole, but most times they don't.

So what makes a 1/4 MOA shooter, or 1/2 MOA for that matter? I don't know. Is it performing to that level of precision half the time, a quarter of the time, or just once-in-a-while?

One web site has a "One MOA All Day Long" challenge. The rules say you must show them a target with five 5-shot groups all on one page with no other holes. If all five shot groups are better than One MOA, you qualify as "MOA ALL DAY". I kinda' like that idea, but given enough time it shouldn't be hard to do. What really matters is if you can perform NOW........ no mulligans. Of course, that's why shooting matches is different from hanging out at the local range shooting group after group.

Bottom line: It's really hard to define precision and accuracy in such a way that I can compare my apples with your oranges. Ill let someone else decide that. All I really know is this. Although my goal is to put ten bucks on my shooting bench and invite you to pick it up if my next 5-shot group isn't better than 1/4 MOA. Unfortunately, I'm a long way from that. But, under no-wind conditions I'll risk ten bucks at the 1/2 MOA level of precision.

I believe your premise is, the shooter is only as good as the group he can produce on demand. And yes, I agree with that premise. I'm not a 1/4 MOA shooter on my best day, but I'm practicing and trying to get there. And you are correct in deducing that my question relates to technical skills, and not so much learned skills such as reading wind. Thanks for the reply.

 

[msinc]

question for you about the belted magnums. they were designed to headspace off the belt. With a factory round headspacing off the belt most find the shoulder of the fired brass moves forward quite a bit. many then when reloading these cases use the shoulder to headspace with and ignore the belt.

are you a belt headspacer or a shoulder headspacer?

what problems are associated with using the shoulder to headspace a belted magnum?

This is an excellent question....yes, they were designed to headspace off the belt, but that doesn't mean they have to. Especially if the reloader has the tools and know how to start doing it off the shoulder.
The shoulder should really not move any more than a case that headspaces off the shoulder, but I agree many do. If it is not moving too much then yeah, just size accordingly and go. The problem comes in when you need more brass and then it has to be fired formed. It is never good to have it moving too far, so if that is the case then really I would rather correct the chamber even if the reloader/owner has a clear understanding and the tools to reload with this in consideration. I always suggest and give the option of having the chamber corrected, but as long as the cases are sized properly then there is no problem.
What do I do??? Well, I like the shoulder and belt to be where they belong. I am in the unique position of having my own machine shop and ability to make the gun right, but if it was mine I would probably let it go and just load accordingly...I don't shoot belted magnums much, a few rounds to zero and a hunting trip or two. Bottom line, either way works fine and will shoot as accurate as the the other. Go on a trip and have to buy some factory ammo and you might wish it was right.

 

[Someoldguy]

You have a PM.

PM replied to. Thank you, Sir.

 

[Someoldguy]

well you are heading down the right path. now what to do with that information?

first i don't really care about my chamber dimensions. i care about my fired brass and only after it has been fired at least 3 times with minimal resizing. when that shoulder is consistent after firing brass is ready. then send 3 pieces of that fired and not resized brass to the die builder of your choice to make a die to match your chamber. that would be a very positive step toward quarter inch or better precision.

now that is assuming you have a rifle capable of consistent 1/4" precision. not likely to happen if the rifle isn't built for it.

Do you think a custom die set is really necessary, provided a standard die is not overworking the brass or destroying what has been gained by fire forming?

No sarcasm here, just a straight-forward question on my part. Thank you.

 

[Richard Coody]

Do you think a custom die set is really necessary, provided a standard die is not overworking the brass or destroying what has been gained by fire forming?

No sarcasm here, just a straight-forward question on my part. Thank you.

depends on what you are trying to do.

if you are going for benchrest accuracy (.25" and less) yes and dozens of other things. But without a rifle that was built to shoot in the 1's and 2's you would be wasting your money.