How exactly is seating depth changes causing the tightening of group size?

[bozo699]

I'm pretty sure a lot of us have witnessed the horrible credibility behind 'trends' in bullet seating(e.g. VLD loar)..

I would assert that "VLD Lore" is the very small majority of seating depth data, and in no way is relevant as a measure of the whole.

The VAST majority of bullet seating depth "lore" is for "typical" style bullets.

Which all shoot very well at similar seating depths or even standard or magazine length.

Bradley,
Respectfully I have to ask, are you a one hole freak like most all of us on this forum or are you like my father,...MOPP ( minute of paper plate ) is close enough? the reason I ask is I have never seen anybody argue so hard that seating depth doesn't matter when EVERYBODY that has ever shot competition looking for one hole!!! knows that it does!! I understand what jlow is after, he realizes it changes group size but his scientific mind can't grasp why so he has to find out why! me ,...I could care less WHY I just KNOW for a FACT that it does matter a LOT!! as a matter of a fact one of the most crucial things you can do to tune a load. Why do you think that ALL bullets shoot there best a certain distance off the lands no matter the bullet,caliber, or anything else?? I thought this was a precision gun forum not a Minute of elk forum!! because if seating depth doesn't matter then either does powder charge, primer selection,bullet selection,or brass choice!! whatever brass will do,mix brands it doesn't matter, a Lee powder scoop, H-4831 because it will work in anything especially grandads 06 which everybody knows is the best gun ever made! a Lee die and a hammer!! Bullets,....just grab some, if there the same caliber it will be fine! Seriously is this what this forum has become,...close is close enough!! I have left a lot of forums because close was close enough, I hope this forum stays precision minded!!

Wayne.

 

[Bradley Walker]

Respectfully I have to ask, are you a one hole freak like most all of us on this forum or are you like my father,...MOPP ( minute of paper plate ) is close enough? the reason I ask is I have never seen anybody argue so hard that seating depth doesn't matter when EVERYBODY that has ever shot competition looking for one hole!!! knows that it does!!

You guys are killing me. That is not what I said. Where did I say that "seating depth doesn't matter"? Holy crap. Talk about hyperbole.

My Krieger barreled space gun shot a 20 shot a .5" group during barrel breaking from 100 yards.... All bullets seated to magazine length... Shooting the same load that nearly every guy on the line shoots... Most every NM Ar-15 on the Highpower line will shoot 1/2 MOA or less these days and they shoot standard length rounds most of the time, even with different barrel lengths and never chase the lands because the bullets were DESIGNED to shoot that way.

Mostly, what I have been saying is the BULLET DESIGN dictates where they tend to shoot, and there are trends.... and YES, there are super duper VLD wind cheater bullets that have caused what I feel is 100s of thousands of words of discussion on the criticality of seating depth to save a 1/4" a drift at 600 yards. I guess if I am saying anything, I am saying I would not pursue a bullet that needs 100s of thousands of words of discussion to gain that very very very slight edge that 1 MPH of wind would create on its own...

My 40x 6BR will shoot 0's at 100 yards. It does it on a regular basis. I realize that nearly all larger groups are due to condition and me... and yes, nearly across the board I am finding that all bullets in that same gun shoot the best at right around .020" to .025" of jump. I think if you called Sierra they would tell you that their bullets usually shoot best there. I have yet to find a "standard" bullet (not a VLD) that improves after it has been powder tuned at that seating depth. I believe that making the ammo with a CONSTANT seating depth is VERY important as I certainly understand that seating depth seems to move the POI.

 

[Bradley Walker]

I'm pretty sure a lot of us have witnessed the horrible credibility behind 'trends' in bullet seating(e.g. VLD loar)..

I would assert that "VLD Lore" is the very small majority of seating depth data, and in no way is relevant as a measure of the whole.

The VAST majority of bullet seating depth "lore" is for "typical" style bullets.

Which all shoot very well at similar seating depths or even standard or magazine length.

Bradley,
Respectfully I have to ask, are you a one hole freak like most all of us on this forum or are you like my father,...MOPP ( minute of paper plate ) is close enough? the reason I ask is I have never seen anybody argue so hard that seating depth doesn't matter when EVERYBODY that has ever shot competition looking for one hole!!! knows that it does!! I understand what jlow is after, he realizes it changes group size but his scientific mind can't grasp why so he has to find out why! me ,...I could care less WHY I just KNOW for a FACT that it does matter a LOT!! as a matter of a fact one of the most crucial things you can do to tune a load. Why do you think that ALL bullets shoot there best a certain distance off the lands no matter the bullet,caliber, or anything else?? I thought this was a precision gun forum not a Minute of elk forum!! because if seating depth doesn't matter then either does powder charge, primer selection,bullet selection,or brass choice!! whatever brass will do,mix brands it doesn't matter, a Lee powder scoop, H-4831 because it will work in anything especially grandads 06 which everybody knows is the best gun ever made! a Lee die and a hammer!! Bullets,....just grab some, if there the same caliber it will be fine! Seriously is this what this forum has become,...close is close enough!! I have left a lot of forums because close was close enough, I hope this forum stays precision minded!!

Wayne.

You do like to rant don't you?

 

[Steve Blair]

My Krieger barreled space gun shot a 20 shot a .5" group during barrel breaking from 100 yards.... All bullets seated to magazine length... Shooting the same load that nearly every guy on the line shoots... Most every NM Ar-15 on the Highpower line will shoot 1/2 MOA or less these days and they shoot standard length rounds most of the time, even with different barrel lengths and never chase the lands because the bullets were DESIGNED to shoot that way.

[br]
I replace barrels long before they degrade to 1/2 MOA. My rifles and loads win matches. If they shot 1/2 MOA, they would not. My .284 Shehane will average under .35" for five 5-shot groups at 100 while not exceeding 15 fps ES. That is the minimum performance required to be competitive, before any other factors are involved. Seating depth and load precision are a large part of that. [br]
If your present accuracy and practices satisfy your needs, great. But don't try to press the point that others cannot do better or that there is no reason to do so. BTW, since you shoot High Power, what is your NRA classification?

 

[bozo699]

I'm pretty sure a lot of us have witnessed the horrible credibility behind 'trends' in bullet seating(e.g. VLD loar)..

I would assert that "VLD Lore" is the very small majority of seating depth data, and in no way is relevant as a measure of the whole.

The VAST majority of bullet seating depth "lore" is for "typical" style bullets.

Which all shoot very well at similar seating depths or even standard or magazine length.

Bradley,
Respectfully I have to ask, are you a one hole freak like most all of us on this forum or are you like my father,...MOPP ( minute of paper plate ) is close enough? the reason I ask is I have never seen anybody argue so hard that seating depth doesn't matter when EVERYBODY that has ever shot competition looking for one hole!!! knows that it does!! I understand what jlow is after, he realizes it changes group size but his scientific mind can't grasp why so he has to find out why! me ,...I could care less WHY I just KNOW for a FACT that it does matter a LOT!! as a matter of a fact one of the most crucial things you can do to tune a load. Why do you think that ALL bullets shoot there best a certain distance off the lands no matter the bullet,caliber, or anything else?? I thought this was a precision gun forum not a Minute of elk forum!! because if seating depth doesn't matter then either does powder charge, primer selection,bullet selection,or brass choice!! whatever brass will do,mix brands it doesn't matter, a Lee powder scoop, H-4831 because it will work in anything especially grandads 06 which everybody knows is the best gun ever made! a Lee die and a hammer!! Bullets,....just grab some, if there the same caliber it will be fine! Seriously is this what this forum has become,...close is close enough!! I have left a lot of forums because close was close enough, I hope this forum stays precision minded!!

Wayne.

You do like to rant don't you?

Bradley,
Yes sir I do!!! especially with comments like this,... I am finding that all bullets in that same gun shoot the best at right around .020" to .025" of jump. and this one,.. I think if you called Sierra they would tell you that their bullets usually shoot best there!! EVERY bullet is different and EVERY gun is different and EVERY powder is different!! My sons 6brx likes the 107 SMK's just touching the lands, My smiths likes them .010 off the lands and mine like them .012 into the lands and his sons likes them .008 into the lands,...all chambered with the same reamer by the same smith, all 1:8 Krieger barrels so you see it isn't a cut and dried mag length seating depth thing!! Oh and my F.F rifle has a 1:10 Hart with a Witchita action likes the 95 grain SMK's .025 off the lands. I am now shooting the 105 Hybrids, they shoot at any shooting depth okay but if you want them to hammer they have a exact seating depth, my loaded round measured with a Hornaday vernier caliper tool measures 1.8260,...NOT 1.825,..not 1.827,...1.826!! I am not the only one that has proven this to be true at our 1K range, mine needs to be .014 off the lands another guy I shoot with needs to be .008 off the lands with the same bullet! If we were happy shooting MOA just about any depth would be okay but when your trying to get below 1/2 moa at 1K Then every .001 COUNTS BIG TIME!! I don't dislike you at all, as a matter of a fact I have enjoyed many of your posts and threads but this one behooves me ???
Wayne.

 

[Bradley Walker]

I am really concerned with people who make WHAT I DO OR WHAT I SAY into my statements about the universe, and start to tell me "they like me but" in a reloading thread, like somehow what I say here has any bearing on anything at all.

If you want to look back in the "pet loads" you will see that a great majority of them are exactly as I described. That's all I was saying. If you look at the across the course shooters and how they load, it is EXACTLY as I described. Many of them can out shoot probably half of the F-class shooters with iron sights!!!

Do whatever you want. I'm not stopping you. If you want to believe you can hold .001" in your ammunition assembly tolerances you GO AHEAD. If you believe your POWDER can hold to the temperature tolerances of load development in a match you keep believing it my friend!!! I don't care if you trickle to the KERNEL...

I don't have to prove anything to any of you guys or show you my resume. I was just chatting about what I have seen. As far as I am concerned this is this kind of crap I detest about OTHER forums. It isn't the PRECISION of the forum I am overly concerned with it is the condescension and self importance... as I see a lot of it in shooting, not to mention a lot of really really bad science and analysis.

"what is your NRA classification"?

Bite me. BTW, this forum is not just for 1K high masters... So, again if you are that awesome you should start your own forum or better yet a Youtube channel and you can just tell everyone how to be awesome like you...

 

[bozo699]

Bradley,
I am sorry you feel that way, I am not better then anybody, as a matter of a fact I am middle of the row in my club but I have seen the advantages of being precise! I want you as a friend not a enemy, I am sorry if I offended you it wasn't my intent! as you said load as you see fit, and I will do the same, take care and shoot straight!
Wayne.

 

[Bradley Walker]

I appreciate that.

I think one mistake here is to assume all "reloading precision" applies to all disciplines the same as long range benchrest...

Point blank benchrest shooters are very precise for example, and have little in common with many of the methods you advocate.

 

[Steve Blair]

"what is your NRA classification"?

Bite me. BTW, this forum is not just for 1K high masters... So, again if you are that awesome you should start your own forum or better yet a Youtube channel and you can just tell everyone how to be awesome like you...

[br]
Yes, as a matter of fact, I do hold an F-Class Long Range High Master certification. However, that is not what this is about. I shoot with a lot of Match and Service Rifle shooters at Camp Pendleton and they have a very different view of ammunition preparation than you do. By requesting your classification, I was trying to get an idea of what performance level you were achieving. Perhaps if you paid more attention to that aspect, you could improve your scores. [br]
There is no point at which I will ever accept "good enough." Excellence is a unending process that involves all aspects of the endeavor. As to your silly comment, I think that speaks volumes about who and what you are.

 

[BoydAllen]

I have always admired the skill of highpower shooters, that being said, bench shooting is certainly different. Each has its own standards and needs. The good thing is that we can learn from both. When I have helped friends spec out custom hunting rifles, I made sure that the combination of magazine, and throat length do not preclude seating the bullets that will be used into the rifling, that way the shooter has more options. And when someone wants to do a better job of shooting a rifle in a manner that does not include the use of a bench, and is looking for tips, I reach back into my memory and repeat what I have absorbed from my conversations with highpower shooters, making it quite clear where the information came from. Between the two, and a good load workup, the results are usually pretty good. It doesn't do much good to have good shooting technique if the rifle is way out of tune, and even the most accurate rifle can be used go miss a shot in the field if the shooter has not learned and practiced how to shoot in the "real world".

 

[Keith Glasscock]

Many of them can out shoot probably half of the F-class shooters with iron sights!!!

...

Bite me. BTW, this forum is not just for 1K high masters... So, again if you are that awesome you should start your own forum or better yet a Youtube channel and you can just tell everyone how to be awesome like you...

I think that there is some serious animosity going around in this conversation.

The whole idea of this forum is for us to be able to learn from one another. Antagonistic comments circumvent the intended purpose.

Bradley,

I see the point you are trying to make. At the same time, not everyone shoots at a 2 MOA 10 ring. Each game has its challenges and requirements. While a super-accurate rifle might not seem necessary with such a large 10 ring, wouldn't it be great to KNOW for CERTAIN that the shot placement was your hold or your wind call and not some random displacement caused by ammunition? Of course it would be, and I'm sure you strive for that.

While I know that I can tune a load at any seating depth I choose, the problem is that sometimes a different seating depth will tune out better. When we look at 1 MOA 10 rings at long range, everything becomes critical. We (f-class shooters) can (and I do) shoot excellent scores and cleans at 600 yards with ammo that isn't top notch. That same ammo will make the wheels fall off when conditions get goofy.

I would also like to cordially invite you to come out and shoot F-class with us. I think the experience would be a great way for each of us to learn something new.

 

[Bradley Walker]

Yes, as a matter of fact, I do hold an F-Class Long Range High Master certification.

Oh, I know. You kind of lead with your credentials... a lot.

Youtube bro... Youtube...

 

[Keith Glasscock]

There is no point at which I will ever accept "good enough." Excellence is a unending process that involves all aspects of the endeavor.

Steve,

I have been preaching for years against the epidemic of TGE (That's Good Enough) in our society. It's good to know that someone else believes as I do.

 

[Bradley Walker]

I would also like to cordially invite you to come out and shoot F-class with us. I think the experience would be a great way for each of us to learn something new.

So far I don't see a huge difference in scores at the local level. I don't see guys with these huge F-class rigs shooting much better than some of the guys in my old club in Ohio could do with a sling and iron sights (we had a few high masters also)... especially when conditions get gusty. Which tells me they all have to shoot in the same wind....

I am sure that is not true at the very highest levels of F-class... Which is what, about 50 guys?

If anyone who has read my posts thinks I am advocating reloading with a rock and a hammer, I think they have mis-read what I said.

 

[Keith Glasscock]

Are you comparing scores numerically, or comparing shot placement vs. the target center? I agree that F-class scores can be quite a bit lower due to the smaller 10 ring, but I have to tell you that F-class rigs don't come with wind-reading LIDAR...

That said, you might be amazed how many really good shooters there are shooting F-class. There are probably more than 40 people between the F-open and F/TR national teams. For each one of them, there is at least another 2 that are as good, but lack the money to travel to big matches.

I really do wish you would come out and play with us - it is a lot of fun!

 

[Bradley Walker]

While I know that I can tune a load at any seating depth I choose, the problem is that sometimes a different seating depth will tune out better.

Yes, I am sure that is true to certain extent but I see a lot of pet these loads that are within a few thousandths for seating depth (RELATIVE) and a few grains of powder for the same bullet, somebody has to admit their are patterns here???

Personally, I have yet to find a load that shoots better into the lands (heresy I know)... In fact, if you look at the record winners at 600 yard bench shooting in the archive several have never retuned their seating depth loads over the life of the barrel. Some chase the lands... Less of a pattern...

 

[necchi]

Folks,
Don't argue with an idiot, he'll drag you down to his level and beat you with experience.

 

[Bradley Walker]

http://bulletin.accurateshooter.com/2012/06/profiles-in-accuracy-jenkins-sets-600-yard-agg-record-with-6br/
Chad gets great accuracy with a pretty “standard” 6mmBR match load: 30.5 grains Varget, CCI 450 primers, Berger 105gr VLDs, in Lapua “Blue Box” brass. (Editor’s Note: That load can be too hot in some guns in summer conditions). Chad loads his ammo with a Redding bushing full-length sizing die with an 0.266″ bushing. Chad says: “That’s a good size for the ‘Blue Box’ Lapua brass (I tried a 0.268″ and I could pull the bullets out with my fingers). I seat my bullets about 0.020″ OFF the lands with a Redding Comp seater die.” The brass that shot the record Agg had about 10-11 firings on it, and Chad has NOT annealed the cases yet. While Chad is a very exacting reloader, he believes in the KISS principle — he doesn’t ream flash holes or uniform primer pockets. While he weighs every load with an RCBS Chargemaster, he normally does not double-check charges with a second balance. Chad tells us: “I just get the Chargemaster to where where it is going consistently and run with it.”

 

[mikecr]

If we can continue on with THIS THREAD;
So far the consensus seems that seating affects timing.
Makes sense.
It's my thoughts that this timing isn't a fine adjustment, but rather a setting of tune window, which can then get more easy or difficult to work with. This, often resulting in relatively huge changes to current/expected grouping with pretty minor changes in seating.

In other words, I think seating 'shapes' a tune window. That it affects every aspect of a load's behavior.
And I wonder if this could be somewhat seen with a strain gauge/pressure trace.

 

[Bradley Walker]

If we can continue on with THIS THREAD;
So far the consensus seems that seating affects timing.
Makes sense.
It's my thoughts that this timing isn't a fine adjustment, but rather a setting of tune window, which can then get more easy or difficult to work with. This, often resulting in relatively huge changes to current/expected grouping with pretty minor changes in seating.

In other words, I think seating 'shapes' a tune window. That it affects every aspect of a load's behavior.
And I wonder if this could be somewhat seen with a strain gauge/pressure trace.

I think that if that guy hadn't written that article stating his timing theory, I could have written an article saying that it was distance to the muzzle or some such other thing and everyone would now be saying its distance... With about as much proof...