Neck Tension issues? (different seating CBTO measurements)

[Apollo]

Just a few points I have picked up and not sure what you are doing or using.

The Bullet Seating Die - Does it have a seating insert designed for seating VLD Bullets (Secant Ogive) or is it the standard Tangent Ogive type that just maybe allowing the bullet meplat to touch the bottom of the seating stem rather than use the ogive.

You could try using one of these on your Calipres to give you a greater footprint for measuring.
http://brtshooterssupply.com.au/product ... -base.html

Unless you have a specific Wall Thickness Micrometer like one of these you are not going to get accurate measurements of case wall thickness. The blade of a calipre isn't going to give you very accurate readings, especially the further into the case neck you try and measure.
http://brtshooterssupply.com.au/product ... 1inch.html

Measuring bullet diameters you really need to be using a very accurate micrometer and take one measurement on the bearing surface of the bullet then another near the base of the bullet at the pressure ring which should be a greater measurement. I use one of these...
http://brtshooterssupply.com.au/product ... 1inch.html

This is all getting very expensive and really only to be considered if you are doing competition precision target shooting or you have plenty of money and just like getting things as exact as possible.

If you are seating, removing and re-seating a bullet in the same case you are going to reduce neck tension as every time you seat a bullet you are expanding the case neck ever so slightly unless you size the case neck every time and each time you do that you are hardening the case neck ever so slightly hence producing a slight amount of spring back compared to a case that has not been touched.

In my view every new (unfired) case should be full length resized to make sure they are all the same, then have a mandrel run down the case neck to expand evenly all cases and then have the neck sized to try and create an even set of cases. In my case I anneal every case every reload using an induction annealer set to give the best annealing I can achieve.

I have measured hundreds of Lapua cases and using the measuring equipment listed above I'll tell you that they are not all the same dimensions even over the same box batch lot. They all have differences and also hence why I skim turn case necks even if the chamber size doesn't require neck turning. Also, you really don't want to get into measuring neck thickness until the case has been fireformed and even fired at least twice as the neck material is still moving around the neck diameter.

If you want to be playing with getting bullet seating correct with being exact say 0.020" off the lands then you need a better measuring system for CBTO measurements like a dedicated measuring case and the appropriate guage to measure it like...
http://brtshooterssupply.com.au/product ... aight.html

Unless you are shooting precision target competition I wouldn't really worry about your 0.010" difference you are getting as long as your loaded rounds fit your magazine and bullets are off the lands so your setting of 0.020" gives you that safety margin. If you want to chase the best accuracy the you may want to consider single shot loading rounds that are say jammed 0.020" to jumped quite some distance say 0.100" or more then that will tell you where that bullet likes to be seated in your rifle. Who knows, it may be some jump away from the lands.

One thing I see you mentioned that you don't understand is the partial seating of a bullet. That means that you don't seat the bullet all the way into the neck in one go, say 50% then rotate the case/bullet say 90 degrees and seat the rest of the way.

I don't use the type of press you are using. All my precision reloading is done with In-Line Dies and an Arbor Press.

Hope all this helps a little with your reloading.

[Apollo]

BTW...

My main precision target shooting is 500 Metre Fly of which I'm hoping to get to the Nationals next month. I don't shoot a Creedmore but something close being a 6.5x47 Lapua of which I have 3 custom built rifles and shoot both Light and Heavy Gun Class. If I'm on song and can concentrate I aim to be in the top few competitors but I'm getting older quick and the eyes/reflexes/ etc are wearing out.

It's an expensive hobby this 500 Metre Fly when you start chasing the top spots.

Hope you enjoy it.

[marksman]

New to reloading, so this is where I have progressed to so far with new brass. Will multiple re seating of a case (dummy(s) in this situation), in other words incrementally pushing down the projectile to desired measurement (CBTO), stuff the neck tension up so that you get different measurements from other cases which had been subjected to the same thing (long story) from a Seating Die? Will not lubricating inside or outside of the case neck cause this issue? All 4 dummys cases have width measurements of the neck after seating within 6/10 thousandths (0.0006) of an inch (micrometer measurements), so seem to be within margins. CBTO measurements vary up to 10 thousandths (0.0100) of an inch difference (2.2510, 2.2545, 2.2610, 2.2615 inches). Press is Forster Co-Ax.

without reading all posts IMO yes
in practice I have found that different neck tensions will cause different measurements

think about it if a bullet is harder to seat it will and does not seat to the same oal as one that slips in easy, the harder to seat projectile will leave a ring impression on the ogive, the difference may be a couple of thou, powder compression can make a difference as well
I have a force dial on my press that shows differing forces used to seat bullets in different cases that shows the different neck tension and oal
you have to understand that sizing brass or seating and pulling bullets can make the brass harder although when pulling a bullet you will make the neck looser as it has been stretched to the size of the bullet that had been seated
and when try to get your oal on a dummy by making small adjustments to the die will get that oal right but the next one you try at that setting will usually be different but only just so most people will make a dummy and use it for setting up the die but give a quarter turn more before seating

if you are seating close to the lands you will need consistency but if you jam or jump you wont have to be so uniform
you must also consider that bullet ogives do vary so it is beneficial to check and batch bullets for consistent oal's

I hope this helps

[cirles]

Just a few points I have picked up and not sure what you are doing or using.

The Bullet Seating Die - Does it have a seating insert designed for seating VLD Bullets (Secant Ogive) or is it the standard Tangent Ogive type that just maybe allowing the bullet meplat to touch the bottom of the seating stem rather than use the ogive.

You could try using one of these on your Calipres to give you a greater footprint for measuring.
http://brtshooterssupply.com.au/product ... -base.html

Unless you have a specific Wall Thickness Micrometer like one of these you are not going to get accurate measurements of case wall thickness. The blade of a calipre isn't going to give you very accurate readings, especially the further into the case neck you try and measure.
http://brtshooterssupply.com.au/product ... 1inch.html

Measuring bullet diameters you really need to be using a very accurate micrometer and take one measurement on the bearing surface of the bullet then another near the base of the bullet at the pressure ring which should be a greater measurement. I use one of these...
http://brtshooterssupply.com.au/product ... 1inch.html

This is all getting very expensive and really only to be considered if you are doing competition precision target shooting or you have plenty of money and just like getting things as exact as possible.

If you are seating, removing and re-seating a bullet in the same case you are going to reduce neck tension as every time you seat a bullet you are expanding the case neck ever so slightly unless you size the case neck every time and each time you do that you are hardening the case neck ever so slightly hence producing a slight amount of spring back compared to a case that has not been touched.

In my view every new (unfired) case should be full length resized to make sure they are all the same, then have a mandrel run down the case neck to expand evenly all cases and then have the neck sized to try and create an even set of cases. In my case I anneal every case every reload using an induction annealer set to give the best annealing I can achieve.

I have measured hundreds of Lapua cases and using the measuring equipment listed above I'll tell you that they are not all the same dimensions even over the same box batch lot. They all have differences and also hence why I skim turn case necks even if the chamber size doesn't require neck turning. Also, you really don't want to get into measuring neck thickness until the case has been fireformed and even fired at least twice as the neck material is still moving around the neck diameter.

If you want to be playing with getting bullet seating correct with being exact say 0.020" off the lands then you need a better measuring system for CBTO measurements like a dedicated measuring case and the appropriate guage to measure it like...
http://brtshooterssupply.com.au/product ... aight.html

Unless you are shooting precision target competition I wouldn't really worry about your 0.010" difference you are getting as long as your loaded rounds fit your magazine and bullets are off the lands so your setting of 0.020" gives you that safety margin. If you want to chase the best accuracy the you may want to consider single shot loading rounds that are say jammed 0.020" to jumped quite some distance say 0.100" or more then that will tell you where that bullet likes to be seated in your rifle. Who knows, it may be some jump away from the lands.

One thing I see you mentioned that you don't understand is the partial seating of a bullet. That means that you don't seat the bullet all the way into the neck in one go, say 50% then rotate the case/bullet say 90 degrees and seat the rest of the way.

I don't use the type of press you are using. All my precision reloading is done with In-Line Dies and an Arbor Press.

Hope all this helps a little with your reloading.

Hi Apollo,
Thanks for the input. I have just purchased the the Hornady Anvil you indicated as thought this may be a solution to making vernier measurements easier to take. I have the same micrometer you indicated here as well but managed to get it much cheaper somewhere else. Did not want to go to the expense of the wall thickness micrometer as not interested in neck turning, but was informed of it for the Lapua cases I use by the person purchased from, same people you have referenced here, BRT of Queensland (as with most of my equipment so far). I understand that all cases may not have this thickness, or be concentric in that thickness but the micrometer measurements I took for those 4 cases were within 0.0006, so seem to be fine.

I am not after competition shooting type lengths/methods for accuracy, just as much as I can with equipment I currently have. So not neck turning, concentricity setups, weighing of cases, bullets, volumes etc for me. Just the dies I have..

Seating Die is the Forster 'Ultra Micrometer Seater Die' Do not have a clue what type this is regarding ogive shapes but another person in this thread did mention this (seating stem/adjustment screw interfering with the bullet tip) as a possible reason, so thanks for reaffirming this. You wouldn't happen to know would you (using Berger VLD Target 140 grain).

Just some clarification regarding the seating aspect you wrote, when you say '... removing and re-seating a bullet in the same case you are going to reduce neck tension...' do you mean the actual projectile (bullet) is removed from the case & then re seated again or simply the act of seating the bullet, then open press up & adjust measurement on the die again incrementally (a small amount), and then close press again to re seat? In other words I was just pushing the bullet in a little bit further every time (multiple times) until I reached the desired measurement wanted (would only do this for a dummy round so I had a reference for setting up the die next time for the same situation - have 300 Lapua cases).

Thanks for all the other input regarding issues to look into regarding getting accuracy, sounds like you do competition shooting & to compete at that level all the things you have listed here are what people are doing. For me, even in the 500 meter fly shoot, I am not there to compete at the top level so much as have a good time but also extract as much accuracy as possible from the rifle without going to the extremes of the competition guys.

[cirles]

New to reloading, so this is where I have progressed to so far with new brass. Will multiple re seating of a case (dummy(s) in this situation), in other words incrementally pushing down the projectile to desired measurement (CBTO), stuff the neck tension up so that you get different measurements from other cases which had been subjected to the same thing (long story) from a Seating Die? Will not lubricating inside or outside of the case neck cause this issue? All 4 dummys cases have width measurements of the neck after seating within 6/10 thousandths (0.0006) of an inch (micrometer measurements), so seem to be within margins. CBTO measurements vary up to 10 thousandths (0.0100) of an inch difference (2.2510, 2.2545, 2.2610, 2.2615 inches). Press is Forster Co-Ax.

without reading all posts IMO yes
in practice I have found that different neck tensions will cause different measurements

think about it if a bullet is harder to seat it will and does not seat to the same oal as one that slips in easy, the harder to seat projectile will leave a ring impression on the ogive, the difference may be a couple of thou, powder compression can make a difference as well
I have a force dial on my press that shows differing forces used to seat bullets in different cases that shows the different neck tension and oal
you have to understand that sizing brass or seating and pulling bullets can make the brass harder although when pulling a bullet you will make the neck looser as it has been stretched to the size of the bullet that had been seated
and when try to get your oal on a dummy by making small adjustments to the die will get that oal right but the next one you try at that setting will usually be different but only just so most people will make a dummy and use it for setting up the die but give a quarter turn more before seating

if you are seating close to the lands you will need consistency but if you jam or jump you wont have to be so uniform
you must also consider that bullet ogives do vary so it is beneficial to check and batch bullets for consistent oal's

I hope this helps

Hi Marksman,

Yes it all helps. It sound like you are indicating there will be a difference but the difference I experienced for 2 of those rounds seems excessive (0.010) but another person on this thread seemed to indicate it may not be. It looks like I need to lubricate the necks to knock out any variance for pressure when pressing a bullet (other than dinged brass). And as mentioned earlier I was simply pushing the bullet in a bit at a time (never removing the bullet from the case) till I reached the desired measurement.

Another thing I should mention is that I do not in any way, shape or form want to seat 'Jam'ed. That scares the hell out of me because I see it as a potential area where pressure issues become much harder to control, ie. the jaming amount/measurement effects how much pressure produced so getting that exactyl right with measurements oal, neck tension is just too risky for my blood. I understand many comp shooters do it so it is doable, but not for me as a beginner on this journey.

[Apollo]

"cirles"

I have a couple of the Hornady Anvils, not sure if this still happens but Stuart Elliott used to modify them slightly by drilling a small part of the centre so that it provided a better surface in case there was a slight dimple in the middle of say a bullet that wouldn't sit properly. Probably doesn't matter much for general use. I also have a range of inserts and kit from Hornady for measuring bullets and cases. All handy when one is just checking or setting stuff up. However, a lot of this I don't use much any more. I know my measurements so checking a CBTO I do just use a Sinclair Nut to check seating each reloading session. I jam bullets generally 0.020" or there abouts since my neck tension is very low and closing the bolt does what is known as "soft seating" ie the bolt pushed the bullet onto the lands but really not much further.

I am not familiar with Forster Dies but somewhere in the info for your specific die it should mention something about the seating stem or alternatives. You could test the seating stem by say putting a small dob of something on the meplat to see if it bottoms out on the seating stem You should also not ever see a mark on the bullet ogive from the seating stem if all is correct unless for some reason the seating pressure is excessive. I use 130gr Berger VLD's as I found the 140gr were too heavy for my calibre to provide the accuracy I wanted, now Berger have shortened the length of the 130gr VLD and it doesn't work as accurate as it did in the past so I switched to Copperhead Bullets, however now Ken has a supply problem with J4 Jackets and is switching those to Sierra Jackets...so to see if they perform.

I was talking about removing the bullet and re-seating the bullet in the same case over and over without sizing the neck each time. Each time you insert the bullet it will open up the neck just that ever so slight amount.

You will have a good time shooting 500M Fly but I bet the bug bites when you have a good days shooting that you feel you can improve on so then you go chasing accuracy from what you have at hand or better.

I started with a .243W Tikka T3 shooting at home on my 500m target. It wasn't long before I started upgrading that and also converted it to a 65.x47L plus ordered a Custom built Long Range Target Rifle. The March Scopes I use cost as much if not far more than the rifles they are mounted on. My reloading gear and components I have would be around 10 grands worth. Farley and SEA Coaxial Front Rests and nearly bought a SEB but the dollars ran out.

Anyway, I love accurate shooting and probably go out about every second day to cull some varmints around home out to say 300 metres to make it easy. Target shooting at a number of distances I believe helps me in not only judging distance but understanding trajectory. General use here from day to day is a .223R Varmint Rifle (CZ527) or a Sako 85 .204Ruger.

Best of luck.

[Apollo]

If this is what you have then you should be right as far as the seating stem goes... See description.

https://brtshooterssupply.com.au/produc ... r-die.html

[cirles]

Apollo,

Thanks for the clarification & suggestion on how to check if the seating stem is an issue, great idea.

It certainly is a hobby where you can spend plenty of dollars on equipment. Wish I had an area to go to (not club) to shoot longer range (1000 meter) but will tackle that in the future as know someone who deals with farmers, so seems the best avenue for pursuing that. I also do Pistol/Revolver metallic silhouette shooting (recently started) in 9mm currently but will progress to large calibre as have always wanted to shoot that ever since I shot a Freedom Arms 454 many, many years ago.

[cirles]

If this is what you have then you should be right as far as the seating stem goes... See description.

https://brtshooterssupply.com.au/produc ... r-die.html

Yes that's it, thanks for confirming this, saves me having to try your suggestion

[SCJ429]

You should do well with your Tikka, they have brilliant barrels on them for a factory unit. I have a Tikka in 223 which can shoot under an inch at 300 and under three inches at 500. You will find 500 metre shooting is quite a challenge and can be humbling when you cannot see what you are doing and the conditions keep changing.

To start out I would keep things simple and concentrate on making straight ammo with light neck tension. If you feel a pill seat with more pressure than usual, set it aside and use it for a sighter. Marksman mentioned that he has a strain gauge on his press so that he can observe this. Inconsistant neck tension is the biggest contributor to poor accuracy which is why guys go to such lengths as neck turning, use bushing dies and regular annealing.

[Apollo]

To add a bit to this, being that I too believe consistent neck tension is vital to doing any reloading with accuracy in mind. Doesn't have to be for competition target shooting but trying to create the most accurate reloading within your own means.

Like Marksman, I too use a strain gauge to watch what is happening with seating bullets but over the years I have seated so many thousands of bullets I can pretty much feel when one is either too loose or too tight so they get marked with a felt pen. Since all my cases are sorted into increasing weight / capacity I don't throw a case unless next time it has the same problem. Using an Arbor press it's quite sensitive as to the force you exert on such a small lever as opposed to a large reloading press. This is what I use with a 0.0005" Dial Gauge...

http://brtshooterssupply.com.au/product ... -2016.html

Like I have said before, I anneal cases every reload with an Induction Annealer..

Mark I version of this .. http://brtshooterssupply.com.au/product ... -unit.html

Everyone is different in their circumstances and reasons for reloading plus some just cannot afford the gear they would like to use. Just enjoy what you can from the best you can make with your own equipment.

[cirles]

To SCJ428 & Apollo,

Thanks guys for your continuing suggestions & thoughts + experience on this reloading & shooting business, in certainly gives me more of an insight into what is involved when you take it too the next level. Annealing after every reload sounds expensive (disregarding initial equipment cost) just in electricity costs alone.

When I decided to buy a rifle & also to reload (mainly for keeping costs down), I never imagined setting up for accuracy would get so complicated. So certainly a learning experience here & I will just keep plugging away till am satisfied with what I can do. I am hoping that the urge to upgrade or acquire even more equipment in the service of more accuracy wont hit me in the future as this has proven to be a costly hobby so far just getting to this point (with admittedly good quality equipment & consumables).

[Apollo]

"cirles" for what it's worth as is a lot of this equipment, it's the initial cost that hurts the most. The more use you get the far cheaper it gets so if you are young you are investing in a lifetime hobby.

The induction annealer uses bugger all power and is super quick. Not actually timed one but say a couple / few seconds and it's done each case. I'm too busy dumping the hot case and grabbing another then inserting it to count the time. Out of interest have a look at the AMP Web Site and watch some of the videos, something to contemplate for the future perhaps.

Another thing to contemplate is that once you have fired all your batch of cases you are going to use at least once they will improve in consistency and accuracy if you make very slight adjustments to chase the accuracy. With my target rounds, since I use 50 rounds for a match I revolve 150 rounds in order. I may have started with 200 cases but one batch of 50 are adds and sods that are in some way different then there are a few I have scrapped that have faults. Those 200 I started with are enough for me to wear out a barrel. Then I have a reserve supply of cases pretty much ready to go if I choose to have a spare barrel blank that I have chambered.

Like bullets and cases, I have spare barrel blanks on hand which is very handy because at times they may not be available for months or a years wait to replace.