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Full Length Resizing For a Bolt Action

RLinNH

Sergeant of the Hide
Full Member
Minuteman
Mar 23, 2019
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I have a question in regards to full length resizing. I for into reloading due to the possible accuracy increases for my 6.5 Bergara HMR. It's the caliber that I am looking forward to hand loading for. I have been reloading for my .223 in preparation in order to learn the basics. Also, I have been reading A LOT. Here's where my dilemma comes in. I have 80 once fired cases. 40 Hornadys, 20 S&B's, and 20 Federals for my 6.5 Creedmoor. All the reading I have seen say that a BIG advantage with reloading is having cases that are formed to your chamber. This occurs after firing the case in your given firearm. The firing "pressure fits" itself to your chamber. So, if that's the case, why would I full length resize the case. Shouldn't I just neck resize?
 
And no, I have yet to hand load for my 6.5 platform. Like I said above. I wanted to learn with my .223 prior. Also, I still have lots of reading to do. Not to mention my caliber conversion plate won't be here until Friday... :cautious:
 
i've only been doing this for a little while but my understanding is as follows:
If you neck size only eventually the case body won't easily chamber. This is because of the case’s elastic properties. The case eventually will harden from the cycles of firing, expansion, cooling and contraction. Ultimately the changes in case dimensions will require a more comprehensive sizing to once again fit the chamber.
 
Hand loading is not successful because cases fit better. That’s a rationalization made by neck sizers because it sounds good. Kind of easy to wrap ones head around, but It’s dead wrong. The ability to tune the load to the gun is why handloads work. Bullet proximity to the lands, consistent neck tension, consistent charge weights, consistent case volume, proper bullet and powder selection. The gun has to function first, and that’s why we FL size cases.
 
So, if that's the case, why would I full length resize the case. Shouldn't I just neck resize?

Because you dont size it all the way back down to saami minimum specs, ideally you only size the full length of the case enough to just create a minimal functional clearance of one or two thousandths of an inch.
Neck sizing: eventually the brass wont spring back enough and youll be using your bolt as the sizing die. Full length every time means that the case is treated the same every firing and it works the same as intended every time.
 
Also, the name of the game is consistency and predictability.

FL sizing it back close to the same size every time is much more consistent than a case that’s different sizes each firing.
 
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All the answers here are why I posted. I have read about the brass having an "elastic" property. Actually, I have learned a lot in the past few weeks in regards to what the entire cartridge goes through during the firing process. Good stuff. But the first time I have heard that it is detrimental to the case to only neck size is here in this thread. Makes sense though as without the full length resize, the case would already be at the chamber max pressure size. Hence, when it is fired again, the brass would need to expand somewhere.

Someone above also mentioned the bullet proximity to the lands. Once I get a load figured out for my platform, I want to research that. IE, how do you know exactly how far your bullet is from the lands?
 
Bump .002” on the shoulder when you full length size. I usually neck size with a Lee collet die and it has served me very well. I bump the shoulder .002” when brass starts getting tighter to chamber. For best consistency fl sizing is best. My fclass rifle is fl sized

My advice is use the same brand brass across the board. Some brass is softer than others and they very in thickness which will play into pressure and neck tension.
 
The term Full Length Sizing is incorrect. FL dies only size about 3/4 of the case. Small base dies size the case closer to factory ammo.
 
If your rounds are going any where except a bench I would advise against neck sizing.

Reliability and forgiveness in fls.
 
Can any of the people or places that are telling you not to full length size claim to be the best in the world at anything, let alone a respective shooting discipline?
 
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The term Full Length Sizing is incorrect. FL dies only size about 3/4 of the case. Small base dies size the case closer to factory ammo.
That’s not quite accurate. Small base dies are just that, smaller in the base. A regular sizer still touches the same areas, just not as much at the base. The exact chamber and die shape will cause that to vary a bit, but everything that touches the chamber during firing is getting sized iN the average sized.
 
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I have a question in regards to full length resizing. I for into reloading due to the possible accuracy increases for my 6.5 Bergara HMR. It's the caliber that I am looking forward to hand loading for. I have been reloading for my .223 in preparation in order to learn the basics. Also, I have been reading A LOT. Here's where my dilemma comes in. I have 80 once fired cases. 40 Hornadys, 20 S&B's, and 20 Federals for my 6.5 Creedmoor. All the reading I have seen say that a BIG advantage with reloading is having cases that are formed to your chamber. This occurs after firing the case in your given firearm. The firing "pressure fits" itself to your chamber. So, if that's the case, why would I full length resize the case. Shouldn't I just neck resize?

The advantage of having brass previously fire formed to your chamber is not that it has assumed your chamber’s dimensions, but that it remembers what it is going to spring back to, therefore the release of the bullet is going to be consistent.
 
I used to neck size only. It started bothering my OCD knowing that my bolt closing force changed with each firing, and wondering when it was going to be time to FL size again, thus creating a case fit that was even more different than what I'd been shooting.

Now I use a Lee collet die to neck size, and a Redding body die to just slightly bump shoulder after every firing.

My OCD is better now, and all my loads are the same each time.
 
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I use a full length sizing die to bump the shoulder back .003. This keeps the brass consistent from sizing to sizing but also minimizes the work being done to the brass each time it is fired and then resized. Fully resizing every time will likely cause case head separation faster then just bumping the shoulder.
 
Just FYI you’ll need a OAL gauge to measure the shoulder bump. Don’t FL every time just based on the manufactures instructions
 
That’s not quite accurate. Small base dies are just that, smaller in the base. A regular sizer still touches the same areas, just not as much at the base. The exact chamber and die shape will cause that to vary a bit, but everything that touches the chamber during firing is getting sized iN the average sized.

A regular die will never touch the base of the case that has been fired in a normal chamber, so the term full length size really is not correct.
A small base die does resize the entire length of the case including the base.

There are many instances where a fired case resized in a Full Length Die will NOT chamber in a different rifles chamber even though it has been full length sized. If the case was really full length sized it should fit any SAAMI chamber but it does not always fit.

Anyway thats my story.
 
I have 80 once fired cases. 40 Hornadys, 20 S&B's, and 20 Federals for my 6.5 Creedmoor.

You're loading those various brands of cases the same, you're very likely going to get different results for each, because . . . they are not the same. There'll be difference case wall thicknesses, which effects the volume within the case and variable volume creates variable pressure's which results in variable MV's. Also, the brass of each are just a little different alloy making one a little softer than another which effects how they respond to expansion and contraction. For example, Federal's brass tends to be softer than most and one of the reasons reloaders s don't get as many reloads from them. If you're just plinking and/or just practicing reloading, then this detail doesn't matter.

All the reading I have seen say that a BIG advantage with reloading is having cases that are formed to your chamber. This occurs after firing the case in your given firearm.

As has already been well stated, the BIG advantage with reloading is in producing that are consistent and tuned to you're particular gun (e.g. controlling power charge and details of the case configuration). . . . especially for the likes of a 6.5 CM. For many people, the other "BIG" advantage is reducing the cost of each cartridge when shooting large quantities of ammo. That a case is "formed to your chamber" is NOT as "BIG" advantage as several other pieces of the reloading process is much more (like powder charges).

So, if that's the case, why would I full length resize the case. Shouldn't I just neck resize?

For many, just FL sizing their cases is simply an easier way to get uniform cases that work well. AND, a FL sized case provides less chance of a stuck case in the chamber (a big issues if one is competing or hunting in poor environment). Neck sizing only (and when I say "only", I'm not excluding having to bump the shoulder back each time - which I do) works just fine and prolongs the case life where it can be reloaded more times than if one is FL sizing each time which you're not hard working the case body. What can be another advantage of neck sizing is you have a case volume that's larger than when when if FL sizing. The extra volume allows for little larger powder charge in the event that one is trying to achieve some accuracy-maximum velocity load.

If one has a mass produced factory chamber, neck sizing along with shoulder bumping provides a case that is more of a custom fit, though it takes more monitoring as a factory can cause more stretching of the case where at some point the case will need FL sizing very once in a while (noticeable by a stiff chambering of the cartridge). Many competitive shooters (depending on the type of shooting they do) have custom chambers as well as custom dies and simply do FL sizing, and in rare cases in some custom chambers, sizing may not be necessary at all. :eek: ;)

Now, are you totally confused yet? :giggle:
 
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Looks like I inadvertently opened the proverbial can of worms. Sorry about that. Thanks to everyone for sharing the knowledge. (y) ?
 
A regular die will never touch the base of the case that has been fired in a normal chamber, so the term full length size really is not correct.
A small base die does resize the entire length of the case including the base.

There are many instances where a fired case resized in a Full Length Die will NOT chamber in a different rifles chamber even though it has been full length sized. If the case was really full length sized it should fit any SAAMI chamber but it does not always fit.

Anyway thats my story.

I have a bucket of 6.5 Creedmoor brass that I picked up at the range. So far I have identified 6 rifles it was fired in based on case dimensions. The fattest case at the base measures .472” and the slimmest .468”. When I size the .472” case it comes out .470-471” and will get stuck in most chambers, I would think.
 
You're loading those various brands of cases the same, you're very likely going to get different results for each, because . . . they are not the same. There'll be difference case wall thicknesses, which effects the volume within the case and variable volume creates variable pressure's which results in variable MV's. Also, the brass of each are just a little different alloy making one a little softer than another which effects how they respond to expansion and contraction. For example, Federal's brass tends to be softer than most and one of the reasons reloaders s don't get as many reloads from them. If you're just plinking and/or just practicing reloading, then this detail doesn't matter.



As has already been well stated, the BIG advantage with reloading is in producing that are consistent and tuned to you're particular gun (e.g. controlling power charge and details of the case configuration). . . . especially for the likes of a 6.5 CM. For many people, the other "BIG" advantage is reducing the cost of each cartridge when shooting large quantities of ammo. That a case is "formed to your chamber" is NOT as "BIG" advantage as several other pieces of the reloading process is much more (like powder charges).



For many, just FL sizing their cases is simply an easier way to get uniform cases that work well. AND, a FL sized case provides less chance of a stuck case in the chamber (a big issues if one is competing or hunting in poor environment). Neck sizing only (and when I say "only", I'm not excluding having to bump the shoulder back each time - which I do) works just fine and prolongs the case life where it can be reloaded more times than if one is FL sizing each time which you're not hard working the case body. What can be another advantage of neck sizing is you have a case volume that's larger than when when if FL sizing. The extra volume allows for little larger powder charge in the event that one is trying to achieve some accuracy-maximum velocity load.

If one has a mass produced factory chamber, neck sizing along with shoulder bumping provides a case that is more of a custom fit, though it takes more monitoring as a factory can cause more stretching of the case where at some point the case will need FL sizing very once in a while (noticeable by a stiff chambering of the cartridge). Many competitive shooters (depending on the type of shooting they do) have custom chambers as well as custom dies and simply do FL sizing, and in rare cases in some custom chambers, sizing may not be necessary at all. :eek: ;)

Now, are you totally confused yet? :giggle:

Thanks for the detailed response. And yes, I am confused, but not as much as I was prior to this thread...:ROFLMAO: As far as the brass goes, I will still use all the brass I have on hand. Although I will keep in mind the variances that can occur due to me using different manufacturers brass. I also have 100 New Brass cases from Sig Sauer on hand...:confused:
 
A regular die will never touch the base of the case that has been fired in a normal chamber, so the term full length size really is not correct.
A small base die does resize the entire length of the case including the base.

There are many instances where a fired case resized in a Full Length Die will NOT chamber in a different rifles chamber even though it has been full length sized. If the case was really full length sized it should fit any SAAMI chamber but it does not always fit.

Anyway thats my story.
Right, because that portion of the case you’re talking about is floating in air. Every bit of the case wall that expanded to the chamber will get sized using a standard die as long as the tolerances between die and chamber aren’t screwed up. A small base die is merely smaller diameter at its base, nothing more. It’ll correct the situation 918v noted above.

6.5 creed in a bighorn TL3 barrel.
838C6E81-1948-4331-94C6-A2087CC599EF.jpeg
 
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If your reloading for accuracy you need consistency as mentioned above its not likely not going to happen with 3 different manufacturers of brass. .I've been using Lapua brass for reloading. It's expensive initially but I think most will agree Its worth it. Full length sizing is giving me good results. You need a tool like a Forester makes that attaches to calipers to measure a fire formed case the adjust your sizing die to just push the shoulder back a couple thousands. Has worked pretty good for me. I'm getting SD's around 6 fps. Just depends how far you want to go down the rabbit hole. Annealing, weighing out every charge.
 
A regular die will never touch the base of the case that has been fired in a normal chamber, so the term full length size really is not correct.
A small base die does resize the entire length of the case including the base.

There are many instances where a fired case resized in a Full Length Die will NOT chamber in a different rifles chamber even though it has been full length sized. If the case was really full length sized it should fit any SAAMI chamber but it does not always fit.

Anyway thats my story.
My Redding body die sizes right to the extractor groove.
 
You're loading those various brands of cases the same, you're very likely going to get different results for each, because . . . they are not the same. There'll be difference case wall thicknesses, which effects the volume within the case and variable volume creates variable pressure's which results in variable MV's. Also, the brass of each are just a little different alloy making one a little softer than another which effects how they respond to expansion and contraction. For example, Federal's brass tends to be softer than most and one of the reasons reloaders s don't get as many reloads from them. If you're just plinking and/or just practicing reloading, then this detail doesn't matter.



As has already been well stated, the BIG advantage with reloading is in producing that are consistent and tuned to you're particular gun (e.g. controlling power charge and details of the case configuration). . . . especially for the likes of a 6.5 CM. For many people, the other "BIG" advantage is reducing the cost of each cartridge when shooting large quantities of ammo. That a case is "formed to your chamber" is NOT as "BIG" advantage as several other pieces of the reloading process is much more (like powder charges).



For many, just FL sizing their cases is simply an easier way to get uniform cases that work well. AND, a FL sized case provides less chance of a stuck case in the chamber (a big issues if one is competing or hunting in poor environment). Neck sizing only (and when I say "only", I'm not excluding having to bump the shoulder back each time - which I do) works just fine and prolongs the case life where it can be reloaded more times than if one is FL sizing each time which you're not hard working the case body. What can be another advantage of neck sizing is you have a case volume that's larger than when when if FL sizing. The extra volume allows for little larger powder charge in the event that one is trying to achieve some accuracy-maximum velocity load.

If one has a mass produced factory chamber, neck sizing along with shoulder bumping provides a case that is more of a custom fit, though it takes more monitoring as a factory can cause more stretching of the case where at some point the case will need FL sizing very once in a while (noticeable by a stiff chambering of the cartridge). Many competitive shooters (depending on the type of shooting they do) have custom chambers as well as custom dies and simply do FL sizing, and in rare cases in some custom chambers, sizing may not be necessary at all. :eek: ;)

Now, are you totally confused yet? :giggle:

Your primer pockets will fail before the case head from FL sizing. Brass life myth has been busted almost as many times as the accuracy myth.
 
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A regular die will never touch the base of the case that has been fired in a normal chamber, so the term full length size really is not correct.
A small base die does resize the entire length of the case including the base.

There are many instances where a fired case resized in a Full Length Die will NOT chamber in a different rifles chamber even though it has been full length sized. If the case was really full length sized it should fit any SAAMI chamber but it does not always fit.

Anyway thats my story.

This is mostly incorrect. A regular FL die will still take the case down .001-.002 down to the .2 line.

A small base die just takes it down more.

If your regular FL die does not size down to the .2 line, then your die does not match your particular brass/chamber. So, if for some reason your dies *never* size all the way down, you have been unlucky enough to never have properly matched dies.

 
Forster had a die customization option whereby you send them a few fire formed cases and they hone the die to more optimally fit your chamber. They can also hone your projectile seating die if you send them a few projectiles. The cost was very reasonable and it took them perhaps 2 weeks if i recall correctly.
 
This is mostly incorrect. A regular FL die will still take the case down .001-.002 down to the .2 line.

A small base die just takes it down more.

If your regular FL die does not size down to the .2 line, then your die does not match your particular brass/chamber. So, if for some reason your dies *never* size all the way down, you have been unlucky enough to never have properly matched dies.




I have checked a few dies and my results seem to reinforce my statements. This Is the method I use.

IMAG2776-20200408-223724830.jpg
 
If all FL dies didn’t size down to the .2 line, then most people would eventually run into primary extraction issues as the brass would eventually be too tight in the chamber.
 
Your primer pockets will fail before the case head from FL sizing. Brass life myth has been busted almost as many times as the accuracy myth.

I've not seen the science for that and would be interested in reading it. Got any links to any?

For over a year now I've been reloading Federal .308 brass to see how far they'd go until the primer pockets failed. Out of 160 cases I had 1 pocket that became too loose after 4 firings and then 1 more at 6 firings. The rest of the cases' pockets held up through 11 firings the the cases heads began to fail, so of course I finally threw them all out (that was actually just recently). I only FL sized them twice, once after the 1st firing and once after 7 firings. I've been told by more than one person that they couldn't get more than 4 firings from Federal brass because of its softness where the primer pockets were failing on them and they were only FL sizing. So, all I can say is that apparently my Federal brass lasted longer than most reports and I attributed that to the neck sizing that I did. Guess I should have done an actual comparison test??? ;)
 
I've not seen the science for that and would be interested in reading it. Got any links to any?

For over a year now I've been reloading Federal .308 brass to see how far they'd go until the primer pockets failed. Out of 160 cases I had 1 pocket that became too loose after 4 firings and then 1 more at 6 firings. The rest of the cases' pockets held up through 11 firings the the cases heads began to fail, so of course I finally threw them all out (that was actually just recently). I only FL sized them twice, once after the 1st firing and once after 7 firings. I've been told by more than one person that they couldn't get more than 4 firings from Federal brass because of its softness where the primer pockets were failing on them and they were only FL sizing. So, all I can say is that apparently my Federal brass lasted longer than most reports and I attributed that to the neck sizing that I did. Guess I should have done an actual comparison test??? ;)
Do you have any world records to your name, and are any of them for shooting?
 
I got 20+ firings out of FC brass and I FL sized every time. It depends on how hot you load them and on the particular lot of brass. There are many ways to kill brass. A lot of reloaders are stupid. They overpressure the cases by loading into the lands, by using data developed in lighter cases, by increasing powder charges until they see pressure signs, etc. If you keep pressure around 55000PSI then your Federal cases will last at least 10 reload cycles.
 
I've not seen the science for that and would be interested in reading it. Got any links to any?

For over a year now I've been reloading Federal .308 brass to see how far they'd go until the primer pockets failed. Out of 160 cases I had 1 pocket that became too loose after 4 firings and then 1 more at 6 firings. The rest of the cases' pockets held up through 11 firings the the cases heads began to fail, so of course I finally threw them all out (that was actually just recently). I only FL sized them twice, once after the 1st firing and once after 7 firings. I've been told by more than one person that they couldn't get more than 4 firings from Federal brass because of its softness where the primer pockets were failing on them and they were only FL sizing. So, all I can say is that apparently my Federal brass lasted longer than most reports and I attributed that to the neck sizing that I did. Guess I should have done an actual comparison test??? ;)

Contact Lou Merdica. I’m sure he can provide you with all the testing you want. Considering he’s the guy most everyone sends all their stuff to for testing.

Please inform him of your breakthrough discovery as he has found FL sizing doesn’t decrease the brass life.

Also, anecdotal stories with junk federal brass.....gtfo. But again, you apparently have it figured out when the rest of the F class and BR guys haven’t.
 
I've not seen the science for that and would be interested in reading it. Got any links to any?

For over a year now I've been reloading Federal .308 brass to see how far they'd go until the primer pockets failed. Out of 160 cases I had 1 pocket that became too loose after 4 firings and then 1 more at 6 firings. The rest of the cases' pockets held up through 11 firings the the cases heads began to fail, so of course I finally threw them all out (that was actually just recently). I only FL sized them twice, once after the 1st firing and once after 7 firings. I've been told by more than one person that they couldn't get more than 4 firings from Federal brass because of its softness where the primer pockets were failing on them and they were only FL sizing. So, all I can say is that apparently my Federal brass lasted longer than most reports and I attributed that to the neck sizing that I did. Guess I should have done an actual comparison test??? ;)

Just remembered, you’re also the guy who thinks he can use calipers to read .0001
 
Also, anecdotal stories with junk federal brass.....gtfo. But again, you apparently have it figured out when the rest of the F class and BR guys haven’t.

You're right about Federal brass being "junk", as it were. And I haven't figured out anything as all I have is anecdotal stories and my own anecdotal experience. That's why I was asking about the science.


Contact Lou Merdica. I’m sure he can provide you with all the testing you want. Considering he’s the guy most everyone sends all their stuff to for testing.

Thanks for the idea. No doubt, Lou Murdica would be a good man to talk to about the science.

Please inform him of your breakthrough discovery as he has found FL sizing doesn’t decrease the brass life.

If I'm ever lucky enough to make any kind of "breakthrough discovery", I'll let the world know. o_O :giggle:
 
I full length size and neck size.
I see absolutely no accuracy difference
I just neck size sometimes because I’m lazy, I’m not shooting in a critical situation and am willing to deal with the possible issues it can induce.
For competition, hunting or critical shots I’d absolutely full length size everything.
 
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I'm another guy who when starting out thought neck sizing was the best way to achieve better accuracy. So that's what I did. Neck sizing was easy, no messy lube to clean off, no need to check and trim length. I was getting 10 - 12 reloads to a case so assumed everything was fine, groups stayed under 1MOA so why change? Now as I keep reading about FL sizing, body dies and such I think I am not doing everything I can to improve my shooting. Starting off I will FL size first, fire form and then neck size for three loading's, then FL size again. I do weigh and sort my brass but don't currently neck turn or anneal cases. Maybe that's next??
 
Full length size your brass EVERY FIRING.
 
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I think it has to do with being lazy? ;) . That and so far I have not seen any real benefit. Could be I have reached the level of my abilities??