• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

FL sizing?

Doc68

I'm an asshole....
Full Member
Minuteman
  • Feb 17, 2014
    6,042
    14,460
    USA
    Ok here is my question. I'm newer to reloading so don't flame me too bad here. I have been just NK sizing brass. Now I want to FL size it all. Can I FL size the stuff that has already been NK sized? And exactly how do you set up the FL sizing die?
     
    Yes you can f/l size neck sized brass. Read my response to your other post for die setup instructions. If you have more questions just ask
     
    I'm brand new to reloading too, I have yet to take my equipment out if the box. Here is how I understand it: only neck size brass shot from your bolt gun. Full size brass when shooting in a semi auto. Full size random range or once fired brass (not from your rifle) then only neck size if shot in your bolt gun, but always full size in semi auto. Why the change of mind? I would think you could full size already neck sized brass, but I'm no expert.
     
    I'm brand new to reloading too, I have yet to take my equipment out if the box. Here is how I understand it: only neck size brass shot from your bolt gun. Full size brass when shooting in a semi auto. Full size random range or once fired brass (not from your rifle) then only neck size if shot in your bolt gun, but always full size in semi auto. Why the change of mind? I would think you could full size already neck sized brass, but I'm no expert.

    Guys, f/l size only. Neck sizing only leads to frustrating problems.
     
    Ice, that's a pretty common thought process but the reality is you can't really expect to neck size only 100% of the time. Eventually you'll have to FL size it and most folks that I know who neck size, FL size every third load or so. Otherwise what will happen is that your case shoulder will get closer and closer to your chamber shoulder dimensions and without any room to expand and spring back, it'll be difficult to lock and unlock and could potentially give you a pressure spike. It this all depends on your rifle too. I've owned bolt guns that needed to be FL sized every time because the chambers were fairly tight.

    The advantage of neck sizing is that you get consistent neck dimensioning without overworking the brass. Brass cases don't get brittle from heat; the get brittle from being work hardened and constantly FL sizing them can overwork the brass. That's why it's common for precision folks to anneal after 3-5 firings to "reset" the grain structure on the brass (thereby preventing them from getting work hardened).

    I used to neck size quite a bit, but now I FL size all the time and use Redding S dies with the neck bushings. These let you control neck tension as part of the FL sizing process.
     
    Some more good to know stuff here. I'm starting to learn the guys I'm surrounded by might not be as knowledgable as I thought, I'm glad I joined this forum. I have yet to purchase a single die, I keep hearing this redding name. I'll have to do more research before I buy a bunch of useless dies.
     
    There aren't a whole lot of useless dies out there. I started with cheap Lee dies and they did me right for the first year, but over time experimented with all kinds of different dies from different manufacturers and can say I wasted a lot of money in the process. There was just a lot of stuff I didn't really need in the end, but I didn't know at the time. Fancy expensive isn't always as useful for YOU - it's all relative to what you're doing.
     
    Yes you can f/l size neck sized brass. Read my response to your other post for die setup instructions. If you have more questions just ask

    As to your questions asked in the other post. I now understand headspace. And I'm turning to FL sizing now because of a few issues as far as run out and not being able to close the bolt. I noticed a big difference between the FL resized brass and the NK sized only brass. They are all closing now with no effort on the bolt. And yes I do know what fire forming is also. A good little read on headspace though. Brings a lot of light not he subject. Thanks for the info and what to read up on!
     
    It's important to remember that brass not only expands on firing, but springs back a bit too. So you want your sized brass to fit the chamber, but with a bit of room for it to expand into. The trick is not letting it expand too much though. For example, if there's too much room for the shoulder to expand into (ie headspace), then it will stretch the brass significantly, leading to a case head separation eventually. If there's not enough room, then the force will propagate to the case mouth and force the brass to squeeze down on the bullet, preventing it from being released. This in turn will cause a potentially dangerous pressure spike.

    This is why bumping the shoulder back 0.002" is the general rule of thumb. With bolt guns even 0.001" can be enough, but knowing exactly how much you're bumping the shoulder is vital. Get a tool like the Sinclair bump gage or Redding Instant Indicator (if you have a turret press or multiple presses) to measure the amount of shoulder bump when setting up your sizing die. And the issue of shoulder bump is precisely why it's important that you setup your sizing dies properly. When I was first starting out I mucked that up a few times and bumped the shoulder too much or too little with frustrating and bad results.
     
    It seems unavoidable to purchase some precision measuring gages. It makes sense, to precisely reload you need to know precisely what your gun measures. I was just reading another post about erosion in the bore, a tool would be pretty hand to keep up on a changing chamber.
     
    Here is a video I made to help explain F/L sizing in more detail.

    <iframe width="480" height="360" src="//www.youtube.com/embed/1HLkOp01o64" frameborder="0" allowfullscreen></iframe>
     
    I also forgot to mention that F/L sizing also sizes the body, which is also important for reliable chambering. Neck sizing doesn't size the body, and leads to chambering issues there as well.
     
    Great video. It honestly does explain a lot. I was one of those people who read some older manuals. It never said that eventually you would have to FL resize ever. Thanks for answering my questions. And not being sarcastic!
     
    Good info, I've always neck sized my brass with good results thus far (been doing this for 15+ years). May have to rethink the way I resize brass...
     
    If there's not enough room, then the force will propagate to the case mouth and force the brass to squeeze down on the bullet, preventing it from being released. This in turn will cause a potentially dangerous pressure spike.

    I've never heard this before. How can the brass ever become longer than the chamber when fired in the same rifle? I understand the need for bumping the shoulder once the brass reaches near zero spring back from chamber dimensions, but don't understand how there could be a "pressure spike".
     
    I've never heard this before. How can the brass ever become longer than the chamber when fired in the same rifle? I understand the need for bumping the shoulder once the brass reaches near zero spring back from chamber dimensions, but don't understand how there could be a "pressure spike".

    I think he is referring to cases that are too long. Most chambers are significantly longer than the average piece of brass will ever be. My 308 has a chamber that measures about 2.04". It would take a lot of firings and effort to get the cases that long. i.e., I would have to really try to get them that long. Unless your chamber is short, you really need not worry about this scenario.
     
    Yup, you often won't find that an issue with factory rifles, but it can be a problem in customs depending on how the chamber was cut.
     
    That was a good vid. I'll have to try to check out some more, my YouTube app didn't pop up but I'll figure out your channel. Die set up is pretty confusing to me, I'll need to do more research on the subject, I'm sure experience helps too. I have a single stage rock chucked supreme, I'm thinking die set up could take me awhile.
     
    Yup, you often won't find that an issue with factory rifles, but it can be a problem in customs depending on how the chamber was cut.

    So you were specifically referring to using a case from one rifle to another rifle then?
     
    No, I was specifically referring to different chamber dimensions. If a chamber is cut to looser dimensions (ie factory rifle), then brass fired in it will be more forgiving when being sized or trimmed. Shoot a tight match chamber (ie custom build) and you'll have to make sure you're bumping the shoulder enough and your trim length leaves enough room for brass to expand. If your brass is sized too close to chamber dimensions, the effect I mentioned can happen.
     
    Of course, you don't have to take my word for it:

    Proper Reloading Practices

    "Properly sizing brass also includes trimming the cases to the proper length for your chamber, and properly deburring/chamfering cases. If the case is longer than the maximum case length listed in your reloading manual, the neck of the case will actually flow into the throat portion of the chamber, “pinching” the bullet or severely increasing neck tension, resulting in high, or even dangerous pressures. This can/will also impede function and accuracy."


    Internal Ballistics - Hornady Manufacturing, Inc

    "When an overlength case is chambered, the mouth or edge of the neck will come up against the throat (left, top) before the bolt has fully closed or the case shoulder has contacted the chamber. The camming action of the bolt is so powerful that it will actually crimp the case mouth fully into the bullet (left, lower middle) and wedge the case so solidly between the bullet and the throat that the neck cannot expand to release the bullet. Chamber pressures in this situation can and most certainly will go dangerously high"
     
    Of course, you don't have to take my word for it:

    Proper Reloading Practices

    "Properly sizing brass also includes trimming the cases to the proper length for your chamber, and properly deburring/chamfering cases. If the case is longer than the maximum case length listed in your reloading manual, the neck of the case will actually flow into the throat portion of the chamber, “pinching” the bullet or severely increasing neck tension, resulting in high, or even dangerous pressures. This can/will also impede function and accuracy."


    Internal Ballistics - Hornady Manufacturing, Inc

    "When an overlength case is chambered, the mouth or edge of the neck will come up against the throat (left, top) before the bolt has fully closed or the case shoulder has contacted the chamber. The camming action of the bolt is so powerful that it will actually crimp the case mouth fully into the bullet (left, lower middle) and wedge the case so solidly between the bullet and the throat that the neck cannot expand to release the bullet. Chamber pressures in this situation can and most certainly will go dangerously high"

    O.K. So you confused the issue. The op is regarding sizing. The articles you cite are referring to trimming, and have nothing to do with shoulder length.
     
    It did not have much to do with the OP's FL sizing, but it's still a important point, and not trimming can be potentially dangerous.
    And to measure your chamber with a gauge is the best way to do it, having a close fit between the neck and the chamber shoulder will reduce backflow greatly and pretty much eliminate carbon rings, the slower the powder burns the slower the chamber seals.
    This often also aids a bit in pressure consistency and helps reduce ES.
    Not something to experiment with if you don't know what your doing though.

    As to FL bushing dies, they tend to not resize the lower portion of the neck, just like the bushing neck sizers. The only 'bushing' dies that solves this problem in my experience is the WTC dies, that use a replaceable neck/shoulder bushing. A wonderful piece of equipment but it's not cheap.
    As for neck tension there is really so many factors involved, that just using a bushing die certainly won't get you consistent results, if you skip the rest of the process.
    So in my opinion a honed FL die that fits your chamber is a better option, that can be attained for a reasonable cost and will give you the 'neck tension' you desire.

    As far as headspace gauges goes, i use a single stage press just like the op, for my sizing that is.
    If you want a tool that's fast and easy to use to check headspace, the Innovative Technologies Digital headspace gauge is a wonderful tool.
    It has a few other potential uses too, although i have other tools for that.

    I prefer this method over the instant indicator on my harrel's turret press, while checking seating depth with Bob greens comparator, i have a fast and easy way to check both, and the comparator is clearly better then any others i've tried.
    My turret press is currently only used for decapping die, expander die and a tipping die.
     
    Exterior Ballistics Sierra Bullets
    http://www.snipershide.com/shooting/snipers-hide-reloading/245093-fl-sizing.html

    Full Length Sizing

    Full length sizing is the most commonly used form of resizing. Full length sizing dies reduce the neck and body dimensions of a fired case to allow free and easy chambering. In most instances, full length sizing will reduce the case dimensions enough to allow it to be used interchangeably in several different rifles chambered for the same cartridge. Contrary to popular opinion, full length resizing is commonly used by the vast majority of competitive shooters, especially in those disciplines where rapid-fire is involved. It should be clearly understood that full length sizing does not reduce a fired case to its original, unfired dimensions. The goal here is to bring the case dimensions down far enough to allow the reloaded case to be chambered without difficulty.

    Adjustment of the full length die calls for the die body to be screwed down in the press until it contacts the shell holder at the top of the ram’s stroke. If the ammunition is to be reused in the same gun the cases were originally fired in, back the die off 1/2 to 3/4 of a turn and size a lightly lubricated case. Wipe the case dry, and chamber it in the gun. If any resistance is felt, lower the die body another 1/8 of a turn (or less), and repeat the process with another fired case. This is repeated until the action will just close without resistance. When this has been accomplished, set the lock ring to secure the die in place. This method will ensure that the fired cases are resized with a minimum amount of headspace. This case has now been “custom fitted” to that particular chamber.

    This will normally provide the best case life and accuracy, but does require that the ammunition only be used in the gun in which it was originally fired. If the ammunition is to be used in a different gun of the same chambering, of course!, the sizing die should be adjusted down until it just contacts the shell holder at the top of the ram’s stroke.

    This results in a slightly greater amount of headspace, but will allow the ammunition to be used in several different guns. Whichever adjustment style is used, full length sizing is generally the best sizing method for most shooting situations.

    KTLapua-b_zps8d1abc2c.jpg


    A full length resized case is supported in the rear by the bolt face and by the bullet in the throat. The full length resized case does not touch the chamber walls along the body and neck of the case. Meaning any case misalignment either in the body or neck of the case is reduced to a minimum. (or none at all) This can "NOT" be said about neck sizing only and if a cartridge case has uneven case wall thickness the thin side of the case expands more and induces bullet alignment errors and increased runout.

    chamber-neck-diagram-with-cartridge2x_zps7395df40.jpg
     
    Last edited:
    It did not have much to do with the OP's FL sizing, but it's still a important point, and not trimming can be potentially dangerous.

    And since the OP mentioned he was new to reloading, it seemed worth mentioning.
     
    Exterior Ballistics Sierra Bullets
    http://www.snipershide.com/shooting/snipers-hide-reloading/245093-fl-sizing.html

    Full Length Sizing

    Full length sizing is the most commonly used form of resizing. Full length sizing dies reduce the neck and body dimensions of a fired case to allow free and easy chambering. In most instances, full length sizing will reduce the case dimensions enough to allow it to be used interchangeably in several different rifles chambered for the same cartridge. Contrary to popular opinion, full length resizing is commonly used by the vast majority of competitive shooters, especially in those disciplines where rapid-fire is involved. It should be clearly understood that full length sizing does not reduce a fired case to its original, unfired dimensions. The goal here is to bring the case dimensions down far enough to allow the reloaded case to be chambered without difficulty.

    Adjustment of the full length die calls for the die body to be screwed down in the press until it contacts the shell holder at the top of the ram’s stroke. If the ammunition is to be reused in the same gun the cases were originally fired in, back the die off 1/2 to 3/4 of a turn and size a lightly lubricated case. Wipe the case dry, and chamber it in the gun. If any resistance is felt, lower the die body another 1/8 of a turn (or less), and repeat the process with another fired case. This is repeated until the action will just close without resistance. When this has been accomplished, set the lock ring to secure the die in place. This method will ensure that the fired cases are resized with a minimum amount of headspace. This case has now been “custom fitted” to that particular chamber.

    This will normally provide the best case life and accuracy, but does require that the ammunition only be used in the gun in which it was originally fired. If the ammunition is to be used in a different gun of the same chambering, of course!, the sizing die should be adjusted down until it just contacts the shell holder at the top of the ram’s stroke.

    This results in a slightly greater amount of headspace, but will allow the ammunition to be used in several different guns. Whichever adjustment style is used, full length sizing is generally the best sizing method for most shooting situations.

    KTLapua-b_zps8d1abc2c.jpg


    A full length resized case is supported in the rear by the bolt face and by the bullet in the throat. The full length resized case does not touch the chamber walls along the body and neck of the case. Meaning any case misalignment either in the body or neck of the case is reduced to a minimum. (or none at all) This can "NOT" be said about neck sizing only and if a cartridge case has uneven case wall thickness the thin side of the case expands more and induces bullet alignment errors and increased runout.

    chamber-neck-diagram-with-cartridge2x_zps7395df40.jpg

    Awesome info!
     
    " I'll have to do more research before I buy a bunch of useless dies."

    There are no 'useless dies' on the market.
     
    " I'll have to do more research before I buy a bunch of useless dies."

    There are no 'useless dies' on the market.

    Yes, there are. Small base dies if you load for a bolt gun. Please don't ask how I know - it was over 20 years ago that I ignored the "SB" on the box.

    For the novices: A small base die is for autoloaders that chocke on cases resized in a normal FL die. The SB die creates smaller case dimensions that will be rather loose in guns that do not need this.
     
    Last edited:
    Yes, there are. Small base dies if you load for a bolt gun. Please don't ask how I know - it was over 20 years ago that I ignored the "SB" on the box.

    For the novices: A small base die is for autoloaders that chocke on cases resized in a normal FL die. The SB die creates smaller case dimensions that will be rather loose in guns that do not need this.


    Has anyone used the RCBS A/R series sb dies for 5.56 advertised as the black box dies? The reviews I've read are pretty heinous, most stating they are getting a lot of stuck cases. Wouldn't the normal .223/5.56 sb RCBS FL dies work just the same if you "squeeze" them a little more?
     
    Has anyone used the RCBS A/R series sb dies for 5.56 advertised as the black box dies? The reviews I've read are pretty heinous, most stating they are getting a lot of stuck cases. Wouldn't the normal .223/5.56 sb RCBS FL dies work just the same if you "squeeze" them a little more?

    I've got those dies and have loaded close to 1,000 rounds or more with them. The only problem I've had with stuck cases were when I didn't use enough lube (1-2 times). I also shot the best group of my life out of my SPR I built for the class I took. Just over 1/8" three shot group from center to center @ 100 yds, so yeah, I think the dies are fine.
     
    Please forgive this question as I've heard varying information. I am FL sizing and tring as hard as possible for consistency. I am about to start load dev for 175gr 308 and I've heard conflicting information. Crimp or no crimp?
     
    Please forgive this question as I've heard varying information. I am FL sizing and tring as hard as possible for consistency. I am about to start load dev for 175gr 308 and I've heard conflicting information. Crimp or no crimp?

    I think it's safe to say most people don't crimp when shooting for accuracy.
     
    Bart Bobbitt shot a 3.325" 20 shot group at 800 yards with a 308.
    [FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]Krieger used it for an ad in Precision Shooting magazine in 1997.[/FONT]
    [FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]He is a great shot and now great coach.[/FONT]

    [FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]I spent from 1997 struggling to get my first 1" group.[/FONT]
    [FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]I am terrible shot, and no one important.
    [/FONT]
    Bart says to always FL size and push the shoulder back between .001 and .002".


    I just partially resize the neck and get lots of 0.5" 5 shot groups at 100 yards when there is no wind.

    So who ya gonna believe?
    The world's best shot, or some other old guy who is not very good?