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Posted: 6/26/2009 6:24:19 AM EDT
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I've looked thru the FAQ and the last 30 days of posts on resizing because I am sure that this has been hashed over many times....but I didn't fine what I was looking for. I just started reloading and the guy that is teaching me .223 shoots bolt guns and I am reloading for a AR. He pushes the shoulders back .002" and that is what I started doing but seem to have occasional issues with it jamming.
First I am wondering what AR shooters typically push their shoulders back to and Second, I read that lubrication of the brass will affect the push back also. I am using Dillon spray lub and it seems to be working fine. What exactly is the issue with the lubrication? Thanks and sorry for the obvious remedial question Scott |
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Speaking about re-loading .223 Rem. and/or other center fire bottle necked ammo...........
The issue about the lube and "pulling the neck".........has to do with IF you're getting enough lube into the inside of the neck. In some cases a dry steel expander button (or button without enough lube) has been known to pull a neck forward stretching the case neck as it's being withdrawn. So, your brass might NOT be in spec. Some people inspect every re-sized case and round, in an effort to catch the problem. Others, may choose to do spot inspections. Thus, a case (or more) could slip by. Then, depending on the lube............leaving the lube in the neck might contaminate your powder. Cleaning brass AGAIN (after re-sizing and/or trimming) is one way to deal with that issue. Then again, you could pick a different lube (or mica is popular) for the inside of the necks. Before firing............cleaning the lube off of the outside of your ammo, is standard practice. Aloha, Mark PS............some may choose to use a carbide expander button when available. |
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Yes, if you are going to minimally resize, then you have to know that every single piece of brass is pushed back that amount. Many times, your pieces of brass differ in their hardness (temper). The harder brass will spring back more than the softer brass. These pieces will be longer than nominal, even after cycling them through the sizing die.
You may also find a few pieces of brass that just resist sizing altogether. You might have to screw the die down quite a bit to get these to size at all, or you can just throw them away. |
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sbgruen, your friend pushes his shoulder back .002 That means he is moving it back that far based on how far "his" chamber stretches the case when fired. All (most) chambers are different in size, even if only a very small amount.
In order to know where to set your sizing die you need to know the size of "your" chamber. Even if u have several ar's or bolt guns u will find the chambers are slightly different sized or some may be exactly the same. You need to measure your own chamber and set your die accordingly. An RCBS Precision Mic will do exactly that. I believe Sinclair also makes one. When I first started loading .308 in a 700 VS I would occassionally have a tight fitter, even when full length sizing per instructions and all. After using the precision mic I discovered my chamber to be at the absolute SAAMI minimum. Keep in mind SAAMI is an industry standard but by no means a law or anything, some will be bigger and some smaller. I now size, "set my shoulder back", .002-.003 under the fired dimension of "my" chamber (this also makes them .002-.003 below SAAMI minimum). I have NEVER had a problem since. I also loaded a few .223 rounds for an Eagle Arms before my precision mic came in. I found when sized to minimum or using factory ammo the cases were stretching .0013 (thirteen thousandths) That's a lot of overworking on a case that really ain't needed. Use the tool of your choice, but I recommend getting one and using it. |
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sbgruen, your friend pushes his shoulder back .002 That means he is moving it back that far based on how far "his" chamber stretches the case when fired. All (most) chambers are different in size, even if only a very small amount. In order to know where to set your sizing die you need to know the size of "your" chamber. Even if u have several ar's or bolt guns u will find the chambers are slightly different sized or some may be exactly the same. You need to measure your own chamber and set your die accordingly. An RCBS Precision Mic will do exactly that. I believe Sinclair also makes one. When I first started loading .308 in a 700 VS I would occassionally have a tight fitter, even when full length sizing per instructions and all. After using the precision mic I discovered my chamber to be at the absolute SAAMI minimum. Keep in mind SAAMI is an industry standard but by no means a law or anything, some will be bigger and some smaller. I now size, "set my shoulder back", .002-.003 under the fired dimension of "my" chamber (this also makes them .002-.003 below SAAMI minimum). I have NEVER had a problem since. I also loaded a few .223 rounds for an Eagle Arms before my precision mic came in. I found when sized to minimum or using factory ammo the cases were stretching .0013 (thirteen thousandths) That's a lot of overworking on a case that really ain't needed. Use the tool of your choice, but I recommend getting one and using it. The context is sizing cases for the same rifle the cases were fired in. 0.002 inches is a perfect cartridge headspace for AR type rifles. The fired case is essentially the chamber gage. There's a question about lube in the first post - one of the most common problems we see here are questions about cases that were full length sized, but are either slightly too long and chamber slightly hard or stick the bolt closed. This is caused by the expander ball in the sizer die. When the expander is withdrawn from the case, it drags inside the case neck, stretching the case shoulder, which undoes part of the sizing operation. The fix is to use a tiny bit of lube inside the case necks to ease the expander through. From your post and since you're using Dillon spray, I would say you're in fine shape and are probably already covering this step. |
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Thanks for all the info. I may have mis-typed. I am pushing the shoulder back .002 off of my chambers shoulder. I have and have been using the RCBS Precision Mic so I have that taken care of ... I think. (by the way I found out that only the shoulder portion of that gauge is designed to zero...per RCBS helpline. Seemed odd that you would call it a Precision Mic.....)
I never thought about the different spring rates due to the hardening of the brass, possibly those are the ones that are giving me problems. The Dillon expander ball is carbide so I have not used any lube on that at all. I figured with the carbide you didn't need to???? I did borrow a case gauge this weekend and it looks like the chamber in my gun is slightly long. The brass chambers in the gun but most were just slightly over the maximum on the case gauge. Looks like everyone is reloading their brass .002-.003 back from the shoulder of their guns so I guess I am doing that right and the auto loadings and bolt gun guys are doing the same thing. I appreciate all the help. When the rain quits I will run some round thru it and see if I have it working consistently. Thanks again |
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uestions about cases that were full length sized, but are either slightly too long and chamber slightly hard or stick the bolt closed. This is caused by the expander ball in the sizer die. When the expander is withdrawn from the case, it drags inside the case neck, stretching the case shoulder, which undoes part of the sizing operation. The fix is to use a tiny bit of lube inside the case necks to ease the expander through. From your post and since you're using Dillon spray, I would say you're in fine shape and are probably already covering this step. A better fix is to not use an expander. |
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2. Chamfer the OUTSIDE flash hole. You will need a flash hole chamfer/reamer for this operation. Lyman has one that comes with a stop that is supposed to be for the case mouth but can be set to stop on the primer pocket rim too. Once again unscrew it from the wooden handle, chuck it in the drill press and ream away. This step may be considered to be extraneous by some but I kind of like the idea of a tapered hole to direct the fire into the case. Used in combination with the next step I found the velocity spreads were reduced by about 30% compared to the un-chamfered flash holes.
This should get you started. http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=96660#Post96660 3. Chamfer the INSIDE flash hole. Unless you buy Lapua or some other brass which has drilled flash hole most flash holes are pressed into the brass. This can create a burr on the inside of the case. The effect is rather significant in terms of consistency if you leave it there. The drop in my velocity variations simply by removing this was significant. For this step I like the old RCBS Universal or the current Midway EJS Flash Hole Reamer. I specify these because they index on the web of the case as opposed to the mouth. This is important because you don’t have to trim all your brass to an exact length before hand to get the same depth of chamfer. Thanks for the link, I have been thinking this is why my velocity spreads are not very tight, this link convinced me to start doing this |
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Funny...I just noticed all the burs inside of my 308 LC brass...I was doing bulk processing from the brass that I got from Precision Brass....I noticed it when the brass was not fitting all the way down on my Dillon swager rod....
Anyways...how do you measure set back on the shoulder? I just have a + or - on my case gauge... |
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Anyways...how do you measure set back on the shoulder? I just have a + or - on my case gauge... If you have a case gauge, you can measure it off that. Just make sure your calipers are measuring from the top of the gauge to the head of the brass, not measuring the gauge itself. Put a piece of unsized brass in the gauge, and measure it. Write this measurement down. Some people smoke the neck and shoulder so they can see when the die makes contact, and this is a good way. Another way is to screw the die down to make contact with the shellholder, and then back it off a turn. Size the brass gradually by screwing in the die a little at a time, until you see the measurement shrink in length by .002-.003". Once you've done that, check the brass in your chamber, ensuring that the bolt will close on it. |
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Anyways...how do you measure set back on the shoulder? I just have a + or - on my case gauge... If you have a case gauge, you can measure it off that. Just make sure your calipers are measuring from the top of the gauge to the head of the brass, not measuring the gauge itself. Put a piece of unsized brass in the gauge, and measure it. Write this measurement down. Some people smoke the neck and shoulder so they can see when the die makes contact, and this is a good way. Another way is to screw the die down to make contact with the shellholder, and then back it off a turn. Size the brass gradually by screwing in the die a little at a time, until you see the measurement shrink in length by .002-.003". Once you've done that, check the brass in your chamber, ensuring that the bolt will close on it. Thank you...I understand now... ETA..after 35 years of reloading...I really have to say dang....I should of figured that one out... |
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Gau17,
Thanks for the link. It's LIVE here..... http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=96660#Post96660 It's a definite help.........for the issue of consistency w/o the treatment of the flash channel (from the inside). This is especially note worthy for the Dillon Swage owners who do not remove the bur (or consider the bur NOT to be a problem). For the Dillon owners that are wondering, "What the hell is he referring to?" Sometimes, the Dillon's internal support rod will crush the bur, leaving it obstructing or partially obstructing the flash channel. Some owners say it's not a problem as the primer's flash will clear the channel. And, some think that it's a matter of the degree of obstruction. Well........I guess that this "obstruction" issue also has merit with the obstruction due to the cleaning of media stuck in the flash channel. 3. Chamfer the INSIDE flash hole. Unless you buy Lapua or some other brass which has drilled flash hole most flash holes are pressed into the brass. This can create a burr on the inside of the case. The effect is rather significant in terms of consistency if you leave it there. The drop in my velocity variations simply by removing this was significant. For this step I like the old RCBS Universal or the current Midway EJS Flash Hole Reamer. I specify these because they index on the web of the case as opposed to the mouth. This is important because you don’t have to trim all your brass to an exact length before hand to get the same depth of chamfer.
My red added for emphasis. But then, for the Dillon owners that don't care (or if you're just loading plinking ammo)........so be it. Aloha, Mark |
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Gau17, Thanks for the link. It's LIVE here..... http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=96660#Post96660 It's a definite help.........for the issue of consistency w/o the treatment of the flash channel (from the inside). This is especially note worthy for the Dillon Swage owners who do not remove the bur (or consider the bur NOT to be a problem). For the Dillon owners that are wondering, "What the hell is he referring to?" Sometimes, the Dillon's internal support rod will crush the bur, leaving it obstructing or partially obstructing the flash channel. Some owners say it's not a problem as the primer's flash will clear the channel. And, some think that it's a matter of the degree of obstruction. Well........I guess that this "obstruction" issue also has merit with the obstruction due to the cleaning of media stuck in the flash channel. 3. Chamfer the INSIDE flash hole. Unless you buy Lapua or some other brass which has drilled flash hole most flash holes are pressed into the brass. This can create a burr on the inside of the case. The effect is rather significant in terms of consistency if you leave it there. The drop in my velocity variations simply by removing this was significant. For this step I like the old RCBS Universal or the current Midway EJS Flash Hole Reamer. I specify these because they index on the web of the case as opposed to the mouth. This is important because you don’t have to trim all your brass to an exact length before hand to get the same depth of chamfer.
My red added for emphasis. But then, for the Dillon owners that don't care (or if you're just loading plinking ammo)........so be it. Aloha, Mark Mark ....again....interesting...I just had this problem with my LC 308 brass...I am glad it was just not me....this is my plinking brass, so I am not too concerned...I actually went "ghetto" on the brass...smacked it down on the swager rod with the plastic end of a screwdriver and then cleared the primer hole with an awl... Now, I know why...thanks... My Lapua brass for my bolt gun...never have to worry about this.... |
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LOL 'Borg I'm more than a little curious why you think an expander ball, which may or may not have been machined round and on center, sitting on a threaded stem that probably wasn't tapped true, and can possibly pop out the shoulder when it's pulled back out, can benefit brass that's thin on one side. Not to mention that you're working the brass 2x as much as necessary. Once when the the die sizes it and then again when the expander ball drags back through. This also means the die is over working the brass, if it has to be punched back out once it's been through the die. Of course, this leads to shorter brass life. But that must be the price you pay for brass that's "week on one side." |
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LOL, sorry, my spelling is "week"
During my BR starting period, I found that if you removed the expander on an unturned neck that your neck was "lopsided", when you seated a bullet. But if the necks were turned, you didn't have that problem. You could measure it with any of the good case spinners, or even a "V" block and dial indicator. Using the internal expander did better than no expander, using the external expander did even better This was before going to hand dies. Try putting a un-expanded, loaded round in a case spinner, measure at the neck and see. 'Borg |
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