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View Full Version : Here is an honest question for ya. Head space??



skeetlee
02-14-2011, 07:32 PM
Here is a situation i am having with my 22ppc brass that i am just not quite sure why it is this way. My head space has a little variance from case to case, and the brass was all fired out of the same rifle, multiple times. I have been working with 20 cases thus far, and 7 of them will have a head space reading of 1.4443 after fired, and the other 13 will have a reading of 1.4458 after firing. This poses a small problem when resizing. I have my die set up so that i feel the slightest bit of resistance on the bolt while closing. Just like Tony and Jack say to do. I have the die set for the longer cases. When i run the shorter cases through the die, the shoulders get bumped back to far. Why is this? If the die is set, and isn't moving how does the brass measure differently? I can compensate for this while at home, because i check every piece of brass in the rifle after FL sizing to make sure it is properly re-sized. If i am at a match i can not do this, as it is against the rules. I have marked the shorter cases so i dont get them mixed up with the others with an orange marker. I guess i dont really understand why the measurements are different to begin with, and i also dont really understand why the die doesn't push all the shoulders back to the exact same measurement. Does this have to do with how the brass was turned? Do i need to just discard the shorter cases, or use them for foulers? Even the shorter cases are not necessarily getting pushed back all that far (with in .001 of where they need to be) but i don't feel the resistance from the bolt when chambering them. I don't really see any real issues on the target, but i haven't shot them mixed with the longer cases either. I keep them separated. The only other thing i might add is this. These were my first 22ppc .100 short cases that i had ever made and i pushed the shoulders back about .005 to far when i made them. I now push them back were there is some real resistance from the bolt when fire forming them. in other words i set them up to have a + .001 head space reading when fire forming that way they are formed nice and straight. Although i have formed some of the brass that i made properly (10 of them) and i still see this same issue after two firings. What do you make of all this fellas? What should i do while at a shoot? I know what my reading with the harrells tool needs to be, so i can check them this way, but i don't really want to have the extra worry of keeping them separated, and accidentally getting them mixed up in the heat of battle. I suppose i will just not take the shorter cases so this doesn't happen, but this doesn't fix the issue. How can i keep this from continuing? Thanks, and i hope i haven't confused anyone. I'm not very good at typing, and writing, and explaining things. I know this isn't life changing or anything but these sorts of things matter to me because i am trying to do the best i can, and I am trying to be prepared the best i can be. Anyone else ever have this issue? Lee

Nader
02-14-2011, 09:51 PM
Lee,
I don't think your problem is unique to the .22 short ppc. If you take 20 pcs of brass and subject it to different pressure in a ladder test or with lighter or heavier bullets it will resize differently,even with the same die setting.If you run your tighter cases through your sizer die again it should uniform the feel in the gun. You need to watch your neck trim as the cases exposed to more pressure will flow( grow) more than the cases exposed to less pressure.
I'll usually work up a load then re-size once or twice through the die,whatever it takes to get a uniform stripped bolt drop, followed by a trim. If the barrel looks real good,I will bring in new brass after the load development,then my match brass will be exposed to the same repetitive pressure and will behave in a more uniform fashion.
Hope this helps,
Joel

jackie schmidt
02-14-2011, 11:30 PM
Skeet, with all due respect to two HOF members, I do not beleive that "feel" is anywhere near a precision way to acsertain any information as far as how much shoulder bump you are achieveing during sizing. There are other variables that can cause resistance.

I have personally seen shooters use the feel method, not knowing that the end rsults were as much as .005+ bump on the shoulder.

Set your die up so that by actual measurement, you are bumping the shoulders back the correct amount, and trust it. .......jackie

skeetlee
02-15-2011, 06:25 AM
Thanks fellas. i do measure each and every one as well as check it in the rifle. i can tell that my FL die is a great fit to this chamber. I use lube on my brass but the die is so close i dont really even need to. I use the little tool provided with the Harrell's die and it confirms what i am finding. I do understand what your saying though. I will just go by my measurement. thanks Lee

HovisKM
02-15-2011, 03:26 PM
Lee,

I don't know if you made a mistake in your explanation but if you didn't, I know what your problem is.

Pop you primers out before you measure a case for set back. I keep an old wilson stem around for doing that. You might be getting the primer in the measurement. I think this because you stated that you were setting the shoulders back to far on the short cases. If there shorter than the others, you can't set the shoulder back further with the same die setting.

22ppc short cases are always a pain. I learned a long time ago to not over think them....especially if there shooting great. I wasted a lot of time and money second guessing the sizing. Went through multiple dies, etc. One thing for sure, don't necssarily trust you harrell thingy, I found out the ones I had didn't have the exact same shoulder angle as the reamer, thus wouldn't give good readings.

This is one area I do have to disagree with Jackie on. If you know your chamber, and you know your die, setting by feel is the best way. I have spun cases on a 1:24000 comparator and found the feel to be more accurate that I could measure. That is !!!! If you chamber and die are a match.

Hovis

jackie schmidt
02-15-2011, 05:21 PM
Skeet, another thing, you should always use lube on a case. I can take a typical case, size it with no lube, and then one and size it with lube, (I use nothing but imperial wax), and they will NOT be the same size, or set back.

Simply put, there are a lot of minor "stacked variables" that can occur during this entire proccess. Exccessive friction is one you can negate with lube.

Hovis, I actually agree with you, in that a shooter who is very familiar with every aspect of his equipment can do as you said, but I believe Skeet is still in the learning proccess. In a situation where a few thousanths makes a difference, I just think that you cannot beat actually measuring the results of what the die is doing.

Skeet, as an added note, over time, you will discover cases that simply develop a mind of their own, and do not respond as did the others to the sizing proccess. At matches, after I ahve verified the "bump" on cases, I will often strip the bolt and cycle every resized case through the Rifle, and any that have that tight feeling, or that catch at the top of the stroke, get set aside for such mundane duty as practice..........jackie

HovisKM
02-15-2011, 05:26 PM
Jackie,

I agree.

Hovis

Wildcatter
02-15-2011, 06:26 PM
Skeet, with all due respect to two HOF members, I do not beleive that "feel" is anywhere near a precision way to acsertain any information as far as how much shoulder bump you are achieveing during sizing. There are other variables that can cause resistance.

....jackie

Just how do you justify that bolt handle feel, in the chamber the case will be shot in, is not an accurate measure of case size? What can you measure off of that would be more accurate to case fit in the chamber than the chamber shoulder to bolt face fit:confused:

I am with Tony Boyer, he knows what he is talking about. Twice as many H of F points to prove it.

skeetlee
02-15-2011, 07:52 PM
Thanks fellas. I am still new to the benchrest thing but i do understand how most things work. When i spoke about pushing the shoulders back to far to start with, i was speaking about the process of making the cases. The cases i sent you keven were around .006 to short on headspace compared to the chamber. The second batch i made i made sure that the headspace of the case would be a crush fit in the chamber, for the first firing. What i am not good at is typing, and explaining my findings with words, so please excuse me on this. I do the best i can. All i mean was that the first batch of brass i made I had to blow the shoulders forward .005 to .006 instead of them being a crush fit. Im not sure this has much to do with what i am finding here or not. What i think my situation is after talking with Boyd is simply the difference in spring back or case hardness? I think this is a real possibility anyway. The cases are shooting fine so you are right Kevin, i shouldn't even worry about any of this. I just like to know why certain things are the way they are, and i think it makes for good conversation. Plus it is winter time and i have cabin fever. I pop my primers out with a little tool i have so it isnt the primer causing the different readings.
One case will come out of the rifle with a reading of 1.4442 and another will come out with a reading of 1.4435 or similar. Not a big difference, but enough difference that when i go to FL size them, some will re-size just right and some will be pushed back a little to far. Thats what i really dont understand is how the die that is in a fixed position, can push the shoulders back to, two different readings? Is it you think just spring back? I do think that the process these little case go through while forming them is quite a strain. I annealed two cases with each reading i am finding, and i am going to shoot these 4 cases and see if this has any merit.
I hope i dont sound like a guy that is always having trouble because that isnt the case. I love the technical part of all this and it interest me very much. I also figure if there is anything i can do to eliminate things like this, it will make for a much simpler situation here at home or at a match. In other words i like to do things properly, and if there is something i cant figure out, i dont hesitate to ask. I also get a lot of PM's from folks thanking me for the topics and discussions i bring to the table as some fellas are afraid or reluctant or to whatever to bring these types of questions for all to see. Like i said i find this all very fascinating and i am simply trying to find my level of perfection. I just want to do all i can because it means that much to me to do so. So in essence, life is good, maybe to good, since things kinds of things are all i really worry about. Thanks as always! Lee


I always use Imperial wax when sizing my cases. All i meant was that the die really seems to be a good solid match to my chamber. This die i have resizes just right. not to much but not to little either. the little headspace tool that came with this die from Harrells seems to be spot on with what i am feeling and from the readings i am getting. I know that if my brass reads 1.4443ish that it will fit in this chamber with just the right amount of bolt feel with the firing pin removed so i do trust what i am finding and i trust the reading as well. I had a little trouble with another 22ppc barrel i had finding a good fitting die, but this one seems spot on. actually it doesn't seem spot on, it is spot on. I wish i owned the reamer that cut these barrels, but i bought these barrels new but second hand, and the smith that chambered these two barrels i have doesn't remember if he cut the chamber's with his die or the customers. So when these barrels are gone i will have to buy a reamer and have a new custom die made. I think the rifle is going to be a real shooter, i just have to learn the art of tuning, and that in itself can be a real challenge to do and do properly. I enjoy it though, and help for you guys it shouldn't be anything i cant handle with due time. Once my range is complete i will be set up were i can really focus on learning these trades without interruption from the novice AR guys that frequent our public range. Some of those guys like to go down range and look at every shot they take. I'm good with that though!! Lee

jackie schmidt
02-15-2011, 07:57 PM
When Tony was holding his schools, he always advised shooters to measure and verify the the amount of "bump" that they were achieving with the die setting. I have one friend that to his amazement, was actually bumping his brass as much as .008 using the "feel" method. Tony showd him the correct way to measure the correct amount that the die was producing. This Shooter is a regular poster on this Forum, perhaps he will chime in.

Just curious Wildcatter. What is your name. For some reason, I cannot recall it.......jackie

jackie schmidt
02-15-2011, 09:07 PM
"Once My Range Is Complete". Your making me cry here, Skeet. I guess the only thing that would make me cry more is if you said,........... "in my back yard".........jackie

Jhart
02-15-2011, 09:47 PM
"Once My Range Is Complete". Your making me cry here, Skeet. I guess the only thing that would make me cry more is if you said,........... "in my back yard".........jackie

It is in his back yard !!

skeetlee
02-15-2011, 09:58 PM
Ya kinda. My folks built a new home on one of our farms and they are letting me and my best shooting buddy jhart have our own shooting range. we didnt have the time to finish it, or even start it this year, as we were in a hurry to complete the house and get mom and dad moved in before the snow flew, but we will start on it this spring. its just up the road a couple miles from were i live so it will be real nice. Just 180 yards but i am very grateful for those 180 yards!! Lee

jackie schmidt
02-15-2011, 10:15 PM
To Hell with Crying, I will just proceed right to Dying........jackie

Andy Cross
02-16-2011, 04:17 AM
Having read through all the posts I am a bit bewildered as to why BR shooters would be FL resizing. The last batch of 6ppc brass I prepared I initially FL resized the new cases. Then neck turned them to fit the chamber and fire formed them. After that for the next year all I needed to do was neck size them.

So my question is why would BR shooters need to FL resize after the initial tune up ?

Andy

JerrySharrett
02-16-2011, 09:12 AM
Having read through all the posts I am a bit bewildered as to why BR shooters would be FL resizing. The last batch of 6ppc brass I prepared I initially FL resized the new cases. Then neck turned them to fit the chamber and fire formed them. After that for the next year all I needed to do was neck size them.

So my question is why would BR shooters need to FL resize after the initial tune up ?

Andy
Andy, after V133 came along shooters found out that it shot best "balls to the wall". Like 3450-3480 fps.

That is why we/they FL now. We got it hotter' n' 'ell.

I shot BR group for 2 years before I even owned a FL sizer.

I don't shoot that hot now but I do feel there is more consistency in brass-to-chamber fit by FL sizing with a die that is made to fit your chamber.

virg
02-16-2011, 10:08 AM
Having read through all the posts I am a bit bewildered as to why BR shooters would be FL resizing. The last batch of 6ppc brass I prepared I initially FL resized the new cases. Then neck turned them to fit the chamber and fire formed them. After that for the next year all I needed to do was neck size them.

So my question is why would BR shooters need to FL resize after the initial tune up ?

Andy

For years it was the holy grail to just neck size brass after fire forming with the benchrest crowd. However, in the last few years, shooters have gotten tired of tight bolts after a few loadings and some shooters have adopted the "running" technique where they get all five shots off as fast as possible in the same condition. Tight fitting brass is a huge handicap here. So....after finding that full length resizing did not affect accuracy, it is now the common practice to full length resize after each shooting. A fast, easy-to-close bolt, is a good thing.

virg

HovisKM
02-16-2011, 01:40 PM
Skeet,

Are you depriming your cases prior to measuring them initially (without sizing). If your not, your measurements can be all over the place.


Also, pushing the shoulder back about .005 to far for short cases is the preferred method if neck reaming isn't done, just turning. What this allows is to turn to the shoulder, which will allow part of the neck to become part of the shoulder upon fireforming, thus eliminating the dreaded donut at the neck shoulder junction. I don't know how many times you have fired the cases yet but with the shorts, you will need three firings on them before they settle in length and straightness. I've made thousands of them and that always holds true.

Hovis

skeetlee
02-16-2011, 05:59 PM
Kevin
Thanks for the info. I had no idea about needing to push them back the extra .005 before turning them. I hope the rest of these cases that i formed are ok. I pushed them back so they would crush fit for the first firing. Can i go back and inside ream them or will this cause problems now? These cases have 7 or 8 firings on them. One thing i am confident about is my measuring process. I have no primer interference or any other problems i can think of. There is simply about .001 difference in this lot of 20 cases. the majority are the proper measurement and 7 of them measure the exact same but .001 shorter than the majority. Im not going to really worry about this any longer. I will just separate them and use them for practice. I can run these short cases into the FL die and size everything without pushing the shoulders back to far. I just don't cam over the press and they seem to be fine.
I guess now i need to know what i should do with these other cases i have made that i didn't push back the shoulders the extra .005? See this was worth while. I didnt have any idea about this, and now i do. Thanks men! Lee

I had Mr Norm Wills turn the other 22ppc .100 short brass that i formed and there is no donut so i am assuming Norm inside reamed these cases. Norm does great brass work and i think these will be great!!

JerrySharrett
02-16-2011, 06:17 PM
I wonder about this "dreaded donut" issue. In 100/200 benchrest and the regular PPC case the bullet base will be no where near the donut area.

alinwa
02-16-2011, 06:55 PM
Skeet, do yourself a favor.

Form a case...... Cut it open and look at it, measure it. See for yourself that the "dreaded donut" is nothing more than thicker shoulder brass that's now neck brass. Donuts, or the complete lack thereof, are definitely articacts of the case forming and maintenance procedure but be careful how you eliminate them.

I STRONGLY disagree with giving yourself .005 slop in your chamber trying to FF brass without a donut. Buy a setup from Jim Borden to see it done correctly, your cases will be crush-fit in the chamber for perfect ff, and NO DONUT....

Then again, maybe I'm completely misunderstanding the .005.....

That said, Jerry's right.

I've got cases that have 2/10 inch of "donut" or thick brass in the neck. You can't force a bullet into the area and still chamber the round. And no bad effects.

opinionsby





al

skeetlee
02-16-2011, 07:53 PM
Al
After reading your opinion on the crush fit, thats why i formed this second batch the way i did. I wanted the crush fit so it would help form a straighter case from the get go, and they are straight. Not as much as a wiggle on my Sinclair tool. The donut issue really isn't an issue as far as my seating depths. I am above the donut by quite a bit. On the cases than norm wills turned for me after i formed them, there isnt even a donut. I can drop a bullet all the way down into a fired case if i wanted to. It just isnt there. Norm must have reamed it out for me. he does a fine job on the brass i send him!!
I have been sitting here studying my targets from the past couple weeks and i see several small groups that have one bullet high or low out of the group. No paper between them but they are out by almost a hole bullet. When you see this what does it make you think? Thanks Lee

JD Mock
02-16-2011, 07:58 PM
Skeet, when I used the feel method...back when I first began shooting BR, Pat Byrne told me to get a "do hickey" (barrel stub w/chamber reamer run in enough to provide a stop) to measure shoulder set back. He went on to tell me that one often feels the pressure from the back of the case and not the shoulder. The barrel stub do hickey is much better than the brass thingy that Harrel provides. Jackie has given you good advice...as well as several others. Try to set your shoulder back by no more than .001 and all will be well. Good shooting....James

skeetlee
02-16-2011, 09:26 PM
Will do. I think the ejector pin can also have some effect if you dont know what you are feeling. Now one more quick thing here. Like i said above what would be the first thing that comes to your mind when you are seeing really small groups but one shot going out high or low? No paper in between but pretty close to a full bullet out. What would you think? I know there could be several reasons but what would you think about first? Lee

tzander
02-16-2011, 11:47 PM
SEATING DEPTH.SEATING DEPTH.SEATING DEPTH Thats where I would look. Tony

Al Nyhus
02-17-2011, 08:07 AM
I STRONGLY disagree with giving yourself .005 slop in your chamber trying to FF brass without a donut. al

Al, my method of f-forming cases involves pushing the shoulder back .020-.025 from the 'crush' point. F-formed cases come out dead straight, with z-e-r-o donuts and they fit the chamber perfectly. Annealing before f-forming, a skosh of lube on the case and a good jam.....it never doesn't work. Double negative intended. ;)

JerrySharrett
02-17-2011, 08:55 AM
lube on the case and a good jam.....it never doesn't work. Double negative intended. ;)

Al Nyhus, do not you not mean in your "good jam" to mean jam of the bullet to hold the case base in place. Triple negative not intended...I lost count somewhere.

Al Nyhus
02-17-2011, 09:10 AM
Al Nyhus, do not you not mean in your "good jam" to mean jam of the bullet to hold the case base in place. Triple negative not intended...I lost count somewhere.

Jerry: I didn't never not mean not to don't never jam the bullet. :D

Never, not ever, jamming the bullet doesn't always never mean not to ever use preserves instead of jam or jelly. I'm a marmalade guy myself, hence the need to mostly always on every each occasion, lube the cases. :cool:

Stay warm, buddy. -Al

JerrySharrett
02-17-2011, 02:39 PM
Jerry: I didn't never not mean not to don't never jam the bullet. :D

Never, not ever, jamming the bullet doesn't always never mean not to ever use preserves instead of jam or jelly. I'm a marmalade guy myself, hence the need to mostly always on every each occasion, lube the cases. :cool:

Stay warm, buddy. -Al

Well, who would have never thought that. Me, I never never a' dreamed that. Well, I never, in all my born days!

Stay warm, I just looked and it is 72F...gotta go shot.