Head Space, What am I Missing??
- Thread starter Doyle231
- Start date
That's what I was thinking but there's no apparent difference in the body measurements between the two cases. Going to try setting the shoulder back just a hair more and then possibly a body die. We'll see??
How are you measuring "head space"? What H/S tool are you using? If the case shoulders are bumped to the same size, they both will chamber. The only other way they wouldn't would be due to the case web being too large. This can happen, but is pretty rare. I've had it happen to me in a Steyr SSG 69 that has avery tight chamber at the case web. Needed a S/B die, which did work.
You say that there's no difference in the body dimensions. Does that include the neck diameter after loading?
Also, you say the one does not chamber. At what point does it hang up? Does it stop the bolt from closing completely or does the bolt almost close but won't go into battery? I once had an issue where certain necks were thicker and after loading would not chamber due to being too tight in that area. I've also seen cases that were not chamferred flare out slightly after loading and that would catch/bind in the chamber.
Also, you say the one does not chamber. At what point does it hang up? Does it stop the bolt from closing completely or does the bolt almost close but won't go into battery? I once had an issue where certain necks were thicker and after loading would not chamber due to being too tight in that area. I've also seen cases that were not chamferred flare out slightly after loading and that would catch/bind in the chamber.
This is the best comment on the thread. The two pieces of brass were most likely not fired in the chamber in question before the resize.
FLIGHT762 - I'm measuring with a dial caliper and Hornady headspace gauge/comparator (base to datum line). Could be the case web but I'm not seeing it when I measure with the dial caliper, may have to get the dial micrometer out. I have considered a small base die but I'm not convinced yet.
DAVETOOLEY - 5 Gallon bucket containing once fired brass from my 700 LTR and AI MK-III. This is the first time sizing brass out of the AI in FL Die that was set up on brass from the 700 LTR. Unfortunately, I have no way of differentiating the 700 LTR brass from the AI brass. Ten cases pulled from the bucket and sized in a FL Die will have identical headspace measurement (after sizing, not before). Out of the ten, one or two will not chamber in the 700 LTR, all will chamber in AI.
LASH - Haven't checked neck diameter after loading yet. Bolt won't close without significant pressure on the bolt handle. It starts to but is very stiff. If forced all the way into battery everything will be locked up.
SHOOT4FUN - 2/3 of the brass in the above mentioned 5 Gallon bucket was fired from the 700 LTR, 1/3 fired from the AI MK-III. The brass in question is not chambering in the 700 LTR but will chamber without issue in the AI. So yes, I believe you are on the right track.
The question remains, without being able to retroactively sort the brass (700 LTR from AI) what is the best reloading procedure to size ALL of the brass in the bucket so that it will chamber in both the 700 LTR and the AI??? Keep in mind, the headspace dimensions of brass from both rifles is identical after sizing, so I can't believe I'm fighting a headspace issue although it is certainly symptomatic of a headspace problem. Thoughts??? And yes, BTW, I WON"T be mixing brass anymore!!!
Talk about a story problem!!!!
DAVETOOLEY - 5 Gallon bucket containing once fired brass from my 700 LTR and AI MK-III. This is the first time sizing brass out of the AI in FL Die that was set up on brass from the 700 LTR. Unfortunately, I have no way of differentiating the 700 LTR brass from the AI brass. Ten cases pulled from the bucket and sized in a FL Die will have identical headspace measurement (after sizing, not before). Out of the ten, one or two will not chamber in the 700 LTR, all will chamber in AI.
LASH - Haven't checked neck diameter after loading yet. Bolt won't close without significant pressure on the bolt handle. It starts to but is very stiff. If forced all the way into battery everything will be locked up.
SHOOT4FUN - 2/3 of the brass in the above mentioned 5 Gallon bucket was fired from the 700 LTR, 1/3 fired from the AI MK-III. The brass in question is not chambering in the 700 LTR but will chamber without issue in the AI. So yes, I believe you are on the right track.
The question remains, without being able to retroactively sort the brass (700 LTR from AI) what is the best reloading procedure to size ALL of the brass in the bucket so that it will chamber in both the 700 LTR and the AI??? Keep in mind, the headspace dimensions of brass from both rifles is identical after sizing, so I can't believe I'm fighting a headspace issue although it is certainly symptomatic of a headspace problem. Thoughts??? And yes, BTW, I WON"T be mixing brass anymore!!!
Talk about a story problem!!!!
Before buying a small base die, take some of the cases that won't chamber in your 700 LTR. Turn your F/L in another 1/16th of a turn (a 1/8th turn moves the die .009"). Bump the shoulders .002" more and see if they then chamber. You just might be on the cusp of having the case shoulders bumped back enough for the LTR.
I use the Hornady comparator. The numbers I get on mine tell me exactly where I am at on shoulder to case base length. I reload for about 5- 308 rifles. I have taken measurements in all of the rifles and I have the numbers on each rifle where they need to have the shoulders bumped back to chamber easily. The numbers don't lie, a shoulder length of .xxx" will chamber and a shoulder length of .XXX" will not chamber. In order to move the case shoulders slightly for the different rifles, I use a set of Redding competition shell holders that lets me adjust the bump with out having to adjust the F/L die.
On my SSG 69, case webs larger than .468.5" would not chamber. That is the only rifle of the many 308 rifles I've owned that actually needed a small base die. The only small base die that worked was a Redding small base body die. A RCBS or Forster 308 Win national match S/B die wouldn't get the web small enough for the SSG 69.
I use the Hornady comparator. The numbers I get on mine tell me exactly where I am at on shoulder to case base length. I reload for about 5- 308 rifles. I have taken measurements in all of the rifles and I have the numbers on each rifle where they need to have the shoulders bumped back to chamber easily. The numbers don't lie, a shoulder length of .xxx" will chamber and a shoulder length of .XXX" will not chamber. In order to move the case shoulders slightly for the different rifles, I use a set of Redding competition shell holders that lets me adjust the bump with out having to adjust the F/L die.
On my SSG 69, case webs larger than .468.5" would not chamber. That is the only rifle of the many 308 rifles I've owned that actually needed a small base die. The only small base die that worked was a Redding small base body die. A RCBS or Forster 308 Win national match S/B die wouldn't get the web small enough for the SSG 69.
My experience with AI factory barrels (not including the AINA Tooley barrels) is they were chambered "spaciously" in order to accommodate different types of ammo and harsh conditions. I do believe a small base die will fix the issue of which brass came from which. If you're curious enough you could take a blade mic that measures down to .0001" and measure a few case heads just to see how much expansion dif there is between the LTR & AI chambers.
I believe FLIGHT762 gave you your best answer. With all the information you've given it looks like the AI has the larger/longer chamber. With mixed brass you've got to size for each gun separately or size all your brass for the smallest chamber. If you run your brass through a SB die at this point it'll probably squeeze more length back into the case.
BTW, way to set us up man. It sounded like you had two cases fired through the same gun in your OP. LMAO.
BTW, way to set us up man. It sounded like you had two cases fired through the same gun in your OP. LMAO.
take a black marker and color the entire case that doesnt fit. put in into the chamber and try to close the bolt on it with a little bit of pressure, use common sense on this meaning dont lock it up but make sure you are applying a little bit of force to mark the case.
this will tell you where you are hitting at on the case and it didnt cost you a damn thing. tumbler will remove the marker from the case if you are worried about it.
i would highly suggest a small base die on the first time you are reloading any brass that is not virgin brass. this will size everything down to 100% fit into your chamber and then expand to match your chamber almost perfectly. then from there bump the shoulders back from the measurement you get from the first firing.
I would keep the brass separated as you stated so then the brass will only be firing in that one chamber.
this will tell you where you are hitting at on the case and it didnt cost you a damn thing. tumbler will remove the marker from the case if you are worried about it.
i would highly suggest a small base die on the first time you are reloading any brass that is not virgin brass. this will size everything down to 100% fit into your chamber and then expand to match your chamber almost perfectly. then from there bump the shoulders back from the measurement you get from the first firing.
I would keep the brass separated as you stated so then the brass will only be firing in that one chamber.
UPDATE!!
So I took BearNaked's advice and got my Sharpie out. After coloring all of the case but the neck and chambering the case there's a bright ring that circumscribes the case at the web.
I also noticed that when just inserting the same case into the chamber it sticks with just finger pressure without even closing the bolt. So what's the concensus? Body die? Small base body die? Or try getting more of the case up into a regular FL die?
So I took BearNaked's advice and got my Sharpie out. After coloring all of the case but the neck and chambering the case there's a bright ring that circumscribes the case at the web.
I also noticed that when just inserting the same case into the chamber it sticks with just finger pressure without even closing the bolt. So what's the concensus? Body die? Small base body die? Or try getting more of the case up into a regular FL die?
Attachments
And, before using a small base die, please check for impending "Incipient Case Head Separation";
https://www.youtube.com/watch?v=dppyuA0lmYU
https://www.youtube.com/watch?v=dppyuA0lmYU
Threadcutter308,
I've never heard of or seen ICHS in once fired brass but the thought did cross my mind. No indications of case head separation in this case.
Generally agreed. However, the shiny ring around the area just above the head is sometimes a precursor to separation. I mentioned it because its an easy check.
If you feel you NEED a S/B die, my recommendation would be to buy the Redding "Small Base Body Die" it will take down the web of any case that was fired in a large chamber. Use it once on fired brass. Because the body die doesn't size the neck and doesn't have an expander ball, the lubed cases glide easily through the die. You can then take the cases and run them through your regular die and you're done.
You can also repair incorrectly sized loaded ammo with a body die. I've done it a number of times. The die runs about $35.00.
You can also repair incorrectly sized loaded ammo with a body die. I've done it a number of times. The die runs about $35.00.
Based on that picture, I would get a small base die. I think i am running the RCBS die that FLIGHT762 mentioned and it has relieved my headaches. I run the brass up there 2-3 times just to make sure i dont get much spring back since that has hurt me with only running it once up in the die and why i will agree with Mr Flight again on using it on loaded ammo. (ran it up the die and then through the bullet seater again since the brass would most likely flow upwards pushing the bullet closer to the lands without seating it back down again.)
the Sharpie is a great tool for reloading and its cheap. TOP SECRET HINT: i also right down my charges on my brass when testing just in case your thumbs quit working and you drop a box full of loaded roads all of the floor with no way of knowing what load is what. also helps with checking brass measurements, primer pockets, etc after firing when i get back from the range.
