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I have a headspace question, probably different from the norm.
Bolt will not close on my GO gauge
bolt will close on my hand loaded rounds.
How is this Possible?
308
Lee dies
FL sized
winchester brass
175 TMK's
mag length
24" savage factory fluted barrel.
How did you get in this position?
You are sizing your brass smaller than spec(maybe). Although if your bolt will not close on a GO gauge, then you have a headspace issue on the 'small' side. Can you measure your sized brass and report back? assuming your GO gauge is correct.
Once your FL die is touching brass how many(much) rotations/turns are you turning it down?
Rusty shackle hit it. You will not be able to chamber a factory load. It is probably only a few thousandths.
The fix is to set the headspace to the gauge. Then once you have fired your handloads, back off a 1/4 turn on the die then close in on your headspace with you fired brass until the case chambers. Small adjustments and the amount of lube you use is important.
There is a learning curve here but ultimately you will be a better Savage smith and a better handloader. A tool that can help you are ones that measure case headspace. there are many but the popular one for guys with a reasonably accurate set of calipers is the Hornady LNL case headspace guage. these will come in handy along with some additions if you ever start trying to measure the length of your ogive to base.
Ok guys,
i see what you are saying, and I agree .
How I got in this position, I have two rifles with the same bolt head. 7mm08 and 308. I put the 708 bolt in the 308 rifle. It has a PTG bolt head. It will not close on the go gauge. In the 308. So I see where the headspace is too tight. Makes perfect sense.
It really didnt occur occur to me the different bolt head would be different deminsions but (after a few seconds of rational thought) I know now and understand it definitely will.
Turn die down 1-1/2 turn past touching the shell holder. So I am probably undersizing the brass.
I just discovered the loaded rounds it will close on are my fire formed and neck sized rounds.
I think i will will invest in the case head space gauge
i have the olive to base gauge for I set my 708 Berger 180 VLD's to .010 off lands.
There is no need to turn it that far past contact. If you need to touch the shell holder on the base of the die your chamber is set too small or your brass is in need of some annealing right? Well most of the time anyway.
So when I said backk off a quarter turn I intended that to be from first contact. From reading your post I feel like you are together enough to get that though.
The lee press has a positive stop unless you grind or mill it off. Most other presses cam over.
I will back it off and turn it down a little at a time to get where I need to be.
Im not sure where I got the setting for the die. But I can see it is not the right way to do it.
Gives me a great excuse to buy more tooling for the bench.
Thanks guys to to all of you that took time to lend your input. Very much appreciated.
The fix is to get a gunsmith to bring your chamber to specs, but touching it with a finish reamer.
Randyc
Thanks for explaining what happend, makes sense now.
????Quote:
Originally Posted by jim_k
A bit of a generalization, but most factory loads today will fit even when the go gauge will only let the bolt close half way.
I am of the opinion that if the bolt closes half way the bolt lugs are half way on the lug ubutments and you are probably less that .001 from the low end of the headspace minimum. So your assertion stands to reason.
No it is not.Quote:
Originally Posted by jim_k
First the head space is too tight.Quote:
Originally Posted by olddav
Second you are crunching back your cases so far you are making them fit.
I would adjust the head space so you can at least mostly close the bolt on the Go gaure.
Then:
The better way ito deal with re-size s to get Hornady kit that measures a shell case on the shoulder.
http://www.hornady.com/store/Lock-N-...h-Body-1-Each/
You measure a fired case (out of a single gun).
Adjust the dies very loose and size. You keep doing that until you get .002 shoulder bump back (that's ideal, it will vary a bit as cases are not perfect)
That case is now sized for that chamber.
Repeat with another case if you have another chamber in the same cartridge. If they are close and you case does not cause bolt hard to close in both you are good.
Otherwise its a compromise of bumping it back to .003 or .004 so they both cross fit.
The downside is that the bases will crack sooner (just above the thickest part)
Ideally you get the head space adjusted so close that they fit in both guns with the .002 bump back.
Nice on a Savage you might be able to do that.
Or you can Separate out the cases and only fire them in that gun
Different case mfg is the easier way to keep them separate.
A side note, with 1 1/2 turns your cases are really scrunched. Watch them carefully, they are going to crack at the base or get a ridge inside in 5 or fewer rounds. Get a paper clip and see if you can feel it down at the base. If you are fortunate they don't break off, just crack and enough left to extract. if not then you need a case extracting tool to get the case remnant out.
I don't know why the Die mfgs have not changed their approach, but they recommend you touch the shell holder in the press and then 1/8 to 1/4 turn.
That is far too much. Its a extremely course thread and a very small amount of turning gets you a relatively lot of distance.
If you have some range pickup brass to practice with that's better. Get the idea of it
That Body that clamps to the blade of your calipers also is used for the OGVIE adaptors that touch the shoulder (OBIGE) of a bullet giving you much better COAL as the bullet tips are out by a lot (OGIVE is as well but not nearly as much as tips)
I actual got the Bullet one and then made my own case adaptor's by darling the 45 caliber bullet one out.
Its not important you hit the case shoulder exact, just that you are on it about midway. The adaptors aren't that much, it just tickled me to make my own tool.
Whole set covers all cartridges.
A lot of this is not in basic reloading and should be, the dies have the same instructions they they had 40 years ago.
Now my brain hurts and I may have stated some of this wrong so correct me if I did.
It not as straight forward as when I started (i.e. most of us did not know better and the knowledge was not spread out if anyone knew or did it). I don't know how far back the minimum bump back goes. It was not common when I started that's for sure.
I would highly recommend measuring your reloads, depending on how grossly undersized they are it could be a safety concern. Same condition as having excessive headspace. ...Kaboom. :o
I set my headspace off a inert factory cartridge. When I was done, it would not close all the way on the go gauge. Out of 100 factory rounds, maybe only two or three were hard to close on the brand I headspaced on.
Another brand of ammo was even looser, no hard closes at all.
When I reloaded the ammo, I used a hornady comparator to just bump them back in a full resizer die.
So, it can work, as long as the cases are properly sized for that chamber.
The simple solution is to just loosen the barrel nut and reset the headspace. Or, change back the bolt head.
As far as "grossly undersized" being dangerous, how much would that be given the jump from SAAMI spec to Ackley Improved is relatively larger for fireforming the AI cases?
Without a gage to measure your base to shoulder dimension before and after FL sizing, you really have no way of ascertaining that what you are doing is correct.
And if you are not keeping your brass trimmed to sami specs after FL sizing, you risk a chamber explosion from a pinched bullet.
For best brass life, listen to what the experts are saying (above) and only work your brass enough to fit YOUR chamber. Anything more just shortens brass life and possibly yours too if it fails catastrophically.
I guess you guy's didn't read where the OP swapped the bolts from his two rifles. That is the problem,not his head space. If he will use the correct bolt with each rifle,the problem is solved!
A chamber should be .005 larger than than commercial ammo(ideally), the no-go gage is +0.005 over a go-gage and the field-gage is 0.009 over the go-gage, this would give commercial ammo .014 head space when fired in a chamber that a field-gage fit in.
Head space and it's effect on a cartridge: head space allows the case to stretch, with decent brass, the case will stretch that far once......, the problem comes when someone reloads the case by resizing the fired case back to minimum length, loads the case and fires it again, and repeats the procedure until the brass fatigues and separates. To avoid this, once the shoulder moves out, leave it out, use a feeler gage equal in thickness to the amount of head space to adjust the gap between the shell holder and bottom of the die with the ram up, this adjustments prevents the sizing process from moving the shoulder back.
As a rule of thumb, brass was not designed to stretch more than .006". That is the allowable given in a couple of books(IIRC). Stretch beyond that could result in case separations, and depending on the case, that could be near the case head, or further up.
GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gage is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.
NO-GO: Corresponds to the maximum headspace recommended for gunsmiths chambering new firearms. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. The NO-GO gage is essential for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.
FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI’s specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin
Hope this helps
Per my post above, FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin, so anything more than 0.014 is a recipe for disaster IMHO.Quote:
Originally Posted by hereinaz
My thought was if he swapped bolts back and had grossly undersized reloads for his 'new' headspace. Without having measures on both setups and dimensions of his reloads it sounds like really unnecessary risks. Hopefully OP takes a moment to get things all sorted out before proceeding.
Oh, I think everybody got that, but it was still an opportunity to pass along good information, Txhillbilly.Quote:
Originally Posted by Txhillbilly
While I do not advocate it, my Mode of 1917 rifles are way out on the ragged edge of field reject. Just about fail.
No issues (so far) as long as the brass stays with that chamber.
It is going to fire form out a lot and stretch as it does that and may lower case life. I don't shoot huge amounts though so don't know for sure.
Definitely more better not to stretch them any more than the minimum needed.
You are right, my brain finally caught up with that but it was too late!Quote:
Originally Posted by Txhillbilly
Still a lot of good discussions and info.