Setting up a new rifle, I typically try some factory fodder, and then use that fire formed brass to work up some loads. Occasionally the factory stuff shoots up to my standards, and I'll buy a case or so for that rig.

I just set up a rifle and the factory stuff I tried shot awesome. I measured the 'headspace' of the fire formed brass with the Stoney Point tool, and it was 1.9655.
Then I measured the factory ammo, and it was 1.980, both cases chamber with what feels like a standard bolt pressure.

Now I wonder what gives, how does the firing of the round cause the shoulder to set back from the original measurement? Should I just set my die for this rifle to just bump the shoulder back a couple thousandths from the fired measurement??? This is what I usually do, with the goal of PFLRS.........I cannot feel any difference in chambering the rounds with the different measurements at all, so that is compounding my confusement.

Thoughts????

Remember that the Headspace datum is a point/ring somewhere on the angle.
Measure (with your caliper) to both the body/shoulder and shoulder/neck junction on 3 cartridges (fired, chambered but not fired, factory new). It's not hard to get a consistant (within a couple thousanths) measurment while doing this. You should be able to figgure out "why" your seeing a fired case that is measuring .015 shorter on your SP tool (that's a bunch of crush).
You might want to "smoke" the chambered but unfired case to see where it is contacting the chamber.

Wow--I've never seen anything like that and I've had the kit for about 3 years. What caliber and what bushing are you using for the measurement??

I don't see how that could happen. Check your math. You must be subtracting the 2" that the bushing and holder add to the measurement in order to get the 1.9655 or 1.980" measurements. Just leave the 2" in and see if the fire formed shoulder is further back than the factory. Can't happen.

Woods and Kraky, I don't see how it can happen either. I'm not sure which bushing, but it is the one that centers on the shoulder of the cartridge, .270 Win. I actually put the gauge on a digital caliper (very high quality Mitotoyu) and zero them with the calipers closed on the gauge. I've checked a bunch of the brass from the once fired and the complete cartridges from the same box and these are the measurements I'm seeing. I'll go down to the basement here shortly and see if my eyes were just playing tricks on me, but I wrote the measurements down the first go round.?????

quote:

Originally posted by Fish30114:
... I measured the 'headspace' of the fire formed brass with the Stoney Point tool, and it was 1.9655.
Then I measured the factory ammo, and it was 1.980, both cases chamber with what feels like a standard bolt pressure. ...

Hey Fish, If you want to avoid some headaches, take the Stoney Point Tool out of the Reloading Room and give it to your wife. Then hand her a Pistol/Revolver and tell her if "ANYONE" asks for it to just go on and put them out of their misery.

There are two relatively simple answers "why" the Fired Case amd the Factory Ammo would "both ... chamber with what feels like a standard bolt pressure. And as you discovered, the "Stoney Point fiasco" is totally usless to help you figure it out.

Rather than kill the thread by telling you, lets see who all knows. I feel sure many will. If they don't, I'll jump back in later.

Best of luck to you.

Hot Core, that advice is pretty easy to accept right now! I went down and checked my measurements just a bit ago, and they are right, I even tried another bushing that indexed in a slightly different position on the shoulder, and same difference......

I need a plate of your good tomatoes and some thinking time.....hadn't had a good 'mater in a while.

I'll look forward to some insight, the only guess I have is that the 'taper' of the shoulder is slightly different in my rifle vs the factory fodder, or my reloadiing die as well????

Regards--Don

HC properly diagnosed my problem. the Lee die I was using sized the case too short. check a "virgin" case and then check it after sizing.

And yes, I like my Stoney Point stuff which showed me just what was happening. i should have measeured the case before sizing. Who would believe a FL sizing die would undersize.

Sorry HC

Hey, he just said it was fire formed, he didn't say he'd sized it. That would change everything!



I suppose we're talking about this Stoney Point Gauge

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=479704

My guess is that the firefirmed case ends up with a bit sharper shoulder than the unfired case thus causing the gage to give a more accurate measurment.

I'm assuming that he sized the cases first. I always do.

Yeo, the Stoney Point see the second example.

Bill, Woods is right, fireformed, NOT sized. I mentioned the possibility of even my die having a different 'shoulder taper' as well as my rifle vs the factory fodder, perhaps that confused the issue.

I haven't resized any of this fireformed brass yet, I will, but I am trying to figure out the shorter after firing than before situation.

I'm thinking what Wstrnhntr said, I'm at a loss otherwise.....

Oh and yes Woods, it is the Stoney Point gage you posted the link to.

Try measuring a factory load after chambering and NOT firing. See if the headspace lenght seems to be altered at all. The chamber may be tight and the bolt camming over will size the shoulder down if this is the case. There is little pressurer needed on the bolt handle to pinch a case 0.002" or so if this is the problem. The shorter measurment at any rate is the true spec of that chamber and the factory ammo size is moot as long as the round chambers.

quote:

Originally posted by Hot Core:

There are two relatively simple answers "why" the Fired Case amd the Factory Ammo would "both ... chamber with what feels like a standard bolt pressure. totally usless to help you figure it out.

Hey HC, I could come up with a couple of answers for your statement, but I can't imagine a couple of reasons if you said it like this:

"there are two, relatively simple answers "why" the Fired Case had the shoulder move backwards toward the case head rather than expand out to fit the chamber"

Now if you are going to say that the Stoney Point Gauge is giving the wrong measurements that is just not possible .

I suppose you are enjoying watching us squirm like a worm on a hook, so go ahead pitch us in and see if you catch a fish (30114).

quote:

pitch us in and see if you catch a fish (30114).

I love my kit and won't reload without it. I do reload for alot of friends (which takes away some of my credibility as being a smart reloader). One other trick to use when measureing fired cases (and it won't help in this case) is to make sure you deprime before measuring as primers sometimes will throw your measurements off by a couple .001".

Ol' Joe, tried the unfired ammo and chambered several, was kinda hoping you were right, and that the bolt/chamber was sort of resizing the case prior to firing, but no dice. I've quintuple checked the measurements, and the case shoulder on the unfired ammo is definitely longer than the fired cases. It isn't a huge amount, but it is certainly enough that there should be a difference in feel when closing the bolt! My guess is the angle on the shoulder thing as Wstrnhntr suggested as the leading candidate for an answer-- I haven't 'smoked' a shoulder yet but may this evening--

Kraky, the bushings I am using are the B and C, and in both the B & C bushing the measurements are different. Slightly less difference with the B bushing.........

Do fired cartridges expand to the chamber dimensions..... without "springing back" some?!!

If they didn't...... wouldn't that make extraction difficult? Think about it!

Could that explain the difference between chamber measurement and fired case?!!

It's certainly possible for a case to come out of the chamber shorter than when it went in. It's mentioned all the time on cast bullet boards as a problem, but can occur with any relatively mild load in a rimless bottleneck case. The firing pin drives the case forward enough to shorten it slightly. The expanding gas inside the case isn't of high enough pressure to stretch the head of the case back against the bolt face as the case wall grips the side of the chamber. Out it comes, shortened.

quote:

Originally posted by woods:
..Now if you are going to say that the Stoney Point Gauge is giving the wrong measurements that is just not possible ....

Hey Woods, By golly, that was " 1. " possibility.

And our old buddy "Ricochet" is providing great insight toward " 2. ".
---

If it is at all possible for you "SPT fiasco" users to create a "Clear Spot" in your on-board thinker(I have great confidence in all of you to do this, even though you got sucked-in on the fiasco), here is what I consider all the hints you need - when added to what Ricochet mentioned:

quote:

Originally posted by Fish:
I measured the 'headspace' of the fire formed brass with the Stoney Point tool, and it was 1.9655. Then I measured the factory ammo, and it was 1.980, Accept both measurements as good, accurate numbers (even though they came from the SPT fiasco).

quote:

both cases chamber with what feels like a standard bolt pressure.

---

I'm guessing Fish means there is "more" force required to close the Bolt on the "shorter"(as measured per the fiasco) fired case, than with no case in the chamber at all. (If not, then Ricochet hit the correct answer and you need go no farther in my response.)

This additional required Force is not necessarily because of the "Shoulder having moved Forward".

Hint: Another "case dimension" that changes during firing can also be responsible for the additional force.

Hint 2: This other dimension is not measured when using the SPT fiasco.

What dimension is it?

I think that HC is saying that the case diameter has expanded (too big a chamber?) which might take up some of the length of the case when expanding the diameter.

Nope, the "SP" won't measure that. You only need a caliber.

Nope, Nope, Nope

"both cases chamber with what feels like a standard bolt pressure"

does not equal

"I'm guessing Fish means there is "more" force required to close the Bolt on the "shorter" fired case"

He's saying that he can not feel a crush fit in either one and can not detect a difference (that he noted).

Let's go back to base and see if the parameters are correct

• The fired case was 1.9655"
  
• The unfired factory round was 1.980"
  
• There was no difference detected when chambering either one
  
• The fired case was unsized

Now if the unfired factory round chambered normally then what happened was firing the shell created .0145" of headspace. Ricochet said that the firing pin pushed the case forward hard enough to move the shoulder back that far and the entire case then stuck to the chamber walls so that it did not move back to the bolt face? Don't you think it would blow the primer out also?

Unconvinced!



Also, your #1 possibility could only happen with operator error. Fish has always seemed like an "up to date" guy (even if he can't grow tomatoes) that could learn to use the Stoney Point, not like trying to "teach an old dog new tricks".

Woods is correct about his interpretation. There is no additional force in closing the bolt on either--most notably the longer measured round, definitely not like the crush fit I get all the time when using the SPF tool, and just bump the shoulder back.

Ocassionally I will just keep tweaking the die in until the bolt closes easily, and then back off a tiny bit at a time til I get a slight crush fit. That is not present on either of these cases/cartridges. I would kind of buy Ricochets suggestion, except this is factory ammo, not known for light loads, I have checked the other dimensions of the case, and it is the same as I can measure on any of my other .270 cases.

I haven't 'smoked' a case yet in the ammo or fired cases to see if the shoulder is contacting in a different spot, but that is still what makes the most sense to me....As to mis measuring, I've been so confounded that I had a buddy measure the case and ammo and tell me the measurements without me telling him what I had found, and he got the EXACT same dimensions.

He said it just makes sense, 'cause it's my rifle, and I want to take it on our upcoming Antelope hunt. I have 3 other .270's in this same rifle, and no such issues. At least the factory ammo shoots great. I'm wondering if what DaMan said might be a contributing (or sole) factor as I have seem some pretty significant springback in brass after resizing. I'm going to take a few more measurements of the case diameter and see if there is some increase I didn't pick up, I can see where that would 'take up' some of the case length, and the shoulder be shorter due to this, I did take a measurement just below the shoulder, and at the pressure ring, wasn't ultra careful, but the same as several other pieces of brass fired in different .270's, but then again, I guess that dimension could spring back too..

Still noodling---Don

I could be wrong, but here it goes. I have a SPT Aol gauge. I have to average my measurements with it. They are very hard to get to line up the same way every time. So it might not be operator error as much as some slop in the tool. If that is not the case, my guess is that your chamber is over sized. When the gun is fired brass almost turns liquid, pressure is expanding. Your brass expanded to meet the walls of the chamber. If you pull the sides of something away from each other the object will get short unless you stretch it foward also. The bullet is releasing before it gets to stretch foward. Take a measurement of the case body tow or three from the head to the shoulders. I bet you case body is much fatter on the fired rounds. Neck size and seat the bullet into the lands.

quote:

Originally posted by Fish30114:
Woods is correct

It is good to see that.

quote:

...There is no additional force in closing the bolt on either

Then our old buddy at the Still(Bill Mc), Ricochet and now me are all in agreement as to what happened.

The Case simply Expanded at the Pressure Ring and along the Body during firing, which caused the Case Shoulder to pull back slightly and the SPT fiasco measurement to be "shorter".

I am a bit amazed that the Factory Cartridge apparently was loaded at a low enough Pressure, or that the Annealing at the Shoulder was done incorrectly, to prevent the Factory Cartridge from properly Fire Forming to the Chamber.

quote:

definitely not like the crush fit I get all the time when using the SPF tool, and just bump the shoulder back.

Try a normal Fire Forming Load in a couple of those cases and see if that will put the Case Shoulder "out" to the distance you expect it to be.

And I would use the old "L-shaped" Feeler Gauge inside the Case just to make sure a Groove has not started forming Insipient Case Head Separations.

quote:

I would kind of buy Ricochets suggestion, except this is factory ammo, not known for light loads, I have checked the other dimensions of the case, and it is the same as I can measure on any of my other .270 cases.

I agree, that is the "strange part" - that it did not Fire Form properly.

quote:

....As to mis measuring, I've been so confounded that I had a buddy measure the case and ammo and tell me the measurements without me telling him what I had found, and he got the EXACT same dimensions.

If he was also using the SPT fiasco, that is "even STRANGER!!!"

quote:

I'm going to take a few more measurements of the case diameter and see if there is some increase I didn't pick up, I can see where that would 'take up' some of the case length, and the shoulder be shorter due to this, I did take a measurement just below the shoulder, and at the pressure ring, wasn't ultra careful, but the same as several other pieces of brass fired in different .270's, but then again, I guess that dimension could spring back too...

You need to be using a 0.0001" capable Micrometer. Though a 0.001" capable Caliper will show that the Pressure Ring has "Expanded", the accuracy of the measurement is not of much use.

When you take the Pressure Ring measurement, "rotate" the case between the Micrometer's Anvils looking for the widest diameter. The brass does not usually Expand and Contract in a manner so that the Pressure Ring is perfectly concentric. If a person just takes a random measurement around the Pressure Ring, he has 179 chances out of 180 of missing the high spot.
---

Now for the REALLY important part:

The majority of the Tomatoes are beginning to slow down. Had to mow the back 40 yesterday and was somewhat surprised to see a dozen or so vines " Blooming ". I have serious doubts they will make a small Tomatoes before old Jack Frost comes to visit.

Butternut Squash is looking good and a neighbors tiny ornamental Peaches(Ping Pong Ball size) have finally began ripening. No one likes them but me because they are not as sweet as a normal Peach. Seem to do realllllly well on the Diet though.
---

Try Fire Forming a few of those strange Cases and see if they won't start acting correctly.

Best of luck to all you folks - especially the SPT fiasco users.

tomato hint. a little late now but when the weather gets hot, tap each blossom to help in the fertilization process.

The part of this discussion that really has my interest is the "back to the still" part..............

Hot core, thanks. I will take my micrometer to the cases tonight. I've got very good tools, a starret and a couple of Mitotoyu micrometers. I'll take a stab at reforming the fired cases with some loads that are full power but sub-max that work well in the other .270 rifles I have.

Will definitely do the paper clip thing to check for the start of case head sep.

It's been so damn hot here in Georgia, that I think a capable person may have been able to still have some tomatoes going, I have to admit that I didn't even try this year--work and bosses have been horrible.

I'm going to try some on my deck next year in some sort of a planter--hopefully it's easier than trouble -shooting funky brass dimensions.

To the range this coming weekend and to NM for antelope next weekend, hope this rifle makes the cut!!!

Thanks everyone--Don

El Deguello, there's a mighty fine corn crop in the mountains this year.

Fish, I'm not but about 20-30 miles from you.

Well just got home, will measure the cases bodies and report back later tonight.

Bill, glad to know it, maybe we can grab a cup of coffee sometime. I like to visit the Bargain Barn now and then, even though they don't stock much gear I like, just the odds and ends, and then the special order stuff. If you live in Jasper it sure is a great area.

Take care--Don

Hey Bill Mc, Thanks for the Tip! Does accidentally smashing into the vines with the mower count?

quote:

Originally posted by Fish30114:
Hot core, thanks. I will take my micrometer to the cases tonight. I've got very good tools, a starret and a couple of Mitotoyu micrometers. I'll take a stab at reforming the fired cases with some loads that are full power but sub-max that work well in the other .270 rifles I have...

Hey Don, Sounds like you are headed in the right direction. Only thing I'd "caution" you about is being careful with the Sizing Die.

It you are using a Full Length Sizer Die, it will begin reforming the Case walls and cause the Shoulder to move forward. There is little to no chance at all that any of your 270Wins will have the same length Chamber, so if you have it set-up for one rifle, it may end up being too long or too short for this rifle.

I prefer to have a separate Die Set for each rifle with it's own Shell Holder in the box so I don't have to go hunting the correct one. A person could get by with a separate Sizing Die for each rifle just as well. But trying to adjust a single Die set for multiple rifles chambered for the same cartridge just wouldn't be fun for "me".
---

Had to spend a lot of time "watering" the Tomatoes this year.
---

quote:

...maybe we can grab a cup of coffee sometime.

I'd "guess" Bill Mc is not running a coffee Still!

Hot core, it may have been you, but one of the 'sages' here on AR got me talked into setting up a seperate sizing die for every rifle, so I do. I'll just bump the shoulder back a tiny bit on this brass and then fire a batch with a known accuracy load, and if that works, then great, otherwise I'll implement my version of the Audette ladder to get the bullet I want shooting reasonably.

Maybe Bill can spill a bit of whatever he is distilling into a cup of joe!!

Hot Core, what do you suggest to measure head space with as opposed to the Stony Point tool?

quote:

Originally posted by Hot Core:

Now for the REALLY important part:

The majority of the Tomatoes are beginning to slow down. Had to mow the back 40 yesterday and was somewhat surprised to see a dozen or so vines " Blooming ". I have serious doubts they will make a small Tomatoes before old Jack Frost comes to visit.

Butternut Squash is looking good and a neighbors tiny ornamental Peaches(Ping Pong Ball size) have finally began ripening. No one likes them but me because they are not as sweet as a normal Peach. Seem to do realllllly well on the Diet though.
---

PECANS!



Got so many this year the only limbs left on the trees are the ones that drooped to the ground and that helps support their weight. It is discouraging to have to haul off all those limbs that break off to the burn pile, they're full of pecans and it sounds like a firing range when the fire hits them and they start exploding!

Hey Don, Don't know about the "sage" part for me, but there is an abundance of very knowledgeable Reloaders on AR.

Best of luck to you on the Loads.
---

quote:

Originally posted by b beyer:
Hot Core, what do you suggest to measure head space with as opposed to the Stony Point tool?

Hey Bob, I just go by "feel" to set the Full Length(FL) Sizer to Partial-Full Length Resize(P-FLR).

When I Fire Form new cases, I use a robust SAFE Load which will expand the case and move the Shoulder forward if needed. Then as I set-up for P-FLRing, I screw the FL Die into the press and Resize a case just a bit, wipe the Lube off and try it in the Chamber.

I eventually get to a point where the Bolt is extremely difficult to close and then I take the FL Die into the press just a tiny bit more, resize a case, wipe off the lube and try it. When I get to the point that I have a slight "crush fit" then I've achieved essentially Zero Headspace.

As you know, that causes the CenterLine of the Case to be closer to alignment with the CenterLine of the Chamber than Neck Sizing does. And even with my "Hunting Rifles" I can see a slight difference in group size when running a Blind Test against Neck Sized cases.

I'd heard that a lot of the BenchRest folks are switching to P-FLR for the same reason. Have you noticed that happening? Do you P-FLR?
---

Hey Woods, There is a Pecan Company about 3 miles from where I used to spend the majority of my Hunting time. We would stop by and pick up a truck load of "spills" which hit the floor that they were going to throw away. The Deer love them about as well as I do.

Those are some whopping big pecans!

That's something I really miss up here in Northeast Tennessee. No pecans here. Lots of black walnuts, though. They're a lot harder to get into.

Well, I think the mystery is over. It seems to be a combo of several of the postulated theories. First of all, Hot Core, the case body was slightly larger at every measurement I could consisitenly take than the factory ammo, and firformed brass from some of my other .270's. Secondly, when I smoked the shoulder and found the point of contact in the chamber it was definitely lower on the shoulder than the Stoney Point gauge point of contact, a 'sharper' shoulder if you will, which I think made most of the difference. In short, it appears that the shoulder changed when fireformed to be steeper, and thereby giving a shorter 'headspace' measurement.

Thanks for all the feedback guys, this is the kind of help that makes AR so great---

Next Spring I'll have to see what advice you have for deck grown tomatoes Hot Core.

Regards all--Don

Hey Don, Glad to hear you got it all figured out. Just a bit "shorter" and wider than the other chambers.

As long as it is accurate, who gives a quack.
---

1. Plant early.
2. Water every day it does not rain.
3. Cover with sheets during frosts.
3. Replant the ones the frost kills.
4. Keep watering.
5. If you have Rabbit issues, a 5mm Sheridan Blue Streak works right well.
6. More water.
7. Watch for Tobacco Worms if Tobacco is being grown nearby.
8. Ahh..., give them some water!

Regarding the separate dies for different guns.....you guy have alot more money than me!
Sinclair sells a shim kit for (I think) about $10. It's called "skips shims". You get a packet of shims from .002" to .010". Once you have the shim kit and the stoney point you never have to reset a die again. For me I like about .003" headspace for hunting rifles figuring for possible dirt, water, ice, snow in the chamber. I use the stoney point to tell me how many shims to put under the die and that's how it set it up without ever touching a lock ring. And with numberous guns and 3 years of having the Stoney point it has always steered ME in the right direction.

quote:

Sinclair sells a shim kit for (I think) about $10. It's called "skips shims". You get a packet of shims from .002" to .010". Once you have the shim kit and the stoney point you never have to reset a die again

I use to do the same with a old set of "feeler gages"