case length question

mendozer
With store bought bullets , they have .003-4 case headspace, yours are closing with some resistance. Most likely your at zero, a steady diet of zero chambering could gall your bolt locking lugs. When sizing your cases you should check the sized case in your chamber to see how they feel. Just another .001 from where you are now ,you'll probably be at .001 case headspace & your bolt will close just right. Is the snug chambering coming from the case or the bullet being jammed.? Did you load the hard chambering rounds hot.?
 
bullets weren't jamming. the chamber wasn't overly hot when loading. I could touch it. I'll get one of those temperature stickers soon though.

Would this be a matter of messing with my die?
 
mendozer
Yes , screw the sizing die down a little more to bump the case shoulder back a little more. Try the sized case, then try it in your rifles chamfer, if you feel that same resistance, screw the die down just a little more. Are you seating your bullets to jump to the lands or touch the lands ? How many rounds did you fire & how did they shoot?
 
mendozer
If you have a .010" jump from the lands, your hard chambering most likely was from not sizing your cases down enough. For hunting .002 for accuracy .001 to .002
 
how can I measure out .002 headspace or are you saying that by turning it just a bit to make it chamber easier I'm doing roughly that.
 
Aren't you measuring the case with the caliper & the Hornady comparator attached. That measures base to datum line on the case shoulder. Measure the sized case with the hard chambering in the comparator , screw the sizing die down slightly measure, try in the rifles chamber , keep adjusting , when it chambers just right , record that measurement. That's your perfect case headspace.
 
aaah. I'm using the comparator for bullet seating depth and case to ogive measurements. Since I have that go-no go gauge for headspace I just toss them in there and if they seat flush I move on.
 
Your headspace gauge tells you if your case meets SAAMI standards, but those standards allow for a degree of interference fit as the bolt squeezes the case and it expands to fit the chamber. If you look at the SAAMI drawing for 30-06, you will see the maximum case head-to-shoulder datum dimension (upper drawing) is longer than the minimum chamber breech face to shoulder datum dimension (lower drawing). A comparator, like the case inserts for a Hornady comparator, or the improvised case comparator below, will let you see whether you have actually sized the case shorter than it came out of the chamber. The headspace gauge will guarantee that it can fit, but the comparator shows you if that fit will be easy or not.

poormancomparator_zps061e19f7.jpg


Note that 30-06 may need a slightly narrow spacer as they tend to be bored oversize. That on measured 0.410" ID. I've used a 3/8" (0.375") bronze bushing journal for .30-06 before, and that works well.



Mendozer said:
Once I fire brass in my chamber, isn't it technically going to conform to my chamber?
Click to expand...

Only when neck sizing-only. Full length sizing a bottleneck case first makes it longer then shorter again after the die shoulder pushes the shoulder back (see below).

Shoulder%20Setback%20and%20Growth%20II_zpsvgwe5rip.jpg


So, the problem can be that the length from the casehead to the shoulder is too long to fit your chamber if the case wasn't driven far enough up into the die. If there is any gap between the top deck of the shell holder and the mouth of the die at the top of the sizing stroke, even a crack of light (see this Lee help video for how to check for this) tightening the die down will help. However, if the die and shell deck already make solid contact at the top of the stroke, it won't help. You then want to try F. Guffey's method to test for a tall die or a short chamber. Remove the decapper from the die and slip a feeler gauge between the case head and the bottom of the shell holder slot. Try 0.001" then see how a case fits your chamber. If it's still firm, try 0.002". The feeler gauge drives the case deeper into the sizing die by the thickness of the gauge. Keep testing gauges until you find what is needed to get a fit. Usually, however, it turns out to be die adjustment.

If you are into brewing, you probably visit a beer and wine making supplier from time to time. Get a little citric acid there. If it's expensive, you can get it in Ball brand among the canning supplies at Walmart in the fall. Dissolve two tablespoons in a gallon of water. This is very close to the formula Hornady sells for ultrasonic case cleaning after dilution. You can add a few drops of dishwashing liquid to help wet and suspend dirt if you want to. Simple Green is probably too alkaline and might neutralize the acidity, but you can experiment. The citric acid not only cleans well, it leaves the surface of the brass relatively passivated so it doesn't corrode easily. If you like how this works there are much less expensive sources of larger quantities of citric acid. I bought 10 lbs for less than $25 postpaid from here; enough for 200 gallons of cleaning solution at about 12.5 cents a gallon).
 
mendozer
Had a feeling your measuring wasn't right. Better when you realize it. I think you should get the comparator inserts for measuring base to datum, then you'll be able first size the case properly, from base to datum to fit your chamber. Then change the insert to get the proper bullet length & measurement to refer to. With the right tools, its easy to find & repeat that good shooting round. For now you can size & try in your chamber, size the case so it chambers with resistance, then lower your die a little at a time until it chambers with a very slight resistance on the close. Once you have the right comparator you record that measurement , that's most likely zero case headspace. Lower the die a little more , check measurement .002 less then you zero is good for accuracy & hunting. My chamber for my 308 is 1.6315 you will be able to do the same.
 
Thanks Uncle nick,

Your experience is much appreciated.

You seems to be a very smart experienced person.
That is completely logical what you say. If the case has enough pressure (powder charge) to cling to the chamber before it gets pushed back against the bolt face then we may have a STRETCH.

I only taper crimp all my pistol and revolver cartridges.

I feel on this forum (Firing Line) there are way more experienced people than in others like Cast Boolits. Although this seems to be a bigger forum as well but overall experience and science levels are higher as I see it.
 
that was very informative. I love pictures and technical data. Ok so I have the bullet comparator, not the headspace gaude UncleNick linked. That's for headspace measurement. I'll need to either get that or try chambering and dialing the screw back as mentioned by cw308.

Hornady's C bushing for 30.06 says .375". Is this thing a straight tube of that diameter? B/c if so I'll just hit the hardware store like UncleNick said. I don't know what a bronze journal is though
 
found the bushing on ebay for 10 bucks so I ordered it. I'll take measurements when it comes for the rounds I just fired and see what's up and the newly sized ones as well.
 
Hornady's C bushing for 30.06 says .375". Is this thing a straight tube of that diameter? B/c if so I'll just hit the hardware store like UncleNick said. I don't know what a bronze journal is though
Click to expand...

If you hit the hardware store you will require therapy. Reloaders are infatuated with 'be kind to their cases' '. Not me, I want the edge of the hole to be so sharp it imprints on the shoulder of the case. I want my datums be 'the datum'. I want everything to agree; like SAMMI, my gages, my cases and my chambers. I am the fan of transfers and standards and I am the fan of verifying. If I do not have sharp edges I can not verify.

F. Guffey
 
mendoze

Whether a bushing or the insert for the comparator, the hole that the bullet fits in should be a straight edge with no bevel.. What ever tool you use attached to your caliper is subtracted from your base to datum or ogive measurement.
 
Oh so the gauge has a built in edge that hits the datum dead on? I guess I'll see when it arrives.
Click to expand...

No, the difference between a spot on gage and a comparator is the edge. If the tool has a radius it is a comparator. I know, manufacturers sell more tolls when they make a reloader believe they are measuring head space. And they understand the gimmick of 'Search', they include 'HEAD SPACE' in the name of the tool to make it easier to find and reloaders do not know the difference.

It got complicated when the user could not correlate measurements to standards. It should not be a problem if the user understands the concept of zero; for most reloaders it is easier to assume.

F. Guffey
 
ok got my bushing in today. Put it on my caliper base and got 2.040" exactly for one of the recently fired cases. 2.043" for one that's resized but not yet fired. so does that mean my shoulder is .003" too long and the die needs to be screwed back out?

Also the instructions it came with suggest that (and you alluded to it earlier) to back off .002" from the fire formed case. So I should want it to be 2.042 or 2.038?
 
ok got my bushing in today. Put it on my caliper base and got 2.040" exactly for one of the recently fired cases. 2.043" for one that's resized but not yet fired. so does that mean my shoulder is .003" too long and the die needs to be screwed back out?
Click to expand...

You assumed the case was sized, The case body is sized when reduce in diameter, when the case body is reduced in diameter the shoulder of the case takes on the appearance of having a radius meaning the shoulder is pushed out. And then the shoulder contacts the shoulder of the die, in the perfect world the case is sized and reduced in length between the shoulder of the case and case head; but there are time the case has more resistance to sizing than the press can overcome. It is about that time the die must be lowered and a better lube helps.

When determining the winner between the case and press I measure the gap between the bottom of the die and top of the shell holder with the companion tool to the press, the feeler gage.

F. Guffey
 
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