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Old December 12, 2012, 05:35 PM   #1
NHSHOOTER
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Chamber length

What is the best way to check your chamber length so that your bullet is not contacting the rifling???
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Old December 12, 2012, 05:44 PM   #2
schmellba99
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Midway, Wideners and I'm sure several others make chamber plugs you can buy for next to nothing.

Take a fired case from your chamber and shorten the neck to about half of what it is normally, insert the plug where it just stays in the neck, and close the bolt. The shoulder of the plug is a couple of thousandths larger than your bore, so it cannot enter the throat or rifling - instead it shoulders at the end of your chamber.

Carefully remove the round and measure the OAL. Repeat 3-5 times and average out the measurements. This will be the chamber length of your rifle.

Trim your brass to .003" short of that and you are good to go.

You can also get a Hornady modified case and an OAL gauge. The case is threaded at the primer pocket and threads onto the OAL gauge. It has a rod that slides through the gauge into the case. You put the projectile you are going to load into the neck of the modified case (it will be slightly loose) and insert the gauge into the chamber, then push the rod until the projectile won't go forward any further. Remove and measure with a comparator. This won't tell you your actual chamber measurement, but rather that particular type of projectile length from the head of the case to where it contacts the lands.
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Old December 12, 2012, 06:24 PM   #3
F. Guffey
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Chamber Length": Chamber length is an unknown term to reloaders, Maximum overall case length is not the same chamber length.

COL, case overall length, not to be confused with case length.

Answer, purchase another tool, there are many business willing to take your money.

I am the fan of transfers, standards and verifying, I make standards for the chamber, standards allow me to transfer chamber dimensions to the dies, off the land? Off the lands is controlled by the seating die. I drill the primer pocket/flash hole to a diameter large enough for a cleaning rod. After drilling the hole in the primer pocket/flash hole I seat a pullet in the sized case, then I chamber the case in the chamber with out the bolt. The hole allows me to push the bullet out of the case and into the lands. When the bullet contacts the lands I quit pushing and remove the case.

I use the case to (as a transfer) adjust my seating die, I install the case in the shell holder, raise the ram and adjust the seating die down to the crimp portion of the die (THEN BACK_OFF!), stop then secure the die to the press with the lock ring. after securing die to the press I adjust the seater plug down to the bullet, then stop, then secure the seater plug stem with the lock nut.

The seating die is adjusted to .000” off the lands, the height of the stem above the die is adjusted to .000” off the lands, to increase bullet jump (off the lands) lower the seater plug stem, keeping up with ‘off the lands’ is easy if the dial caliper was adjusted to zero. I have no interest in using cases that are maximum overall length, I am the fan of bullet jump, I want my bullets to have running start, my interest when pushing a bullet out to the lands is to determine if someone had reamed the throat to allow for moving the bullet out to increase case capacity. I have found chambers that were so long the extra length allowed the bullet to come out of the case before it made contact with the lands.

Some shred the neck of the case to make it easier, I am the fan of bullet hold, I want all the bullet hold I can get, because when loading that chamber with the bullet in the transfer case I use the transfer case to set the die ‘up’ ever time.

F. Guffey
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Old December 12, 2012, 06:31 PM   #4
F. Guffey
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then there is the length of the chamber from the bolt face to the shoulder of the chamber, with the bolt removed and the difficult reloaders have determining the length of the chamber it would be helpful for reloaders to be able to determine the length of the chamber. When pushing the bullet out of the case the length of the chamber from the bolt face to the shoulder of the chamber will be longer than the length of the case from the head of the case to the shoulder of the case, meaning when determining to the lands the difference between the two measurements would be required to be added to the maximum overall length to have .000” off the lands.

Last edited by F. Guffey; December 12, 2012 at 07:34 PM. Reason: change an i to an o
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Old December 12, 2012, 07:07 PM   #5
polyphemus
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Chamber depth is measured with your vernier caliper's depth gauge.
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Old December 12, 2012, 07:33 PM   #6
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“Chamber depth is measured with your vernier caliper's depth gauge”

http://www.globalindustrial.com/g/to...neral-dividers

Again, I am the fan of standards, transfers and verifying. I make gages, I measure the length of the chamber with a standard, then I measure the standard.

I do have a height gage with a vernier scale, it is 4 ft. tall, I have micrometers with a vernier scale, I do not have a vernier cliper gage.

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Old December 12, 2012, 07:52 PM   #7
hounddawg
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OP read this

http://www.larrywillis.com/OAL.html
__________________
Government is like a baby. An alimentary canal with a big appetite at one end and no sense of responsibility at the other. - Ronald Reagan
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Old December 12, 2012, 08:48 PM   #8
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Hornady LNL OAL Gauge, and the Bullet Comparator.
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Old December 12, 2012, 09:21 PM   #9
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Quote"I do have a height gage with a vernier scale, it is 4 ft. tall, I have micrometers with a vernier scale, I do not have a vernier cliper gage."
Perhaps you should be looking to include this measuring instrument to your
extensive collection,it is very precise and versatile it is used to measure O.D.'s
I.D.'s and depths,it comes in analog,dial and digital versions,it will give you a
reading within a couple of tenths or better depending on quality and when it comes to measuring something like chamber bore depths it is far more accurate
than those overpriced head space cylinders which tell you almost nothing about
the dimension you are trying to check.
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Old December 12, 2012, 10:42 PM   #10
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C
Quote:
hamber Length": Chamber length is an unknown term to reloaders, Maximum overall case length is not the same chamber length.
Darn, and I thought I was a re-loader. Now I have to figure out what I am.

Guess simple is it, that's got to be it, I always wondered though.
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Old December 13, 2012, 12:20 AM   #11
F. Guffey
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"C
Quote:
Chamber Length": Chamber length is an unknown term to reloaders, Maximum overall case length is not the same as chamber length.

Darn, and I thought I was a re-loader. Now I have to figure out what I am.

Guess simple is it, that's got to be it, I always wondered though"




Reloaders go straight to ‘HEAD SPACE’, a politically correct term, head space is nice, in the real world someone talks to me about head space, I ask “What is the length of the chamber? ”, again, head space is nice, the only useful information to me is the length of the chamber from the bolt face to the shoulder of the chamber.

The term ‘Length of the chamber’ from the bolt face to the shoulder of the chamber is not a term reloaders are familiar with, to the reloader the term is head space. Then there is DATUM as in measured from, some forms still use the line with the arrow and the term ‘datum line. To me when determining the length of the chamber I measure from the datum, flat surface to the bolt face, when measuring the length of a case I measure from the shoulder/datum (flat surfac) to the head of the case

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Old December 13, 2012, 01:08 PM   #12
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My point is that some get caught up in the super mumbo jumbo of absolute technically and loose the perspective that most of us live in a world where its not that picky.

Yes you can go as far as you want, me, I am simple. Chamber length is how far the bullet will go forward before it hits the lands.

Its different from gun to fun and if you measure it, then you can custom load to length using a COAL that is less than the contact point. You can load just to them or back a bit to be safer and further back is better for a hunting round.

Frankly when I read posts like that my eyes glaze over. I am not planning on putting a spacecraft into orbit that has to go 500 billion miles and hit a pin size target at the end.
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Old December 13, 2012, 01:23 PM   #13
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What ever happened to smoking the bullet to find out when it touched the lands??
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Old December 13, 2012, 02:36 PM   #14
NHSHOOTER
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OK Jaguar, How do I smoke the case? I tried putting magic marker on it but either I wasnt hitting the lands or it dried to fast..HELP
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Old December 13, 2012, 08:20 PM   #15
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Quote:
How do I smoke the case? I tried putting magic marker on it but either I wasnt hitting the lands or it dried to fast..HELP
The magic marker should be dry. You are looking where the lands scrape off the marker.

To smoke the bullet, I use a candle and hold it down into the flame (not above it). It will smoke it. Remember if you are tying to find the maximum OAL of the loaded round, smoke the bullet. If you are setting your FL die to just touch the shoulder of the case, smoke the shoulder.

My guess is you didn't reach the lands. The marks will be obvious.
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Old December 13, 2012, 08:39 PM   #16
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Or, you could just spend the 25 bucks and get the Hornady gauge...

I'll bet some of you guys reload your brass 30 times you're so cheap....
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Old December 13, 2012, 09:05 PM   #17
Rusty35
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Quote:
polyphemus
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Quote"I do have a height gage with a vernier scale, it is 4 ft. tall, I have micrometers with a vernier scale, I do not have a vernier cliper gage."
Perhaps you should be looking to include this measuring instrument to your
extensive collection,it is very precise and versatile it is used to measure O.D.'s
I.D.'s and depths,it comes in analog,dial and digital versions,it will give you a
reading within a couple of tenths or better depending on quality and when it comes to measuring something like chamber bore depths it is far more accurate
than those overpriced head space cylinders which tell you almost nothing about
the dimension you are trying to check.
Never seen a digital Vernier caliper, or a dial vernier caliper for that matter.

I have seen Vernier calipers, and dial calipers and digital calipers.
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Old December 13, 2012, 10:13 PM   #18
reynolds357
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I used to care about such things. Then I had a world record holding bench rest shooter tell me he did not give a flip about them and I should not either. I started following his advice. Take a known accurate powder and charge weight. Jam it into the lands and shoot a 5 shot test string. Back it up .02 and shoot a test group. Keep backing it up until the group gets better or worse. As long as it is getting better, keep going. When it gets worse, head the other way in .01 increments. When you get the most accurate length, then start playing with powder.
As a side note of caution, dont jam a Weatherby in the lands. Its a whole different creature.
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Old December 14, 2012, 09:55 AM   #19
polyphemus
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Quote:To smoke the bullet, I use a candle and hold it down into the flame (not above it)."
Just keep in mind that copper is highly conductive and will be in contact with gun powder while you apply a flame to it.be safe man.
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Old December 14, 2012, 10:21 AM   #20
Brian Pfleuger
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Quote:
Originally Posted by polyphemus View Post
Quote:To smoke the bullet, I use a candle and hold it down into the flame (not above it)."
Just keep in mind that copper is highly conductive and will be in contact with gun powder while you apply a flame to it.be safe man.
I would sincerely hope that no one does this with a loaded round!
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Old December 14, 2012, 12:20 PM   #21
F. Guffey
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Tobnpr,


“Or, you could just spend the 25 bucks and get the Hornady gauge...

I'll bet some of you guys reload your brass 30 times you're so cheap....”

The OP can pile tools up on the reloading table until the reloader can not see the wall for all the tools, not my problem, it is their problem. Getting the dimension of the chamber to the seater die is a matter of making a transfer, after making the transfer use the transfer use the transfer to adjust the die.

Or purchase another tool then us the press to seat a bullet until it agrees with the Hornady/Sinclair and now Foster’s new tool, I am told it cost $150.00++, Again, I make transfers, standards and I am the fan of verifying.

No shop tools? No shop skills? Pile up the tools, not cheap. I started with forming dies, not cheap, the forming dies made forming expensive cases affordable, after the fist 100 cases the tool is paid for, the next 100 require time with no additional cost, just time only.

Firing a case multiple times requires skill, I have no interest in firing a case for the sole purpose of bragging rights, I have seen cases that have been fired and fired and fired etc., I have seen cases that someone CLAIMED! they fired 45 times, in the real world when someone makes the claim, I ask “How do I know you did not get to 10 times then skip firing the case the next 30 times then pick up the count at 41. I have seen cases that were so ragged I ask the proud owner of the rifle/case if that was the only case they owned, on one occasion I offered to form 2 hundred cases for free. by that time he was not talking to me. Then he went to someone else, the other someone else pulled the case apart and ask the same question “Is the only case you own? Then he measured the case body thickness, .0025”, the proud owner of the case was informed “.0025” is a good thickness for paper but not a 35 Whelen case.

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Old December 14, 2012, 01:20 PM   #22
RC20
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As long as the re-loading is done safety, all the mumbo jumbo being espoused is just that, mumbo jumbo.

Incoherent rambling is more like it.

Sheese, give it a rest.

We all settle in on what works for us. Some is our own, some from well founded sources (reloading manuals and books) some is from what others have to offer.
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Old December 14, 2012, 01:32 PM   #23
polyphemus
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Quote:" I have seen Vernier calipers, and dial calipers and digital calipers."
Now that you've seen the different types,you should consider owning at least
one of them,the Vernier scaled type requires a little practice to read but if you can read tenths on a pair of mics you should be good to go.
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Old December 14, 2012, 07:17 PM   #24
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" all the mumbo jumbo being espoused is just that, mumbo jumbo."
Really?
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Old December 14, 2012, 10:36 PM   #25
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polyphemus
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Quote:" I have seen Vernier calipers, and dial calipers and digital calipers."
Now that you've seen the different types,you should consider owning at least
one of them,the Vernier scaled type requires a little practice to read but if you can read tenths on a pair of mics you should be good to go.

I have all three types of calipers, I have Vernier calipers up to 24"

I learned to read a Vernier scale over 40 years ago.
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