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Discussion Starter · #1 ·
How many of the members on this board have ever checked the headspace on their 336, 1895, or 1894 ?
If so how did you do it?
 

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One way of doing it is to take a n empty full length sized case and insert a fired primer. Using a die that has a decapping pin expander smaller than the ID of the case mouth, push the primer out of the primer pocket about .015" or so. To do that, place the case on top of, not in the shellholder.

Insert the case into the rifle and close the bolt. Remove and measure the length of the case over the primer and compare that to the length of the case. There's your headspace.

w30wcf
 

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Discussion Starter · #3 ·
One way of doing it is to take a n empty full length sized case and insert a fired primer. Using a die that has a decapping pin expander smaller than the ID of the case mouth, push the primer out of the primer pocket about .015" or so. To do that, place the case on top of, not in the shellholder.

Insert the case into the rifle and close the bolt. Remove and measure the length of the case over the primer and compare that to the length of the case. There's your headspace.

w30wcf
What are the maximum headspace measurement (lengths) for .357 mag, 30-30 and 45-70? Or, where can you find that data?
 

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What are the maximum headspace measurement (lengths) for .357 mag, 30-30 and 45-70? Or, where can you find that data?
here is a link to SAMMI There are drawings of most cartridges SAAMI
I made a set for my 25-20 on a lathe. Rimless are more complicated.
 

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If it isn't too far of a thread drift, while we are on the subject, what is the negative side effect or indicators of too much head space? I know too little is usually noticed by a hard to close bolt but I'm not familiar with what can happen when it is too loose or how to identify that other than checking it professionally.
 

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what is the negative side effect or indicators of too much head space?
You can get light primer strikes and/or case separations, primers backing out can be an indicator, a ring around the case above the case head is a sign of pending separation.
 

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I've used the primer method. And I've also loaded 30-30 by setting the fl size die to only bump the shoulder down a couple thou therefore headspacing on the shoulder eliminating the issue. Dedicated ammo for that rifle only. I regularly set my die up this way on my 35 rem.
 

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Am I missing something here? The 30-30 is a rimmed cartridge. Rimmed cartridges headspace on the rim, not the bottleneck.

Are you trying to figure the distance between the boltface and the cartridge base? If so, add successive pieces of transparent tape (Scotch) to the base until the bolt refuses to close. Then measure that. Or for a quick and dirty estimation, use a small pellet of modeling clay on the cartridge base and see how much it squishes when the bolt closes. (Clean it off afterward.)

Or are you trying to measure the maximum case length between the base and the bottleneck as if it were to headspace from the shoulder? To maximize case capacity or so?

Light primer strikes are more often from a short firing pin than from increased headspace on a lever gun.
 

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Max tolerance for Marlins IIRC is .008

The primer deal is a good way to check it. Using play dough or similar small round piece of clay on the case head will do it also.
 

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If you ever run across a 30-30 with excessive headspace and primers are backing out a bit setting the FL die will help. Yes they are intended to headspace on the rim. Same principle as a body die.
 

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Discussion Starter · #15 ·
One way of doing it is to take a n empty full length sized case and insert a fired primer. Using a die that has a decapping pin expander smaller than the ID of the case mouth, push the primer out of the primer pocket about .015" or so. To do that, place the case on top of, not in the shellholder.

Insert the case into the rifle and close the bolt. Remove and measure the length of the case over the primer and compare that to the length of the case. There's your headspace.

w30wcf
Tried this method this afternoon on 2 1895 rifles; worked very well; it gives you the exact headspace dimension for that particular rifle. I actually have headspace gauges for 45-70 and I've got to tell you they are very difficult to use in a levergun. Brownell has instructions for checking headspace in a levergun that uses a locking bolt but it is not a straight forward process like checking headspace on a bolt gun. The actual headspace gauges only tell you if it is ok or not ok. The spent primer method allows you to acquire the exact headspace dimension. I tried it three separate times for each rifle and the dimension came in within one thousandth on each try.
 

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Cases fired in my Marlin 30-30 get that ring,even factory loads,but my Winchester doesn't.
Thought it was a Marlin thing.
I think I know what you're saying, if it's like my 30A was (had JES punch it out to a 356Win :biggrin:) that is just the case swelling to the loose chamber, the separation ring will be a skinny line where the head is separating from the body.
 
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I think I know what you're saying, if it's like my 30A was (had JES punch it out to a 356Win :biggrin:) that is just the case swelling to the loose chamber, the separation ring will be a skinny line where the head is separating from the body.
When I first shot my rifle I was ecstatic.It fit me like a glove and was so accurate.When I got home and studied the cases I was dismayed.The cases were a two toned color with a noticeable bulge.When I miked the case it was slightly under max SAMMI specs and the ones shot out of the Winchester were slightly over minimum.For now I am shooting minimum book loads or slightly under.This rifle is a 336 SC built in 1999.I worry about the longevity of my cases.Not sure what I am going to do with it.
 

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One other method I'm sure would work well. Go to an automotive and order some .010 plastigage. Comes with a chart you can compare the used gage with. It compresses and spreads out giving you the gap. Mostly used to check crankshaft bearing clearances when you are rebuilding a motor.
 

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One other method I'm sure would work well. Go to an automotive and order some .010 plastigage. Comes with a chart you can compare the used gage with. It compresses and spreads out giving you the gap. Mostly used to check crankshaft bearing clearances when you are rebuilding a motor.
And it's easy to use, and leaves no mess. I happen to have a pack of it too, leftover from engine rebuilding.
 

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When I was "shopping" for Marlins, I headspaced them with gauges. Sellers agreed to let me do that, btw.
I ended up buying an '80 model that would close on a "no go" and not a "field". That was the best one I found. My primers protrude a smidge.
I would like to know with a better sampling universe what Marlin rifles tend to "run" in headspace dimensions.
My theory is they're "generous" in headspace from the factory.
 
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