How much tension when determining the "jam"

[brickeyee]

I would be interested in hearing your thoughts on how much tension to use when determining the "Jam" seating depth. It seems if you use to much tension the bullet will resist jamming and just scratch the bullet making light tension better as the bullet will be able to move to the the jam seating depth.
JPM

Making precision measurements takes a very light touch.

And for even higher precision a defined touch from a spring on one side of a measuring tool.

Micrometers use a ratchet mechanism commonly to achieve a uniform loading.
Even more precise tools often us a spring loaded anvil to measure against with a witness mark to show when the correct load is present.

You want to barely touch the soft jacket against toe start of the leade.

 

[Boyd Allen]

I believe the original poster on this thread, the one that asked the question, was asking about jam. That is why I answered about jam. For myself, I seat both in relation to touch and jam, depending on the situation.

 

[Pete Wass]

What I do

Pete - tell us what you do that's different from the video....

Before I start anything I make sure my cases are totally full length resized, meaning the butt pushed back with a Small base die and then the length I have determined is appropriate to fit the chamber. I then seat a bullet and close the bolt to see where I'm at. If I can't open the bolt, I know I am likely .020" or more into the lands so I lightly tap the bullet out still seated in the case.

I use Forster Micrometer seating dies so I go find that length, loosening the seating stem and then touching the bullet with the stem and lock the nut down. I then crank 15 thou "In " with the stem and crunch it. I also user an old multi station press. I polish the bullet with .000 steel wool and go cycle the case through the action, look at the land marks on the bullet. I know then, roughly, from many many time of doing this process where I am at. I continue pushing the bullet in, cranking the die in and polishing at every cycle. I do this until I can very faintly see where the ullet touched the lands. This becomes my benchmark. I measure this using a stony point compairitor on a dial vernier and writ. it on that case in magic marker and place the case among the lot of bullets I just seated from. It stays with them until they are gone. one can not feel that touch mark.

From all the testing I have done, absolute one bullet hole accuracy occurs at a specific length and have proven many times that .001" will open the hole up. Along with that, I find it absolutely necessary to load weighed charges, weighed on a laboratory grade balance and yes, I do not believe most barrels will forgive a tenth more or less. I've proven it to myself hundreds of times. Mebby some folks aren't as particular about shooting the absolutely smallest holed they can but I want to know what the smallest hole the gun will shoot is and anything other than as perfect ammo as one can make will do it.

So, that's it. I don''t depend on feel for anything except for where the shoulder of re-sized cases touches the shoulder when I close the bolt. Feel sometimes is a precision thing, using a micrometer, for instance, it it doesn't have a ratchet but feel is subjective.

Pete

 

[Pete Wass]

One area that needs attention

is the size of seating stems. This subject was mauled to death years ago but needs to be recycled. If seating stems had bigger holes in them, we would all be able to load more accurate ammo. Seating stems use the tippey top of bullets to seat with. If they touched the bullets slightly the bullets would touch the lands, the variability in bullets would be emade to be no issue in loading. Irregular length ogive slopes is where the variability in loaded OAL's comes from. It's a rare lot of bullets that does not have variability in the length of the ogive slopes.

I know some folks have made their own bigger stems but the die companies could help out a lot if they would change this. I had a conversation with an engineer from a die company years ago who told me his company was aware but did not want to re-engineer and have to scrap existing stem stock.

Pete

 

[Boyd Allen]

http://www.xxicsi.com/calibrated-bullet-seater.html

 

[retired]

lol
sorry boyd
but the scotch tape locking method
on a $300 tool ?
not out of my wallet.
i'll wait for version 2.

 

[Boyd Allen]

The only Scotch tape that I see is across the top to have something to write the bullet on. I will say that if you are going that far, having that information engraved should not be out of the question, since the stems are bullet specific. Back in the day, when March scopes came out, I wondered who would pay that much, and again with the B&A triggers came to this country. What I learned from those was that there are people who will pay for something that works better, for whom that much money is not even a consideration. You will notice that I have not said that I ran right out an bought one. My connection to any one bullet is much more tenuous, and I have not been having problems with consistency with small production bullets that are typical of short range, but if I were more bucks up and making a serious run on something, that would be another matter.

 

[retired]

read the full description
lock the fine micrometer like stem in place with scotch tape
after marking the setting with a marker

 

[Gene Beggs]

Interesting

It's so interesting to hear how others accomplish the various tasks involved in loading for extreme rifle accuracy. Case prep, fireforming, sizing, bullet seating, powder charges, tuning etc. Some go to extreme lengths wasting time with trivial, obsessive compulsive procedures that contribute nothing to accuracy, such as cleaning primer pockets each time, brushing out case necks, reaming flashholes, polishing cases, washing cases, weighing charges to the nearest gazillionth of a grain, weight sorting cases and bullets, making seating depth changes of .001, breaking in barrels with one shot and clean, cleaning after every five shot match,,,etc, etc.

During the past thirty years, I too have wasted untold hours with many of these things that were not only a waste of time but in some cases actually detrimental to the end result. Have you read Warren Page's book? The name of which escapes me at the moment, but it has been said that as a rifleman, he had no peer. In his book, he stated that he wasted no time with what he called the niceties such as cleaning primer pockets and other trivia.

At some point in my life, I finally realized that I definitely had more yesterdays than tomorrows. So I try not to waste time with anything that really doesn't matter anyway. As long as we are having fun and satisfied with the way we're doing things; what else matters, huh?

Good shootin' guys !

Later, Gene Beggs

 

[Michael Huebner]

The Accurate Rifle - Warren Page

It's so interesting to hear how others accomplish the various tasks involved in loading for extreme rifle accuracy. Case prep, fireforming, sizing, bullet seating, powder charges, tuning etc. Some go to extreme lengths wasting time with trivial, obsessive compulsive procedures that contribute nothing to accuracy, such as cleaning primer pockets each time, brushing out case necks, reaming flashholes, polishing cases, washing cases, weighing charges to the nearest gazillionth of a grain, weight sorting cases and bullets, making seating depth changes of .001, breaking in barrels with one shot and clean, cleaning after every five shot match,,,etc
During the past thirty years, I too have wasted untold hours with many of these things that were not only a waste of time but in some cases actually detrimental to the end result. Have you read Warren Page's book? The name of which escapes me at the moment, but it has been said that as a rifleman, he had no peer. In his book, he stated that he wasted no time with what he called the niceties such as cleaning primer pockets and other trivia.

At some point in my life, I finally realized that I definitely had more yesterdays than tomorrows. So I try not to waste time with anything that really doesn't matter anyway. As long as we are having fun and satisfied with the way we're doing things; what else matters, huh?

Good shootin' guys !

Later, Gene Beggs

THE ACCURATE RIFLE - WARREN PAGE

I tend to agree, that is why I claim the exact touch with a magnifier or smoked bullet or the YouTube above etc does not really matter so much.
The Hornady tool gets me close enough and I get the hard jam as well for reference.

Michael

 

[Pete Wass]

It's really about

how one feels about what they are doing, not necessarily what things feel like and what one is willing to accept as "Perfection"in their mind. I have always found it interesting that most demand absolute dead nuts accuracy in building a rifle but then "Accept " good enough for ammo, the one thing that makes the perfect creation perform. Doesn't square with me and never will.

Pete

 

[Gene Beggs]

THE ACCURATE RIFLE - WARREN PAGE

I tend to agree, that is why I claim the exact touch with a magnifier or smoked bullet or the YouTube above etc does not really matter so much.
The Hornady tool gets me close enough and I get the hard jam as well for reference.

Michael

Thank you Michael. Now I remember, "The Accurate Rifle" by Warren Page.
I loaned out my copy several years ago and I guess it was not returned but I certainly enjoyed reading the book. That was only about 35 years ago as I was getting back into shooting after a lifetime of involvement with flying which was my life from age four. I can't believe I finally got enough of it, but hey, there are other things that I finally got enough of too; you know?

Warren Page ! I never met him but I have an older friend who knew him well. I understand Page was a no bull sort of guy and you did not have to wait long to hear what was on his mind or how he felt about something. It seems the upper echelons of the shooting sports have always had an abundance of such strong willed characters, and I say that with a smile on my lips and in no way mean it as derogatory.

We accuracy minded riflemen of today are so fortunate to have the internet with which we can stay in touch and share information as never before.

Good shootin' guys !

Gene Beggs

 

[Gene Beggs]

Good Post Pete !

Before I start anything I make sure my cases are totally full length resized, meaning the butt pushed back with a Small base die and then the length I have determined is appropriate to fit the chamber. I then seat a bullet and close the bolt to see where I'm at. If I can't open the bolt, I know I am likely .020" or more into the lands so I lightly tap the bullet out still seated in the case.

I use Forster Micrometer seating dies so I go find that length, loosening the seating stem and then touching the bullet with the stem and lock the nut down. I then crank 15 thou "In " with the stem and crunch it. I also user an old multi station press. I polish the bullet with .000 steel wool and go cycle the case through the action, look at the land marks on the bullet. I know then, roughly, from many many time of doing this process where I am at. I continue pushing the bullet in, cranking the die in and polishing at every cycle. I do this until I can very faintly see where the ullet touched the lands. This becomes my benchmark. I measure this using a stony point compairitor on a dial vernier and writ. it on that case in magic marker and place the case among the lot of bullets I just seated from. It stays with them until they are gone. one can not feel that touch mark.

From all the testing I have done, absolute one bullet hole accuracy occurs at a specific length and have proven many times that .001" will open the hole up. Along with that, I find it absolutely necessary to load weighed charges, weighed on a laboratory grade balance and yes, I do not believe most barrels will forgive a tenth more or less. I've proven it to myself hundreds of times. Mebby some folks aren't as particular about shooting the absolutely smallest holed they can but I want to know what the smallest hole the gun will shoot is and anything other than as perfect ammo as one can make will do it.

So, that's it. I don''t depend on feel for anything except for where the shoulder of re-sized cases touches the shoulder when I close the bolt. Feel sometimes is a precision thing, using a micrometer, for instance, it it doesn't have a ratchet but feel is subjective.

Pete

Pete, I have read and reread your description of how you find the lands and establish seating depth and I must say, 'It is, no doubt, very precise!

May I say again what an honor it was to shoot and visit with you in my tunnel facility. I hope you can stop by again someday. In the meantime, we can always stay in contact and share information here on BR Central.

Thanks Wilbur for hosting all of us here on BR Central.

Later,

Gene Beggs

 

[Dave Coots]

read the full description
lock the fine micrometer like stem in place with scotch tape
after marking the setting with a marker

If the tool amounted to anything they would use duct tape.

 

[Gene Beggs]

Good Point

is the size of seating stems. This subject was mauled to death years ago but needs to be recycled. If seating stems had bigger holes in them, we would all be able to load more accurate ammo. Seating stems use the tippey top of bullets to seat with. If they touched the bullets slightly the bullets would touch the lands, the variability in bullets would be emade to be no issue in loading. Irregular length ogive slopes is where the variability in loaded OAL's comes from. It's a rare lot of bullets that does not have variability in the length of the ogive slopes.

I know some folks have made their own bigger stems but the die companies could help out a lot if they would change this. I had a conversation with an engineer from a die company years ago who told me his company was aware but did not want to re-engineer and have to scrap existing stem stock.

Pete

You make a good point Pete. Your reasoning is why I like to create my own seat for the bullet nose of my Wilson straight-line seaters. If you use the seater stems as they come from the box they will work fine for most purposes but if one wants the utmost consistency for benchrest purposes they can easily be improved.

On a small lathe, I drill out slightly larger and deeper, the hole in the stem so the contact point on the bullet is farther down rather than up at as you say, 'The tippey top.' I also break and polish the sharp shoulder inside the stem to lessen the chances of marking the bullet and to prevent them from sticking. If all is well, the loaded round will drop free from the seater die on its own when it is lifted from the base of the arbor press.

Later,

Gene Beggs

 

[retired]

they make and sell vld type seating stems

 

[Gene Beggs]

read the full description
lock the fine micrometer like stem in place with scotch tape
after marking the setting with a marker

Mr Retired, you are obviously a very knowledgeable man of substance and I can understand why you and many others prefer to remain anonymous on these forums but I would be greatly honored if you would send me an e-mail telling me a little more about yourself. genebeggs@cableone.net

Thank you sir

Gene Beggs

 

[wfcustom]

I would be interested in hearing your thoughts on how much tension to use when determining the "Jam" seating depth. It seems if you use to much tension the bullet will resist jamming and just scratch the bullet making light tension better as the bullet will be able to move to the the jam seating depth.
JPM

To answer the op's question, I will give my opinion on what the definition of jam is:
Using the neck tension you will use on your competition rounds, in that barrel, seat several bullets long and chamber in your rifle. They will usually come out the same if your case necks are prepared properly.
That is your jam for that bullet,those cases,and that chamber. If your gunsmith is decent, all your barrels from him done with that reamer should be the same, but you still have to verify it.

I have this conversation at least once a month, and I can't tell you how difficult it is for most shooters to understand the concept.
IMHO There is only one definition of jam, varying only if neck tension changes.
For those who ask why use jam as a starting point, you only have to go one way when checking seating depth.
As a side note, I am finding that Gene's advise of just off the lands (.020-.025 off jam) seems to work pretty consistently once I got over the idea that FB bullets had to be jammed.
Just one man's opinion, worth what I charge for it.
Greg

 

[Gene Beggs]

Excellent Post

To answer the op's question, I will give my opinion on what the definition of jam is:
Using the neck tension you will use on your competition rounds, in that barrel, seat several bullets long and chamber in your rifle. They will usually come out the same if your case necks are prepared properly.
That is your jam for that bullet,those cases,and that chamber. If your gunsmith is decent, all your barrels from him done with that reamer should be the same, but you still have to verify it.

I have this conversation at least once a month, and I can't tell you how difficult it is for most shooters to understand the concept.
IMHO There is only one definition of jam, varying only if neck tension changes.
For those who ask why use jam as a starting point, you only have to go one way when checking seating depth.
As a side note, I am finding that Gene's advise of just off the lands (.020-.025 off jam) seems to work pretty consistently once I got over the idea that FB bullets had to be jammed.
Just one man's opinion, worth what I charge for it.
Greg

Greg, it couldn't be said any better.

Like you, I have often wondered why so many shooters have trouble understanding what seems to be a simple concept. I'm glad you are getting good results with, 'Just off the lands.' I have been experimenting and teaching in the 100 yard tunnel for fifteen years and that has always proved to be best for 6mm and 22 caliber benchrest rifles. I can see no difference in the way boattails and flat-base bullets tune except for the fact that boattails are easier to seat.

Later,

Gene Beggs

 

[gabe ledesma]

Ok yall thats a wrap, that purdy much covers everything everyone wanted to know about jam but was afraid to ask. Now lets move on to chapter 2, short or long freebores-bullet ogives double radius or no radius on the bullets-small meplot or big meplot, does it matter? What should we start with next? Batter up