I'm not saying loading long is better or worse. Just trying to determine a good/safe process to test various COALs within an acceptable range.
Reloading close to lands vs adequate bullet-neck engagement
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I'm not saying loading long is better or worse. Just trying to determine a good/safe process to test various COALs within an acceptable range.
JFrank
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Generally speaking Tikka’s have a REALLY long leade /freebore so actually reaching the lands or very near may take a 140 gr smk that has a much longer bearing surface and a tangent design or suffer the results of not having much bullet in the neck.
I have competition rifles with dedicated chambers to run my bullets as much as .025 in to the lands, I use plenty of bullet hold to avoid the I’ll fate AJ spoke of. Keep working and keep asking , beware of shadow talkers and u tube reloader’s that can’t have there method vetted in open forum. Try brushing the necks as part of your prep routine, most of the guys do with great results. I’m not an annealer so I can’t comment on neck prep prior or after the deed.
Stay tuned
J
JFrank
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@Varminterror
Nice job
Nice job
Varminterror
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Yes, that illustration I found on the web, just to be able to point out the interference point. Side to side isn’t important. Just a matter of making sure there is enough clearance where the ball isn’t wedging itself into the neck before the neck of the die has let go of the case neck.
If you have very consistent brass, for example, after having neck turned (which you don’t want to do), then you’ll benefit from expanding in some way. This gives a uniform, round interior diameter, rather than potentially having a uniform OUTSIDE diameter, meaning and lumps, bumps, and thick parts would be on the inside, creating inconsistent contact with your bullet.
If you are NOT neck turning, then bushing sizing then mandrel expanding is the way to go - that way the ID is pushed back to a consistent diameter and any inconsistencies inherent to the brass are at least minimized by pushing them to the outside.
Well, nothing wrong with 140 gn SMK. My thoughts were moving in that direction. Now that I know they will sit deep enough in the case and still run close to the lands if I want, makes choice easier.
"I have competition rifles with dedicated chambers to run my bullets as much as .025 in to the lands." .025 jump?
"Brushing the necks". Nylon brush with case lube into the neck?
Dry lube -- Graphite or MotorMica -- not case lube
But that's just me.
(FWIW: If you're pulling rims off withdrawing the expander ball, you have bigger problems than dry necks.
I suggest screwing the decapper/expander further in/down to ensure neck clearance to start.
And notwithstanding "it only lasts a few cycles," spray inside the sizing die an see what happens.)
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JFrank
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The carbon is the case lube however the expander ball seems to drag on any rough carbon left n the necks so a couple passes with an appropriate diameter nylon bore brush will eliminate most of the sticking when sizing. ( there is no down side to this that I know of )
in my discipline lrbr we leave the carbon in the necks and brush lightly giving a consistent bullet seating pressure.
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Varminterror
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If you’re dry tumbling, then the residual carbon and any dust typically does a great job of lubricating necks, without additional lube.
If you’re wet tumbling or ultrasonic cleaning, additional lubrication is needed.
JFrank
Member
Even better,
I don’t tumble either way, shows yeah what I know.. l need to get out more into the other disciplines, there’s tons of great info to be had.
J
sure, but why not just do this inside SAMMI specs and published load data?
Varminterror
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SAAMI specification for COAL 1) is a number, not a range, so there is no “inside” this data, 2) is generic and has absolutely nothing to do with specific bullets any shooter is actually using, and 3) does not always represent the actual dimensions of the real chamber cut into a real barrel.
SAAMI COAL’s are near worthless to real world loaders.
Varminterror
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Revisiting this thread this morning, I’m seeing a little remaining confusion and likely a bit of deserved frustration, and thought I might address these a little more directly:
Popular mythos for “perfection” in load development is typically based on the standards of benchrest competition, as there truly is no format which shoots smaller groups, no format which produces greater, or even equivalent, precision downrange. Short range benchrest being the undisputed kings of precision.
In the grand evolution of short range benchrest competition, a well proven “standard” was developed, which effectively pointed to very specific combinations of small case 6mm cartridges like PPC and BR, with long case necks (to reflect the flame front from the shoulder angle within the neck rather than project out into the rifling), neck turned for a tight, concentric fit in the tight dimension chamber necks (to only expand enough to release the bullet), firing flat based bullets with secant ogives (for long, consistent bearing surface contact with minimized blow by) seated with their base ahead of the neck/shoulder junction (to eliminate lateral destabilizing or deforming forces on the bearing surface), jammed into the lands 20-40 thousandths (to ensure consistent introduction of the ogive into the leade, and to produce greater resistance in initial stage and promote more reliable and consistent primary ignition)… in general, anyone following that recipe will shoot itty bitty groups. Really itty bitty groups, and almost ridiculously reliably.
That connection between ridiculously small groups with that particular recipe earned its reputation as the path to the pinnacle of precision.
HOWEVER - jamming bullets into the lands comes with consequences for any shooting sport in which that round can’t be sent down range. For example, in hunting fields, trying to eject that round after a fruitless hunt will typically leave the bullet stuck in the bore, spilling powder into the action, and requiring a rod to remove the bullet, disassembling the round. Same problem for pretty much ALL shooting pastimes except benchrest… so nobody else wants to jam bullets…
But now we’ve changed the recipe… unfortunately, secant ogive bullets don’t do a good job of “finding the leade” on their own when jumped, as they do not have a smooth transition between ogive and bearing surface. So they’re much more sensitive to jump - which is why we see most bullets with tangent or hybrid ogives these days. These ogive designs offer more forgiveness to jump as they’re more prone to centering themselves in the bore than secant ogives…
Even worse, maybe we want to shoot at long distances where the advantage of a boattail bullet over a flat base bullet outweighs the disadvantage it brings on raw group size…
So now we’ve changed the perfect recipe even more by changing ogive, how are we ever supposed to shoot small groups now? When we’re no longer following the blessed path?
We do this:
No, we’re not likely to shoot as small with a jumping hybrid as we could with a jammed Column, but if we find a sweet spot where the bullet seems to consistently find center and promote reliable primary ignition, then we still have a chance to shoot small-ish groups with alternative recipes. No, we’re not going to set small group world records, but we’re also not competing in that format to do so anyway…
So we have a few options here:
1) Use bullets which are known to be very forgiving of jump distance. For example, the 105 Berger Hybrids are very forgiving - I run them from 5thou off to 140 thou off of the lands in my match rifles and they always produce sub-1/2moa groups, which is smaller than I’ll ever need. Alternatively, I found the 107 SMK’s to be very jump sensitive, so I’d have to chase the lands to keep them shooting well - screw that noise, at the volume I’m shooting, I’d have to change seating depth within a single match!
AND
2) Shoot a high volume array of seating depths to find an optimal jump for your bullet, then chase the lands through your barrel life to sustain that jump.
OR
3) Shoot a high volume array of seating depths to find a consistency node where adjacent seating depths all shoot repeatably small groups. Then you can leave the depth alone longer between adjustments.
OR
4) Given a very forgiving bullet (#1), just set it and forget it. You’ll start close and the leade will burn away from your bullets, and you’ll slide through your optimal jump and through your consistency node over time, and group sizes might grow and shrink .1-.2” along the way, but the overall precision of the rifle will always be within the demands of your tasks. This is the method I choose for my match rifles - I shoot 105 Berger Hybrids because I don’t have to do anything at all for seating depth tests within the context of my chosen competition. I just load in a powder node and shoot until the barrels are toast, then start over.
Jim is jamming his bullets into the lands 0.025”. Not jumping, jamming. His rounds are too long to plunk-fit dimensionally into the chamber, and require force on closing the bolt to jam the bullets into the leade. Again, the idea here is that he has ideal control over how every bullet engages the leade, and the increased resistance to initial movement of the bullet due to that contact gives him more reliable primary ignition… it ain’t for everybody, but Jim is competing in Benchrest, where that degree of precision is critical. A difference in first place versus last…
Popular mythos for “perfection” in load development is typically based on the standards of benchrest competition, as there truly is no format which shoots smaller groups, no format which produces greater, or even equivalent, precision downrange. Short range benchrest being the undisputed kings of precision.
In the grand evolution of short range benchrest competition, a well proven “standard” was developed, which effectively pointed to very specific combinations of small case 6mm cartridges like PPC and BR, with long case necks (to reflect the flame front from the shoulder angle within the neck rather than project out into the rifling), neck turned for a tight, concentric fit in the tight dimension chamber necks (to only expand enough to release the bullet), firing flat based bullets with secant ogives (for long, consistent bearing surface contact with minimized blow by) seated with their base ahead of the neck/shoulder junction (to eliminate lateral destabilizing or deforming forces on the bearing surface), jammed into the lands 20-40 thousandths (to ensure consistent introduction of the ogive into the leade, and to produce greater resistance in initial stage and promote more reliable and consistent primary ignition)… in general, anyone following that recipe will shoot itty bitty groups. Really itty bitty groups, and almost ridiculously reliably.
That connection between ridiculously small groups with that particular recipe earned its reputation as the path to the pinnacle of precision.
HOWEVER - jamming bullets into the lands comes with consequences for any shooting sport in which that round can’t be sent down range. For example, in hunting fields, trying to eject that round after a fruitless hunt will typically leave the bullet stuck in the bore, spilling powder into the action, and requiring a rod to remove the bullet, disassembling the round. Same problem for pretty much ALL shooting pastimes except benchrest… so nobody else wants to jam bullets…
But now we’ve changed the recipe… unfortunately, secant ogive bullets don’t do a good job of “finding the leade” on their own when jumped, as they do not have a smooth transition between ogive and bearing surface. So they’re much more sensitive to jump - which is why we see most bullets with tangent or hybrid ogives these days. These ogive designs offer more forgiveness to jump as they’re more prone to centering themselves in the bore than secant ogives…
Even worse, maybe we want to shoot at long distances where the advantage of a boattail bullet over a flat base bullet outweighs the disadvantage it brings on raw group size…
So now we’ve changed the perfect recipe even more by changing ogive, how are we ever supposed to shoot small groups now? When we’re no longer following the blessed path?
We do this:
No, we’re not likely to shoot as small with a jumping hybrid as we could with a jammed Column, but if we find a sweet spot where the bullet seems to consistently find center and promote reliable primary ignition, then we still have a chance to shoot small-ish groups with alternative recipes. No, we’re not going to set small group world records, but we’re also not competing in that format to do so anyway…
So we have a few options here:
1) Use bullets which are known to be very forgiving of jump distance. For example, the 105 Berger Hybrids are very forgiving - I run them from 5thou off to 140 thou off of the lands in my match rifles and they always produce sub-1/2moa groups, which is smaller than I’ll ever need. Alternatively, I found the 107 SMK’s to be very jump sensitive, so I’d have to chase the lands to keep them shooting well - screw that noise, at the volume I’m shooting, I’d have to change seating depth within a single match!
AND
2) Shoot a high volume array of seating depths to find an optimal jump for your bullet, then chase the lands through your barrel life to sustain that jump.
OR
3) Shoot a high volume array of seating depths to find a consistency node where adjacent seating depths all shoot repeatably small groups. Then you can leave the depth alone longer between adjustments.
OR
4) Given a very forgiving bullet (#1), just set it and forget it. You’ll start close and the leade will burn away from your bullets, and you’ll slide through your optimal jump and through your consistency node over time, and group sizes might grow and shrink .1-.2” along the way, but the overall precision of the rifle will always be within the demands of your tasks. This is the method I choose for my match rifles - I shoot 105 Berger Hybrids because I don’t have to do anything at all for seating depth tests within the context of my chosen competition. I just load in a powder node and shoot until the barrels are toast, then start over.
Jim is jamming his bullets into the lands 0.025”. Not jumping, jamming. His rounds are too long to plunk-fit dimensionally into the chamber, and require force on closing the bolt to jam the bullets into the leade. Again, the idea here is that he has ideal control over how every bullet engages the leade, and the increased resistance to initial movement of the bullet due to that contact gives him more reliable primary ignition… it ain’t for everybody, but Jim is competing in Benchrest, where that degree of precision is critical. A difference in first place versus last…
JFrank
Member
We like to think long range guys are shooting smaller than short range guys, they just aren’t shooting far enough to see there mistakes.
JFrank
Member
I’ll add another tidd bit without getting long winded and for the guys that insist on jamming a bullet is to start with plenty of bullet hold/neck tension, one or two thousand isn’t going to do it ( that’s called soft seating for a one way trip) your going to need to size the necks down three to five thousand under a loaded round or perhaps suffer the fate VT mentioned.
Varminterror
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We like to think long range guys are shooting smaller than short range guys, they just aren’t shooting far enough to see there mistakes.
Yeah, amigo, I choke every time I find myself typing to acknowledge that it’s the short range voodoo black magic witch doctors which shoot the smallest, smaller than us long range guys who are doing itty bitty stuff way out where it’s actually hard
But credit where it’s due.
JFrank
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the bullet makers publish specs and data is out there.
Varminterror
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Even the COAL numbers from the bullet manufacturers are still generic lengths based on some chamber which is NOT cut into your actual barrel, and may not represent a jump distance which is optimal for that bullet profile within your actual rifle.
It may not, but it probably does. Very, Very likely IMHO.
Varminterror
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Very, Very rarely.
Almost always, book COAL’s will be really long jumps, intentionally, to ensure the generic ammo they’d produce will fit and function safely in all chambers. Reaching the lands in many brands takes a LOT longer than book values - Rem, Tikka, Wby, Savage all have famously long freebores in factory barrels. I’ve done load development for hundreds of factory rifles, it’s exceptionally rare for book values to actually be anywhere near the lands, so you have to pray your bullet tolerates a lot of jump if you’re trusting book COAL’s.
Sure... OK... but..... WHAT?
My amateur guess is that if you load .025 past jam, the round will compress about .021 on chambering. You're saying you load necks so tight that they actually are able to cram the bullet 0.25 into lands? Apparently. I'm chicken to try that- but what do I know....
Also, sorry for not participating, but my job as truck mechanic pulls me away from this thread.
I'm still seeing resistance when sizing after having made sure stem/expander is low enough. Possible defective die. Will compare to cheap Lee die set when I have time.
I'm getting advice that I need to review my neck prep- references to brushing inside of neck. Please provide more detail. As mentioned earlier, my process: decap, tumble in walnut media, lube with Hornady One-Shot, size. Mentioning of "carbon": carbon is on the inside of neck? Products of fired powder? Carbon here lubes... or seizes?
Thanks so much for your help......
Varminterror
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Unless you are competing in registered benchrest matches, there is no reason for YOU to jam bullets.
But yes, Jim is jamming bullets, and using sufficient neck tension to ensure the bullet jams, rather than being “soft seated” and pushed deeper into the case by the leade.
AJC1
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Brushing your necks is a way of applying lube to the neck. It's a nylon brush at bore size.
JFrank
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It’s not a secret by any means, I have never tumbled a piece of brass in my life, I have no need to do anything except wipe down the outside.
Carbon in the bore is your enemy, carbon inside the neck is your friend.
I realize others do a lot more cleaning, annealing , bubble baths, dry lube, wet lube, etc. but good or bad I’m not one of them.
Carbon in the bore is your enemy, carbon inside the neck is your friend.
I realize others do a lot more cleaning, annealing , bubble baths, dry lube, wet lube, etc. but good or bad I’m not one of them.
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