I read with interest John A.'s article on the effect of varying bullet pull forces compared to the grouping. I think we can put to rest the idea that small variations in seating/pulling makes much difference on group size.
Any other thoughts? I will still be brushing out case necks just to ease the work on the sizing die and M die during the loading process.
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I found it interesting, but have to wonder if the factor is actually "pull" and should be considered resistance to "push" because the pressure of the fired case expands the case as the pressure of burning powder builds. Perhaps bullet pull is over rated as a factor.
Clearly, I am not going to get involved in this, just curious..
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Yes my experience thus far says not a lot of an effect,my son shot his Mauser 96@200 yrds,cast 136 gn Saeco ,18 gns 2207(4198) 3” group on Silver MT electronic ,measured FPS @ target 1300 ish, spread of 10 fps.I loaded the rounds ,neck tension was variable.BTW 1/2 gn of Dacron filler was used,Alox mineral turps mix lube. Cheers Mal in au.
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my mj bench friends assure me the brass expands and leaves the bullet hanging in mid-air before the bullet * hardly * moves ...
maybe we should worry more about that bullet hanging in mid air more than any larger sd's in pressure ... and/or velocity ...from neck dragging ...
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that is with normal straight necks... gotta think that at some point that enough heavy crimp will present some drag ... like one that scrapes lead off when fired ...
ken
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Wow! I have heard of bullets adhering to case necks because of military sealant or just very old ammunition but your experience is new. Sounds like that BAC lube is more of a glue than a lube. If you leave a drop of the stuff on your bench does it become a hard solid? If not, how can it produce a cllck when reseated? It obviously doesn't turn into a solid before application, so it must react with the case or something in the powder to become a solid, puzzle puzzle.
In high pressure cast loads like high velocity experiments or some match loads in 30BR or similar loads, such adhering might cause dangerous pressure -- unless, of course, Ken is right and chamber pressure expands the case neck as the first order of business.
Very interesting.
No apology needed for lever actions we all love them.
John
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In 2005 I had a 30 PPC barrel installed on my XP-100. It shot poorly in 2005. In 2006 I started the season with tightened up neck tension on the seated bullet, using a .002” smaller neck sizing bushing. In June @ a Regional at Windhill, I set (6) new NR’s. And after that I earned quite a few screamers, sometimes one @ every match. Same bullet and powders as 2005. Muzzle velocity was 1950-2100 fps, 170-grain +/- cast bullet, lube for years has been Tom Gray’s #24.
But….I have never messed with inside case mouth/neck cleaning. I see that the same as a John sees primer pocket cleaning….why bother? Inside of the neck condition might be why the 2005 and 2006 loads behaved differently, who knows, not me.
An unscientific, untested observation…maybe it’s the lucky baseball hat thing….if you do something well wearing it, you’ll always wear it. Wrong or right, I think the modified neck tension was important in my situation.
Tom
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Yup. A good read. Reaffirms my faith that under normal circumstances, one does not need to worry much. Watch out for lubes that can be adhesive and provide a chemical crimp.
With rifle in hand, I confidently go forth into the darkness.
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Has anybody measured how much force is required to reseat the bullets after the lube has hardened/adhered? The usual forces to seat or pull are so small compared to the shot to shot variation in chamber pressure that the forces would have to be much larger than usual to make any difference. Do we have any idea of the magnitude of force involved in reseating the bullets? Numbers make the difference between opinion/speculation and finding facts.
In my article on neck tension in Fouling Shot #240 I discussed five different ways that improper neck sizing (too much or too little neck tension) could destroy accuracy.
Too tight -- shaving lead, sizing down the part of the bullet in the neck, upsetting the part out of the neck to a larger diameter, and even bending long bullets.
Too loose -- bullet being pushed back into case before seating firmly into throat, thus ruining"fit"
These are real I have experienced some and have seen all of them reported. Unlike case to case variation in neck tension these cause real degrading of performance. Any one of these might explain Tom's lower accuracy in year one.
John
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my mj bench friends assure me the brass expands and leaves the bullet hanging in mid-air before the bullet * hardly * moves
You can be sure that this is true with cast.... and at low and high velocities. BTDT long ago....
maybe we should worry more about that bullet hanging in mid air more than any larger sd's in pressure ... and/or velocity ...from neck dragging ..
It has been taken care of by a few.... that would listen.... very few
though.************
that is with normal straight necks... gotta think that at some point that enough heavy crimp will present some drag ... like one that scrapes lead off when fired ...
Effective at low velocity and pressure with hard case necks...........
ken
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By nature I think most of us are "do it yourself" types. And setting up a trial and trying to get feedback like Bill suggested is very doable and should be done simply because it would be from the end user's perspective.
But maybe the manufacturers have an opinion that's worth listening to.
Attached is the 2021 Nationals sorted by what lube was used and to the best I could determine, who made the lube.
From the results only 25% loaded at the range. So 75% loaded at home and most probably the week of the competition so this isn't meant to be the definitive answer to who sells the most lube. But it does give you an idea who is selling lube at least to the BR crowd.
So my question is this: Does anyone know anyone at White Label Co or LBT on a first name basis that could ask for their input? Thanks, Bill.
A “Measured Response” is as effective as tongue lashing a stuck door.
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jeff houck
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Aaron
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Wilderness
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Tom Acheson
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John Carlson
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sghart3578
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Spindrift
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alphabrass
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SkinnerD
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MP1886
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