Compress loads and bullet seating depth

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Re: Compress loads and bullet seating depth

Post by bladeracer » 16 Sep 2022, 11:34 am

I lean the opposite way.
Beams only measure within a very narrow window. If you set your scale to weigh 40gn for example, you dump powder in and nothing happens until you get close to 40gn, when the beam finally begins to lift off its rest. Then you trickle it up to be 40gn. It is very precise in that regard. But if you have bumped the adjusting weights without noticing, so it is set to weigh 42gn, or 52gn, you really have no indication that it has moved. This is less of an issue with a low density powder that almost fills the case, if you are two grains over you should see the difference when you look into the case, but not everybody has learned to do that. With a higher-density powder you can dump that 42gn or 52gn charge in the case and not notice.

I recommend that if you are using a beam scale make yourself a check weight that you can drop in the pan before you throw every charge to confirm it is still set to where you wanted it. My mate is still very new to reloading, using the Lee beam scale, and he is using a piece of paper as a check weight.https://enoughgun.com/forum/viewtopic.php?f=2&t=16888&start=30#p293731

With a digital scale there are still ways of messing it up, but I don't recall ever having one self-adjust itself. I don't run them off batteries as that can cause issues when the battery charge decreases - stick with mains power only.

And charge all your brass together, then look across the tops with a torch and confirm that all the powder levels are similar before you seat the bullets.
I also recommend using powder dippers to dump your charges into the pan. Choose the dipper that is just below what you want, throw the charge in the pan and the scale should come up very close to the weight you want, then trickle it up to where you want it. If you use a dipper that throws 39.4gn of whatever powder you are using, when you dump that into the pan the beam should move off its rest - if it doesn't then you know to look for a problem.


bluehorse wrote:While not strictly about compressed loads my subject is powder scales . I had a st of battery scales that I used and calibrated too but they were not 100% consistent so they are put aside politely . ( not thrown to outhouse where they belong } A consistent load is needed for accuracy . I have my balnce scales from long ago that are still good . I discovered that the flat bottom of the pan can give crook inaccurate readings if the powder is not central. The amount of discrepancy depends on the volume of pwder not central . Verifying a load from a thrower then becomes a nightmare if a charge must be centrally located ! I played with the load in the flat bottomed pan and think variations can be as much as 5 tenths of a grain so checkweighing quickly in conjunction with a powder thrower aiming for 2 tenths accuracy is a painstaking exercise .
My fix for this was to use a small ball pein hammer to dome the bottom in the middle so the powder will fall centrally . It does so long as the dish is in the cradle and the charge is all central . . The dome is not all over the bottom but big enough for my loads . I often shake the tray to make the charge centrally located in this tray . It is cumbersome when I am in a hurry but gives better results .
Hope readers can find this useful .
Peter
P.S electronics are faster by a country mile while they are accurate but so many things can upset the electronic tools . The problems arising from inaccuracy or a false zero or calibration are not easy to identify so I like the old fashioned tools more . A foul up is more easy to identify and fix . Tools across the board are the same .. Some tension wrenches do not like being dropped especially on the part that has the scale stamped on it . I have 1 that is a big name but the handle grip with the scale on it is a pressed on fit and dropping this tool can reposition the scale in relation to the mating mark ..Beware ! calibrate tools in some way . Check zero or check with test peices supplied also . Find a method of zeroing scales on your bench often . It is a few minutes work that may save days of frustrations or foul ups .
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Re: Compress loads and bullet seating depth

Post by bladeracer » 16 Sep 2022, 11:41 am

bluehorse wrote:The actual powder cannot be compressed but the shape of the actual powder can be arranged so the load occupies less volume and then the projectile can fit together hopefully.


The powder does actually compress, the grains being broken up is what makes the "crunchy" sound as you seat the bullet. Something like Winchester ball powders are probably much harder to compress, but are so dense I doubt they ever make compressed loads in any cartridge.

AR2209 in .30-06 is probably the most compressed loads I've ever made. I'd seat the bullets, measure them, put them aside. Then when I checked their lengths when I'd finished the batch, the bullets had pushed themselves out to random lengths due to the compression of the powder. When that happens it's a good idea to crimp the bullets in place.
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Re: Compress loads and bullet seating depth

Post by bluehorse » 16 Sep 2022, 12:28 pm

MORE on compressed loads . I find terminology of acompressed load rather misleading But I looked up the online Oxford Dictionary and one definition of the word is to compress something into a smaller space . So by dictionary definition compressed load could be a correct terminology . However I see most people interprete a compressed load as to physically press the load down into the case in question . Due to the type of extruded powder manufactured this is highly improbable that brute force can not win the day after all we are not pressing track pins on a dozer chain using a 200 ton track press but simply putting a projectile onto a brass case ( that appears superficially to be overmfull } . So now is the time for thought and to come up with an idiot proof method of reducing the volume the powder occupies so that there is room for the bullet to fit in place correctly ..
So I think the maufacturers could be more helpful in saying all of this ,. I used a home made powderd dropper using my lathe in the same way it would be made if u bought a ready made item .excenpt home made conjures visions of a very roughly made item . Ask any polished tradesman machinist about his tools he has made and the description of this item can vary widely from in house item to a fabricated tool or simply said home manufactured . Hahahha this is all within our English language .
My preferred method is a light vibtating of the case until the extruded propellantsettles into an acceptable space or volume withing the confines of the case that is the subject of discussion . It may take little work to do ths withoutspilling the charge or it may be a time consuming painful experience until a simple method is arrived at .Brute force in the loading press is undesireable so an alternate way is better . If all else fails change the propellant . or settle for a slightly less charge than desired .. My battery hair clippers vibrated the case quite well without spilling . So u dont have to make an unscheduled trip to the local adult shop for an unmentionable,,, hmmm vibrator . hahahhaha

In conclusion I hope many who have a different understanding of what is required can understand my text here . My aim is not to take the piss from anyone but to clear up yetanother mystery in reloading vernacular .. I have been reloading my own going back over 45 years and never had to "compress a load ). Quite frankly I read the ADI book and this C letter kept popping up . It had me hmmm ------- stumped . So I asked at my nearest gunshop . It had never dawned on me C stood for compressed .. WTF am I gunner compress .. Hence my explanation here . I have a good command of our english language and understand that many do struggle with it . Such is the nature of our written language and I am not trying to be a smart alec . I had already heard of using a powder dropper from an old friend who was a pro buffalo shooter telling me how they loaded P14 3 nought 3 to get the buffaloes using a powder dropper and then putting the projectile back on top . hahahaha . True !! not for the inexperienced or faint hearted . Then he bought a 375 Hand H and used it on a tripod standing .up.some time later after a nasty scare with a large buffalo getting up and charging his brother.. Factual not bush fairy tale ...

Hope I have contributed something
Peter
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Re: Compress loads and bullet seating depth

Post by bladeracer » 16 Sep 2022, 2:21 pm

Pour some powder on your bench and crush it with a spoon, it does compress. The larger the grains are the more it can be compressed.

Compressed load data tells us the charge will be higher than the base of the seated bullet, thus we may need more pressure to seat the bullet, and we may hear the powder being crushed. I look for compressed loads as being a good indication that the powder gives excellent case fill, which is good for safety (if a load of 25gn is listed as compressed, you'll probably notice if you try to stuff 26gn or 30gn in the case), but more importantly it can give more consistent velocity measurements.

My standard .204 load with the 24gn NTX is 30gn of AR2206H. This charge is heaped above the case mouth, so I hold the bullet in place on top of the powder and seat it into the case - it most certainly constitutes a compressed load.

Using some method that allows you better consolidate the powder grains into the case volume, thus reducing the height of the charge still constitutes a "compressed load", even if it means you don't actually have to compress it.


bluehorse wrote:MORE on compressed loads . I find terminology of acompressed load rather misleading But I looked up the online Oxford Dictionary and one definition of the word is to compress something into a smaller space . So by dictionary definition compressed load could be a correct terminology . However I see most people interprete a compressed load as to physically press the load down into the case in question . Due to the type of extruded powder manufactured this is highly improbable that brute force can not win the day after all we are not pressing track pins on a dozer chain using a 200 ton track press but simply putting a projectile onto a brass case ( that appears superficially to be overmfull } . So now is the time for thought and to come up with an idiot proof method of reducing the volume the powder occupies so that there is room for the bullet to fit in place correctly ..
So I think the maufacturers could be more helpful in saying all of this ,. I used a home made powderd dropper using my lathe in the same way it would be made if u bought a ready made item .excenpt home made conjures visions of a very roughly made item . Ask any polished tradesman machinist about his tools he has made and the description of this item can vary widely from in house item to a fabricated tool or simply said home manufactured . Hahahha this is all within our English language .
My preferred method is a light vibtating of the case until the extruded propellantsettles into an acceptable space or volume withing the confines of the case that is the subject of discussion . It may take little work to do ths withoutspilling the charge or it may be a time consuming painful experience until a simple method is arrived at .Brute force in the loading press is undesireable so an alternate way is better . If all else fails change the propellant . or settle for a slightly less charge than desired .. My battery hair clippers vibrated the case quite well without spilling . So u dont have to make an unscheduled trip to the local adult shop for an unmentionable,,, hmmm vibrator . hahahhaha

In conclusion I hope many who have a different understanding of what is required can understand my text here . My aim is not to take the piss from anyone but to clear up yetanother mystery in reloading vernacular .. I have been reloading my own going back over 45 years and never had to "compress a load ). Quite frankly I read the ADI book and this C letter kept popping up . It had me hmmm ------- stumped . So I asked at my nearest gunshop . It had never dawned on me C stood for compressed .. WTF am I gunner compress .. Hence my explanation here . I have a good command of our english language and understand that many do struggle with it . Such is the nature of our written language and I am not trying to be a smart alec . I had already heard of using a powder dropper from an old friend who was a pro buffalo shooter telling me how they loaded P14 3 nought 3 to get the buffaloes using a powder dropper and then putting the projectile back on top . hahahaha . True !! not for the inexperienced or faint hearted . Then he bought a 375 Hand H and used it on a tripod standing .up.some time later after a nasty scare with a large buffalo getting up and charging his brother.. Factual not bush fairy tale ...

Hope I have contributed something
Peter
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Re: Compress loads and bullet seating depth

Post by straightshooter » 19 Sep 2022, 8:19 am

bladeracer
I think you are confusing deforming with compressing.
When one compresses powder with a bullet, what happens is that the interstices between the powder grains are reduced. There inevitably will be some accompanying powder deformation but the majority of compression is due to loss of airspace.
A benefit of a compressed load is that it offers the prospect of more consistent powder ignition leading to less SD in MV.
One thing that has me beat in your post is just how you manage to have powder heaped above the case mouth and then manage to seat a bullet without spilling powder in the process.
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Re: Compress loads and bullet seating depth

Post by Oldbloke » 19 Sep 2022, 9:31 am

Has a "drop tube " been considered/tried?
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Re: Compress loads and bullet seating depth

Post by bladeracer » 19 Sep 2022, 10:36 am

straightshooter wrote:bladeracer
I think you are confusing deforming with compressing.
When one compresses powder with a bullet, what happens is that the interstices between the powder grains are reduced. There inevitably will be some accompanying powder deformation but the majority of compression is due to loss of airspace.
A benefit of a compressed load is that it offers the prospect of more consistent powder ignition leading to less SD in MV.
One thing that has me beat in your post is just how you manage to have powder heaped above the case mouth and then manage to seat a bullet without spilling powder in the process.


What do you believe causes the crunching sound then? I think you are confusing compression with consolidation. Compressing something is going to deform it, consolidation is trying to fit stuff into a smaller volume without deforming it, as with using the drop tube or a vibrator. Compressing powder grains definitely deforms them, they're not that hard.

I'll have to video it next time I'm loading some, but squashing 30gn of powder in is not difficult. Keep in mind the .204 case neck is very small, so the neck only holds a couple of grains, and the slump of the AR2206H is not tall at all. The grains are quite large compared to the size of the hole they're sitting in, all I'm doing is pushing those few grains back into the larger volume of the case body. If I could get 30.1gn to fit in there I'd try it but 30gn is all I can manage, anything more spills over.
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