Compress loads and bullet seating depth

[cruze82]

It is pretty hard to over compress powder and often the projectile just won't stay at the right depth after you seat it- a pain in the arse.

Warrigul can you explain this further please ?

I think I have come across this while working up some loads and in the upper end of the load development I found I would seat the projectile at the desired depth then when I went to chamber the round it felt tight so I removed the round and to see rifling marks on the projectile so I measured at the range and the projectile had moved out of the case 20 thow

can this be caused by an over compressed load ?

[Warrigul]

I've come across it twice when seating, as I like to seat +/- .002" for target use I set the press and go for it checking ALL the loads at the end with a comparator guage and pulling or pushing in further as needed. A couple of times I have had to tap the case a bit to get the projectile to seat at the proper depth, it appeared that the case walls expanded when the projectile was seated(powder doesn't compress) and when the press pressure was off the projectile simply moved back out between .005 and .015".

You can't strictly speaking Compress a load, only pack it in properly. It gets to a certain point and the projectile just won't go in any further.

I am happy to hear other theories on this as I have only encountered it a couple of times and it isn't dependent on neck tension.

[Baronvonrort]

Hi guys,

Reloader on my L plates here.

So 2 questions.

1) You could seat the same bullet higher or lower making it even more compressed.
2) Two different length bullets could be used with the same maximum 'compressed' load but the longer one would compress it more again.

This doesn't seem to be addressed in the load data?

So is it lowest common denominator and will work with all deeply seated long bullets? Or what else?

It is addressed in the ADI data, with the 308 using 110-125 gr projectiles you will find most loads are compressed at maximum loads, the 125 gr lists 2 different projectiles with 2 different max loads both are compressed. (8208)

I also look at pressures when considering max loads, the 308 with 110-125 gr is around 50,000 psi with max loads which is below the 60,000 psi used for some other max loads, my .243 usually has pressures around 50,000 psi with start loads up to 60,000 psi max.

Seating the projectiles higher can give more room in the case, the magazine is what usually restricts how long they can be if using a magazine, I don't know why you would want to seat them lower.

The whole point to load development is to find something that works well for accuracy,when the bullet goes bang there are all sorts of vibrations and harmonics happening in milliseconds, the harmonics of your gun are what they are and not much you can do about that, load development is about matching the harmonics of the gun to the harmonics of the bullet going bang to get the best accuracy, by altering powder loads you are altering the harmonics of the explosion,by experimenting with loads you will discover one that gives superior accuracy over others.

Those with .22lr don't reload so they change ammo brands to find out which one works best to match harmonics of gun to harmonics of explosion, with a centrefire and reloading you can tailor it to suit your gun.

With my .243 the most accurate loads for 55gr are mid loads around 3700 fps,i could push them faster but accuracy falls off so I don't bother, the lower pressures from mid loads might help the barrel last longer.

Start near minimum loads and work up in .2 gr batches till you find the load with best accuracy which is what you are trying to find.

[Tiiger]

A couple of times I have had to tap the case a bit to get the projectile to seat at the proper depth, it appeared that the case walls expanded when the projectile was seated(powder doesn't compress) and when the press pressure was off the projectile simply moved back out between .005 and .015".

So what was the fix? Bump the projie a few times to settle the powder down or it just wouldn't happen?

[Warrigul]

Mostly it was a case of tapping the case a few times to get the powder to settle into decent pattern, but once I had to back the amount off as the same brand of cases had a slightly less water capacity.

Older powder can weigh a fraction less for volume (density is less) than new powder as it dries slightly. This can trip things up a little in all areas of reloading, especially when loading to the max.

[Tiiger]

Older powder can weigh a fraction less for volume (density is less) than new powder as it dries slightly. This can trip things up a little in all areas of reloading, especially when loading to the max.

Hadn't heard that before, how old are we talking for that to take place?

Presumably storage conditions play a big part.

[Warrigul]

It depends a lot on storage, how often you leave the lid off etc etc. I have two batches of 2208 at the moment(a mate insists I use his when reloading for him and he bought a 4kg lot about seven years ago) and the older one is definately lighter for volume.

It's not really a big issue.

[melanie]

It is addressed in the ADI data

When I say it's not addressed I mean they make no reference to it or give any guidelines on seating depth.

I get that things balance out with practicalities like magazines length and not deliberately seating them overly deeply, but I ask as they make no reference to it all directly in their loading information that I have seen.

[Tiiger]

It depends a lot on storage, how often you leave the lid off etc etc. I have two batches of 2208 at the moment(a mate insists I use his when reloading for him and he bought a 4kg lot about seven years ago) and the older one is definately lighter for volume.

It's not really a big issue.

I'd never get anywhere near 7 years anyway, but thanks for the info.

[bluehorse]

I came across compressed load in reloading 222 using Ar2208 .Adi list loads and start loads are listed e.g 23 grains .and max 25.0C. At first I had to scratch my head .what is 25.0C and I enquired at gunshop and was enlightened . that the C stood for compressed and to use a dropper tube to fill case with powder . .
I have been reloading 243 ,22.250 22 hornet k hornet and 22 for more years than i would like to admit and never come across loads that i had to use a dropper to fill the cartridge case so i could fit the projectile into the case and it would give me an overall length that was written into the formula given in the reloading manual. . I used to use Cyril Waterworth "Reloading Simplified" but I had given it to a younger froiend who was beginning reloading some years ago.
For those starting to reload I like it for its simpilcity and plain language used as its title suggests . For a novice I reccomend it but so hard to come by !!
I use balance scales ,I had an experience with electronic pocket scales giving me inaccurate measurements . . Reloading is not to be taken lightly. It can be very dangerous in extreme circumstances . Iam not trying to frighten anyone but if a novice cannot understand the terminology then seek advice from a reliable source ,. All advice in the internet cannot be relied on ! ! ! Check the credentials of the source ..
Next peice of advice I will offer is to be cautious with electronic calipers too or electronic measurement devices . They need constant verification . I have given up on these even good brand names as they can give false readings at times . A dial caliper is usually OK . or the basic vernier caliper ( if u can read it well} There are tutor sites in the net for reading these. .
I prefer micrometers and not electronic ones . I find verniers too hard to read off thousandths and my electronic ones I had issues with ..
For the novice learning how to read micrometers and verniers is aworthwhile exercise . Dont be tooproud to ask a friend to show you or find an internet site to tutor you. . We learnt at high school how to read the dreaded vernier scale and horror of horrors themicrometer screw gauge .. I am a diesel mech by trade so I used them all my working life ,. and they are not difficult once the basics are learnt and if new to reading one then use a pen and paper to do the calculation of inches then tenths then hundredths then thousandths and ten thousandths if it is vernier micrometer. . Once youhave this skill electronic ones are not needed .
Back to pouring the charge into the cartidge case , If it is filling up the case and little room is left for the bullet then the dropper tube or slow filling or tapping the case to settle the powder into a lesser volume . Extruded powder or stick powder is like tiny cylinder shapes under magnification and when it is poured into the case itcan occupy a larger volume than if the case is tapped or vibrated to get the powder to settle into a smaller volume . With the majjority of loads i have done volume has never been an issue ,. I had trouble fitting 23gns of Ar2208 into a 222 case until I made a dropper tube out of a bit of 1/2 inch stainless bar and bored a 1/4 hole thru about a 6inch long peice. Of course every manufacturer has their own versions of a dropper . Mine I made with a neat fit over the neck of case and top took my plastic funnel . Place the case on a peice of printer paper on your bench or table with dropper tube and funnel assembly and then tip your measured charge into the funnel slowly . After practise it will work ok and the paper on bench under case is to show any spillage . . I hope this clarifies the C load . . I am no expert on C loads but compressed loads are simply called compressed I think for want of better terminology , 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 . In my case the 222 took 24 gns easily using my dropper tube arrangement .but 25 grains may be a challenge .
The main reason I wrote this is for clarication and explanation for those starting out reloading . as the way many experienced describe things is not altogether clear . . No offence meant to experienced either ..

[bluehorse]

I read with great interest the articles here about308 compressed loads . I made 1 reply last night about my experience with 222 rem using AR2208. and after a restless night decided to experiment with my308W loading . .I have a new rifle in 308 and as yet unused but I have a bag of ppu brass in 308 and 150 grain Speer soft point flat end .I read about soft point boat tail being a problem load in as much as maximum loads are compressed. I think COMPRESSED is a very poor way to describe the process of filling the case with a charge then having room to fit the projectile in too conforming to the overall length quoted in the ADI load chart for 308win. . I weighed a charge of 47.5 grains of AR 2208 and threw it in a primed case using an ordinary plastic funnel Ihave had for a very long time. It would not fit in the case until i tapped the case so the charge would settle in a bit but Icould see no room for the proctile to go in tto the specified depth to give an overall measurement using a micrometer that was of course .checked for accuracy beforehand . It is the ordinary no frills typical traditional micrometer not electronic version that will tell u anything and mislead if it is not checked before use .
Next step I got my electric hairclippers to try as a vibrator tosettle the powder extrusions into place . Iheld the case in myfingers and putthe plastic case of the clipprs agains the brass case . I could see the powder shuffling road inside the neck but if I put the side of the blade against the case I had powder bounce out ! so I took the companion battery clipper for nose hair and tried these . They made the powder dance too and not as vigorously . I then put a bullet on top and pressed it in .I gt a an overal reading around 2,66 well inside specs ,.So now I withdrew the projectile and bearing in mind the case is new and unfired it is easy to do so. Then I checked my weight and I had my correct charge . I repeated the process with another round and removed the projectile again to prove my load was correct and within specifications . I repeated the process again with the cases that the projectile can slip in on top of the charge for measuring . My measurement after I had vibrated the cartidge was overall length of150 grain speer soft point flat back 2..662 of an inch . . My experiment was to know beforehand what i could expect loading 308W cartridges .NO Smoke and no mirrors and I have not used acronyms for good reason as theycan be confusing and misleading if the reader is not conversant with the names . Iam a diesel mechanic by trade and I used manufacturers manuals to find secifications and methods of assembly . Same with reloading for safety I take the manufacturers specs as the bible to guide me ..
In conclusion I did not compress the load but simply found a method of rearranging the extruded powder to occupya smaller volume in the given brass case and Ido find the word compressed misleading .I also think that the authors of the words compressed loads should be more explicit in the description of how to follow their instructions .
I do hope my experiment is useful for any readers ..
Peter

[bluehorse]

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 .

[bladeracer]

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.

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 .

[bladeracer]

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.

[bluehorse]

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

[bladeracer]

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.

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

[straightshooter]

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.

[Oldbloke]

Has a "drop tube " been considered/tried?

[bladeracer]

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.