compressed load

Discussion in 'The Ammo & Reloading Forum' started by zkovach, Dec 1, 2009.

  1. zkovach

    zkovach Well-Known Member

    Oct 7, 2009
    Going through my reloading the way getting the starter kit for xmas... I noticed compressed loads which tell me that the powder must be packed or compressed in the bullet. How do you do that. I am a bit scared as a begineer to try the compressed load. Any advise to ease my nervousness? Do you need a special tool of some sort?
  2. ggtgary

    ggtgary New Member

    Dec 1, 2009
    It's no biggie. If you have proper loading data it should not be a problem. Your loading press will compress powder the correct amount if you are using the correct measured amount. and proper components. The important thing is not start at the maixmun published load but work up to it, starting with at least 10 percent under maxiimun. If cases are sticky extracting or if primers or cratered then you have too much pressure. That is also the case if your group starts to spread out as you increase the power charge.

  3. 312shooter

    312shooter Well-Known Member

    Mar 17, 2008
    Las Vegas NV
    I have never loaded compressed or a maximum load and have never found the need to. When you get to know reloading you will find accuracy is rarely accomplished with a maximum load, and not worth jeopardizing your firearm and yourself. Some powder/bullet combinations may be in that range but chances are its not the best combination.

    The term "hot load" has been abused and overated by people thinking when a round is jam packed to the mouth with lots and lots of powder somehow its better...well its not! Anyway your compressed load will only be that when the bullet is seated by the seating die into the case neck far enough that it must displace the powder load by compressing it to some degree. If you are new to reloading its just best to avoid this at first. I'm certain that your manuals probably touch on that somewhere. Use a starting load or damn close to it when you begin reloading, then work up. There's alot to be learned in this fun hobby, just learn it by the book -the trial and error method will lead to an error at some point and thats bad news for you and your gun.
    Last edited: Dec 2, 2009
  4. Gearheadpyro

    Gearheadpyro New Member

    Oct 11, 2009
    Charleston, SC
    So long as the load is listed in a manual you should be ok with a compression load.

    I have mixed feelings about them. Compression loads are usually on the hot side, and like 312 Shooter said, that will beat up on your gun and brass more. I too haven't found the need to run something terribly hot, the best accuracy for me is generally somwhere 2-3 grains off of max. On the other hand, If I use a very slow powder then a compression load lets me put more of it in. I use IMR 4350 in some of my .308 Win loads, and they are just ever so lightly compressed. This load is not a hot load because the powder is so slow. The other advantage that some claim with compression loads is that they improve accuracy due to presenting the powder to the flash hole the same every time. I don't have enough experience with them to be able to prove or disprove that.

    Whatever you do, just like 312 Shooter said, DO NOT start at a compression load. Start at a beginning load and work up to where you get the best accuracy while watching for pressure signs.

    Good luck
  5. LDBennett

    LDBennett Well-Known Member

    Dec 20, 2003
    Hesperia, CA
    While compressed loads tend to be full loads and "hot" by nature, there is another problem with compressed loads. Unless the bullet is secure in the case, the pressure from the compression of the powder will push the bullet out in the case over time. In general, a roll crimp into a bullet cannelure is enough to hold the bullet in the case but some bullets don't have cannelures and some don't have to be crimped. We crimp revolver ammo, lever gun ammo, semi-auto rifle ammo. But we normally don't crimp bolt gun ammo. Semi-auto pistol ammo uses a tapper crimp which is less secure.

    The "new" twist to crimping ammo is the Lee Factory Crimp dies for both handgun cartridges and rifle cartridges. That does allow almost any cartridge to have crimped in bullets. It can also make the ammo more consistent shot to shot. I recommend using these dies if you want to crimp your cartridge cases on almost any caliber ammo.

    In my 20+ years of extensive reloading, I have never found it necessary to use compressed loads for anything I reload for (over 30 different cartridges). Newbies to reloading should not attempt to use compressed loads. Newbies should read and re-read then re-read their manuals until they thoroughly understand the process of reloading. Educated reloaders with common sense rarely if ever make reloading mistakes that can hurt the gun or the shooter. Safety first!

  6. carver

    carver Moderator Supporting Member

    A copmpressed load indicates that you have only that powder to work with. Example: .44 Mag using IMR 4227 can be compressed. I have filled the case with IMR 4227, set a bullet on top, and then seated it; compressed load. This is not dangerous with this powder, but is an absolute waste of powder. A lower amount of powder will do the same job, as all the powder will not get burned in a pistol anyway. Try another brand of powder that is faster burning, and you will see better results at a lower cost for reloading.
  7. Bindernut

    Bindernut Well-Known Member

    Oct 24, 2007
    ND, USA
    I'll ditto what LD and gearheadpyro said...and also add that in a rifle cartridge, I prefer a load that fills the case to anywhere from 75-95% of it's volume. Very little room for the powder to shuffle around. I don't have any scientific data that this is better, but a uniform presentation of the powder to the primer flash each time is probably more conducive to accuracy by eliminating that variable.

    Compressed loads I've usually shied away from since I don't usually load up to the max either. A bit less than a max compressed load is usually in that 90-95% filled volume range and that's what I try to go for.

    Also, with a compressed load you need to be aware that different brands (or even different lots) of brass for a specific cartridge might have different internal volumes so a compressed load that is safe in one brand/lot of brass might not be safe in another batch of brass.

    For a newbie reloader, I would probably stay away from a compressed load until I had a bit more experience with some of the other variables of reloading...
  8. LDBennett

    LDBennett Well-Known Member

    Dec 20, 2003
    Hesperia, CA

    On the powder floating around inside a too big case, there was a story in a magazine a year or so ago by an guy who instructed some gun related class. One of his parlor tricks he used in the class was shooting two identically loaded handgun cartridges over a Chronograph. One was presented so as all the powder was forward and the other with all the powder rearward. It made a tremendous difference..... detectable and obviously affected the trajectory of the bullet. It was more than a hundred FPS difference, as I remember it. I don't remember the details exactly but it impressed me as to the impact of a little powder in a large case. Of course, he picked the powder he found maximized the effect, and not all powders are impacted equally and some not at all.

  9. zkovach

    zkovach Well-Known Member

    Oct 7, 2009
    ok thanks for the advice guys i appreciate it!!
  10. res45

    res45 Member

    Sep 21, 2007
    I've been reloading for 25+ years and never once found a need for a compressed load,in fact my most accurate loads are usually 1 or 2 grs. off the MAX loads. Your intended target want know the difference in FPS.
  11. steve4102

    steve4102 Former Guest

    Jan 27, 2006
    Compressed loads are no "Hotter" than any other load. A compressed load is nothing more than loading with a powder that has a burn rate that is a bit slow for cartridge. To get the pressure and velocity up to where they belong ya gotta add powder. Does this make the load "hot" or dangerous. NO, not in the least, as long as you are following published data. Take a look at Hodgdon 30-06 data for example. Lots of loads and several are compressed. Are the compressed loads "Hotter" than the non-compressed loads? NO, running about the same PSI and in many cases running less PSI. Those that jump to the conclusion that "Compression" equals "hot" and "High Pressure" are simply misinformed about what a compressed load really is.

    I load for several rifles and if at all possible I shoot for compressed loads every time. Better accuracy and better SD. So, follow your manuals and if it is a compressed load, compress it, it will shoot just fine and I'll bet more accurate than your fast for cartridge non-compressed loads.

    Oh I almost forgot. Being compressed does NOT mean that you are loading to the Max published data. There are thousands of excellent compressed loads that are well below published max. Just another reloading myth, that "compressed" mean Max.
    Last edited: Dec 2, 2009
  12. zkovach

    zkovach Well-Known Member

    Oct 7, 2009
    I understand i was just curious because there was some data that the min-max grains. were all over 100% but i understand now . Thanks to all.
  13. Freebore

    Freebore Member

    Apr 18, 2009
    Land of the Free
    As I am aware of (and my own experience), most compressed loads are usually associated with slower burning powders, which generally provide a full case but still operate within normal pressure ranges. In fact some compressed loads actually run lower than standard pressures because of the progressive burning rates.
  14. LDBennett

    LDBennett Well-Known Member

    Dec 20, 2003
    Hesperia, CA
    "Hot" is a relative thing. The intent I had in using it was that, while still a published load, it created more velocity than the starting load. I have worked up loads my rifle liked best and it is rarely the Max load. But I also rarely choose powders that need to be compressed even to get to normal pressures. There are plenty of powders to choose from that will never be compressed in the Max load levels.

    Perhaps I am missing out on some loads that are better than mine because I avoid compressed loads but, oh well. Compression of the powder has too many potential pitfalls to go that way, especially for a newbie to reloading. Remember it was a newbie who asked for guidance, not an accomplished reloader with years of experience. The answers here should fit the question asked and who asked it, I would think. We all get to choose how we want to do it but it probably is not a good idea to recommend an advanced reloading technique to a newbie. Down the middle of the road is the best approach for new reloaders. Of course, it is only my opinion and others may have theirs.

  15. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
    Bingo... My only problem with compressed smokeless loads is they sometimes wont ignite and may as well have been loaded without powder. An ideal charge is one that comes close to 90% case capacity. unless of course you seek reduced plinker loads, then you will use a designated powder and a charge density of around 50% case capacity... NOT ALL POWDERS CAN BE USED FOR REDUCED LOADS!!! SOME POWDERS IF LESS THAN RECOMMENDED STARTING IS USED, (MOSTLY RIFLE) WILL CAUSE "DETONATION" FROM TOO MUCH ROOM IN THE CASE... A HIGH PRESSURE SPIKE THAT CAN BE JUST AS DANGEROUS IF NOT MORE DANGEROUS AS AN OVER POWDER CHARGE. Load carefully and mind you recipes;)
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