1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Poor Crimp Effect on Pattern?

Discussion in 'Shooting Related Threads' started by rdf59, Nov 12, 2009.

Thread Status:
Not open for further replies.
  1. rdf59

    rdf59 Member

    Joined:
    Jan 29, 1998
    Messages:
    353
    I have had no trouble with producing excellent crimps on my 12ga reloading. However, my 20ga shells range from slightly good to very lumpy, lousy, crumpled crimps. It makes sense that a good, even crimp would release evenly and not interrupt or change what starts as a good distribution of shot. I extrapolate from that thought that a bad crimp would open at different rates and might disrupt the shot distribution.

    BUT --- I really don't know that to be a fact. Does anyone have any knowledge of tests that were done to check the effect of crimping on shot patterns? The ones I have done -- a few --- were inconclusive to me.
     
  2. JACK

    JACK Well-Known Member Supporting Vendor

    Joined:
    Apr 28, 2006
    Messages:
    14,690
    Location:
    NW Wisconsin
    hug your pattern board
     
  3. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,397
    I don't think anyone will have valid data about this (despite claims to the contrary) unless they have intentionally loaded a good number of shells with sloppy crimps of various types and compared them head to head to the same loads with perfect crimps. And even then there are enough other variables to make any test results inconclusive. One shell with a sloppy crimp shot during a patterning session isn't a valid sample.

    MK
     
  4. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    The resistance provided by the crimp should have an affect on chamber pressure and velocity. Old worn out shells will result in slightly lower velocities but this does not show up until the shell has been reloaded 7-8 times.

    I did one time pattern 4 shells that had irregular, folded crimps. I could not tell any difference in pattern percentages between these 4 irregular crimped shells and 4 shells with nice looking crimps. The problem could have been the small number of shells I had available to test. I would never try to form a conclusion from less than 10 patterns. The patterns are just too variable.

    I can tell you, with great confidence, that if you look at a shell with an irregular crimp and you believe the shell is not very good and will probably not break the target, you will often be correct. You can miss targets with both your mind and your gun.

    Pat Ireland

    Pat Ireland
     
  5. School Teacher

    School Teacher Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,050
    Location:
    Louisville, KY
    When I reload I usually reload about 500 shells. As I box these reloads, I cull any crimp that is not correct. I shoot the culled shells in practice, often mixing 1 oz and 1 1/8 oz loads. The 1 oz loads have size 8 shot and the 1 1/8 oz loads have size 7 1/2 shot.

    I am amazed at how these rejects will often shoot 25's.

    I started culling the poor crimps because I missed targets because I was mentally distracted by loading a poor crimp during a registered shoot.

    IMO, any crimp that is significantly out of order needs to be cut open and examined. You may have an unsafe reload due to too much or too little powder or other problems.

    I have used a MEC Grabber for over 20 years and before that a MEC SizeMaster for 10 years. I upgraded to a MEC 9000 G this summer.

    With the MEC 9000 G, I started experiencing unusual crimps. These were both too high or indented. What I found was that when I brought the press down with no shell in the priming station and a primer in the press, the primer would get picked up by the powder drop tube and stay there.

    I started seeing powder continue to drop from the tube after I moved on to another shell and the reloads dropping out of the last station looked funny. This was with Nobel primers. When I cut the shells open, most had too little powder and I think one had too much. The primer in the drop tube was IMO the cause of the problem.

    This was with my first 100 or so reloads. I have since reloaded about 2000 shells with no problems.

    I really like the MEC 9000 G but it does have its quirks. You really need to watch what is going on while you are reloading. I think I need need to slightly enlarge the business end of the primer drop tube with a Dremmel tool. I plan to ask MEC about this before I make any change.

    Also, with a MEC, be careful not to over tighten the powder and shot bottles and watch the movement of the charge bar with each reload.


    Ed Ward
     
  6. Straight99

    Straight99 Member

    Joined:
    Apr 23, 2007
    Messages:
    336
    Don Zutz did crimp tests years ago in Handloader Magazine. Issues 51, 52 and 59. And others issues. He proved the crimp can make a big differance. He also had articals in Trap and Field about crimp but I don't know the issues.
     
  7. halfmile

    halfmile Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    15,639
    Location:
    Green Bay Wisconsin
    What Pat said.

    I found the old AA hull to become inconsistent after 4/5 loads, and at the time the Remington Premier was good to 10 or more.

    It was easy to tell, the minute the crimp lost its nice flat appearance my 1200 FPS shell would be anywhere from 1135 to 1175 but never 1200.

    At that point the practice tub began to overflow.

    I never found ugly to affect velocity, a misfolded crimp seemed to have as much resistance as a normal looking one.

    And since the shot cup holds the pellets till exiting the barrel, I will say pattern deficiencies would not be logical.

    I could be wrong. I got 98 on a test once.

    HM
     
  8. fssberson

    fssberson Active Member

    Joined:
    Jan 29, 1998
    Messages:
    2,375
    Ed: You may resent hearing this from a "school principal" [retired], but it may be time to move into a better quality reloader. Most of us go through a transition stage of Mecs, Pacific Hornaday's [360], into P/W's and then the Spolar with hydraulics. At each stage, you will say to to yourself, "Wow, what a better machine." More important than the crimp is that the wad is not cocked in the shell. Some of the old timers use to take a piece of masking tape over the end of the shell and shoot it for practice... the target broke. Fred
     
  9. Charles.F.Phillips

    Charles.F.Phillips TS Member

    Joined:
    Oct 6, 2009
    Messages:
    330
    OK guys and gals, riddle me this: At what point do you retire your cases? I use AA's and I rarely get more than 5 reloads. On the third reloading, I usually find one, maybe two cases where the split at the fold extends all the way to the top and separates. At that point, I just replace the individual case and continue. However, after the fifth reloading, I usually find splits reaching the top now becoming a pattern, so I chuck the lot and start with new (once-fired) cases.

    I used a Lee Load-All for 25 years, but I now use a Sizemaster and the crimps are about the same.

    I've seen claims of 10 and in one case, 20 reloadings of AA cases! Are these guys doing something different, or do you think they're just using worn out cases to the point of falling apart?
     
  10. wolfram

    wolfram Well-Known Member

    Joined:
    Jul 17, 2007
    Messages:
    6,258
    Charles, I don't keep accurate tabs on the number of loadings but I take a look at the hulls as I'm about to put them into the loader and make a decision about trashing them. Splits in the crimp section or darkened brittle plastic are reason to trash them. I usually load Remington STS or GC and am guessing the reload life is between 6 and 10 but certainly not 20. Pehaps I could get another loading or two from my culled hulls but why? Even if there isn't a performance issue, you just don't want scruffy looking ammo. It has to do with those mind tricks that Pat was talking about.
     
  11. snglfoot

    snglfoot Member

    Joined:
    May 22, 2006
    Messages:
    380
    When I started loading, I would mark the cases to count the number of time it had been reloaded, but most of the time I ran out of room to mark, before I found the shell non-serviceable, so I don't bother any more, just check and load or "chuck" them. Mostly AA's.
    Norman
     
  12. hmb

    hmb Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,417
    Adjust your reloading machine so you get nice crimps. HMB
     
  13. Charles.F.Phillips

    Charles.F.Phillips TS Member

    Joined:
    Oct 6, 2009
    Messages:
    330
    HMB,

    I'm not sure I need to. The crimps are nice and flat with no opening and the rim is tapered for good feeding. I had no adjustment on the Load-All, but the Sizemaster seems to already be adjusted correctly.
     
  14. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    Straight99 - Yes, Don Zuts did write several articles describing his testing that showed poor crimps resulted in poor patterns. But, these tests could never be duplicated by anyone else. I suspect Mr. Zuts (a pen name) did much more writing than testing shotgun shells.

    Pat Ireland
     
  15. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,397
    Charles, I discard hulls when I start to see soot circles around my firing pins indicating that the primer seal has started to leak. For AA hulls that comes after the 3rd or 4th reload (unless they split first) and for Remingtons it usually happens at the 6th or 7th. There is still life left in the crimps but i don't need trash in my action.

    MK
     
  16. Straight99

    Straight99 Member

    Joined:
    Apr 23, 2007
    Messages:
    336
    I knew Don Zutz for 30 years and helped him with some of his tests so I know they were spot on. Counted more pellet holes than I care to remember. He verified most of his tests with Hodgdons powder company. He was the Wisconsin State champ in skeet for several years. If he said it worked, it worked.
     
  17. Ahab

    Ahab Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    3,650
    Poor crimps will cause you miss targets if you worry about them!

    If you ignore bad crimps...they will break targets just fine!
     
  18. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    Straight99- Your insight is different from mine. I remember Neil W. making comments similar to the one I made above. I duplicated one of his reported tests and got directly opposite results than he did. I spoke to him about this but he was too busy to talk with me at that time. Do you remember his real name? I was under the impression he wrote under a pen name.

    Pat Ireland
     
  19. Straight99

    Straight99 Member

    Joined:
    Apr 23, 2007
    Messages:
    336
    His real name was Don Zutz but sometime when he wrote an artical on rifles he would use the pen name Don Roberts.
     
  20. OGC Director

    OGC Director TS Member

    Joined:
    Jul 28, 2009
    Messages:
    1,415
    I have run several straights with culled shells because I didn't like the crimp. I reload sts and nitro hulls untill the ends start to split then I load one last time and toss.
     
Thread Status:
Not open for further replies.
Search tags for this page

bad crimp effect

,

bad crimps what to do

,

do bad crimps effect patterns

,

how primers effect shotgun patterns