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

How to measure choke??

Discussion in 'Uncategorized Threads' started by FN in MT, Aug 11, 2008.

Thread Status:
Not open for further replies.
  1. FN in MT

    FN in MT TS Member

    Joined:
    Oct 25, 2007
    Messages:
    297
    Can You simply masure the ID of a choke tube with a standard dial caliper to determine amount of constriction? Or does one need one of those special inside mic's???

    FN in MT
     
  2. Scoutman 06

    Scoutman 06 Member

    Joined:
    Aug 28, 2006
    Messages:
    318
    That might work if you knew for sure the bore of the gun barrel. If the bore dia. wasn't known for sure, a bore guage would be the best for getting an accurate measurement. John
     
  3. FN in MT

    FN in MT TS Member

    Joined:
    Oct 25, 2007
    Messages:
    297
    The data from the Mfg states "Average bore .735".
     
  4. HSLDS

    HSLDS Well-Known Member

    Joined:
    Nov 2, 2006
    Messages:
    6,372
    Location:
    S-E PA
    In theory, yes you can, BUT you need to know where in the tube it is most constricted (it is not always at the muzzle).

    Plus, accurately measuring a round hole with a linear caliper is not easy.

    Try 'what fits' - drop a dime in the tube - does it pass through or not?? If you can find two (round) objects, one of which passes through the other of which just does not the true diameter will be between them.

    Also remember that the "average bore diameter" is just that, an average over many barrel sets - is yours dead on, tight, or loose?. You can play the same "does it fit" game with the bore diameter...
     
  5. hmb

    hmb Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,426
    Not very reliable info is you want to know for sure. HMB
     
  6. FN in MT

    FN in MT TS Member

    Joined:
    Oct 25, 2007
    Messages:
    297
    Heres the deal..... The FULL choke figured at a .735" bore and measuring as carefully as possible with calipers gives me a .688" so that would be a .047" constriction. Which would explain WHY the FULL seems REALLY full.

    The IM tube figures out to .037" and the MOD tube .031". I was curious of the constriction as shooting the IM seems to give me FULL performance and the Full seems to be like shooting SLUGS. Totally smoked or a miss. I recall liking a .036" choke years back in a Perazzi I had, and the IM tube in this gun reminds me of how that gun broke targets.

    I'm going to check the bore at a local Gunsmiths here in a few days. Simply wondering how close I could get. Need to pattern them too but far to windy today.

    Thanks.... FN in MT
     
  7. slowdp

    slowdp TS Member

    Joined:
    May 7, 2007
    Messages:
    779
    Why worry what the constriction is? Shoot the gun and count the pellets in the circle. I have a full that patterns extra full and a modified that patterns full. I also have a full that patterns modified. Constriction may tell you what it should shoot but it may not shoot the way the book says.
     
  8. FN in MT

    FN in MT TS Member

    Joined:
    Oct 25, 2007
    Messages:
    297
    I'm going to pattern it, make a count and figure out a %. Tough to do fighting sheets of 48" newsprint in 30 mph winds. Have to wait for another day.

    FN in MT
     
  9. Quack Shot

    Quack Shot Active Member

    Joined:
    Mar 14, 2006
    Messages:
    4,003
    A micrometer or vernier/dial/electronic caliper and a set of snap bore guages can work to check the bore several inches away from the end, and the tightest constriction in the choke. Harbor freight sells a set for less than $10. You just need to use them properly in order to get an accurate reading. There is a knack to rock and pull them through the area to be measured. A little practice and you'll be on the money. A dedicated choke/bore guage is a good investment, but not needed just to measure a choke and bore.
     
  10. ric3677

    ric3677 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    3,512
    Location:
    Montana
    I was glad you made it to the shoot Frank....thanks for coming and good shooting.

    Rick
     
  11. halfmile

    halfmile Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    15,643
    Location:
    Green Bay Wisconsin
    i'm with quack shot, been doing it that way for years. I have a piece of pipe that fits on my hole guage so I can stick it about 7 inches down the bore to measure.

    The hole guage will measure the constricted part easily, and you should transfer the measurement to a micrometer.

    HM
     
  12. Fritzboy

    Fritzboy TS Member

    Joined:
    Feb 15, 2008
    Messages:
    255
    Squeeze it
     
  13. FN in MT

    FN in MT TS Member

    Joined:
    Oct 25, 2007
    Messages:
    297
    Ric,

    Gt Falls is the Club I started at twenty years ago. The Club and so many of the members are MY trapshooting memories. Had a good time. A good shoot. Too bad we have to fight that WIND from time to time!!

    FN in MT
     
Thread Status:
Not open for further replies.