Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Question on accuracy

Discussion in 'Blackpowder' started by Offthehook, Jan 7, 2017.

  1. Offthehook

    Offthehook Member

    Joined:
    Dec 30, 2014
    Messages:
    77
    Location:
    Southern CT
    Have a new pair of single action Colt clones in 44-40 shooting 3f BP with 200grRNFP bullets. Took them to the range to print them on paper. Ten shots each pistol off padded rest. Nice tight groups from each at 25 feet. One dead center bullseye, the other dead center 3 inches low. Front sights exactly the same height.

    I have filed down many a front sight to raise point of impact on pairs of pistols but just wonder what other factors might cause one to shoot lower than the other?

    Any thoughts?
     
  2. lburgau@aol.com

    lburgau@aol.com Member

    Joined:
    Jul 25, 2015
    Messages:
    76
    Location:
    LaPlace or SE Louisiana
    I'm no expert, there's people on this site that know much more than i. But I use to reload for center fire ammo, .45 acp, .45 LC, .44 mag and special, that's about all I can recall. Rather than filing down the front sight you can load a heavier projectile to lower poi.
    Do you weigh each powder charge? I loaded for accuracy and weighed the powder charges, grouped projectiles in 2 grain increments, like 200 and 202 grains in one group and 197-199 grain.
    If you want to load the same load in each gun then you will have to make adjustments to the sights. Anyway, I'd still group projectiles according to weight.
     
  3. rodwha

    rodwha Member

    Joined:
    Oct 28, 2011
    Messages:
    2,682
    Location:
    Texas
    Generally heavier projectiles raise the POI.
     
    ironworkerwill and Dog Soldier like this.
  4. 44 Dave

    44 Dave Member

    Joined:
    Apr 9, 2012
    Messages:
    604
    Location:
    Northern Wisconsin
    How close to an exact pair are they, serial # close? I have "a pair" of Cattlemen .44-40s 3 years apart that have different barrel/cylinder gap and I can not interchange cylinders unless the cylinder bushing is switched.
    See if swapping cylinders changes anything.
    By the way both of them had an issue with the machining where the hand comes out of the recoil shield, there was a ridge that the cartridge would catch on especially with the barrel pointed up.
     
    lburgau@aol.com likes this.
  5. lburgau@aol.com

    lburgau@aol.com Member

    Joined:
    Jul 25, 2015
    Messages:
    76
    Location:
    LaPlace or SE Louisiana
    Did I have that backwards? I figured a heavier bullet would lessen the velocity thus lowering POI. I've said before I'm a newbee. I haven't even really shot a gun since the '99 and I can only remember dropping a hammer on a BP once, for sure. But I thought I had it right.
     
  6. Offthehook

    Offthehook Member

    Joined:
    Dec 30, 2014
    Messages:
    77
    Location:
    Southern CT
    Thanks for your thoughts gents. All my ammo is very consistent. 10 shot groups for each pistol is at 2''. The only difference between the two is in the elevation.

    Lightening the load ( use of filler vs full case black powder made a little difference) raised poi slightly but not enough to correct completely..

    I borrowed a few 180 gr rnfp bullets but they, to my surprise, made almost no difference in poi from the 200 gr rnfp bullets..

    My calculation to adjust the front sight is the standard. Amount of error in inches X sight radius (distance from back of front sight to rear sight DIVIDED BY the number of inches to target.

    in this case 3" X 6.5" / 300 = .065" or 1/16th of an inch or 1.651mm.

    The pistols are not consecutive but very close, 36 apart.

    Swapping cylinders is a good thought, I will see if that will have any effect. They are stamped with the serial number of each pistol and tolerances are quite tight.

    We shall see before I start filing away.

    Any other thoughts appreciated.
     
    lburgau@aol.com likes this.
  7. Oohrah!

    Oohrah! Member

    Joined:
    Apr 23, 2016
    Messages:
    98
    Location:
    Hewitt, TX
    That's what I thought als0.
     
  8. leo96150

    leo96150 Member

    Joined:
    Mar 15, 2014
    Messages:
    16
    Heavier bullet takes longer to exit the barrel, thereby leaving the barrel later in the recoil arc. Also that difference in POI is not unusual for some of the Italian clones.
     
    lburgau@aol.com likes this.
  9. Cowhide Cliff

    Cowhide Cliff Member

    Joined:
    Aug 6, 2015
    Messages:
    284
    In my experience almost always POI is higher with a heavier bullet in a revolver. I've found this especially true with BP since you're not cutting back powder charge much if any for a heavier bullet.
     
  10. Cowhide Cliff

    Cowhide Cliff Member

    Joined:
    Aug 6, 2015
    Messages:
    284
    Sounds like your load is grouping well for each pistol so you may have to adjust the sight. Have you checked velocity, is the barrel/cylinder gap the same on each?
     
    lburgau@aol.com likes this.
  11. Offthehook

    Offthehook Member

    Joined:
    Dec 30, 2014
    Messages:
    77
    Location:
    Southern CT
    Checked with gunsmith. He feels the barrel crown may be culprit. Called mfr. and they also feel crown is issue. They will work on pistol and turn around quickly.

    We will see.
     
  12. Offthehook

    Offthehook Member

    Joined:
    Dec 30, 2014
    Messages:
    77
    Location:
    Southern CT
    Some photos of groups

    image.jpeg image.jpeg
     

    Attached Files:

  13. PapaG

    PapaG Member

    Joined:
    Sep 12, 2010
    Messages:
    2,058
    Location:
    Il
    Heavier bullet equals lower velocity equals more barrel time equals more barrel rise gives higher poi.
    Had a Rem replica 45 Colt that was ten inches high with factory loads. Had to go to the Lyman hollow base 450225, I think, at 155 grains to print dead on.
     
  14. Offthehook

    Offthehook Member

    Joined:
    Dec 30, 2014
    Messages:
    77
    Location:
    Southern CT
    image.jpeg Thanks to all that offered experience and suggestions. Given the short distances and light loads shot in CAS changing the loads did not give me what I needed. Sent low shooting pistol to Taylor & Company in Winchester, VA. They turned the pistol back in just over a week and after shooting at the range today I am satisfied with the repair. I will call this week to talk to the gunsmith to see exactly what was done.

    I have to say that everyone I talked to at Taylor & Company was top notch. From the original sale to after sale service. Polite, helpful, knowledgable and I cannot say enough. The best customer service I have experienced in a long time.

    I would not hesitate to do business with them at any time.
     
    rodwha likes this.

Share This Page