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45 LC low velocity part 2

dandak1
The topic was locked before I could respond to anybody!! First of all, thanks to all of you. I did forget to put in my original post that the bbl/cyl gap was measured at 0.005". Bbl length is 5 1/2". I am going to give Unique a try...just never liked it because it burns so dirty, altho i hear the newer stuff burns cleaner. A friend at work is going to bring in a small amount so i can chrono with that load. I SURE hope Unique is not position sensitive...the last thing I am going to do is settle the powder before each shot!!!
As far a long bbl vs short bbl causing the difference, I cant believe there would be 200 fps less going from any 7 1/2" barrel to a 5 1/2" barrel, so the problem cannot be there.
I ordered new springs from Colt so i'll take the Wolf springs out and see what that accomplishes. If nothing else it should end the misfires with the magnum primers.
I'll try to keep everybody posted as to what hopefully will work.
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  • tsr1965
    The threads in this forum are locked out at 10 posts, normally. It is figured that most of the valuable information has been recieved by then.

    You might want to see if the books you are using lists the testing method they use. Many use a test barrel...sometomes with ports to simulate the barrel/cylinder gap, sometimes not. Your barrel/cylinder gap, at 0.005", is on the outside edge of most tolerences, but not out of shape for the old Colt SAA. I would not push that SAA to hard, so you can enjoy it much longer.

    Best
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  • beantownshootah
    quote:Originally posted by tsr1965

    You might want to see if the books you are using lists the testing method they use. Many use a test barrel...sometomes with ports to simulate the barrel/cylinder gap, sometimes not. Your barrel/cylinder gap, at 0.005", is on the outside edge of most tolerences, but not out of shape for the old Colt SAA. I would not push that SAA to hard, so you can enjoy it much longer.

    I don't know what spec is for old Colt revolvers, but for what its worth, I've heard that factory spec on older Smith and Wesson revolvers is 0.003" - 0.008".

    In *general* less is better and for a modern gun, ideal is probably somewhere between 0.004" - 0.006".

    Less than 0.003" and you may start to see cylinder binding from fouling at the gap. Greater than 0.010" and apart from a significant reduction in velocity, you may start to get powder "spitting" or other problems. A gap that big probably ought to be corrected.

    For a Black powder gun, a bigger gap (eg 0.008") is acceptable since these guns tend to foul faster.

    Anyway, if the gap here is 0.005", then that's probably right about where it should be, and I certainly wouldn't mess with it or worry about it further.

    One other caveat is that the gap diameter can change based on cylinder "wiggle" or "end shake". So whomever is measuring it should also check it while manually oulling back on the cylinder to see if this is a factor.
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  • givette
    Read your post. Stay away from magnum primers, and the light strike/misfire problem will all but disappear. Also, you can take your sweet time changing the mainspring (that would be the only spring needed to be changed to increase primer strike).

    Now, in a 51/2bbl Colt SAA (test gun used in data below (Lyman #44 manual)

    Bullet: 255gr cast (Lyman mould #454424)
    Primer: Non-Magnum Large Pistol
    Powder: Unique
    Starting load: 8.0gr (847fps-51/2in bbl)
    Maximum load: 10.0gr (1011fps-51/2in bbl)

    Unique powder likes (and your sights are set up for) the heavier bullet. Heavier bullet allows for more complete burn. There will be some unburned flakes with Unique. Comes with the territory, I'm afraid. Best, Joe
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  • dandak1
    I measured the gap myself, and took out all the end play before measurement. I knew the gap was in tolerance, I just forgot to mention it in my first post.
    Givette, I am going to pick up some Unique, maybe today. I also am considering the Lyman 454190 mould (currently using the Lee 452 SWC as I prefer the aluminium moulds..I know...I am an oddball!! But after 35 years of doing this stuff I know what casts easier for me!)). But I do want to go to a bigger dia to match my throats better (remember they are .455 - .456). Taffin loves the 8.0 Unique load with a 250 Lead also, the load you mention. It will be interesting to see what velocities I get with this set-up. I will post them here after I get the mould and do some casting.
    I have to change the sear/bolt spring because an entire Wolf spring kit(sear/bolt spring, base pin spring, mainspring) was put in, and I want it back to factory trigger pull (..the oddball in me coming out again!). If it is too heavy then I always have the option of putting the wolf spring back. I head out west every year from Ohio for backpacking/hiking. I plan on this Colt SAA to be my trail gun and I want a heavier pull than the Wolf kit gives, since this wont be shot on balmy cowboy action days, but rather with frozen hands, in the rain, etc. The Wolf spring kit is just a tad too light for my tastes.
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  • tsr1965
    quote:Originally posted by dandak1
    I measured the gap myself, and took out all the end play before measurement. I knew the gap was in tolerance, I just forgot to mention it in my first post.
    Givette, I am going to pick up some Unique, maybe today. I also am considering the Lyman 454190 mould (currently using the Lee 452 SWC as I prefer the aluminium moulds..I know...I am an oddball!! But after 35 years of doing this stuff I know what casts easier for me!)). But I do want to go to a bigger dia to match my throats better (remember they are .455 - .456). Taffin loves the 8.0 Unique load with a 250 Lead also, the load you mention. It will be interesting to see what velocities I get with this set-up. I will post them here after I get the mould and do some casting.
    I have to change the sear/bolt spring because an entire Wolf spring kit(sear/bolt spring, base pin spring, mainspring) was put in, and I want it back to factory trigger pull (..the oddball in me coming out again!). If it is too heavy then I always have the option of putting the wolf spring back. I head out west every year from Ohio for backpacking/hiking. I plan on this Colt SAA to be my trail gun and I want a heavier pull than the Wolf kit gives, since this wont be shot on balmy cowboy action days, but rather with frozen hands, in the rain, etc. The Wolf spring kit is just a tad too light for my tastes.


    If you took out all the endplay, that means upon firing the cylinder will set back, and the gap will be even more...the gap should be measured in worst case scenario. If you have excessive endshake in that cylinder, then it is time to get new bushings and shims.

    Best
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  • dandak1
    Right, I pulled the cylinder back and measured it that way. could just barely get a 0.005" feeler gauge in there.
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  • givette
    Sidenote: Pre WWII 1st production run SAA's were barrel dia. of .454.
    Post WWII 2nd production run SAA's (and custom guns thereafter) are .451 barrel diameter. I didn't catch what one you have. Best again, Joe
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  • rsnyder55
    What type of chrony are you using and have you shot factory loads over it to see if you can get factory published velocities?
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  • dandak1
    Groove is .452", bore is .443". Using a Chrony brand chronograph. No factory loads yet, but I tested the chrony with other guns and it was okay. Besides, you can feel that some of my loads that should not have been wimpy, were wimpy.
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  • dandak1
    Okay, tried Unique. Success! 8.0 grains with the 255 gn lead is supposed to give around 850 and I am right there at 836fps!! Triple seven is right there too (824fps=me, book = 838)! I am now happy again[:D]. Still cant understand tho why IMR4227 was so low (699fps vs 890), Trailboss (610fps vs 730), and 231 (748fps vs 875). These were all with standard primers.
    Also tried Pyrodex RS (857fps) and P (872fps). Boy, let me tell you, those guys in the old west sure had a potent load with them.
    Givette, Alliant lists 8.0 as their max load for the 45 LC. Lyman shows 10 as max. I know manuals often show discordant results, but a load 25% above the manufacturers maximum????? Is #44 their latest manual? Just wondering. The 8.0 load is all I need in this Colt....I wont go higher as it does all I want it to. Have Dads blackhawk if I want to make a cannon out of a 45.
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