StainLess Steel MediaRotoMetals2Inline FabricationTitan Reloading
Ballisti-CastMidSouth Shooters SupplyLee PrecisionGraf & Sons
Results 1 to 10 of 10

Thread: Forcing Cone an Cylinder gap

  1. #1
    Boolit Man
    Join Date
    May 2012
    Location
    SoCal
    Posts
    123

    Forcing Cone an Cylinder gap

    I have a .500 S&W with a .008 gap between the forcing cone an cylinder. Seems to be too much. All my other revolvers are between .002 an .003. Is this because of this particular caliber? Would I benefit for spending the $250.00 to change this to say .003 or is it a waste of my money?

  2. #2
    Vendor Sponsor


    lathesmith's Avatar
    Join Date
    Nov 2006
    Location
    Springfield, Missouri
    Posts
    1,356
    Ghost,
    A typical revolver B/C gap is .006, some run a little less, and some are up to .010. Those .002-.003 seem pretty tight, sometimes binding after a few shots can become a problem, due to heat expansion and accumulating residues.

    Which leads to an excellent point: While on a "normal" power revolver a .008 gap would be to me a little wide, I don't think that's the case with that .500 monster you have there. Remember, you have a LOT of powder and lead going through that B/C area, and messing with that B/C gap on that gun strikes me as possibly being a bad idea. If the gun shoots pretty good and doesn't spit too bad, I'd leave it alone. If you do decide to let someone mess with it, make sure they have experience with the power levels you are dealing with in that revolver, because some trial-and-error is probably going to be necessary to fine-tune things. If it was my gun and shot pretty well, I think I'd rather spend my $250 on something else.

    lathesmith

  3. #3
    Boolit Man
    Join Date
    May 2012
    Location
    SoCal
    Posts
    123
    I do over think many things. I just couldn't believe that gap. I don't have problems with build up on the cylinders. i keep them very clean even while out shooting. A new product I have found " Frog Lube " takes care of build up in no time. But the powder burn on the cylinder comes back on the sides about a 1/2 - 3/4 inch which I'm not used to.
    Thank you very much for your input an I plan on talking with you again about sizers when I get that far.

  4. #4
    Boolit Man
    Join Date
    May 2012
    Location
    SoCal
    Posts
    123
    I have one more question for you as you seem to know sizers pretty well. I'm thinking about getting the Magma Star. I know it cost a few more bucks then the rest, but I can't find a post of them wearing out either. Now I'm new to casting, except for blackpowder balls. Would this be money well spent or should I go with a Lee, Lyman or RCBS for now? I plan on casting for 15 different calibers. How hard is the change over between each? Can I use GC in the Magma Star.
    Thank You an say hi to my birth state of MO. ( Sikeston )

  5. #5
    Vendor Sponsor


    lathesmith's Avatar
    Join Date
    Nov 2006
    Location
    Springfield, Missouri
    Posts
    1,356
    Ghost,
    A Star is always a good investment, they hold their value well, and as you mention they almost never wear out. However, I think it all depends on how much shooting you do. A good rule of thumb is, if you use 4-cavity (and more) bullet molds, and a progressive loader, and use it a lot, you NEED a Star to help you speed things up. If, however, you are satisfied with 1- and 2- cavity molds, and do most of your loading on a single-stage press, and only shoot a few hundred up to a few thousand rounds per year, a Star might be overkill, and you would probably be just about as happy with a lower-cost Lyman or RCBS machine.

    Die-changing for any of these lubesizers is easily accomplished in a few minutes, a Star included. Anything you can do with a Lyman/RCBS machine you can do with a Star, including gas checks, and do it much faster.

    Keep reading on the forums here, there is LOTS of great info and experience, and plenty of guys willing to share. It's a great place for new and experienced shooters and casters alike to learn more about casting and shooting!

    lathesmith

  6. #6
    Boolit Man
    Join Date
    May 2012
    Location
    SoCal
    Posts
    123
    Thank you very much. I have two Dillons an two Rocks. It seems I spend more time. Reloading then shooting, but I enjoy reloading. I think casting is going to be just as much fun. You are right about this site, it's amazing.

  7. #7
    Boolit Master

    Join Date
    Apr 2008
    Location
    Phoenix, Arizona
    Posts
    4,753
    The spec for Ruger on barrel to cyl gap is .012". That siad I had a barrel set back on a blackhawk so it was .002" on the 357 cyl. and .002" on a 9mm cyl. rechambered to 356 GNR.
    Did not spit as much out the sides.

    I read and article on the X frame that S&W had problems with erosion so had to do things like polishing the forcing cone. I think if it shot good I would leave it alone.

  8. #8
    Boolit Master
    Join Date
    May 2012
    Location
    Alaska
    Posts
    966
    Personally I'm partial to tighter cylinder/barrel gaps if the cylinder/frame fit is tight enough to allow it. A wide cylinder/barrel gap allows a portion of your hot expanding gases from the burning powder to be wasted vs. working to push the bullet out of the barrel, not to mention increasing top strap cutting and concussion to you. To my way of thinking, the gap should be 0.002-003". Tight gaps only gum up a gun if you're using mild loads. Full house loads are self cleaning.

  9. #9
    Boolit Master
    Join Date
    Mar 2005
    Location
    Deep South Texas
    Posts
    10,185
    .008 is within spec. I see no need to spend $250.00 to fix a problem that does not exist. Like others I would like it a little tighter, but not for $250.00. You might loose a little velocity at .008 but your pistol has horsepower to spare.
    Disclaimer: The above is not holy writ. It is just my opinion based on my experience and knowledge. Your mileage may vary.

  10. #10
    Boolit Master
    Join Date
    Jun 2012
    Location
    Space Coast, Florida
    Posts
    158
    I have 2 old cop guns (mdl 15 and 13) that both boast a whopping 12 thousanths gap. They shoot great and look grat, why monkey with them at great expense in the pursuit of 20 fps? I don't see a benefit to anything under 8 thousanths, they tend to lock up right quick with dirtier loads. 950 fps beats the 1000 fps bullet that won't shoot due to a locked up cylinder. 8 is fine.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check