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460 Rowland

Discussion in 'Gunsmithing' started by aarolar, Dec 12, 2011.

  1. aarolar

    aarolar

    36
    0
    Nov 1, 2011
    South East Georgia
    I have been doing a lot of research lately and I am thinking very hard about setting my glock up to run 460 Rowland. From my research the Rowland has the exact same case capacity the only reason it's longer is to prevent someone from loading a hot ass case into a non compatable firearm. Please read this article it goes over it all very well.

    http://www.realguns.com/archives/106.htm

    From what is said here the Rowland runs at 38k psi which is right on par with most modern pistol rounds like 40S&W, 10MM, 357Sig ect. and if a glock can handle these rounds why can't it handle the Rowland? The way I am seeing it standard ACP is way neutered simply because that is where it started and because there are 100+ year old guns chambered for ACP. They can't really step it up because these older guns couldn't handle these pressures.

    My plans of now are to start with super and very carefully and cautiously work up and see what happens. I am going to start with a KKM standard length barrel with a SS guiderod and 22lb spring. Since super brass is so damn hard to find I am going to order Rowland brass and just trim it down to standard length and work with that. What I am looking for from yall is someone to question my thought patterns and keep me on my toes I am really convinced there is so much more to be gained from the 45 platform and I plan to test my theorys, so feel free to add whatever you feel is relevant. All I ask is that you have an open mind on the subject and keep the discussion on topic...
     
  2. Bushflyr

    Bushflyr ʇno uıƃuɐɥ ʇsnɾ Millennium Member

    3,532
    3
    Mar 17, 1999
    Western WA
    Looks like a good plan. You'll probably get better info over in the reloading forum. According to that site you'd probably be better off searching for the Super brass due to the thicker web and base. It should be stronger. Disregard the max OAL and load as long as you can get away with in your gun.

    Great project. Wear gloves and a face shield. :supergrin:

    And read this thread http://www.glocktalk.com/forums/showthread.php?t=1363112
     
    Last edited: Dec 13, 2011

  3. aarolar

    aarolar

    36
    0
    Nov 1, 2011
    South East Georgia
    Already seen it trust me I have read most everything avaliable on this subject. I emailed Jonny Rowland monday and it turns out that he actually has kits for a glock ready to ship, the kit contains a barrel, guide rod and spring for 319 bucks +shipping. I have a feeling it's a rip off because I can buy a lone wolf barrel, guide rod, and spring for much less that what he's offering. I think Im gonna pass on his kit for now and progress along the path I already started on.
     
  4. speedweapon

    speedweapon Gort

    332
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    Apr 27, 2006
    SW FL
    What kind of front sight will you be using?

    Just wondering.......
     
  5. RWBlue

    RWBlue Mr. CISSP, CISA CLM

    23,551
    848
    Jan 24, 2004
    Do a search on my user name and 45Super I try to comment on anyone who plans on making the change.

    If I understand it correctly you will try to push the round hard to very hard, in doing this you will kill your gun. Not with a Kaboom, but beating the slide against the frame. I suggest that you look into getting a barrel with a compensator. If you don't want the compensator, just don't push the round that hard.

    I would also suggest contacting star brass and letting them know you want 45Super brass. If enough people make the request, then everyone will have more 45Super brass to work with.
     
  6. Jim Watson

    Jim Watson

    4,340
    70
    Jul 10, 2001
    Alabama
    Does this mean you will overload ammunition at standard ACP case and chamber length and CALL it a Rowland? Scary.
     
  7. aarolar

    aarolar

    36
    0
    Nov 1, 2011
    South East Georgia
    That is exactly what the 460 Rowland is the extra length gives absoutely no useful case capacity what so ever. Read the article I posted and you will understand.
     
  8. aarolar

    aarolar

    36
    0
    Nov 1, 2011
    South East Georgia
    I have come to terms with this and realize I more than likely won't be able to push it quite as far without a comp I may still get a threaded barrel and try a comp just to see. One thing that keeps coming back to mind is that guys are running 10mm rounds with as much if not more ME everyday with no comp how come those guns arent coming apart left and right? Not saying your wrong just something else to ponder...
     
  9. RWBlue

    RWBlue Mr. CISSP, CISA CLM

    23,551
    848
    Jan 24, 2004
    With a good barrel, you can go beyond 10mm (grs bullet * velocity) before having any case issues.

    The comp increases lock time so it reduces the forces on the slide.


    Now, me, I don't have a comp per say. I have a suppressor. Normally with a Glock a suppressor needs a LID to operate. With my heavy loads, I didn't need a LID. The gun cycled fine. I beat up my Glock pretty bad as I developed heavy loads. I am not someplace I can continue to work on my balistic studies, so .....no comp, no G20 upper, no G20 upper with 40S&W barrel or 357Sig barrel or .....
     
  10. DanaT

    DanaT Pharaoh

    You guys are missing some basics.


    Pressure = pounds / square inch

    If you take the square inches out (by multiplying) then you get forceon the slide.

    So lets assume 10mm at 37500psi and 45 at 37500psi.

    10mm (0.401/2)^2 * pi * 37500 = 4735lbf
    45 = (0.451/2)^2 * pi * 37500 = 5990lbf

    So, now, the force on the slide, at the same pressure, is 26% higher with a .45 caliber bullet than a 40 caliber bullet (this is 26% more surface area of the bullet).

    Later I can post a link (I am not at home) but adding a spring helps slide battering but does not help lock-up. You have a mass spring system. The initial movement of the slide is almost entirely dependant upon mass and not spring. Keep in mind a spring has a force that is measured as "k" meaning that the more the spring is compressed the more force it exerts. This means at the beginning of the cycle, that spring adds much less to the system that when it is compressed. Now to combat this, a longerand stiffer spring can be added (this means force is added because the spring is pre-compressed).

    The general statement is force is very high on this combination. It must be accounted for.

    I would want a 10mm slide (for the additional mass) to start making this pistol.

    -Dana
     
  11. Bushflyr

    Bushflyr ʇno uıƃuɐɥ ʇsnɾ Millennium Member

    3,532
    3
    Mar 17, 1999
    Western WA
    Which is why, as RWBlue posted, the Rowland sites all say a comp is required. The force on the comp delays unlocking. You could start with a 10mm slide, but I don't think the .45 barrel wit fit through the hole in the end. I haven't measured though.
     
    Last edited: Dec 21, 2011
  12. DanaT

    DanaT Pharaoh

    I doubt it would fit. Thats why I said start with a 10mm slide. By "start" I meant as a starting point for modification.

    I am not seeing in the FBD how a compensator at the end of the barrel delays unlocking.

    Movement starts when force starts which is when ignition of the powder starts.

    This is the book that I was talking about that explains locking time well as well as cycle rate (this is the mass-spring system). It talks about automatic weapons, but the same formulas apply to semi-auto although with a semi you don't have as critical of rounds per minute (cycle rate).

    http://www.worldcat.org/title/engin...tic-weapons-1970/oclc/506047197[url] -Dana
     
  13. Bushflyr

    Bushflyr ʇno uıƃuɐɥ ʇsnɾ Millennium Member

    3,532
    3
    Mar 17, 1999
    Western WA
    The forward push of the gas on the baffles in the comp provides a pretty significant amount of forward force on the barrel/slide unit thus delaying unlocking and reducing slide velocity; Especially in the case of a high pressure round like the 460.

    I've actually had guns where the comp was so effective it wouldn't cycle without a lighter spring and one where it wouldn't cycle with the comp on at all no matter how light a spring I put in it.
     
  14. ckrockets

    ckrockets

    225
    0
    Feb 18, 2009
    My understanding is the 460 Rowland brass is stronger then normal 45 ACP brass so you can run it at a higher pressure and the added length is so you can't shoot it out just any pistol chambered in 45 ACP.

    When I say stronger I believe it has a thicker webbing and heat treated differently.

    Call Starline they can probably tell you exactly what they do differently.
     
  15. DanaT

    DanaT Pharaoh

    I am just not seeing how the compensator will help much.

    Just putting some qucik data into quickload, it gives a pressure/distance curve.

    [​IMG]

    Pmax is reached in the 1st half inch of bullet travel. By the time the bullet hits the compensators the pressure is down to around 5000psi.

    Now, assuming that the compensators are cut at a 45 degree angle, that means that only 70% of the gas force is applied opposite to the bullet travel direction. Moreover to keep it locked that 45 degrees must be pointing towards the shooter. Most likely the venting will be straigt up to reduce muzzle rise and have very little effect on lockup.

    I suspect that the compensator that was mentioned in the previous post that the gun would not cycle correct when attached may have had more to due with weight than anything.

    -Dana
     
  16. RWBlue

    RWBlue Mr. CISSP, CISA CLM

    23,551
    848
    Jan 24, 2004
    You are measuring the wrong end of the cartridge.
     
  17. RWBlue

    RWBlue Mr. CISSP, CISA CLM

    23,551
    848
    Jan 24, 2004
     
  18. RWBlue

    RWBlue Mr. CISSP, CISA CLM

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    Jan 24, 2004
    Starline would not tell me crap when I called them years ago.

    What I can tell you is 45ACP brass is not all the same. 45Super brass is not the same as 45ACP. I believe 45Super is stronger than 45ACP.

    If you are using an after market barrel with good support and not trying to max out the cartridge, I am not sure if it makes a difference with some 45ACP brass.
     
  19. RWBlue

    RWBlue Mr. CISSP, CISA CLM

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    Jan 24, 2004
    I don't think it takes much force to keep a Glock locked up. Put your thumb behind the slide and watch the gun not cycle.
     
  20. DanaT

    DanaT Pharaoh

    It is relative.

    The mass of a G21 slide/barrel/spring (the moving components) is 600grams. The G20 is 654grams.

    To put those number in perspective that is 1.32 pounds and 1.44 pounds respectively. We are not talking large forces to resist movement due to slide mass.

    Think about these forces. It is easy to exert 1 pound with a finger. A 5 pound trigger is glock standard. You can easily apply that with your thumb.

    Just some quick (ok, not so quick but done earlier so now quick) indicate that to achieve the timing/lockup similar to a stock glock, a 460 Rowland at 1200ft/sec with a 230gr bullet built using a 654gram slide, needs about a 36 pound spring.

    -Dana