ideal rate of twist (MLP firearms and shooting thread)

Discussion in 'The Backstage' started by JMV, May 28, 2010.

  1. cybermgk

    cybermgk Singin' the body lectric Platinum Supporter Premium Member V.I.P. Member

    Messages:
    13,963
    Likes Received:
    18,775
    Joined:
    Jul 7, 2011
    Great minds think alike bilbarstow? LOL, I JUST went through that process and came home Wed with a Springfield Range Officer.

    I tried a Rock Island, a Ruger, Taurus, Colt and the SA RO. Feel, hand fit, my accuracy with it, trigger etc, the Range Officer ran away with it for me. Yea, it's a couple of hundred more than the Rock Island, little more than the Ruger.

    Range Officer comes stock with adjustable rear sight, competition 4 lb pull trigger and match grade barrel and bushing, cocobolo grips, forged match grade slide and frame (same as their TMP model). Same precision fit as the TMP models too.

    Only downside on it is the front site being black along with the rear sight. Fixing that with a little paint.

    I punched almost bullet sized groupings with it at 7 yards, and 2" at 25 yards.
     
  2. cooljuk

    cooljuk Transducer Producer Premium Member

    Messages:
    14,720
    Likes Received:
    19,862
    Joined:
    Mar 12, 2009
    That's really cool! I've got a mini Laserlyte which I sight my pistols and rough-in my rifles with. I had no idea there was a shot-pattern version. I'm gonna put that on my radar, as I've got another Holosun red dot on the way, which will find a home on my 590. I know it probably doesn't need it 90% of the time but I do shoot slugs now and then and it's not adding any weight in the grand scheme of things.

    One thing I've wondered from time to time - My bore sight, itself, has adjustment screws. How would one calibrate it? A "laser bore sighter sighter" perhaps? ...or is that just for factory use? No mention in the manual.
     
    Kris Ford and Frogfur like this.
  3. cooljuk

    cooljuk Transducer Producer Premium Member

    Messages:
    14,720
    Likes Received:
    19,862
    Joined:
    Mar 12, 2009
    Also, thanks for the LOP info, Froggy. That's something I've been meaning to learn more about and will revisit some instructional videos on now. I did look into it when setting up my shotgun stock, initially, but have completely forgotten the methodology of how I came to the LOP I used. Worth revisiting for me.
     
    Kris Ford and Frogfur like this.
  4. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    LOP IS measured from the face of the trigger to the end of the stock, including any recoil pad.
     
    Kris Ford likes this.
  5. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    I use a bore laser. Preferably one you can see good in day light, or at the range. I set the rifle/shotgun up on some sort of steady rest and pretty much match them up so the laser sight sits over directly on top of the front bore laser beam. Then adjust the laser sight to sit directly on the tip post rather than on top. From there, i shoot and fine tune the laser until it points directly to where the shots are going. @40ft. This will cover a 30"circle.
    The further away, the bigger the laserlyte gets.
    Pretty easy.
    For shotguns-
     
    Last edited: Nov 11, 2017
    cooljuk and Kris Ford like this.
  6. SteveC

    SteveC Village Elder V.I.P. Member

    Messages:
    8,383
    Likes Received:
    16,030
    Joined:
    Apr 8, 2012

    So, I shoot Steel Challenge matches with a RO in 9mm. I shoot this gun in Production Class. And, IMO, it's the best production-class gun out there. You just need to change the front sight (which is allowable in this class).

    The stock black front post is for precision target shooting, along with the narrow gaps between the blade and the rear sight. This does not work well for shooting anything BUT bullseye match targets.

    I put a Dawson Precision FO front sight on my gun. It's pretty easy to do, if you have basic mechanical aptitude. Dave Dawson even has an instructional video showing how to do it. The RO does have the front sight pinned, so you will need a punch to drive that pin.

    Here's the finished gun, with the stock grips replaced (also allowed in this class) with a Houge grip.

    IMG_0861.JPG


    Here's the factory front sight removed... you can see where it was pinned to the slide.

    IMG_0855.JPG
     
    ehb, cybermgk, Kris Ford and 2 others like this.
  7. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    That is really nice Steve.
     
    SteveC likes this.
  8. 45WinMag

    45WinMag Senior Member

    Messages:
    6,299
    Likes Received:
    11,620
    Joined:
    Jul 1, 2009
    Upper arrived for my 607 type build. I was on a waiting list for NoDak 601 repro uppers, and I got an e-mail that they had one for me. It arrived yesterday. Some 607 rifles had 601 uppers (slickside) and some had A1 uppers. I wanted to go with the 601 upper for my 607.

    I have an old original chrome Colt slick (no serrations) bolt carrier that I am using with a new manufactured bolt.

    The charging handle is a NoDak repro anodized in the same grey as the upper (the anodizing for NoDak is done by US Anodizing - their "XM Grey" is an accurate match for late Colt grey, darker than the 601 and civilian SP1, it's the color of M16 anodizing before Colt switched to black).

    I was lucky to find the barrel in the correct 10" length. This is not a standard length for an AR barrel (10.5" is the closest standard length). You almost always have to have a barrel cut down and re-threaded to make a 607. The flash hider on a real 607 butts up directly against the front sight block. A .5" gap between the flash hider and the front sight block that results from using an unaltered 10.5" barrel doesn't look right at all. JSE surplus had a run of YHM barrels that YHM cut .5" short accidentally (they were supposed to be 10.5") at a deep discount, so I not only got the correct length in a factory barrel, it cost me less than $100. The only thing that is incorrect is the barrel diameter (it is .75" instead of pencil profile), but the only portion of the barrel that is visible is the gap between the two legs of the front sight block, so I'm not too concerned with it.

    The front sight block is a Fulton Armory. It is non-F height, with no bayo lug (correct for a 607 - I don't have to grind off the lug and refinish). It is a set screw block, so I will put a dab of CA in the set screw heads and paint over the glue to hide the fact that the block isn't pinned. If I ever need to remove or adjust the block, I can melt the CA out of the head with acetone.

    Flash hider is a 3-prong. If the Hearing Protection Act ever passes, it will be replaced with a repro of a Colt moderator. Either the 3-prong or the moderator is correct for a 607.

    The handguards will be cut down triangular rifle handguards. I bought a repro of the rear triangular handguard cap (even the repros can be hard to find). I have a set of repro triangular rifle handguards ordered from Brownells to cut down (I have several sets of original triangular handguards lying around, but I dislike cutting up anything original, even if they aren't rare). The commercially available triangular carbine handguards offered by some vendors aren't period correct for any rifle; the rear of those handguards are contained by the slip ring like ordinary rifle handguards, not a metal rear cap in the slip ring like the 607. The original Colt 607 rifles all used altered rifle handguards with a triangular rear cap.

    The slip ring is an original Colt flat ring.


    When I mill out the 80% NoDak lower that will be this rifle's receiver, I will send it to US Anodizing for the same finish before I submit the Form 1 to make it an SBR. Until the SBR paperwork is approved, this upper will reside on a pistol lower and the NoDak lower will be assembled into a 16" rifle.

    This is the lower (haven't milled it out yet, so it legally isn't even a firearm) with the airsoft 607 stock that I am altering to use an entry stock buffer tube. I will dismantle the metal parts of the stock and DuraKote them Colt Grey before I assemble the rifle.

    The pistol grip will be cut down like some of the 607 grips. I have a repro from Brownells for this. I have several original M16 grips in my parts box (most are nicely mottled), but again I dislike altering anything original.

     
    Last edited: Nov 11, 2017
    ehb, Kris Ford, Frogfur and 1 other person like this.
  9. SteveC

    SteveC Village Elder V.I.P. Member

    Messages:
    8,383
    Likes Received:
    16,030
    Joined:
    Apr 8, 2012
    Here's the video showing the replacement of the front sight, that I referenced in my post above.

     
    Kris Ford, bilbarstow and Frogfur like this.
  10. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    I've actually been considering a 10.5" upper to make a 9mm pistol.
     
    Kris Ford and 45WinMag like this.
  11. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    That is an excellent post and good addition here. I've promoted all along, you guys can do allot of work yourselves.
    Assume.
     
    Kris Ford and SteveC like this.
  12. 45WinMag

    45WinMag Senior Member

    Messages:
    6,299
    Likes Received:
    11,620
    Joined:
    Jul 1, 2009
    There's no need to go 10.5" with a 9mm if you don't really want to go that long. The 9mm ARs are blowback, not gas operated, so there are no issues with the gas and dwell being finicky with extremely short barrels. I've seen commercially manufactured 9mm AR barrels as short as 4".
     
    Kris Ford and Frogfur like this.
  13. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    The 10mm and the 40 Smith & Wesson-

    I personally have never owned either one of these calibers, but was always interested in both of them, and have worked on a few semi-autos chambered for them.

    They are very close in performance, with the 10mm having a bit of an edge, if you can handle the recoil. Both, for all practical purposes being .40 caliber.

    The difference being, the 40 S&W is actually something like .0005" larger in bullet diameter. Additionally, the 40S&W having a slightly shorter case length of .850" as opposed to the 10mm which as an OAL of .992"

    I don't believe that in the past, factory loads took advantage of .40 S&W potential really. Perhaps today they do. The other advantage of the 10mm is the ability to handle 200gr. projectiles whereas the .40 S&W tops out at 180gr. At least in load data. Both handle hard cast bullets -(#2 Alloy)well, and have nice jacketed bullet available. Anyone else got anything different ?

    The mean working pressure for the 10mm is 37000psi, with a maximum of 44400psi.
    I actually consider the .40 S&W a superior cartridge design.
     
    Kris Ford likes this.
  14. cooljuk

    cooljuk Transducer Producer Premium Member

    Messages:
    14,720
    Likes Received:
    19,862
    Joined:
    Mar 12, 2009

    That is cool! I had envisioned it to be a muzzle or chamber mounted bore site for setting up optics. I didn't realize it was more of a weapon-light style aiming device in itself. Not something I really have a need for but I might have to write Santa a letter because it sure would be a very cool toy!

    I was given some pumpkins, squash, and cabbage that's past its prime AND my truck just got new rear control arms and front suspension that needs to be tested off road. When I add all that up, with shotguns on my mind, I see myself having a VERY FUN day in the woods tomorrow!

    I'm thinking Pike National Forrest, as there's a "common public range" that I don't usually like to shoot at, but I do like to stop there and clean up the trash that other shooters leave behind. ....including useful brass. :)

    Maybe I'll get some video, but I do find that fussing with cameras can suck the fun right out of a nice shooting experience.
     
    Frogfur and Kris Ford like this.
  15. cooljuk

    cooljuk Transducer Producer Premium Member

    Messages:
    14,720
    Likes Received:
    19,862
    Joined:
    Mar 12, 2009
    "Product Discontinued by Manufacturer
    LaserLyte RML Kryptonyte Center Mass Laser For AR/AK Rifles And Shotguns CM-15 has been discontinued by LaserLyte and is no longer available."

    [​IMG]


    Ok, so they still make a red one. ...but green is cooler!
     
  16. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    I haven't seen the red variety, but my green laser you can see at high noon a sunny day, and you can see it for as far as I can see.
    It works fantastic. Here is mine mounted on the AR with the pressure switch for night use, or let's face it, intimidation.
    These operate either as a single beam (As is set for the rifle) or set for shotguns with the shot pattern as in the video. Just swap out the laser on the other weapon platform's rail.

    20171111_140805.jpg

    IMG_20171111_141746_3613.jpg
    A weapon for self defense can't be limited to daytime. For my use, it has to be 24/7 capable unless I can get the bad guys to promise to wait til daylight before they attack.
    Frankly, in my experience, the best time to get killed is during a cease fire..:cheers2:
     
    Last edited: Nov 11, 2017
    cooljuk and Kris Ford like this.
  17. Frogfur

    Frogfur Senior Member

    Messages:
    18,369
    Likes Received:
    31,982
    Joined:
    Jan 18, 2013
    I'll bet you can find one if you really want green.
     
    cooljuk likes this.
  18. Kris Ford

    Kris Ford Senior Member

    Messages:
    4,754
    Likes Received:
    4,053
    Joined:
    Dec 17, 2011
    God..just itching to get my AR off of lay-a-way!!!!!
     
    Last edited: Nov 11, 2017
    Frogfur likes this.
  19. Hairless_Ape

    Hairless_Ape Doc Premium Member

    Messages:
    6,512
    Likes Received:
    12,070
    Joined:
    Feb 20, 2010
    I'm feeling a little impatient on the AR front too, Kris. Been putting off finishing my current project until the Black Friday sales. All I need to complete it is a lower and BCG. It's been a long 2 months.
     
    Kris Ford likes this.
  20. Digger

    Digger Dingo Lover! V.I.P. Member

    Messages:
    6,393
    Likes Received:
    9,862
    Joined:
    Apr 25, 2012
    At least you blokes can have semi autos!

    Sigh~
     
    Frogfur likes this.

Share This Page