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My 3Gun AR15: JP Short-range Tactical Sight (SRTS) & TA11 Pictures

Discussion in 'Rifle Country' started by Zak Smith, Sep 27, 2003.

  1. Zak Smith

    Zak Smith Moderator Staff Member

    Here are a couple pictures of my current AR-15 setup for 3Gun. Main optic is a TA11 on an ARMS #19S. On the float tube at 2:30 o'clock, I have mounted the JP Enterprises SRTS (Short-range tactical sight). It's like having a set of pistol sights up there, and is good out to about 30 yards. It is really fast at 0-10 yards.

    The point of having a SRTS instead of a JPoint or Doctor as short-range sight is that it's still legal for Modified class in 3Gun.


    More pictures here: http://www.demigod.org/~zak/pictures/2003-09-18-thumbnails.shtml

    For those of you who don't really know what 3Gun is "about":
    And here's my "tactical disclaimer":
  2. Onslaught

    Onslaught Well-Known Member

    Very nice rig!

    Are you a fellow leftie? It's just that, given the SRTS placement and the angle of your pics, I felt like I was on the "correct" side for a change...
  3. Chugach

    Chugach Well-Known Member

    Zak, thanks for sharing a really interesting and complete set of pics. IIRC, you posted a thread about this fairly recently without photos, right? I recognized some of the stages without even reading the photo captions.

    Nicely done...
  4. Zak Smith

    Zak Smith Moderator Staff Member


    You still shoot it from the "non loudy" end. :D

    Seriously, not a leftie. The short-range iron sight is used by rotating the gun approx 45 degrees counter-clockwise for righties - basically stick your strong-side elbow out to rotate the rifle. I suppose you could put it on the "weak side" of the handguard, but I haven't seen anyone try that yet.


    Yeah, I posted the full report of that match in this thread: "Zak's RM3G Report". I've made some changes to the rifle since then, including the SRTS.

    The rifle is based on a Rock River "Special Build" 16" carbine with 1-in-9" twist barrel. It's full bull profile behind the gas block and Hbar in front. The handguard is the Armalite fiberglass/aluminum free-float tube (helps to prevent burns!). The rear stock is the CavArms "C1" A1-length stock, and the pistol grip is their rubberized Falcon. The changes up to here were mainly ergonomic and thermal-related.

    I then had JP Enterprises mount their adjustable/tunable gas block and their "Bennie Cooley Comp." The comp essentially eliminates the recoil impulse and any muzzle movement but is extremely loud (I always now wear muffs and plugs); the gas block allows me to tune down the amount of gas until I have just enough to operate the bolt (and some margin for reliability) - that reduces the shock from the bolt carrier slamming to the rear.

    Finally, the main optic is a Trijicon TA11 ACOG ("donut-of-death") mounted on an ARMS #19S (which allows quick removal and reattachment while maintaining zero - then I can slap on an ARMS #40 and a front sight post to shoot IDPA/rifle or Limited 3Gun). Then the SRTS is mounted to a short tac-rail at the 2:30 position on the tube, which just connects through to a threaded plate on the inside. The ACOG is wearing a bicycle-tube "prophylactic" device which in its retracted state as pictured allows nearly the same reticle brightness as without it, but when pulled over the fiber-optic tube, dims the reticle making it appear smaller and finer.

    The bipod is your average Harris.

    If I were building another AR for 3Gun, I'd make the following changes: use JP trigger instead of two-stage; use JP's lightweight (aluminum) bolt carrier; use lighter profile 18-20" barrel with 1-in-8" twist and full-length gas system; use a lighter float tube.

  5. Futo Inu

    Futo Inu member

    Very nice!

    But is there any way to get that ACOG a little lower? Are you getting a good check weld?
  6. curt

    curt Well-Known Member

    very nice and well thought out. I've been thinking about trying 3 gun sounds like fun. Do you find that having a thicker barrel like you seem to have slows you down when shooting in close?
  7. 4v50 Gary

    4v50 Gary Moderator Staff Member

    Interesting with the (not quite) "gansta" iron sights. Does that work well if you're prone and shooting from cover or through a loophole?
  8. ShaiVong

    ShaiVong Well-Known Member

    Wow. That looks like a HOOT.

    If I were to do three gun though, one would have to be an Enfield or 10/22 :rolleyes:
  9. another okie

    another okie Well-Known Member

    The most recent USPSA journal mentioned that several folks with 16" ARs had failed to make the power factor at nationals. Have you chronoed your competition rounds? The power factor is 160 minor/340 major (pages 94-95 in 14th edition rule book). A 55 grain bullet would have to be smoking to make that, and that's tougher out of a 16" barrel. I know almost everyone uses a 16" AR at the two matches I've been to, but I'm wondering if that's the right choice if you're planning on trying a sanctioned match, where they check such things.
  10. ShaiVong

    ShaiVong Well-Known Member

    They got kicked out because their gun didnt have enough Newtons spraying out the end? Whats the point behind that?
  11. Zak Smith

    Zak Smith Moderator Staff Member

    Futo Inu,

    I am using the ARMS #19S quick-release mount, made of aluminum, for the ACOG. Trijicon sells a steel thumbscrew mount # TA51 whch mounts it a couple tenths of an inch lower than the #19S.

    To get the ACOG any lower, you basically have to get rid of the mount itself and affix the ACOG directly to the upper. JP has a new CTR-02 upper design with a feature called the IAI (Integral ACOG Interface) which is basically a female "slot" machined in the flat-top cross-rails and two holes drilled through the upper: the ACOG's base rail fits in the slot and you just screw in from inside the upper. I have also seen an AR upper that just had two holes drilled and the ACOG rail sat on top of the cross-rails, pulled down onto the receiver by screws in the same manner.

    Re: cheek weld- I shoot nose-to-charging handle so I use that as an "index" on the gun (and that explains why my ACOG is mounted so far forward). While sighting through the scope I can sometimes notice the height difference, but I've never noticed it "at speed." The TA11 has a lot of eye relief (2.4") which is forgiving to misalignment.


    The barrel you see is very thick in back of the gas block - you just see it in the first picture. The only real advantage of a heavier barrel is that the heavier rifle will dampen your body's movement and vibration which is useful for long-range precision shots. I would just as soon have a lighter rifle - the extra mass sure can't be making me go faster. The reduction in recoil normally associated with a heavy barrel is completely moot if you have an effective comp on the muzzle, like I have here.

    4v50 Gary,

    Prone should work, though I haven't tried it in a match yet. Just roll your strong-side wrist in. As for ports, in the last local 3Gun match we had to shoot through a horizontal slot about 2" wide, which was only about 2' off the ground. Any sighting system arranged vertically would be blocked by the upper piece of wood. I think this one would have worked, but in the moment without having practiced either, it was easier to pick up the glowing donut of the TA11 with the rifle turned sideways. The tip of the post is still just over 2" from the bore, radially.


    I'd like to try shooting an old bolt battle rifle in a match, but a 48-round stages requires a hell of a lot of stripper clips.

    another okie,

    Yes, I have Power Factor covered. As you said, it's 160PF for minor. A 55gr needn't be "smoking" to make minor; it's only 2909fps. Some of the commercial 55gr won't make 2909fps in a 16", but all real M193 I've tried sure does. The South Africal surlpus M193 I've been shooting for a couple years chrono'd at 3060fps in this gun, which is 168 PF. The ammo I usually use for matches is the Black Hills 68gr HPBT, at 2670fps for 181PF (it moves the far flasher targets better and shoots softer than the M193). Like you suggested, a 16" is not the best thing to use. Most of the winners at big matches shoot 20" or 18" barrels - mainly because of the gas system length, I believe.

  12. Zak Smith

    Zak Smith Moderator Staff Member

    re: USPSA rules.

    Many of the large 3Gun matches do not USPSA rules. The ones I know of are WC3Gun/SWAT, RM3GM, and SMM3G. RM3GM and SMM3G both use "Modified IMGA" rules which are substantially different from IPSC, notably in how targets are scored (1A or 2BCD's = neutralized, no points, FTN = time penalty) and what equipment divisions exist (e.g. no PF, "Tactical Scoped", etc).

  13. Andrew Wyatt

    Andrew Wyatt Well-Known Member

    I got to play with the JP tactical short range sights at the SWAT match.

    assuming they're rugged, i see no reason why they wouldn't be combat worthy.

    I did shoot one of the stages at the swat match with an enfield. the stage was 30 rounds, and required 3 magazine changes. it was quite doable, and my time was not more than 10 seconds slower than the run i made with the mini-14.

    I wonder how well the JP backup sights would work on brobee biter's Ar-15/870 stock rail doodad.
  14. Zak Smith

    Zak Smith Moderator Staff Member


    The only part that's plastic in the SRTS is the front post, and it could presumably be replaced with a regular A2 post.

  15. Andrew Wyatt

    Andrew Wyatt Well-Known Member

    darnit. now i'm thinking of getting one with an XS sights big dot tritium sight.
  16. Futo Inu

    Futo Inu member

    Shaivong, no, you don't get thrown out - you compete (if you want to), but your score is not official if you don't make minor, IINM. If you make minor, but don't make major, you do compete head to head on score, but a slight miss is scored a little less. Center hits (or very close) are scored the same as major - idea being, a center hit is a deadly hit, even is a little "underpowered", but a slightly off hit (around the edges of the torso) do not score well unless you have the "major" power gun.

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