dchang0

I ended up buying the Precision Reflex "Cantilever Mount." Check out the photos--this sucker has WAAAAY more "Actual" Extension than the Larue LT139, exactly as expected from the measurements I took at SHOT. In the photos, both mounts are shown flush with the front edge of the upper receiver, without crossing over onto the handguard. The Precision Reflex mount is NOT QD, like the Larue.

Add one more to the list of EER one-piece mounts. I went to SHOT 2016 and saw the Precision Reflex, Inc. "Cantilever Mount" here: http://www.precisionreflex.com/Detail.aspx?PROD=186502&CAT=4275 It has 2 5/8" of "Actual" Extension as measured on the demo units they had at the show. The weight per their website is 8.3oz. The thumbscrews for mounting look pretty heavy--replacing them with the optional lock nuts would probably save some weight.

Got these "Actual" Extension measurements from my buddy: PRI Gator Grip #05-068-30H Almost 3" 9.8 oz Bobro Precision Optic Mount, Extended 2 1/8" (Probably equal to the Larue or a few hundredths shorter.) 7.7 oz ADM Scout-X Just over 2" (Probably due to the rear ring not being all the way up flush with the front edge.)

I got this helpful photo from a good buddy. The mounts are all held with the front edges of the bases lined up with each other. From top to bottom: ADM Scout-X Larue LT139 PRI Gator Grip #05-068-30H Bobro Precision Optic Mount, Extended He says the ADM, Larue, and Bobro all pretty much have the same "Actual" Extension forward and that the perspective of the photo can be misleading (making the Bobro look better). Obviously the PRI just destroys the others. It probably extends even further than the Vortex. Note that it is built a lot like a separate rail + two rings. But the weight has got to be insane with all that aluminum bulk. (I can confirm from the specs on Bobro's website that their extension is likely the same as the Larue's. They say that the inside distance between rings is 2.15", and if the rear ring is all the way at the front of the base, as it certainly seems is true, then the "Actual" Extension of the Bobro would be the same as that for the Larue LT139 (2.14").)

Based on the photos and the reports of "distance between the rings", the Vortex 3"-extension mount probably beats the ADM Scout X. If the distance between the Vortex's rings is really 2.5" then the actual extension may really be 2.5", since the Vortex's rear ring appears to be right up at the front edge of the base. You report 2.25" for the distance between the ADM Scout X's rings, and the rear ring is not quite up to the front edge of the base. The Actual Extension may be the same or even less than the Larue's 2.14" We definitely need actual measurements to settle this guesswork...

Amazon answers say that the Vortex 30mm mount with 3" nominal extension has the rings 2.5" apart, which is pretty far. This guy Tristan says: http://www.amazon.com/Vortex-Cantilever-Mount-Absolute-Co-Witness/dp/B009QJLBDQ "Between the rings is 2.5 inches from the outsides of the rings measures 4.75 inches width of individual ring is just shy of 5 eigths of 1 inch. Base is 3.25 inches in length. 6.75 inches in total length. Hope it helps Tristan answered on July 14, 2015" If the numbers are correct, then the "Actual" Extension is PROBABLY: 3" - 5/8" = 2.375" <=== Only correct if the 3" nominal extension is measured from the front edge of the base. OR 6.75" - 3.25" - 5/8" = 2.875" <=== Can't possibly be right, even though it should be. Should be under 2.5" (distance between rings). I guess Tristan's measurements are wrong.

Thanks for the tips, guys. "Actual" Extension measurements on the ADM Scout X and Vortex 3" (nominal) extension mount would be awesome, AND they'll help future buyers do the math on their setups. That idea with the separate rings and rail is a good one--although the weight is probably a couple whole ounces higher than a one-piece mount. I'll treat that as my last resort option and keep looking for a one-piece mount. No worries about the upside-down photo, ac4wordplay--the point comes across crystal clear--thanks!

To start off this reference, here's the "Actual" Extension for the Aero Precision Ultralight SPR mount (nominal extension of 2in.): 1.58in. Yeah, so I bought one of these and was sorely disappointed to find out that it just doesn't work for me. So it'll go up on ebay soon enough.

There's a problem that's been plaguing me for a while. I'm a Nose To Charging Handle shooter because I use the charging handle to index a consistent cheekweld. When forced to back off of the charging handle, I find that parallax becomes an issue because I'm sort of "floating in space" without a kinesthetic reference. But, there don't seem to be many 30mm "extended eye relief" scope mounts that can really mount my scope far enough forward for me to touch my nose to the charging handle AND get the proper eye relief. I really need to mount my scope about 1/4in. further forward than it is right now to get it perfect. I have a Larue SPR-E LT139 mount, and while it says that it's a 3" extension, the reality is that the width of the front scope ring detracts from this amount. Thus, two different scope mounts can both say they are 3" extension, but the scope itself could end up further forward on one mount than the other. The dimension that really matters for comparison between mounts is the one in the attached drawing I made. Let's call it the "Actual" Extension, since it takes out the dimensions that don't count towards the forward position of the scope. I mount the scope mount all the way forward at the very front edge of the upper receiver (not going over onto the handguard). Then, I push the scope as far forward as it will go, which is almost always determined by the rear edge of the front scope ring, where the turrets will butt up against. On the Larue LT139, that "Actual" Extension measurement is 2.14" I basically need this to be 2.40" or 2.50", but I'll take even as low as 2.25" because every bit counts. Can you guys help me find a new scope mount by providing the crucial measurement from your various brands? It has to be 30mm and have a centerline between 1.50" and 1.44" above the rail (1.50" is preferred). And it would, hopefully, have greater than 2.14" for the measurement indicated. Thanks very much! I'm sure other NTCH shooters are dying to find this info too. Oh, and if you happen to know the mount's weight, that would help too.

Thanks to a tip from lumberjack149, I looked into the comparative weights of the Vinci extended mag tubes out there. The 10rd RCI X-Rail I have weighs 17.1oz fully assembled, no ammo, and Nordic tells me their total-of-10-rounds MXT-VINCI-7 weighs 14oz fully assembled, no ammo. I purposefully compared apples to apples with both tubes being 10rds total capacity each. Fully assembled means in both cases: the part of the tube that fits into the foregrip with the twist-lock collar and release button (holds 3 rounds), the part of the tube that extends out the front of the foregrip and that holds the extra rounds (7 in both cases), spring, end cap, and follower. Thus, I can reduce the overall weight of my Vinci by just under 3oz. by swapping tubes. This may solve the intermittent problem with short-stroking low-recoil slugs. Hopefully this helps someone. On a side note, I am looking at the Lancer carbon fiber extension tube, which is ridiculously light, but it requires the factory Benelli Vinci 5-rd mag tube as a base, and Benelli refuses to sell these to anyone except law enforcement (thanks to Obama's signing statement of some bill a couple of years ago regarding importing of sporting shotguns). So I will likely not ever be able to fully-assemble or test the Lancer tube. The Benelli factory 5-rd tube is widely available in Europe and comes standard on the Benelli Italy Vinci SpeedBolt model.

Thanks for the advice--I've looked at Atlanta Arms & Ammo's website, and when I try to use their Dealer Locator page, it produces results that are all the way across the country. I don't know if this means there aren't any dealers nearer the West Coast at all or if their website is just broken. So, in short, are there any shops that carry Atlanta Arms' ammo near or in SoCal? Based on all the great advice in this thread, I think I will probably be standardizing on Hornady Steel Match 75gr after I replace my barrel. Price is right and its ballistics are probably not that different than the 75gr stuff I'm using now. Thanks!

Thanks--will do!

A good ballistic calculator/computer software will allow you to calculate precisely where to expect the bullets to hit at any point along their trajectory. Thus, you could punch in that you have zeroed at 200yds, input ALL your ballistic data (especially chrono speeds and ballistic coefficient), and then you can confirm that the software's calculations for POI are correct at various distances up to 200yds (try 50, 100, 150, 200). Once you are certain the software has got your system down and can accurately predict the trajectory beyond 200yds, you can then figure out where on your scope's vertical axis those 300yd, 400yd, 500yd POIs should be and see if they really line up with the expected stadia lines. In other words, you model what you do know and can confirm in the real world (POIs at all ranges up to 200yds), you test the model against the real world (up to 200yds), then you trust the model to be correct for what you don't know and can't confirm (ranges greater than 200yds), and you use the model to determine whether your scope's stadia lines are right or not. IIRC, Knights Armament makes a ballistic computer app called Bulletflight for Android or iOS, but I have not used it, so I don't know if it will do what I described above. I expect it would, since it is pretty hardcore.

I'm really impressed by the quality and ergonomics of the Yugo M92s. You'd have to build one as a pistol or SBR or pin a ridiculously long brake on it, but the build quality is outstanding, and it's just fun to shoot. I can hit a 10" steel plate out to 200yds consistently with a 2MOA red dot on one--good enough for the local tactical matches but not good enough for the local 3-gun matches. Keep in mind that this is with a 10" barrel and crappy steel cased Russian surplus, not the higher-quality brass-cased ammo.

I think you'll simply have to figure this one out by trial and error. The trade-off between FOV and "seeing around the tube" (i.e. situational awareness and seeing the next target in one's periphery) as well as the "sharp dot" is something that only you can arrive at. I have tried pretty much every location on the rail, from all the way out to all the way in, and I arrived at a spot just forward of where I would ordinarily place a 1-4X scope. This ends up being about 4" between my eyeball and the subjective lens.

OP: Have you looked at the Noveske NSR or the Troy Alpha? Both have smaller diameters, which makes it easier for me to wrap my forward hand around them. The NSR is wicked light for an aluminum rail.

Yeah, 2.75" for slugs. The only time I have seen anybody use 3" to good effect is for spinning MGM spinners with one shot of heavy birdshot (usually 3" magnum turkey loads). But this is such a huge time advantage and does such a number on the targets that many matches ban this trick.

I chose to post this question here rather than on the more general sites to avoid the inevitable flame war about whether a forward assist is necessary or not. Let's just assume I'm building a DPMS-compatible low-profile .308 upper receiver on a POF billet lower and I absolutely have to have a working forward assist on it, one that has actual working FA serrations that aren't just for cosmetics. What part combinations are known to work? For instance, the Young Mfg. chrome .308 bolt carrier has FA serrations, but word is that the serrations are too low for some uppers--the pawl ends up touching the BCG above the serrations. Which uppers DO work with the Young Mfg. chrome .308 BCG? Or, perhaps someone knows firsthand that XYZ brand and model of BCG works perfectly with ABC brand and model of low-profile DPMS-compatible stripped upper. I'd prefer a lighter BCG over a heavier one, but heavier ones are okay if they just plain work. Any tips? Thanks in advance!

I LOVE the Young Mfg. Super Light Chrome BCG and run them in all my uppers. Have got thousands of rounds through them by now. Buy direct from Young--their price often beats the online sellers.

If you are just starting out, I would recommend some standard-power slugs first. Buy just a few rounds, not a full case. The reason is that when you are at your first 3-gun match, you want to rule out as many frustrating malfunctions as possible, and short-stroking on a shotgun due to underpowered ammo is really, really, really frustrating. I'm hoping you will have a blast at your first match and keep coming back to shoot more; you can always start tuning your gear as you go along. That said, a good starting round for slugs is Winchester Ranger Low Recoil or Federal Law Enforcement Low Recoil (yes, I just said to use standard-power stuff first--this is for when you start trying low-recoil stuff). Seems to work perfectly in most any shotgun and shoots well enough.

Thanks very much for the answers, guys! Re: 9" at 450yd on a 10" plate: That's okay. I'm all right with this low margin of error as a trade-off for a lower price per round. Obviously I won't kick a 1MOA, under-40 cents/rd ammo out of bed, but I'm okay with a 2MOA ammo at worst. Re: Reloading out of the question: One kaboom and the subsequent repair cost wipes out a lot of the savings of shooting reloads. It also is in my case cheaper to put in more hours at work to buy factory loads than it is to crank the handle on a press--not that I want to put more hours in at work, so there is still the goal to minimize cost while maximizing participation in the local 3-gun matches. Re: Maybe I need a new barrel: I probably do--that's in the works too. Oh crap, just realized that all the ammo testing I'm about to do will be moot if I change my barrel out in three months or so... Guess I gotta change it out sooner. Re: Freedom Munitions 55gr .223 reloads group: It's meh stuff. Yes, it's reloaded ammo--I bought it only because nothing else was available during the most recent ammo craze about 1.5 years ago. I'd say it gets me 3MOA (through my barrel--YRMV) right now, so it is frustrating to shoot at the targets 350yds or more. It takes 2-3 more rounds than the 75gr stuff to make the hit per 10" plate. Luckily, there are only 3 such plates at Piru, so it's not too bad. Re: AE/Federal .223 55gr Several of you have recommended this with impressive results through your barrels. I used to use it as my blaster ammo, and it grouped well enough (not 1MOA, but <2MOA), but I stopped using it at the time because its zero is very far off from my 75gr match ammo zero. Obviously, once I go back to a single, medium-priced ammo for the whole match, that won't be a problem, so this is probably the direction I'll go in, IF I can find the ammo. Seems pretty popular around here and sells out quickly. Re: Federal XM193 5.56 55gr I've heard this is pretty much the same ammo as the AE/Federal .223 55gr, but it grouped worse for me: typically 3MOA at the time, so I stopped buying it. Re: PMC Bronze .223 55gr That was my blaster ammo until I ran out of it about three months ago and was forced to start using the Freedom Munitions stuff. My barrel seems to like it more than the AE/Federal .223 55gr. Re: Wolf Gold, PMC X-Tac 55gr and Hornady Steel Match: Thanks for the tips on these! I've never tried any one of them and will buy a 200-250rd batch of each and give them a try. Re: Fiocchi Exacta 77gr: Too rich for my blood! Probably shoots great, but at Midway's prices and 3-gun quantities, I couldn't run this round. Thanks for the tip, though.

I'm running out of my former stockpile of "match" factory 75gr .223 ammo, and given the cost of the same round (now about 55 cents per round), it's probably time to find a better factory round, something that is less costly but still "good enough" for 10" steel plates at 450yds. "Good enough" here means <2MOA but not necessarily <1MOA. Basically, I'm looking for something that is cheap enough that I won't feel bad using it for the close-range IPSC targets but just barely good enough to hit the long-range targets without costing as much as the "match" ammo. In other words: .223 or 5.56 factory new (I do not reload any more and do not trust reloaded ammo) bullet does not attract a magnet between the cost of brass-cased 55gr factory new ammo (approx 35 cents per thousand now) and 69gr "match" factory new ammo (as low as 50 cents per thousand now). Closer to 35 cents per round is better than closer to 50 cents per round, obviously. consistently <2MOA I figure there has to be something "in between" or "all-purpose" or "best all-around" ammo for the 3-gun sport. Muzzle velocity doesn't matter to me so much as tight grouping. If it matters, I am currently running a MSTN/Noveske JLT 17" rifle-gas 1/8 twist "Mod 0" chamber barrel that was sub-MOA when new. Not sure what MOA it shoots now, but it's certainly less than 2MOA with the 75gr PRVI Partizan match .223 I am running now. Thanks in advance.

Lucky! Some other Vinci owners have reported the same problem with low-recoil slugs short-stroking that I have. A little larger is okay by me. How much heavier in grams are we talking about? It would be awesome if you could make an extended bolt handle that takes screw-in or snap-in inserts so that we can fill it up with a solid tungsten plug or leave it empty and light (for those of us who want a lighter overall bolt weight for the really, really, really light loads).

I love my Vinci but am looking for a solution to a serious problem: it short-strokes on low-recoil slugs (1300fps and under) when running the heavy 10rd RCI (Roth) tube. (It functions outstandingly with even the cheapest birdshot, strangely enough. It also runs these low-power slugs fine when I put the original 3rd OEM tube back in, lowering the overall weight of the gun.) The result is that it shoves the empty hull back into the chamber, and I have to manually rack the bolt after each slug shot. So, the solution is to go with the Benelli Vinci Speed Bolt which is HEAVIER than the standard bolt due to tungsten inserts. (Heavier may seem incorrect, but due to the inertia action, increasing the mass of the bolt keeps it closed longer, forcing more energy to be stored in the inertia spring, which allows lighter loads to unlock and open the bolt.) But getting one of these Speed Bolts has been tough. I have the part number, but Benelli won't sell it to me direct, and none of the retailers Benelli pointed me to seems to be interested in special-ordering it for me. SO! What I would like to see is a HEAVIER bolt handle to emulate the tungsten inserts in the Speed Bolt. A bolt handle that sticks out roughly the same as the original but weighs more would be awesome. (I don't like the huge bolt handles that stick out a lot more than the OEM one--I've accidentally struck the edges of barricades with such handles, causing seriously-un-fun malfunctions to clear.) In the interim, I'll be switching back to my M2, even though I much prefer the Vinci, just because it can cycle the low-recoil slugs. As soon as I can get the Vinci to cycle these low-recoil slugs, it becomes my go-to shotgun again. Yes, I could always run higher-power slugs, but I am a skinny guy, and regular slugs are brutal on my shoulder. They lead to a nasty flinch that defeats the accuracy needed for slug shots. --- I would definitely buy an extended safety and a heavier bolt handle. I would not buy the bolt release.

Hmm. It might work on the Vinci, which seems to have a stronger recoil spring than the M2/M1. The stronger recoil spring might hold the bolt closed. However, it might also imbalance the action if the recoil spring overpowers the inertia spring. I can see why Benelli chose to increase the mass of the bolt body in the Vinci Speed Bolt rather than mess with the springs. The Benelli tech did say that the inertia spring in the Speed Bolt is the same as in the non-Speed Bolt bolt. If I can't buy the Speed Bolt, I guess I'll have to figure out how to reduce the overall mass of my entire shotgun. It cycles the old B&P slugs that don't work now just fine when using the factory 3rd magazine tube. With that tube, the Vinci is very, very light. Now, with the RCI Xtension 10rd tube, the entire shotgun weighs quite a bit more and won't cycle the low recoil slugs I like. Thanks for your help, guys. I'd like to cut the overall weight of my Vinci anyway. It is annoying to load weak-hand while held at the shoulder.