Cover photo by Stan Nielsen   Copyright © 2000
Eugene Nielsen
The Tango 51
Tack Driving Tactical Rifle from Tac Ops 

by
Eugene Nielsen

SWAT Article I first met Mike Rescigno, the owner of Tactical Operations, Inc., and one of a handful of Class 2 manufacturers of Class 3 weapons in California, at a recent TREXPO exhibition.  Rescigno, who apprenticed under Master Gunsmith Freddy Brunner, approached me with a prototype of a new 7.62x51 NATO (.308 Win) tactical rifle, the Tango 51, that his company was coming out with.

 The workmanship and attention to detail on the prototype were superb, but what really intrigued me were the sub-1/4 minute of angle (MOA) accuracy claims that he made for the rifle.  I figured that this guy had to be either full of BS or had come up with a better way of doing things.  As we talked further, I suspected the latter had to be the case.  Still, I remained a skeptic.

 Rescigno promised that he would get back to me as soon as the rifles were in full production.  Some time passed, and just when I began to wonder if I would ever hear back from him, he called and asked me to meet him at a local law enforcement range for a demonstration of the rifle’s capabilities.

 The conditions at the range were not ideal as there were cross-winds.  Still, the rifle was producing groups of under 1/4 MOA.  All shooting was done at a range of 112 yards with a bipod from the prone position with no rear rest.  I was impressed but Rescigno insisted that the rifle could do even better.  At the range, Chris Colelli, a member of the San Fernando (California) PD’s Special Response Team, which is one of a growing number of agencies using Tac Ops rifle, said that he once fired a three shot, 1/4-inch group at 200 yards with his department’s Tango 51.  Colelli’s target is now framed and hanging on the wall in his lieutenant’s office.

Several weeks later I met again with Rescigno and Colelli at a public shooting range for additional hands-on testing and evaluation of the rifle.  The handling and performance of the rifle were superb.

While at the range, Rescigno fired a three-shot, one-hole group from sandbags at a distance of 100 yards using Federal Gold Medal 168-grain BTHP.  The group was shot with the sound suppressor attached.  When we measured the group, it measured just under 1/16ths of an inch!  You read correctly, under1/6ths of an inch -- this isn’t a misprint.  I wouldn’t have believed it myself if I hadn’t witnessed it through the spotting scope as it was fired.

 As an aside, the Tac Ops 30 suppressor, although extremely compact, proved to be very quiet.  Although I didn’t have the necessary equipment to measure the decibel (dB) reduction, I would estimate the dB range of the suppressed Tango 51 rifle to fall somewhere between that of a .22 LR and .22 Magnum rimfire rifle.  Actually, all that was probably heard was the result of the supersonic “crack’ produced by the bullet travelling down range.

 The Tango 51 is by far the most accurate rifle of its type that I have ever fired.  I asked Max Maven, Tac Ops’ gunsmith how they accomplished this level of accuracy in their rifles.  Maven, who has a considerable background in military-related “black projects” for the US government, was quite forthright in his answers, going into the construction of the Tango 51 in considerable detail. 

 According to Maven, most of the ideas that Tac Ops has on building rifles came from the questions that they asked.  They discovered that building an accurate rifle was really an engineering problem.  But, as Maven states, fortunately in engineering there are lots of right answers.  Because Tac Ops asked different questions than others that are working in the same field, some of their answers and notions are pretty much backwards from popular thinking. Their first objective question was “what works?”  The second question was “why does it work?” Finally, they asked “is there anything else that works better?”

One thing that Tac Ops noticed was that many sporting rifles that were made out of old, loose military Mausers still shot extremely well.  When Tac Ops investigated they found out that the more accurate rifles all had snug, on-axis chambers with minimum head space.  This confirmed that cartridge alignment was critical and even more important than having a close fitting, expensive action.  Later on, while reviewing the gun literature, Tac Ops found that the whole cartridge alignment and bullet fit issue was really resolved by the cast lead rifle bullet crowd.  They proved that a long, correctly shaped throat and lead were critical.

 The answer to accuracy is basic  -- get the cartridge to correctly fit the barrel and correctly fit in the throat and keep from moving while it’s fired.  Beyond that, everything else besides the barrel is just support.  For this reason, it’s really important to remove as much of the receivers influence on the cartridge as possible.  If you do that, according to Tac Ops, the rifle will work well even if it’s dirty.  Tac Ops adds that it’s still a precision instrument.  They state that if you need a “trench rifle” you “probably need to get something like a stock Mauser 98.”

 The methods Tac Ops uses to achieve mechanical accuracy aren’t so different from the methods used by other rifle builders.  They just pay extreme attention to detail. Each rifle is virtually made one at a time by the Tac Ops crew.  According to Tac Ops, they use the best available materials for the job that they’re doing.  Rescigno is fanatic about it.  When nothing else exists as an available part or tool, they just build it themselves.

 Although they have developed some special ways and tools, according to Tac Ops, everything is really out there if one reads the literature.  They pretty much derived it by asking intelligent questions and sifting through the available literature.  The only really proprietary things that they do is procedural.  It’s the order in which they do things, where they make their cuts.  Also, their reamer designs are “a little proprietary” since they took some time to work them out.

 According to Tac Ops, the barrel has been called the heart of the rifle.  A good barrel is essential to accuracy.  They use either Krieger barrels or their own chrome-moly barrels made for them by a major barrel manufacturer.  Both barrels, when properly installed have given one-hole accuracy levels.  Tac Ops states that a good barrel , even with average receiver preparation, will usually give 1/2 to one MOA accuracy but precision installation usually gives much better results.

 When it comes to the heavy barrel contour, Rescigno is adamant about only using Krieger, as he feels that they make the finest barrels.  Also, Krieger cryogenically treats their barrels prior to shipment.  In addition, Tac Ops also “cryo” treats the barreled actions once all blueprinting is done.

 Tac Ops’ metal work begins with a Remington M700 receiver.  The receiver is inspected for straightness and concentricity and alignment of the screw holes for mounting of the scope. The receiver is then trued on a ground mandrel in the lathe and the action is faced. They also turn the outside diameter if necessary to correct any minor eccentricities.  Very eccentric actions are rejected.

 The receiver’s locking lugs are then faced for squareness, parallelism and concentricity.  At all times they try to hold their tolerances to .0001” to .0002”.  The lug machining that they do is important because the stock dimensions in a Remington receiver are far too coarse for them to use as is.  Some rifle builders feel that they can overcome this problem by lapping in the bolt lugs.  Tac Ops’ experience is that correct machining is faster and more accurate.

 The lugs are faced front and back and the nose diameter is trued.  The front of the bolt is also touched.  The firing pin hole is checked for concentricity and the bolt face is checked with an indicator for squareness as well.  The bolt face is only machined if necessary.  Most of the time no face work is needed.

  Bad bolts are rejected.  If everything is good except for the firing pin hole being off center, they install a new bolt face insert and then the firing pin tip hole is bored on-center in the lathe with the bolt indicated zero.  Also, at this time a Sako extractor is installed if the customer has ordered one.

 The bolt is now lapped to the receiver with fine valve grinding compound.  They only lap the bolt for 15 to 35 lifts of the bolt handle.  Tac Ops has heard stories of long lapping sessions at other companies to get the bolt seated.  Excess lapping makes the locking lugs slightly conical.  This can cause the bolt to try to self center under chambering pressure.  They have contact but the bolt may not center on the chamber, causing cartridge misalignment which is fatal to accuracy.  Excess lapping can also groove and gall the receiver lugs if the abrasive isn’t frequently renewed during the lapping process.

 The barrel is fit to the receiver in a small lathe.  The barrel is indicated true and coaxial at both ends, being put through the hollow lathe spindle and held at both ends by two chucks.  Tac Ops never uses a steady rest when chambering or turning a barrel.  All barrels have some wind-up and spring in them.  If a steady rest is employed it can cause “chattering” and roughness in the chamber.

 The barrel is mounted in the headstock chucks and the barrel bore is indicated in to 00 runout, radial and axial.  The barrel shank for the recoil lug is turned and the threads are cut.  The nose recess for the bolt is cut with a small boring bar, rather than a form tool, so they can achieve the correct fit with the machined bolt nose.

 The barrel shank and the threads on the barrels are a bit larger than the standard Remington barrels, since they chase out the receiver threads to a larger size when they straighten the receiver. 

 The chamber in the barrel is now cut.  Cutting the chamber is the most important operation in building the barreled action.  There must be minimum clearance in the neck and throat.  The bullet nose profile needs to fit into the lead like a machine taper fitting together.  You need as long a contact area as possible between the lead and the bullet nose profile.

 Tac Ops has different reamers for different bullet nose profiles.  Most customers ask them to set up the rifles for Federal Gold Medal ammunition.  Federals are their standard test ammo since, according to Tac Ops, “it’s really the gold standard for factory ammo.” 
 When they cut the chamber, they use a floating reamer holder that’s adjustable for the amount of freedom that the reamer has.  Even if the bore of the barrel is curved, the reamer will still follow the bore without cutting an oval or oversized chamber. 

 Tac Ops uses reamers ground to their own design.  The reamers are cut slowly at about 200-300 rpm.  The reamers are advanced at no more than .050” at a time between cleanings.  This takes considerably more time, but it gives a good, sharp burnished chamber.

 After the chamber is finished, the barrel, recoil lug and receiver are assembled. Any chamber distorting that’s caused by mounting the barrel is removed by hand reaming after assembly.  The last .005” are reamed by hand using a ground guide in the bolt body bore of the receiver to center and keep the reamer aligned so they don’t  “ruin a good receiver or a good chamber.”

 A little of the chamber length is lost during barrel installation due to crush.  Crush is the amount of metal that’s displaced when the barrel is torqued.  Usually it’s necessary to allow for about .002” crush when the barrel is torqued in.

 They use headspace gauges that are ground in steps of .002” and they hold the headspace to less that .001”.  As a result, both bolt lugs are already seated with some pressure when a cartridge is chambered.  This prevents bolt movement during ignition of the cartridge.  Any bolt movement would result in cartridge misalignment and be detrimental to accuracy.

 The close tolerance fits do reduce the rifle’s tolerance for dirt. Tac Ops compensates for that by machining in “mud gutters” during the receiver and bolt preparation. 

 The barrel is next cut to length and crowned.  The muzzle is threaded for a sound suppressor and capped if that is ordered.  They use a modified, recessed target crown on all of the barrels. The bolt handle is threaded for an extended knob and any final finish work is attended to.

 Tac Ops uses the standard Remington trigger, which they disassemble and tune.  Tac Ops feels that the standard trigger is as good as anything on the market.  He isn’t alone in this opinion.  The US Marine Corps has been using standard Remington triggers for over 30 years.  Rescigno likes a light, crisp trigger pull.  The trigger is adjusted to between 2 1/4 to 2 1/2 pounds, unless the customer specifies differently.

 Tac Ops likes to use McMillan stocks and pillar bed the actions in MarineTex, a high-strength epoxy with low shrinkage that is virtually impervious to solvents.  This bedding technique gives better support for the relatively flexible Remington M700 action.  Using this technique, they are also able to bed under the chamber section when they’re using heavy contour barrels and avoid straining the action or causing any misalignment of the bolt and receiver.

 The work on the stocks is done by Jason Crawford, who also does some of the work on the suppressors.  The stocks are painted with epoxy paint.  If texturing is desired by the customer, this is prior to painting.

 According to Tac Ops, if you put on a really fat barrel on a Remington and it’s cantilevered from the receiver bedding, the weight of the barrel bending the action will unseat the lower lug.  This will cause vertical stringing when you shoot the rifle.  Bedding under the chamber helps prevent this.

 Tac Ops feels that stocks with aluminum bedding blocks, such as the HS Precision,  are OK only if the barrel contour isn’t too heavy, since there isn’t any support under the chamber.  Also, aluminum bedding blocks are OK only if the outside dimensions of cylindrical receivers are accurately finished.  If the outside of the receiver is irregular, when the receiver is pulled down into the v-shaped aluminum bedding block, the receiver will twist.  The twisting of the receiver will likely cause one of the lugs on the bolt to become unseated.  This in turn causes inaccuracy.

 Tac Ops likes to use MK IV Leopold rings and bases because of their strength. They drill out the standard 6x48 screw holes and machine the bases and receiver to 8x40.  The base is mounted to the receiver with hardened screws.

 All of the rifles are hand engraved with the company name.  As a personal touch, Rescigno likes to have the BDL floorplates hand engraved with the customer’s law enforcement, military or government logo.

 When all metal work is completed, the barreled actions are sent to Paul Boss for cryogenic treatment.  The rifles are sent to Walter Birdsong’s for his proprietary Teflon finish. Tac Ops rifles are finished in a two-tone, Black TÒ and Green TÒ finish.  The finish is highly wear resistant, has excellent lubricity and is extremely corrosion resistant.  The finish was developed by Birdsong specifically for use on weapons and is specified by the FBI and numerous government agencies. Tac Ops holds Birdsong’s finish in the highest esteem. They have tried other finishes but none gave the performance of Birdsong’s.  The Los Angeles County Sheriff’s Special Enforcement Bureau (SEB) conducted a rigorous T&E  and came to the same conclusion.

 After the finished rifle gets back and the final assembly is completed, Rescigno personally takes each rifle out to the range and shoots it.  The rifles are shot at 100 yards with Federal Gold Medal.  Everyone that I’ve spoken to says Rescigno is a perfectionist.   If there are any problems that become apparent during range testing are addressed and corrected.

 Tactical teams now using the Tango 51 include the SEB, Beverly Hills PD SWAT, Rialto PD SWAT, San Fernando PD SRT, Tulare PD SWAT, and the West Covina PD SWAT.

 I have spoken to representatives from most of the agencies that are using the Tango 51.  Without fail, everyone that I have spoken to, including Chris Colelli, Tommy Lambrecht of the SEB, Jade Marsh of the Rialto PD SWAT and John Robinson of the West Covina PD SWAT, has only high praise for the rifle and the customer service that Tac Ops provides.  Marine Corps Special Operations Training Group (SOTG) instructor Staff Sergeant Jeff “Skully” Escalderone also has nothing but praise for the rifle.
 For customers with special needs, a take-down version of the Tango 51, the Charlie 51, is also available.  Tac Ops is also coming out with an Alpha series rifle, similar to the Tango 51 but in a different caliber, as the result of the request of a federal law enforcement agency, which I am not at liberty to name.  Rest assured, S.W.A.T. plans to test these as well and report back to readers.

 

 SOURCE
Tactical Operations, Inc. 
433 North Camden Dr. 4th Fl. #239
Beverly Hills, Ca 90210
Phone 310 275-8797
Fax   323 933-3521