Ferret50 by Spider Firearms

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Most of your questions reguarding the Ferret50 as well as 50BMG in general will be answered here.

If you are just getting into the 50BMG shooting sports, or are just looking, let me first start out by saying "welcome". The 50BMG sport as with any sport that involves man and machine can be quite complicated. Your level of involvement in the complexities is completely up to you. However, the technical challenges and methods of addresssing them are at play everytime you pull the trigger. Our job at Spider Firearms is not only to provide you with quality equipment, but also to provide the information necessary in the pursuit of shooting perfection. We not only design and manufacture but shoot as well. In our pursuit of perfection we consult research scientists in chenistry and physics, engieers, military snipers and shooting competitors to help solve the puzzeling challenges of shooting very large caliber weapons. The information below is intended to help you, the customer, in choosing the right rifle for you as well as aiding you in your progress of developing your skills with your rifle.

If your questions are not answered here, please call us at 407-957-3617. Thank you

First we will start with a detailed description of the Ferret50 uppers and the F-50/Multi-Caliber lowers. Then we will get into some frequiently asked questions about our product.

Details of the Ferret50 upper.

The Ferret 50 is a true bolt-action single-shot 50BMG rifle conversion for any AR-15 or AR-10 series rifle. It is designed to work with the geometry of the AR by allowing the bolt tube to slide directly back into the lower receiver. Close mating tolerances and a very effective muzzle brake ensure there is minimal stress to your lower.

Each Ferret50 includes a complete upper with brake, scope rail, removable bipod, a pair of solid stainless takedown pins, and an improved hammer.

The Ferret50 was designed using the latest CAD/CAM software. It is manufactured on American made Haas CNC machines, using only the highest grade 4130 and 4140 chrome-moly steel, and then heat treated. Operation of the Ferret50 is smooth and reliable by tolerances that are kept as low as +-.002".

The bolt is a three lug design with a total of 1.35 square inches of shear area, able to withstand four times the force exherted by the 50BMG cartridge. Operation is simple, by rotating the handle 60 degrees and pulling back to load, just like any other bolt action. The bolt and loading port feature positive extraction that will ease out the most stubborn cases. The spring loaded extractor has a wide grip to reduce damage to the case rim.

The firingpin is designed to reduce primer flow and pierced primers in hot ammunition. The firing pin also features a safety device that blocks the pin's forward movement when the bolt is open. The scoperail is elevated .750" above the receiver and is made to MIL-STD-1913 specifications. Sloped scope rails are also available for $25.00 in 20MOA, 30MOA, or 60MOA.

While all Ferret50 parts are manufactured in-house, barrels are manufactured exclusively by Lothar Walther which have been completely finished by them per our specifications. This includes precise thread diameter, pitch, heavy contour and crowning to match our muzzle brake. Standard barrels are chrome-moly steel, 1:15 twist and have a specialized match chamber that accepts both military surplus and match ammunition and still produces reliable accuracy. Barrels are free floating in the vented handguard and can easily be changed. The headspace is also adjustable. Barrels are available in 18", 29", and 36" lengths, and are made from standard 4140 chrome-moly steel. Stainless steel barrels are available in 29" and 36". We also carry the brand new Lothar Walther Supermatch stainless barrels. Available in 29" or 36" with chambers for hybrid-match,competition, borerider and turned neck ammo.

The bipod is a simple, yet sturdy design. The legs fold forward and adjust for height. It is attached to the handguard with three screws and will adjust for cant. Longer bipods are available for shooting in a comfortable prone position.

The muzzle brake is of the Fish Gill type and reduces recoil to the level of a .308, but is more of a push than a kick. In spite of this huge reduction in recoil, there is no effect on accuracy.The brake is threaded left hand and is indexed by a shim located on the muzzle face.

Testing has shown an accuracy improvement with this brake. At 300yds, the average group is .8MOA with a best group of .5MOA using AP military surplus and a standard barrel. Supermatch barrels are capable of .2MOA utilizing match ammunition and an experienced marksman.

Muzzle velocity is approximately 2600fps from an 18" barrel, 2800fps from 29", and 2900 fps from 36". Maximum effective range is approximately 900 yards from an 18" barrel, 1300 yards from 29", and 1450 yards from 36". (This data was compiled from testing at sea level, during F90 degree temperature, using 1952 Lake City API ammo.)

The improved hammer is designed to wind the spring tighter. That coupled with greater mass located at the end of the hammer results in a more reliable ignition of the primer. The sear engagement surface allows for better trigger pull than a stock AR hammer.

Each Ferret50 is test fired and inspected. They are then parkerized with a manganese phosphate solution to match the standard AR finish.

If you have further questions or you are ready to order, just give us a call at 407-957-3617. We are open almost everyday.

Details of the F-50/Multi-Caliber lower.

The F-50/Multi-Caliber single-shot lower is manufactured entirely from 4130 steel for superior strength, stability, and durability. The lower features a lower rail on the buttstock for a sandbag or rest for supporting the rifle. The cheekrest is at the same level as the standard A2 buttstock. Length of pull is 14.5" (standard A2 is 13.5). The Buttstock is clearanced behind the pistol grip to allow comfortable shooting positions. The pistol grip is a standard A2 grip, and the recoil pad is a Pachmayr 325.

The lower comes standard with a competition hammer/trigger set that are adjustable for creep and overtravel. The trigger pull is very smooth and breaks like glass at approx 1LB. We use chrome-silicon hammer and trigger springs and secure the componants with anti-walk pins.

The lower further reduces recoil by adding 7lb to the wight in the rifle, and in the right place for stability during the launch of the projectile.

Customized options include: an adjustable 2-axis cheekrest ( up and down/tilt front to back), a detachable rear monopod (also made from 4130 steel, with an ergonomically placed thumb screw for easy maneuverability), and specific length of pull for a first-class fit.

The end result of the features of both our uppers and lowers is that you shoot smaller groups. The launching of projectiles is consistant due to the design of the bolt, receiver and barrel. Sighting is consistant due to the ridgid scoperail. The entire weapon is ridgid, which prevents eratic sight picture movement during the launching of the projectile. The shooter can relax and be comfortable during the shooting session. In short, the Ferret50 is made so that YOU can shoot well.

What barrel should I get?

When choosing a barrel, ther are a few things to keep in mind. Storage, transport, ammo, recoil and shooting distance.

The 18" inch barrels, abailable only in chrome-moly steel with a hybrid chamber, are effective to approx 900yd. The advantages are that it is easy to transport and store. Also, a Ferret50 with an 18" barrel can be shoulder fired by the average person. The 18" barrels have the least recoil and velocity.

The 29" barrels are effective to approx 1300yd and is the favored barrel length of our customers.

The 36" barrel will yield the most velocity from a given load, but also yields the most recoil. Effective range is approx 1600yd. Most of our customers who shoot competition choose the 36" barrel.

Our 29" and 36" barrels are available in Chrome-moly, stainless and Supermatch stainless.

Chrome-moly is the basic barrel line and feature only the hybrid-match chamber. These barrels are perfect for casual fun shooters and rock busters.

The stainless barrels also come only with the hybrid-match chamber. The advantage of the stainless is that the material resists throat erosion and bore wear better. They also look great.

The Supermatch Stainless barrels are a match shooters dream. Along with the benifits of the stainless barrel material, these barrels undergo other processes and inspection give the customer top performance. These barrels foul less than the average barrel. There are four chambers currectly available for these barrels; hybrid-match, competition-match, borerider and a chamber for turned case necks.

All of our rifles come with the standard 1:15 right hand twist, 8 lands and grooves. Optional barrel twists are 1:12.7 and 1:9.5.

What is MOA, and what amount should I get in my scoperail?

MOA stands for Minute of Angle, and is a measurement of an arc of a circle. A circle in generally broken down into 360 degrees. Each degree can be further broken down into 60 minutes of a degree of angle. And further than that each minute of a degree can be broken down into 60 arc seconds of a minute of angle. So, 60 arc seconds = one minute of angle, 60 minutes of angle = one degree, and 360 degrees completes a circle.

MOA is applied to your scoperail by making the front of the scoperail lower than the rear of the scoperail. When your scope is mounted to this "sloped" rail, it is mounted at an angle relative to your riflebore centerline. Since the scope is what is "pointed" at the target, the barrel is "pointed" at a higher verticle position than your target. You might be asking "isn't the internal scope adjustment supposed to do this"? The answer is yes, to some degree (excuse the pun). Your projectiles travel in the air to your target in an arc we call trajectory. The further the taget is, the higher the arc needs to be to reach the target. From a 100yd zero we need to add 25 to 30 MOA to our scope's elevation adjustment to hit a target at 1000yd. Shooting farther requires adding more elevation to our scope's adjustment. Since the average scope has about 80 MOA of elevation adjustment (which equals about 40 MOA from center adjustment to max elevation) we will run out of elevation adjustment at 1200 to 1500yd. Additional to that, at the extended ranges where we need a very clear sight picture, the erector tube (part of the scopes internal adjuster) will have us looking through the edges of the objective lens. Our best sight picture is when our elevation and windage adjustments are nearest to center. By angling the scoperail we not only add to the overall elevtion adjustment possable, we are looking through more of the center of the scope which will give us the best sight picture.

In general, if you plan on shooting out to 800yd and no more, a flat scoperail will be best. If you plan on shooting 200 to 1000yd a 30MOA scoperail will be best. If your shooting will be from 600 to 2000+yd a 60MOA scoperail will be best. If you plan on shooting past 2000yd, we may need to build a custom scoperail for you. It is important to review your scope choices before choosing a scoperail since not all scopes have the same amount of adjustment or light gathering abilities (which is another topic in itself).

What is the difference between the standard receiver and the extended receiver?

Both receivers are designed to be used with the 50BMG rounds, and both have an extractor and ejector. The visual difference is the extended receiver is one inch longer than the standard. The functional difference is that the standard receiver will eject spent shells, but requires pressing the rear of the extractor to remove a live round, the extended receiver will eject both spent and live rounds. The scoperail on the standard receiver is 6" long (length of picitinny rail), the scoperail on the extended receiver is 7.75" long. Both the standard and the extended receivers are designed to fit the AR-15 lowers as well as our F-50/Multi-Caliber lowers. Our A-10 type Ferret50 receiver is the same as the extended receiver except that it is designed to fit the AR-10 lowers.

What makes the Ferret50 product line "modular"?

All of the componants are designed to be changed, at the user level, to modify the weapon system to meet the need of the desired application. Barrels are changable at the user level as is the handguard. An example would be taking an 18" upper with a standard handguard and changing the barrel to a 36" with a long handguard. The handguard is threaded on the barrel ahead of the receiver and is used to lock the barrel in place.

The lowers can be changed in seconds. Since our F-50/Multi-Caliber lower has the same takedown pin and hammer/trigger location, you can go from an AR lower to our lower with out any modifications. What is really nice is that you can have a F-50/Multi-caliber lower setup for you and change uppers in seconds. An example is that my SuperComp Ferret50 rifle, the lower is setup and adjusted for me. To shoot military surplus I swap uppers to a standard 29" Ferret50. I then can go out and get plenty of trigger time without spending a lot on ammo. When I am ready to shoot some match ammo, I put my SuperComp upper back on. If I then want to change calibers, I simply swap uppers. I keep two to four uppers for my one lower which allows me to do all kings of shooting. Its like haveing several custom-match rifles.