CSI SR-798 (Mossberg 500)
Date product posted
Wed February 20, 2008
CSI Mossberg 500 Spring Shotgun review by Booligan
Discuss the review here.
Table of Contents:
Real Steel History
Gun first impressions
Preparing gun for firing
Real Steel History:
The Mossberg 500 is a shotgun manufactured by O.F. Mossberg & Sons. Rather than a single model, the 500 is really a series of widely varying hammerless, pump action repeaters, all of which share the same basic receiver and action, but differ in bore size, barrel length, choke options, as well as stock and forearm materials.
The name "Model 500" covers an entire family of pump shotguns designed to chamber 3" (76.2mm) shells. The standard model holds five 2 3/4" (70mm) or four 3" shells in the magazine and one in the chamber. The Model 500 is available in 12 gauge, 20 gauge, and .410 bore, with the 12 gauge being the most popular.
Taken from wikipedia.org
This replica is based off of a 20 gauge, 16” barrel model.
Real Mossberg 500 shotgun
I’ve had my eye on this particular shotgun ever since Evike announced it. They are currently the only US based retailer who carries it. It is sold there as the “Matrix Metal M-500 SWAT Airsoft Training Weapon Shotgun” and is priced at $24.99. I ordered it, and an extra magazine on Friday night, and it arrived at my door on Monday morning, using standard UPS ground shipping. Overall, I was pleased with the service I received from Evike.
RSOV.com has this model, as well as the stockless pistol grip version, but they are located in Hong Kong. TSD is supposed to be rebranding this as well, but I have yet to see it. I have seen this gun being sold overseas by Cybergun, with full Mossberg trademarks, but at a higher price.
The gun arrived in a gloss black box, with the letters “CSI” printed in red on the upper left corner, and the model number “SR-798” printed on the lower left. The box also had the normal consumer safety warnings plastered on every surface of the box. There are no images of what’s actually inside the box, nor does it have the gun’s name on it anywhere.
Box art (or lack thereof)
Inside the box was the gun, with the stock detached, one magazine, cleaning/unjamming rod, pistol mag style speedloader, stock attachment hardware, small Phillips head screwdriver, a one page manual, and the normal bag of cheap bbs. The manual has decent diagrams, but some of the worst “Engrish” that I have ever seen. “Press down the button up the plank, then pull to move the valve door, pulling once each time to shoot a bullet. (connect the hair)”. Apparently, that is how you pump the gun…
The speedloader is of the now ubiquitous pistol magazine style, and holds approximately 100 rounds. It fills the magazine well, and rarely jams up.
Gun first impressions:
The gun comes to you with the stock removed, in order to fit into a smaller box. Thankfully, it includes all the tools and hardware needed to assemble it fully. You need to slide the stock onto the rear of the receiver, aligning the tracks, and pushing it on until it is flush with the receiver. You then can screw in the included self tapping screws, using the included screwdriver. Do not over tighten the screws, as they tap into the plastic, and could strip if over tightened. Once installed, the stock is very secure, and doesn’t wobble or move at all.
Installing the stock
Insert screws here, mirrored on other side
The M500 tips the scales at 3.5 lbs, and is 36.5” long, with the stock installed. The outer barrel is 16” long, and has a “bore” of 16mm (0.60”) which is more or less the same bore as a 20 gauge shotgun.
The externals of this particular replica are composed mainly of plastic, with a few metal decorative and structural parts. The pump guide “magazine” tube, pump connecter arm, and removable heatshield are made of metal. The heatshield is painted with a mildly textured semi gloss black paint, as is the pump tube. The heatshield is removable, by unscrewing the two Phillips head screws located at the front of the shield, and sliding the whole assembly forwards, and off of the gun. With the heatshield removed, you can see that there is a mild seam line visible down the length of the barrel. The outer barrel is plastic, and measures 16” long. At the bottom of the barrel mounting block, there is a plastic sling mount stud, but no actual sling mount.
Barrel and pump
Closeup of heatshield
Gun with heatshield removed
Closeup of barrel, showing sling mount stud
The receiver is plastic, and has six screws holding it together; four on the right side, and two on the left. The hop-up adjuster is located on the right side, where the shell ejection port would be on the actual gun. It is adjusted by sliding it forwards for more hop, and backwards for less. There is a mock safety switch on the top of the receiver, but is serves no purpose. Mine has already fallen off, so I suggest you super glue it onto the receiver. The actual safety is located back and to the left of the trigger. The trigger assembly is plastic, and takes about 8 pounds of force to fire.
Receiver, showing hop-up adjuster
Closeup of hop-up adjuster
Trigger assembly, actual safety shown
The stock is plastic, with a removable rubber butt pad installed. There are seven screws holding the stock together. They are all on the right side, and two are hidden under the butt pad. The butt pad is textured, as to prevent the gun from slipping off your shoulder while firing. The grip portion of the stock is also textured, and is very comfortable to hold. The trigger is a little far away from the grip, and some users with short fingers may have problems reaching it. There is a seam line that runs the length of the stock, but it is not felt while handling the gun.
Rubber butt pad
Textured pistol grip
The pump handle is ribbed for enhanced grip, and is connected to the internal firing assembly by a metal linkage bar, located on the left side. The pump handle has a visible seam line running along both sides, but it is not easily felt. The pump travel is a hair under 2.5”, and takes about 10 pounds of force to manipulate. There is a bit of rotational looseness in the pump handle, but I don’t foresee it as a becoming a problem. The pump tube is metal, and is removed by unscrewing it counterclockwise, just like the UTG/DE shotguns.
The magazine release is on the bottom of the gun, in front of the magazine, and is a push button type of release. To eject the magazine, you must push the button, and pull the flush mounted magazine out of the gun. It does not pop out or eject on its own, you must pull it out manually.
Bottom of receiver, mag release button shown
There are no iron sights, nor are their any methods of attaching other sighting systems. You aim this gun by looking down the barrel, and estimating your point of aim. You could probably mount a rail on the top, using either very shallow screws, or a strong adhesive like “Gorilla Glue”.
Overall, the gun has externals that far surpass its $25 price. It is very rigid, with no creaks or wobbles, and should stand up to the typical abuse most airsofters put their equipment through.
The gun has no trademarks whatsoever. The only writing on the gun is under the hop-up adjuster, and labels which way the slider moves to adjust the hop-up.
The design of the magazine is what initially attracted me to this particular replica. I hated the look of the UTG/DE magazines, which stuck out about 2” from the bottom of the gun. This replica uses plastic flush mount magazines, which are practically invisible when installed in the gun. They hold 16 rounds, and feed all but the last one, giving you 15 usable rounds. The magazine is constructed of a semi-transparent plastic, which allows you to see how many rounds they contain with the magazine taken out of the gun. This gun is actually compatible with the UTG/DE mags, and they lock in and feed perfectly. They still stick out the bottom of the gun, just like on the UTG/DE. I do not have a UTG gun on hand to test if the CSI mags will work in it, but they are a few millimeters longer than the UTG mags, and may not fit in the UTG/DE gun. Extra magazines for this gun are available at Evike for $6.99 each.
Mag compared with UTG mag
UTG mag in CSI gun
Preparing gun for firing:
In order to fire the CSI M500, you mush first load the included magazine with 16 rounds, using either the included speedloader, or one of your own. You then click the magazine into the gun, ensuring it is flush with the bottom of the receiver. After loading the magazine into the gun, you must pump the handle back until it clicks, and slide it forwards until it clicks again. It is designed to fire one bb at a time, but the pump does not lock in the forwards position, so you can pump the handle multiple times to give you multiple projectiles with each shot. Your range and velocity will be decreased by doing this, plus it may damage the gun. You can also slam fire the gun by holding down the trigger and pumping the gun, but his may lead to internal damage, and premature wear on the gun. The safety is located next to the trigger, and is a slider bar style. You slide it forwards to put the gun on safe, and slide it back to put it on fire mode.
Being that this is a spring powered gun, you must pump it before each shot.
Using the Poor Man’s Chrono method, the gun chronoes at 350-370 fps using .20s, as it punches easily through both sides of a can, but only cracks the bottom. This is very respectable for a $25 gun! The short range accuracy is on par with other guns in its class. I am able to get 4.5” 10 shot groupings at 40 feet, using 0.20 gram TSD bbs. Long range accuracy leaves a bit to be desired. The shots are inconsistent at ranges further than 120 feet, and are unpredictable as to how they will go off target. The shots go side to side, as well as dropping short or going too high. This can definitely be attributed to the 6.14 mm ID barrel, as well as a sub-par hop-up design. Torso hits are pretty much a crap shoot at further than 120 feet. One thing to take note of, if the hop-up is turned all the way off, bbs have a tendency to roll out the barrel when cocked. This can be remedied by keeping the hop-up turned slightly on all the time.
I would put maximum effective range at 90 feet, which makes this gun good for mid range woodland/desert play, or for CQB. You should be able to accurately hit a torso sized target at ranges less than 90 feet 9 out of 10 times.
PMT (Poor Man's Target) test at 40' from a bench rest position (Uncircled hit on top of target was a non-aimed flub)
With everything else being strikingly similar to the UTG/DE shotguns, I was inclined to believe that the internals will be similar as well. The inner barrel is metal, and appears to be made of aluminum. It is 307mm long, and the retaining notch is 1/4" away from the base. The inner barrel can actually be another 85mm longer before it hits the end of the muzzle. The inner diameter is 6.14mm, measured using digital calipers, making it the widest stock barrel that I have ever seen. DB Customs has a 6.01mm tightbore barrel available for this gun, and is a wise upgrade choice!
You disassemble this replica just like the UTG/DE guns, by first unscrewing the pump tube plug, and sliding the outer barrel off the gun, towards the front. You can then unscrew the pump tube, and remove the pump handle. The rest is identical to the UTG, just take out all of the screws.
The guns internals are all plastic, from the trigger sears to the cylinder. The only metal parts inside are the spring, pump arm, and the body alignment pins. This is identical to the DE/UTG guns. The gun has the same dual sear setup, with one for regular fire (the one with two sears) and one for slam fire (it is sandwiched inside the normal sear). For enhanced life, I suggest removing the slam fire mechanism, and only keep the normal firing sear in place.
Shot into magwell
Shot down the barrel, showing inner barrel
Internals are the same as the UTG
Inner barrel/hop-up is not the same. It is a similar design, but the retention cuts are in a different place. DB custom tightbore barrels are available.
Being that this is a cheap springer, your upgrade and modification options are slim. DB Customs has a 6.01mm tightbore barrel made especially for this gun. You can always custom paint it, or find a way to attach a rail or other sight on it. Internal mods will have to be custom, as there are no off the shelf products for this gun, except for the TB barrel. I plan on turning it into a close replica of the M97 Trench Shotgun from WW2. This can be achieved by painting the pump handle and stock in a woodgrain pattern, and adding a bayonet mount to the muzzle. It won’t be exact, but it’ll be close enough for me!
This is the goal. Do any of my loadouts need a WW2 trench shotgun? No. Will I be making it anyways? Oh yes!
Very inexpensive - $25
Unique M500 style
Flush mount magazines
UTG/DE magazine compatibility
Rubber butt pad
Single bb firing shotgun
Some seam lines
Questionable long range accuracy
Mostly plastic construction
Abundance of screw holes
Low capacity magazines
Hard to find in the US
If you are looking for an inexpensive shotgun, but hate the looks of the UTG/DE guns, than the CSI M500 is perfect for you. Its performance is better in most regards, and looks much better, in my opinion, all for the same price. It is quite formidable in springer games, as well as offering a unique challenge for normal games.
Would I buy this again? I’ve already ordered two more!
Size comparison between M16 and MP5K PDW