S&T ST870 Marine Magnum Spring Pump Action Shotgun

S&T
Code:
227.99
  • Full metal construction
  • Single shot - 400 FPS +/- 10%
  • 6.03mm Tightbore inner barrel & TDC HOP-up

If you like a challenge in game, this will certainly give you that! The S&T ST870 Marine Magnum is a single-shot pump action shotgun boasting full metal construction, a 6.03mm tightbore inner barrel, a TDC HOP-up unit and 400 FPS +/- 10% out of the box. "But why on earth would I want a single-shot, high FPS shotgun?" we hear you ask...

The ST870 may not be your CQB platform of choice, but it fulfils a different role. This shotgun is intended to simulate a real M870 shotgun firing 12 gauge slugs which are a single, solid projectile intended for long-range engagements and hunting. This means the ST870 falls into the same class as DMRs and Sniper Rifles when it comes to skirmishing, with the added challenge that there are no iron sights or rails to be found. If you are finding skirmish life a bit too easy with a sniper rifle, the ST870 will make you work even harder but give you even more satisfaction when you land the kill!

Full description

Description

Perfect for those with high standards of realism and those who like a challenge, the ST870 Spring Pump Action Shotgun replicas the real steel "Marine Magnum" variant of the M870, finished in silver across the metal parts simulating the anti-corrosion electroless nickel plating of the real thing. If you run a USMC loadout, this is the perfect shotgun, but it doesn't come without its quirks!

Based on the Maruzen Type 870 internal design, the ST870 is a single-shot spring action shotgun with an average FPS of around 400 on a 0.2g BB. This means the ST870 falls into the same class as bolt action sniper rifles when it comes to skirmishing but with the faster pump-action loading mechanism and the added challenge of no sights, and no way to mount any! While you won't be taking this beast into CQB, this is the perfect platform for a long-range skirmisher who seeks a challenge to match their skillset.

Starting at the front we can see the lengthy 20-inch outer barrel and extended mock magazine tube, giving the ST870 its military-style looks. The inner barrel inside is 500mm in overall length and is a 6.03mm tightbore, promising superb and not very shotgun-like accuracy and consistency rivalling sniper rifles. The outer barrel is devoid of iron sights or any other details, providing a smooth profile which flares out slightly near the receiver/chamber, just like the real M870.

On the left side of the barrel, we are treated to realistic trademarks in the form of "12GA. FOR 2 3/4 IN. SHELLS" in finely engraved text. This marking is in the same location as the real deal, positioned as such to permit barrel swaps, as is common with M870 shotguns. The TDC HOP-up adjuster is located on the top of the outer barrel, close to the receiver. This takes the form of a grub key adjuster which requires a small Allen key to adjust. The TDC HOP-up unit style is known for its effectiveness with heavy-weight BBs, providing direct pressure to the top of the HOP-up rubber for a stronger HOP-up effect and less side-to-side shot deviation.

Running on alloy cocking arms just below the outer barrel we have the pump grip which is constructed from high-density polymer. The grip is textured to provide ample traction in any weather conditions and is surprisingly easy to rack for such a high FPS platform. While the ST870 may lack iron sights, it can still duke it out in the woods thanks to its high FPS and the fast pump action which can easily put more rounds down in a shorter timeframe than the traditional sniper rifle's bolt action mech.

Moving rearwards, we come to the receiver which is constructed from alloy and finished in silver, matching the real anti-corrosion finish present on the real "Marine" variant of the M870. The finish looks fantastic, as it does across the shotgun's other metal parts, making it stand out in game while maintaining a realistic look ideal for a USMC loadout. On the left side of the receiver, we are treated to more realistic trademarks, reading "Model 870 SUPER MAGNUM" in bold, stylised text matching that of the real manufacturer.

On the right side of the receiver, we can find the detailed mock bolt carrier which is correctly shaped and includes a mock extractor, giving this single-shot M870 a far more realistic look than the tri-shot models. When it comes to sizing, the ST870 is almost bang on 1:1 dimensions, giving it a much slimmer and more realistic feel than the bulkier tri-shot models which make realism compromises to fit the larger tri-shot mech inside. The magazine well is located on the bottom and accepts S&T 22rnd low-cap magazines, though being based on the Maruzen, it should also accept Maruzen and G&P Type 870 magazines.

The trigger and trigger guard assembly is positioned just to the rear of the magazine well and includes a cross bolt safety just behind the trigger. When engaged, the cross bolt safety will lock the trigger and protrude on the right side, putting it easily within reach of the trigger finger for quick actuation and intuitive handling. When the safety is off, the cross bolt button will protrude on the left side with a red ring surrounding it to indicate that the shotgun is hot.

On the left side of the trigger guard, we can find the dummy bolt release which usually functions as the shell door latch on tri-shot shotguns. On the real M870, this control allows you to unlock the bolt and eject a loaded cartridge should you need to switch ammo types or unload without firing. On the ST870, this control is a dummy but is nonetheless a separate part to avoid the telltale signs of this shotgun being a replica.

At the rear, we have a fixed stock with a semi-pistol grip configuration, giving this M870 the classic full-sized shotgun look. The semi-pistol grip features diamond checkering to provide optimal grip and the stock setup itself is constructed from high-density polymer with a textured surface and no rattle or flex to be found. The butt plate is made from rubber, patterned after real steel recoil pads, providing superb wet-weather traction with an S&T logo recessed into the design.

The ST870 is based on the Maruzen Type 870 internal design but is fitted with a 6.03mm tightbore inner barrel to provide the accuracy and range a slug shotgun simulator needs. The TDC HOP-up design is also a nice improvement over the G&P and Maruzen variants and has the potential to make this shotty a real tack driver down range. The lack of sights or the ability to mount them will hold back all but the most skilful skirmishers but those who do rise to the challenge will appreciate the ST870 for its realism, fast pump action mechanism and sniper rifle like range.

If your CQB primary is a tri-shot and you want to keep living that pump action life, the ST870 is the ideal outdoors primary for you. The perfect companion to an authentic US Marine Corps loadout or the experienced skirmisher who wants to test their skills, the ST870 is a stunner with its flawless finish, perfect 1:1 dimensions and the high FPS to do real steel slug shotguns the justice they deserve in Airsoft!

Features

  • Full metal construction
  • 6.03mm Tightbore inner barrel - Great accuracy potential
  • Single shot shotgun - High FPS, TDC HOP-up, simulates a real shotgun using slugs
  • Authentic "Marine Magnum" silver finish - Replicates the anti-corrosion finish applied to USMC M870s
  • 20" Barrel & extended mock magazine tube - A full size, no messing around shotgun!
  • High-density polymer pump handle - Ribbed for extra grip, very high-quality polymer
  • "Model 870 SUPER MAGNUM" Trademarks on the receiver - Looks great, just like the real 870
  • "12GA. FOR 2 3/4 IN. SHELLS" Marked on the outer barrel - Very realistic
  • TDC Adjustable HOP-up unit - Grub key adjuster, on the top of the outer barrel
  • Fixed stock with semi-pistol grip - Textured grip, rubber butt plate for wet weather use
  • Feeds from Maruzen/S&T/G&P style single shot shotgun magazines - Includes 1x 22rnd mag
  • Cannot be "Slam fired" - Don't try it!

Package Includes

  • S&T ST870 Marine Magnum Spring Pump Action Shotgun
  • 22rnd Low-cap magazine
  • User manual

Specification

General

Weapon Construction External
Weapon Type
Shotgun
Over 18 Only Icon
Over 18
Yes
Icon UKARA - United Kingdom Airsoft Retailer Association
Defence / UKARA Required
Yes, No,
FPS Icon
FPS (Feet Per Second), using 0.20g BB
Approx. 400fps ± 10%, using 0.20g BB
Site Legal Icon
Site Legal, using 0.20g BB
Yes
Screwdriver Icon
Pre-Built
Yes
Package
Included Items
Magazine
Skill Level Icon
User Skill Level
Experienced Player

Weight and Dimension

Weight KG Icon
Weight (KG)
Approx. 2.8kg
Weapon Length Collapsed
Length (Collapsed)
104cm
Weapon Length Extended
Length (Extended)
104cm

Construction

Colour Wheel Greyscale
Primary Colour
Silver
Colour Wheel Greyscale
Secondary Colour
Black
Construction Icon
Construction
Steel front sling point, body pins & screws. Alloy outer barrel, mock mag tube, charging arms, receiver & trigger guard. High density polymer stock & pump grip. Rubber butt plate.
Weapon Construction External
External Construction
Polymer
Alloy
Rubber
Steel
Gearbox Icon
Internal Construction
Polymer
Alloy
Aluminium
Steel

Weapon Specific

Power Source Icon
Powered By
Spring
Blowback Icon
Blowback
None
Weapon Platform
Shotgun, M870 ,
Magazine Style Icon
Magazine Style
Shotgun, Long Gun Magazine, M870, Maruzen/G&P/S&T style single shot Type 870 magazine,
Fire Select Icon
Fire Selector
PatrolBase | Fire Select Safe
Safe
Pump Action
Fire
Weapon Safety Features Icon
Safety Features
Trigger Lock
Shooter Configuration Icon
Shooter Configuration
Right Handed
Weapon Configuration Icon
Weapon Configuration
Pump Action
Weapon Scale Icon
Weapon Scale
1:1
Suggested BB Weight
0.25g

Hop-Up

Hop-Up Unit Icon
Hop-Up Unit
Yes
Hop-Up Unit Adjuster Icon
Hop-Up Adjuster
TDC
Hop-Up Unit Location Icon
Hop-Up Location
On the outer barrel, just in front of the receiver. Adjustable using an Allen key

Furniture

Weapon Furniture Icon
Furniture
  • Fixed Stock
  • Textured Semi-pistol grip
  • sling point
  • Ribbed handguards
  • Rubber butt plate
Rail System Icon
Rail System
None
Icon Stock Positions
Stock Setting
Fixed
Sight Type Icon
Sight Type
None
Sling Plate Icon
Sling Options
Loop , Magazine tube,

Barrel

Outer Barrel Length (in)
20''
Inner Barrel Diameter
6.03mm
Inner Barrel Length
500mm

Magazine Specific

Magazine Type
Low Capacity , Shotgun Magazine,
Magazine BB Capacity
Approx. 22 Rounds
Magazine BB Fill Method
Speed Loader
Magazine BB Fill Location
Top

Product Testing Data

Notepad Icon
Test Description
400 FPS +/- 10%
Notepad Icon
Tested Using
0.2g ASG BLASTER
Notepad Icon
Test Date
06/11/2023

Size guide

Joule Charts

Special Instructions

These table can be used as a reference to see if the BB weight you are using will be over acceptable Joulage limits at some Airsoft Sites in the UK. To check if the weight can be used chrono your weapon using the BB you intend to use, and then compare it to the chart.

FPS, Power and Joule Limits can vary from site to site, so please get in touch with where you're going to play with in advance to avoid disappointment.

Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, with a 350fps limit for Automatic Replicas, 400fps for Semi-Automatic Replicas, and 500fps for Bolt Action Replicas.

Tap the tabs below to open the relevant chart for your replica.

Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, and is the equivalent of 350fps, using 0.20g BB resulting in an upper limit of 1.14j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
325 0.98 1.23 1.37 1.47 1.57 1.77 1.96 2.11 2.21 2.45
328 1.00 1.25 1.40 1.50 1.60 1.80 2.00 2.15 2.25 2.50
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
335 1.04 1.30 1.46 1.56 1.67 1.88 2.09 2.24 2.35 2.61
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
345 1.11 1.38 1.55 1.66 1.77 1.99 2.21 2.38 2.49 2.76
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
355 1.17 1.46 1.64 1.76 1.87 2.11 2.34 2.52 2.63 2.93
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01

Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 400fps, using 0.20g BB resulting in an upper limit of 1.49j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01
370 1.27 1.59 1.78 1.91 2.03 2.29 2.54 2.73 2.86 3.18
380 1.34 1.68 1.88 2.01 2.15 2.41 2.68 2.88 3.02 3.35
390 1.41 1.77 1.98 2.12 2.26 2.54 2.83 3.04 3.18 3.53
400 1.49 1.86 2.08 2.23 2.38 2.68 2.97 3.20 3.34 3.72
410 1.56 1.95 2.19 2.34 2.50 2.81 3.12 3.36 3.51 3.90

Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 500fps, using 0.20g BB resulting in an upper limit of 2.32j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01
370 1.27 1.59 1.78 1.91 2.03 2.29 2.54 2.73 2.86 3.18
380 1.34 1.68 1.88 2.01 2.15 2.41 2.68 2.88 3.02 3.35
390 1.41 1.77 1.98 2.12 2.26 2.54 2.83 3.04 3.18 3.53
400 1.49 1.86 2.08 2.23 2.38 2.68 2.97 3.20 3.34 3.72
410 1.56 1.95 2.19 2.34 2.50 2.81 3.12 3.36 3.51 3.90
420 1.64 2.05 2.29 2.46 2.62 2.95 3.28 3.52 3.69 4.10
430 1.72 2.15 2.40 2.58 2.75 3.09 3.44 3.69 3.86 4.29
440 1.80 2.25 2.52 2.70 2.88 3.24 3.60 3.87 4.05 4.50
450 1.88 2.35 2.63 2.82 3.01 3.39 3.76 4.04 4.23 4.70
460 1.97 2.46 2.75 2.95 3.15 3.54 3.93 4.23 4.42 4.91
470 2.05 2.57 2.87 3.08 3.28 3.69 4.10 4.41 4.62 5.13
480 2.14 2.68 3.00 3.21 3.42 3.85 4.28 4.60 4.82 5.35
490 2.23 2.79 3.12 3.35 3.57 4.02 4.46 4.80 5.02 5.58
500 2.32 2.90 3.25 3.48 3.72 4.18 4.65 4.99 5.23 5.81
510 2.42 3.02 3.38 3.62 3.87 4.35 4.83 5.20 5.44 6.04