Maruzen – CA870 – Project Shotty

Manufacturer: Maruzen (Japan)
Type: Spring Pump Shotgun
Date Acquired: 12/2004

Maruzen – CA870 with TGS Stock System

If you saw a previous posting on my M1100, I was planning on adding the TGS stock system to that gun, but after looking at the gas feed system and the fact that specific M1100 is no longer in production (and may never be again). I decided it would be better if I just picked up a CA870 where I knew i wouldn't bugger up a perfectly good gas system.

I purchased this as a CA870 full stock.

Maruzen – CA870 with TGS Stock System

The CA870 itself is a good spring shotty, but it's only single shot unlike the Marui spring shotguns. if I were to skirmish with a shotgun I wouldn't take this gun though since I have a Marui Spas 12 and M1100.

The fun part of this project for me is the fact all addons are from the Real Steel world. Some minor alterations were needed to the Real Steel parts to make them work. These are posted here

Tip: The screw used for the stock is a 6mm coarse threaded screw. Hope that saves you time at the hardware store Wink

Items included in the project:

  • Maruzen CA870 CQB Full Stock
  • TGS M4 Stock adapter
  • M4 Collapsible Stock System
  • M4 Collapsible Stock Shoulder Pad
  • M4 Collapsible Stock Cheek Rest
  • Bushmaster HK91 Style Cushioned Sure Grip

Great CA870 Upgrade info is

I'm personally not planning on doing any more upgrades to this gun. It just suppressed my urge to get a real FN Tactical pump shotgun for the moment Wink

G&P CA870 22Rds Short Magazine

Edit: Aug 31, 2006

Added the G&P Long Barrel system.

Size comparison to a TM SPAS12

Added the G&P Tactical Light Foregrip

Chrono Results (FPS) Stock?
.20 BB's
Min: 290.80
Max: 294.50
Avg: 293.20

.25 BB's
Min: 269.00
Max: 272.43
Avg: 270.56

Chrono Results (FPS)?After Adding G&P Long Front Barrel ?
.20 BB's
Min: 307.62
Max: 321.34
Avg: 311.85