Hello all. I've been running a BBTac M62 (ASG M40A3 clone) for the past year, and wanted to share what I've learned about the gun so far, since there is a lot of misinformation regarding the platform (and scant correct info about it).
Stock my gun shot 450FPS the first outing, and quickly settled in the 410-430FPS range (1.6J). With hop up nearly maxed, the gun lifted both .36 and .4g bbs out to 200-220ft (laster straight), whereupon they'd fall like a rock.
The gun is easy to disassemble, and the stock hex screws are contained in the stock, making them impossible to lose. The stock is where much of the cost savings happened, and while it is certainly durable enough for play it doesn't feel high quality. Overall ergonomics are nice - to the point where I've gotten to quite like it. Interior part quality is sufficient for the price you pay - not top quality by any stretch, but not bottom barrel stuff either.
While stock performance was borderline impressive for an $80 rifle, I wanted my rifle to reach out quite a bit further. Given I was 1.2J lower than my field limit, I thought this would be pretty easy to accomplish. However upgrading has proven to be a challenge - not because there are not available parts, but because the gun is a mix of systems and no one really has figured out which parts are which. So, I decided to start this thread with my findings, so that others might have an easier time upgrading their rifles if they so desire.
Currently, my rifle is shooting accurately but still stuck at 1.8J - last tested with a Laylax SP170 spring. Seal is good everywhere except cylinder - best I can tell I'm leaking severely past the piston, causing my loss. I am about to purchase some new o-rings to hopefully address this issue.
Stock Specifications
Performance
.4g bb out to 220ft flat, then quick drop (hop up nearly maxed)
Spring
Verified Upgrades
Springs
- SSG96 Cylinder Head - Seals well without teflon tape, and extends further into the bucking (perfect length).
Hop Up
- Maple Leaf Crazy Jet 430mm
Trigger Assembly
- L96 Trigger Sear - Only the sear itself fits - sear assembly does not.
Possible Upgrades
- Type 96/APS2 Piston - Not 45 degrees, needed for stock trigger-assembly.
Helpful Links
T4nk's Build Playlist
SiliconeSword's Upgrade/Mod Guide
BlackDog's Compatibility List
Jeppe's Notes
Stock my gun shot 450FPS the first outing, and quickly settled in the 410-430FPS range (1.6J). With hop up nearly maxed, the gun lifted both .36 and .4g bbs out to 200-220ft (laster straight), whereupon they'd fall like a rock.
The gun is easy to disassemble, and the stock hex screws are contained in the stock, making them impossible to lose. The stock is where much of the cost savings happened, and while it is certainly durable enough for play it doesn't feel high quality. Overall ergonomics are nice - to the point where I've gotten to quite like it. Interior part quality is sufficient for the price you pay - not top quality by any stretch, but not bottom barrel stuff either.
While stock performance was borderline impressive for an $80 rifle, I wanted my rifle to reach out quite a bit further. Given I was 1.2J lower than my field limit, I thought this would be pretty easy to accomplish. However upgrading has proven to be a challenge - not because there are not available parts, but because the gun is a mix of systems and no one really has figured out which parts are which. So, I decided to start this thread with my findings, so that others might have an easier time upgrading their rifles if they so desire.
Currently, my rifle is shooting accurately but still stuck at 1.8J - last tested with a Laylax SP170 spring. Seal is good everywhere except cylinder - best I can tell I'm leaking severely past the piston, causing my loss. I am about to purchase some new o-rings to hopefully address this issue.
Stock Specifications
Performance
.4g bb out to 220ft flat, then quick drop (hop up nearly maxed)
Spring
- Length = 8.5in / 216mm
- Outer Diameter (OD) .41 in / 10.5 mm
- Seems to be VSR-10 spec
- Length = 116mm
- Diameter = 0.75 in / 19.05mm
- Stroke length = 4.5 in
- O-ring is 20mm x 3mm (maybe 3.5mm)
- Inner diameter = ~12mm - does not accept 13mm springs
- 45 degree
- Length = 456mm
- Bridged (unbridge with dikes to install Maple Leaf Buckings)
- Length = 9.5in (end to end, not including head nor bolt assembly)
- Diameter = 7/8in / 22.2 mm
- Estimated Volume = 44.34 cm^3 / 2.71 in^3
- APS2 spec
- Custom brass cylinder head (APS2 spec)
- Hop Up unit is VSR-10 clone. Only difference is bucking slit is on opposite side
- Maple Leaf buckings will fit, but will require shortening and removal of slit guide due to above.
Verified Upgrades
Springs
- S&T Upgrade Spring for M40A3 - 500fps when new, quickly dropped to 410-430 range.
- SSG springs do not work, as they are 13mm outer diameter and thus don't fit into stock piston.
- Laylax SP170 Spring for VSR-10 - Fits, and had great power initially. Quickly dropped to 1.8J range with heavy bbs.
- SSG96 Cylinder Head - Seals well without teflon tape, and extends further into the bucking (perfect length).
Hop Up
- Maple Leaf VSR-10 buckings - requires shaving off guide bar and shortening feed-size length. Mr Hop 2020 70 degree and 2021 80 degree work great.
- Action Army Hop Up Chamber - Requires magazine modification, and removes ability to quickly adjust hop up.
- Maple Leaf Crazy Jet 430mm
Trigger Assembly
- L96 Trigger Sear - Only the sear itself fits - sear assembly does not.
Possible Upgrades
- Type 96/APS2 Piston - Not 45 degrees, needed for stock trigger-assembly.
Helpful Links
T4nk's Build Playlist
SiliconeSword's Upgrade/Mod Guide
BlackDog's Compatibility List
Jeppe's Notes