[Whamhammer]

Hi all,

I have a 2018 model of Classic Army’s M110 SASS (model AR014M) with an ECS mosfet and trigger. This is the full length M110 that comes with a quad pic-rail and the smooth outer barrel to mount the quick mount suppressor.

Even though this comes with CA’s V2.5 GB, including a non-ported bore-up compression set; I have problems making above 1.9J w/.32g (or pretty much any weight) bb’s. I have tried running between M140 - M170 spring, and have also run a few thinner spacers, and no luck. I have checked the air seal, and the air seal is tight, including the air nozzle. The goal is to have above 2.0J with .43-.48g bb’s.

I have been using CA’s CNC hop-up for M4’s, is it is a mirror image (dimensionally) to the plastic chamber that came

M4 CNC Aluminium Hop-up Chamber for Blowback Version (P507M)

I have tried an Elvish Tactical R-hopped Prometheus 407x6.03mm SS tight-bore with a Modify Soft Flathop bucking, as well as a 300x6.03mm Madbull Steelbull tight-bore with a Maple Leaf MR hop 2021 70’ bucking and Omega nub, the most that I can get is 1.9J w/.32’s and 1.8J w/.43’s (hop on to where .43’s used to be set to, or hop off).

I swapped out the 16.5 tooth piston for a Classic Army 18 tooth piston. The nozzle is the factory Classic Army 23.0mm with o-ring, I did notice that the nozzle exhaust orifice was about 3.5mm, when just about every other nozzle that I have seen is 4.0mm, so I had a friend who works with machine work bore the orifice to 4.0mm , no appreciable improvement.

The air seal and air volume is there, the spring power should be strong enough, everything seems to be the way it should but I cant seen to breach a 2.0J ceiling!

Has anyone had something similar, any solutions?

 

[SiliconeSword]

I recommend that you try and weight your piston as the high pressure spike from a piston is usually more than a bucking can handle, which a heavier piston will smooth out and likely boost power.

@1tonne is the guy to talk to about hardcore DMRs, as I'm lazy and use HPA

 

[Whamhammer]

Does 1Tonne come on frequently, or would I get his attention through another means?

How do most people put weight on the piston, melt fishing weights to inner diameter of the piston? I tried to put a second aluminum piston retainer for a plastic piston, and it ended up not letting the piston go all the way back and locked up the gearbox and chewed a spur gear tooth.

All the guys who know what they are doing, in my area, are stumped on this one.

 

[SiliconeSword]

I think he's been around less these days, but try messaging him or just waiting.

 

[Whamhammer]

When I did have the gearbox apart, I noticed there was some wear on the paint/anodizing on top of the exhaust pipe on the cylinder head; not sure if thats a sign of misalignment or what. My mind is just blown that I can’t produce good power but yet that gearboxes airseal is fine.

I will send a message and see if he has any ideas.

 

[1tonne]

Sorry. I have not read the whole thread but the SR25 is normally pretty easy to get reasonable energy. So chances are you have a leak between your air nozzle and your bucking.

This is what is in my SR25: (3.3 joules on 0.48gm bb's)
-Jing Gong SR25 Receiver
-Retro Arms 8mm SR25 Aluminium Gearbox (Front Dremilled so tappet plate can go further forward. Retro Arms designed the gearbox wrong)
-Retro Arms 8mm bushings (These are really tight and will never move)
-SR25 Stainless Cylinder
-Aluminium Piston
-SHS SR25 Plastic Piston with full metal teeth made to fit 32:1 gears
-JG SR25 Tappet Plate with front filed down by half a mm.
-Add weight to piston. (I guess piston weighs about 30-35gm)
-Retro Arms Adjustable air nozzle (24.2mm long)
-SHS SR25 Gears mixed with Super Shooter 32:1 gears to give me SR25 32:1 Gears
-M190 Spring with a spring spacer added (in total the spring is somewhere between a M200-M210)
-Motor = JG M96 armature with AA R30000 Can (Most powerful motor I have ever seen)(Named the "Frankentonne")
-Orga 6.00mm x 460mm barrel
-G&G Green bucking

 

[Whamhammer]

Sorry. I have not read the whole thread but the SR25 is normally pretty easy to get reasonable energy. So chances are you have a leak between your air nozzle and your bucking.

This is what is in my SR25: (3.3 joules on 0.48gm bb's)
-Jing Gong SR25 Receiver
-Retro Arms 8mm SR25 Aluminium Gearbox (Front Dremilled so tappet plate can go further forward. Retro Arms designed the gearbox wrong)
-Retro Arms 8mm bushings (These are really tight and will never move)
-SR25 Stainless Cylinder
-Aluminium Piston
-SHS SR25 Plastic Piston with full metal teeth made to fit 32:1 gears
-JG SR25 Tappet Plate with front filed down by half a mm.
-Add weight to piston. (I guess piston weighs about 30-35gm)
-Retro Arms Adjustable air nozzle (24.2mm long)
-SHS SR25 Gears mixed with Super Shooter 32:1 gears to give me SR25 32:1 Gears
-M190 Spring with a spring spacer added (in total the spring is somewhere between a M200-M210)
-Motor = JG M96 armature with AA R30000 Can (Most powerful motor I have ever seen)(Named the "Frankentonne")
-Orga 6.00mm x 460mm barrel
-G&G Green bucking

Hi 1Tonne,

My target for my CA M110 is to be able to hit 2.3J with .32g and .48g bb’s (I can take 2.1-2.2J on either/both). With a M155, I was getting 1.88J w.32 & 1.8J w.43’s but now power is not consistent and definitely down. I wouldn’t be surprised if the problem is between the nozzle and the bucking but not sure how to find it (already swapped buckings, put small amount of grease between the inner barrel and bucking and teflon tape at the edge of the bucking. Is there a good online video/writeup that you may point me at, to figure this out?

Have you heard of people swapping out the factory Classic Army 23.0mm nozzle for a standard V2.5 SR25 24.0-24.4mm nozzle and having success? BB feeding is good but I am wondering if the air nozzle isn't going deep enough into the bucking?

 

[1tonne]

Try shaving a little away at the front of the tappet plate. Maybe half a millimetre. This will allow the tappet plate to sit in the bucking further. If you do not want to do this just purchase and try a different air nozzle. (They are reasonably cheap)
Also, at 2.2 joules I would not use 0.48gm. I would use 0.43gm bb's. You will most likely find that this will work way better than 0.48gm.

 

[Whamhammer]

Try shaving a little away at the front of the tappet plate. Maybe half a millimetre. This will allow the tappet plate to sit in the bucking further. If you do not want to do this just purchase and try a different air nozzle. (They are reasonably cheap)
Also, at 2.2 joules I would not use 0.48gm. I would use 0.43gm bb's. You will most likely find that this will work way better than 0.48gm.

1Tonne, it's been hard to source the 23.0mm nozzles that Classic Army uses in its M110's. CA has been hard to get a hold of for anything for a while, been trying to get a replacement bore up compression set (which is what comes in the M110 SASS model), and they don't even return emails or Facebook Messenger IM's (not really happy with them at the moment).

I did notice one odd thing, that may be the issue. The CA M4 EBB CNC Hopup that I have been using, because the one that came with it is weak plastic, has a rotary wheel that is 1mm thicker than the wheel on the original hop up, and it is keeping the hopup from going that much more into the gearboxes nozzle well (and also making me have to use a hammer and pin to push in or out the front receiver pin because its so tight a fit). I am thinking that if I grind 1mm off of the side of the wheel that goes towards the gearbox, that this may fix the issue.

If that doesn't fix the power problem, I do have a SHS 24.1mm SR25 nozzle that I will try to install, and see if that is the fix.

As far as the BB weight and power, I have been using .40-.43g's in the M110, when I was playing at fields that the limits were 1.88J w.32, and I was getting about 270 feet maximum range; some of the bolt action guys at the field that allow 2.3J w.32's are using .48's and getting 300-ish feet or so, and more stable shots. I know I don't have VSR air volume but with the bore up and if I swapped in a 260-300mm 6.02mm inner barrel, its probably not dramatically off (maybe?). I figure I would be able to run .45's and stay around 290 or fps at 2.2J.

At this point, if I can fix the problem, run .43-.45's and be successful, that would be enough for me.

 

[Whamhammer]

OK, took another loom at the hop up(s), it looks like both of them end up having the same fitment. I do notice that both are not having the nozzle up against the lips of the bucking when finished a semi auto shot (piston all the way forward); there is a visible gap that I can see the top of the interior of the hop up between the nozzle and the bucking in the hop up feed hole. My P90 is all the way forward, so I am figuring that is the way its supposed to be.

Does this sound like maybe I could get away with a 24mm nozzle instead of a 23mm?

 

[1tonne]

I would try the 24mm nozzle. It would not hurt. If it does not work, put it back to the original.

 

[SiliconeSword]

Maybe even try 25 and then just shorten it, using a drill and file like a lathe

 

[Whamhammer]

Pulled the gearbox today, and one of the motor plate screws stripped itself and comitted seppuku. Ordered a new grip from Classic Army, directly (along with another hopup, spring guide, bore up cylinder head, and other knickknacks to make the air freight worth while).

Took a break for the day, and will go back at it, later this week.

I also just received all of the parts for Peruns adjustable air nozzle set, and if the 24mmisnt the right length, I will go that route.

Cross your fingers, this might fix six months of heartache!

 

[Whamhammer]

OK…. Finally got off my duff, and put the 24mm nozzle in. With a M155 spring, and .32’s, I am getting 438 FPS and 2.86J. I don't know why Classic Army is putting in a 23mm nozzle, if its just going to creat an air seal issue at the bucking. Who knows.

I am going to try a M125 spring and see if I get down to 1.8xJ, and then check heavy weight BB’s to see what inner barrel length that I am really wanting to use with this combo.
Thanks for all the help guys!

 

[Whamhammer]

I ended up putting a ZCI M130 spring and two spring guide metal ring shims off of some old plastic spring guides that I had from some of the Thompson gearboxes that I upgraded. I got 358 FPS w.32’s; with some hop applied I should be just under 1.88J.

So if a person has the Classic Army M110 SASS, and they go with a non OE bucking, a 24mm nozzle does the trick, and it doesn’t take much spring to get power out of this beast!