Tuning KalibrGun Cricket II Tactical Barrel Reinstallation. Trigger Adjustment. Tuning.

[TTBJ]

I bought the Cricket II Tactical 60 off of the forum. The barrel is loose, it rotate when screwing on the shroud. I can easy rotate the barrel/shroud just by 2 fingers.

After some homeworks, now I know how to do it.

The front/rear clamps are only parts to hold the barrel. Screws (A1/A2/A3) are used to tighten clamps to hold barrel and air tube. The screw is M4x16.

The barrel has a little dent, set at exactly 180 degrees of the barrel port. When fitting the barrel, this dent must be seen through the front screw hole in the picatinny rail. This means that the barrel port and the transfert port are exactly aligned. A pointed barrel locating set screw is used when installing the barrel. It is then taken out once clamp is tightened and is replaced with a normal bolt. The front picatinny rail screw (B) is M4x25, so the set screw is M4.

My questions are:

1. the set screw is cone point or cup point?

2. torque for the 3 clamp screws (A1/A2/A3)?

3. torque for front picatinny rail screw (B)?

4. torque for rear picatinny rail screw (C)? It's M4x20, 5mm short than front screw, only about 3mm thread in clamp, right?

Thanks

 

[TTBJ]

Some informations come from here. https://www.airgunnation.com/threads/cricket-tactical-60-accuracy-problems-fixed.1091619/

Thanks aldea6 and other members.


aldea6 also thinks about "changing the factory front screw by an homemade, longer and pointed one. Care must be taken to be sure the screw engages the dent and tightens the picatinny rail at the same time, so srcew lenght is crucial."

The second idea is "put a short pointed grub screw, tighted just enough to keep the barrel from rotate , and on top put the scope maintening screw , without touching the grub screw.That should release the pressure on the barrel."

Make the accurate lenght srcew is too hard, so I think about the second idea.

1. Fitting the barrel, no way see the dent through the screw hole.I use a toothpick to "feel" the dent.

2. Measure the lenght between bottom of the dent and top of picatinny rail. Toothpick is a good tool! The lenght is about 33mm.

3. Factory screw is about 29mm, also after screwing down, the top of screw is near 1mm lower than top of picatinny rail. So only about 3mm gap between the screw and barrel, it's no enough for a short set screw. Also this gap is the empty part of clamp.

4. Factory screw is M4x25, how about use a shorter M4x20 screw?

5. Drop factory M4x25 to the hold, it's about 6mm higher than top of rail, so the thread will go into clamp about 7mm. If 5mm shorter then only about 2 to 3mm thread left!

So there is no way to put a short set screw.

 

[TTBJ]

KalibrGun Cricket II Tactical 60 .22

 

[TTBJ]

answer myself：

M4 screw has 2 thread size, 0.5 and 0.7. The M4x25 (b) rail screw is 0.7, M4-0.7 x25mm.

14mm/ 20 threads = 0.7mm !

 

[TTBJ]

Local Homedepot only have cup point set screw available.

 

[TTBJ]

Email KalibrGun/ KalibrGun-USA on 07/12.

Got answer from Kalibrgun USA the day before yesterday. It said:

Here's the technical department answer.

1. the set screw is cone point or cup point? cone point

2. torque for the 3 clamp screws (A1/A2/A3)? 6.5 N*m

3. torque for front picatinny rail screw (B)? 4 N*m

4. torque for rear picatinny rail screw (C)? 4 N*m

Hope it helps and have a great day.

 

[TTBJ]

Question #1:

I bought 2 M4x12 cone point set screws on ebay, just $2.38 shipped.

 

[TTBJ]

Question #2:

The torque for the 3 clamp screws (A1/A2/A3) are 6.5 N.m？

It‘s unreasonable. M4-0.7 (class 12.9) screw torque is 4.83 N.m, 6.5 will damage the screw.

 

[TTBJ]

For steel screw in aluminium hole, the mixminimum thread length is 2 time bolt diameter. So M4: 4mm x 2 = 8mm.

I measured A1/A2/A3 = 9.5mm, > 8mm.

Max torque for A1/A2/A3 = 4.83 N.m.

 

[TTBJ]

Question #3:

I measured front picatinny rail screw (B). It's 7mm in the hole. 7mm < 8mm min thread length. Shorter thread = lesser torque.

I calculated, the torque (7mm) is 63/64 max torque. So 4.83 N.m x 63/64 = 4.75 N.m.

KalibrGun-USA said 4 N.m. It's reasonable.

 

[TTBJ]

Question #4. The torque for rear picatinny rail screw (C).

KalibrGun-USA said 4 N.m. It's unreasonable.

The rear picatinny rail screw is M4x20mm. It's 5mm shorter than front screw M4x25mm because the rear clamp trigger rod is above barrel. It's only (7 mm - 5mm = ) 2mm thread in clamp.

I calculated, the torque (2mm) is 7/16 max torque. So 4.83 N.m x 7/16 = 2.11 N.m.

 

[TTBJ]

I alos emailed Charlie Frear @ Georgia Airguns, got answer same day. He said:

"I torque them using wrist strength pretty tight. Make sure you use never seize for aluminum on the threads of the bolt and under the head of the bolt."

Never-seize is a good idea. I will use it for these screws.

 

[TTBJ]

Charlie Frear @ Georgia Airguns best service best knowledge

 

[TTBJ]

The C2T is sold by T**** T**** 4 months ago. I pm/ emailed T**** T**** 2 weeks ago, still no answer.

 

[TTBJ]

The use of Never-Seez Regular Grade requires about 30% less torque while providing the same clamping force on threads. This torque percentage is even lower if Never-Seez is applied to both the threads and bolt cap, which is the preferred method.

 

[TTBJ]

I will use Never-See on both the threads and cap, 40% less torque.

 

[TTBJ]

Finally the max torque with Never-Seez are:

A = 25 in.lbs
B = 21 in.lbs
C = 11 in.lbs

 

[douger]

line uo the divit in the brrel through the scope rail tight up clamps very simple 5 minute job not rocket science

 

[TTBJ]

I will work on the gun next weened.

 

[TTBJ]

line uo the divit in the brrel through the scope rail tight up clamps very simple 5 minute job not rocket science

I don't want to damage these aluminium screw hole.

I am engineer. rocket science