Gun barrel and shimming

[Aux]

Hi all,

 

Just got my first gun and shimmed it following tutorials. However after reassembling i notice the outer barrel of the gun isn't sitting in the centre of the handrails, it's not loose or touch the sides, just doesn't sit in the very centre. Was wondering if more experienced guys in here would know if it affects accuracy performance etc?

 

Also after shimming the gears, there was a noticeable improvement in trigger response, but i can't seem to make it sound like those guns on youtube that sounds like "pop" instead of motor noises. Have i done the shimming wrongly or could it be my motor?

 

I have the Specna arms SA-E08, with specna arms high torque motor (not sure specific model).

 

Cheers

[Rogerborg]

Ahoy and welcome.

 

 

1 hour ago, Aux said:

However after reassembling i notice the outer barrel of the gun isn't sitting in the centre of the handrails, it's not loose or touch the sides, just doesn't sit in the very centre.

 

I'm unclear, did you disassemble the upper / handguard and do anything with the outer barrel?  Or was it already like that?  Do you have a picture of how badly it's off centre?

 

 

1 hour ago, Aux said:

i can't seem to make it sound like those guns on youtube that sounds like "pop" instead of motor noises. Have i done the shimming wrongly or could it be my motor?

 

Have you adjusted the motor height?  You want to move the adjusted screw in gradually until it you can hear it just starting to screech, then back it out. Play around with it a bit to hear the different sounds it makes at different heights, and get it as quiet as you can.

 

You might find that you're comparing against video of short-stroked gearboxes as well, with higher torque motors, running on 11.1V.

 

 

1 hour ago, Aux said:

with specna arms high torque motor (not sure specific model).

 

Specna stock motors are OK, but not great. Most aftermarket motors will be significantly snappier.

[Aux]

11 hours ago, Rogerborg said:

I'm unclear, did you disassemble the upper / handguard and do anything with the outer barrel?  Or was it already like that?  Do you have a picture of how badly it's off centre?

No, i didn't mess with that part of the gun, i had only taken apart the gear box and rearwards of the gun.

 

 

Heres a picture taken from the centre, it might be unclear, but you can kind of see a wider gap on the right than the left, does it really matter? The handguard also wobbles very slightly, unnoticeable when playing.

11 hours ago, Rogerborg said:

Have you adjusted the motor height?  You want to move the adjusted screw in gradually until it you can hear it just starting to screech, then back it out. Play around with it a bit to hear the different sounds it makes at different heights, and get it as quiet as you can.

No i have not, i shall give it a try thanks.

[Pseudotectonic]

Ahoy

 

The problem might be two parts:

1. outer barrel not center / sitting correctly / tightened in the receiver, and/or

2. handguard not center / sitting correctly / tightened in the receiver.

 

 

 

1. To align / center / stablize / rigidify the outer barrel you can shim the insert area (which goes into the receiver) like this:

You want it to feel a little difficult to insert, but once it's in and tightened, it should be very solid.

 

 

 

2. To stablize the handguard I guess you can try tightening the nuts and/or barrel nut to see if it stops wobbling.

If not there are some aftermarket "barrel nut shims" you can put on to tighten it further.

 

 

 

Whether it affects accuracy: yes in a highly controlled environment, but probably will not affect you meaningfully in an actual game.

 

And about shimming gearbox, shimming gearbox is only one of the many steps to great trigger response, there are other areas of upgrades you can look at, like the motor, battery, gear ratio, mosfet precocking etc.

 

You won't get top tier trigger response just from improving the factory shimming. It will help a little, but not all the way. Which it seems you have got the expected result.

[Skara]

I had the Core version (now it's completely different).

 

Barrel not being aligned is pretty common, maybe one of the three handguard retaining grub screws is tighter/looser so it pushes the thing out of alignment.

 

Regarding shimming, the one place where most of the noise comes from is the bevel and pinion area, they are also the weakest link in the chain so it's very important to get them right.

There are multiple guides over the internet to shim those two components, I'll post the two that I found to give the most comprehensive information:

 

[Aux]

6 hours ago, Pseudotectonic said:

1. To align / center / stablize / rigidify the outer barrel you can shim the insert area (which goes into the receiver) like this:

You want it to feel a little difficult to insert, but once it's in and tightened, it should be very solid.

Ok will give that a try

 

6 hours ago, Pseudotectonic said:

To stablize the handguard I guess you can try tightening the nuts and/or barrel nut to see if it stops wobbling.

If not there are some aftermarket "barrel nut shims" you can put on to tighten it further

I seem to only see tiny allen screws on the sides and bottom of handguard, can't see any big bolts that seem to be holding it in would i possibly be on the inside?

 

5 hours ago, Skara said:

I'll post the two that I found to give the most comprehensive information:

Thank you i'll have a watch through

[Skara]

11 hours ago, Aux said:

I seem to only see tiny allen screws on the sides and bottom of handguard, can't see any big bolts that seem to be holding it in would i possibly be on the inside?

Nope, it's only those three grub screws.

Luckily it has anti rotation tabs which effectively lock it in place and prevent loosening.

[Aux]

On 31/03/2025 at 00:34, Rogerborg said:

Specna stock motors are OK

Would you have any recommendations for good motor upgrades? 
there seems to be a lot of motors that says high torque so I’m not sure which to get, something around 50£ and would be a decent upgrade from stock motors. I mainly fire semi auto as I play in an indoor site so rof would be less important, mainly want an upgrade for trigger response and get rid of the cheap aeg noise.

[Pseudotectonic]

I suggest spend a little bit more to get a brushless, specifically this one is really best bang for buck for trigger response for a motor:

 

[Skara]

I would avoid T238 motors, they have a rather high failure rate..

Go Solink or Warhead, these are the two with the less shit quality control of the bunch.

 

A much more cost effective way of upgrading your AEG is to set a very definite goal first, then look at different ways to achieve said goal and choose accordingly.

Swapping random parts without a precise plan often leads to waste of money and time.

[Aux]

2 hours ago, Pseudotectonic said:

I suggest spend a little bit more to get a brushless, specifically this one is really best bang for buck for trigger response for a motor:

 

Have you personally tried it? How is it in terms of reliability as @Skarahas mentioned.

 

2 hours ago, Skara said:

A much more cost effective way of upgrading your AEG is to set a very definite goal first, then look at different ways to achieve said goal and choose accordingly.

Swapping random parts without a precise plan often leads to waste of money and time.

Right got it. Mainly just want to improve the feel and playing experience(trigger response) with the gun really, and make it nice and satisfying to play with. Thought upgrading the motor would be a simple one as i can literally pull it out of the bottom.

[Rogerborg]

Brushless is doubtless where we're going to end up, but I reckon the Big Dragon M140 is great value for money if you don't want to splurge that much.  I'm running 2 of those (and an M160 in a DMR, but avoid the M120) and can't fault them. Running on 11.1V without any short stroking they eat BBs faster than my mags can feed them - I've just introduced some ROF reduction into one gun to calm it down.

[Pseudotectonic]

I don't have the T238 brushless blue but I have heard nothing but good reports from it. Plenty of "builds" floating around reddit using it. I don't remember seeing much reports of failures. If I buy a new motor today that is the one I buy. The T238 blue.

 

Whereas the Warheads are definitely last gen with their 10 ms start delay and slow ramping torque is not the best for trigger response.

[Aux]

Hi all,

After a bit of research, I've ordered a XT high torque motor 22TPA, with some 13:1 shs gears, running with 7.4v lipo(only have one battery at the moment). Is this a good combination or would 16:1 gears be recommended over 13:1? Currently have stock 18:1. 

 

planning on getting Brushless motors when I've saved up more further down the road of airsoft

( the upgrade is with goal to improve trigger response and snapyness. ROF less of a priority)

Edited Saturday at 20:48 by Aux

[Rogerborg]

16 hours ago, Aux said:

upgrade is with goal to improve trigger response and snapyness

 

A mosfet with pre-cocking can do this. The X-ASR in your EDGE is only there for trigger protection, and can actually crap-out if you run a meatier motor (although I've only had that happen on 11.1v).

 

The XT and 13:1 should help, as long as the battery can provide the amperage. As with most of airsoft uPgRaDeZ, the only way to really find out is to try it and see how well it works in your gun.

[Aux]

5 hours ago, Rogerborg said:

 

A mosfet with pre-cocking can do this. The X-ASR in your EDGE is only there for trigger protection, and can actually crap-out if you run a meatier motor (although I've only had that happen on 11.1v).

 

The XT and 13:1 should help, as long as the battery can provide the amperage. As with most of airsoft uPgRaDeZ, the only way to really find out is to try it and see how well it works in your gun.

Yep waiting for akm4 to ship it out now, hopefully it works. 

 

Any particular mosfet you'd recommend?

 

Also are there any websites for cheaper nuprol batteries, 11.1v seems to be a bit pricy on amazon for only around 1200mah,

[Lozart]

13 hours ago, Aux said:

cheaper nuprol batteries, 11.1v seems to be a bit pricy on amazon for only around 1200mah,

 

Don't buy Nuprol batteries.

 

Try these instead https://www.componentshop.co.uk/batteries/airsoft/li-po-packs/11-1v.html

[Rogerborg]

14 hours ago, Aux said:

Any particular mosfet you'd recommend?

 

Perun AB++ is well featured. You'll need to do a bit of soldering.  You can also go with an optical mosfet inside the gearbox, I don't dabble in such sorcery though.

[Aux]

10 hours ago, Lozart said:

 

Don't buy Nuprol batteries.

 

Try these instead https://www.componentshop.co.uk/batteries/airsoft/li-po-packs/11-1v.html

Oh awesome half the price. Any problems with overheating and such at all?

 

9 hours ago, Rogerborg said:

 

Perun AB++ is well featured. You'll need to do a bit of soldering.  You can also go with an optical mosfet inside the gearbox, I don't dabble in such sorcery though.

what about the gate x asr2 is that any good compared to my x asr?

[Quagmire]

Hobbyking is always worth a look for lipos, just make sure you filter by stock in the UK warehouse or you can sometimes wait a while for delivery.

[Colin Allen]

2 hours ago, Aux said:

Oh awesome half the price. Any problems with overheating and such at all?

 

what about the gate x asr2 is that any good compared to my x asr?

Only in that it is supposedly able to deal with higher loads without failing; it does not have the features of a Perun AB++ or Hybrid.

[Lozart]

13 hours ago, Aux said:

Oh awesome half the price. Any problems with overheating and such at all?

 

what about the gate x asr2 is that any good compared to my x asr?

 

If your battery is overheating then either a) you're drawing more current than it can supply - get a bigger battery/fix the problem in the gun or b) you are using shite batteries.

 

The X-ASR 2 is functionally no different than yours. It has a higher overload capacity but that's about it.

[Aux]

49 minutes ago, Lozart said:

 

If your battery is overheating then either a) you're drawing more current than it can supply - get a bigger battery/fix the problem in the gun or b) you are using shite batteries.

 

The X-ASR 2 is functionally no different than yours. It has a higher overload capacity but that's about it.

Got it just ordered some 11.1v from the website, should work fine.