Looking for your opinion

[Kozzie]

So I recently bought an Echo1 AK 74U. I was poking around in the mechbox and I noticed the compression is terrible, no real surprise there. Now I'm looking to replace the compression parts: nozzle, cylinder head, cylinder and piston head.

I'm not too keen on dropping $100's on upgrades into a this gun as I will use it infrequently. So Systema and Promethius are not on my list. I'd like to get a kit and save a bit of money but I haven't been able to find one for the 74U. I've only found kits for a full length AK. This means I would need to buy a separate ported cylinder to match the 260mm barrel in the 74U. And of course I would price out buying a kit vs. individual pieces taking into account the cost of the extra cylinder.

I've been leaning towards Guarder and Modify parts as they fit my budget for this project ($50-$70) and are names that I recognize. But I have so little experience with upgrading guns I wanted to ask for opinions on these brands regarding the parts in question.

1) Do you have any experience with Modify or Guarder compression parts and what is your opinion?

2) Can you recommend another brand that you feel is better or have been impressed by?

3)Regarding the cylinder: I've seen ones that are rated from 200mm-250mm and ones rated from 250mm-300mm. I realize 260 is in the range of the latter of the two but it's right on the boarder and I don't want to cause excessive stresses to the mechbox. Which one would you recommend for a 260mm barrel?

If there is anything that you feel I'm overlooking please let me know.

I appreciate any and all advice
Thanks

Kozzie

[MaciekA]

Originally Posted by Kozzie

So I recently bought an Echo1 AK 74U. I was poking around in the mechbox and I noticed the compression is terrible, no real surprise there. Now I'm looking to replace the compression parts: nozzle, cylinder head, cylinder and piston head.

I'm not too keen on dropping $100's on upgrades into a this gun as I will use it infrequently. So Systema and Promethius are not on my list. I'd like to get a kit and save a bit of money but I haven't been able to find one for the 74U. I've only found kits for a full length AK. This means I would need to buy a separate ported cylinder to match the 260mm barrel in the 74U. And of course I would price out buying a kit vs. individual pieces taking into account the cost of the extra cylinder.

I've been leaning towards Guarder and Modify parts as they fit my budget for this project ($50-$70) and are names that I recognize. But I have so little experience with upgrading guns I wanted to ask for opinions on these brands regarding the parts in question.

1) Do you have any experience with Modify or Guarder compression parts and what is your opinion?

2) Can you recommend another brand that you feel is better or have been impressed by?

3)Regarding the cylinder: I've seen ones that are rated from 200mm-250mm and ones rated from 250mm-300mm. I realize 260 is in the range of the latter of the two but it's right on the boarder and I don't want to cause excessive stresses to the mechbox. Which one would you recommend for a 260mm barrel?

I appreciate any and all advice
Thanks

Kozzie

On question 1 and 2:

Our team is very happy with Modify parts, especially if you brand-match all the bits. Our experience is only with V2 and one G36 (V3), so I cannot speak to whether Modify's AK nozzle is any good, etc.

Here are some random notes that may be useful:

1) The Modify cylinder head has a double o-ring and has a great seal in Modify's cylinder.

2) The Modify transparent purple piston is generally regarded as brittle and catastrophe-prone. You may suffer a rack cave-in if you aren't careful with AoE or are pushing a hard spring at a high RoF. You may wish to keep the piston head, but I'd say ditch the actual piston body and go with an SHS blue -- it is very inexpensive, available locally in Toronto where you can inspect it in person, and known to work in very high fps and RoF setups.

3) The Modify cylinder head is wildly off-spec for the TM G36 body. It has an extra several millimeters of material that's clearly not intended for the TM shell design. I mention this because you should probably visit Toronto Airsoft and ask Frank to let you actually inspect the Modify cylinder head in person to ensure it isn't some completely different cylinder head shape from your AK's. If it is the right spec, it will seal very nicely -- we love the V2 version of this head.

4) The Modify nozzles have an o-ring and create a nice seal around the Modify cylinder head's output. One thing I've noticed quite different from most of my other nozzles is that the end of the nozzle is tapered quite dramatically, whereas most of my other nozzles have a more squared end. This may or may not present issues for your hopup. I found the results of the Modify nozzle's seal to be better in some hopups than others. The Modify hopup obviously had the best compatibility, but that's not going to help your AK project.

5) The cylinder that is included in Modify's compression kits feels great and fits snugly with no play in most gearboxes I've tried it in, including several G&P V2 mechboxes and one JG V3 mechbox.

6) The Guarder clear hopup bucking is really quite great, as many others on this site have suggested numerous times. You just need to be prepared to accidentally tear one apart during installation. I've torn apart 2 during a build in the last 2 months, and so I'll probably double up my order next time. One extra note I'd like to throw in about this is that I found this bucking survived very cold temperatures much better than all the other buckings I've tried. I did have to ease off on hop just a bit, but it did not fail me. I've been testing several other buckings in cold weather (ranging from -7C to -12C) situations, and found that the Guarder beat all the others easily (especially G&P's own bucking, which froze up like a stone and caused backpressure leading to piston stripping).

On question 3, I'd personally keep the inner until I had ruled it out as a "problem", especially if you don't intend on swapping the hopup unit.

[Kozzie]

Thanks "Ma check" for the info on Modify.

I don't plan on switching the barrel just yet. What I meant was that I wanted to match the upgrade cylinder to the barrel with respect to where the porting is located (on the cylinder) achieving similar a volume of air in each respectively.

[THe_Silencer]

When it comes to replacing compression parts on an ACM aeg, I always replace those awful yellowish clear air nozzles right away. I find prommy and King Arms nozzles provide great seal. After that you can choose to replace the compression parts bit by bit depending on how good the stock parts are sealing or just replace them all at once like Mac suggested, preferably with one brand. I personally don't recommend replacing the parts if they are giving you prefect seal. Sometimes getting better compression only takes heating up a pistonhead oring with a lighter, so give that a shot first.

[Kozzie]

That seems like a simple fix I'll try that , thanks.

[Styrak]

Are you sure the cylinder head is bad? Most of the bad airseals I've found are a bad piston/bad piston oring.