Hey.
If you go to around post #55 above, you will see I removed part of the battery compartment.
Effectively, there is a ‘Floor’ and side rails.
Remove them all, tonnes of space, but battery wobbles freely in space.
I removed the floor, but kept side rail, although kept them further apart.
This gives a cradle for the battery to rest in, with some extra room.
The floor acts as an anti rotation rigidity rod, onto the front sight.
Remove it ,and the front sight can move a little.
Thankfully, it’s gel, so pin point accuracy is not a concern.
Withe the front handguard all together, movement is minimal.
Front handguard goes on off easily with no pressure on the battery.
So, floor out, side walls wider is a bit more room for the battery, while also supporting the batt for no rattle…
Ok cool I’ll re-read the earlier post
But my message was regarding how the two halves of the top and lower handguard, how they slide lock together
I’ve sorted it now after a lot of cursing and headache
Was absolutely stiff as all heck n probably could use a light sand at the front of the lower handguard to aid in it sliding into the groove at the front under the front sight
Cheers tho
I think I got the last Sig 551 in Brisbane
The 7.4v stick battery was fit but small plenty of space left and weak for the gear box
The 11.1v stick battery was perfectly fit and no space left but it could be too strong for the gear box
The 8.4v stick battery also perfectly fit and no space left, and I settle for this
1 Like
The 7.4v battery you have there looks like it might be the best fit for my 550
I have the 11.1v gao lag I bought for my Sig 550 but with the 550 handguard it still feels extremely tight putting the handguard covers back on and feels like it compresses the battery a little
when putting the handguard covers back on your 551, how firm a fit is it with the gao lag 11.1v battery in?
I’d get my 551 out and try that 11.1v gao lag battery in it but I’m still sad my young fella fried it, i can’t mess with it until I’m confident enough to perform the surgery required to fix it 
1 Like
Yep… the 8.4v is a winner.
Used on Vas’s pulse rifles too.
bridges the gap, between 7.4 and 11.1v, and fits perfectly into the space provided.
Congrats on the 551… did you get it from M4a1.?.?
M4A1 Townsville has spare mags…
Thanks. Yes, I got it from there
Yes, 11,1v is tight but still fits. but I don’t have confidence with the building quality of the blaster ( it is not as good as E&C blasters). The 11.1v could be too strong for it. 8.4v is a bit smaller in diameter so it fits better.
2 Likes
I might look into getting one of the 8.4v gao lag batteries then. Thanks 
I bought the 7.4v, 11.1v, 8.4v batteries through Aliexpress
1 Like
Yeah that’s where I got the 11.1v gao lag… cheers
Your custom mag’s done @BME
Sig upper mag, AK J12 lower as requested
All works as it should, feels solid, join’s only really visible if you know what you’re looking at. Not sold on that front curve shape, but blame Jin Ming. 
Size comparo to original Sig mag :
Sig mag in receiver :
Sig/AK74U custom mag
Mag can be pulled apart if necessarry, although nothing like a normal mag… so much internal shiatsu to make this work. Base screw and two small black screws for and aft hold it together now. Solid but won’t ever be as strong as the factory one piece shell mags, I wouldn’t recommend sitting on it. 
I won’t post pics of the process unless someone else is tempted to do this… a warning though… it’s a shit-ton of improvising and handtool work.
@shadow187 I know you were keen to do this. 
1 Like
Woot Woot …!!!
Came through with the goods again…!!
Time to reunite it with the tail-less Long Boi, to see if it passes the
"I’ll Be Back " test…!!
I’m sure it will…!!
Thanks. 
Barry’s kinda busy right now…
That’s not a sandwich beemer
That’s a
I’ll be back…!!
Looky here, at what turned up today…
Thanks Mel ABF, for letting it through…!!
Some common sense…!!
The metal kit, is so much better than the 3d print…
The 3d print, was adequate for what it was…
but loose as buggery.
It would have needed a lot of aralditing, to hold it in place.
And, a lot cut from the mount, to allow it to cycle without hitting.
The new kit looks and feels, so much better…
metal kit up top…
i need to get a special battery, to fit the laser.
