Scar bolt lock *about to loose it*

[Dart]

OK this god damn thing is brand new and its already being a pain in the ass. No matter what I do the bolt lock won't work! I have tried every single fix on the internet and still nothing. I got it to lock back for about 3 times than it decided *oh fuck that I am working properly!*

WE scar
co2

Mods tried
Adding material to bolt lock
taking a little bit off the bolt lock well
weakening the spring on the bolt lock


It locks back when I manually charge it but when I fire... nothing. I don't get it, anyone?

[m102404]

Assuming that your upper and lower are sitting/aligned properly...

Lighten the bolt assembly and/or the force that pushing it forward (i.e. the recoil spring)

[Dart]

ok wtf I post this and it just randomly starts working. I swear GBBRs can read.

hmmm maybe thats whats going on, the lower maybe not aligning... there is no wobble in the lower receiver though.

[m102404]

GBBRs and I get along real well...even via the Internet

I willed it to work right...but I've got to do some other stuff now...so it'll fail the next mag. Sorry.

[S.H.I.E.L.D.]

Tyson the GBBR whisperer.

[Dart]

I hate you, it has now stopped working! *facepalm* ok this is frustrating and VA is about to get a refund request. I bought brand new figuring it would work..... you know latest gen of scar and what not. I guess I was wrong.

[Dart]

hey m102404 have you ever tried the T.S.C bolt lock plates?

btw I think the reason it started to catch for a few things there is the hammers rolling bearing axle fell out and created more resistance and slowed the bolt down....

[lt_poncho]

Sorry you can only pray to Tyson once a day...he's back to NeverNever land now!

[Brian McIlmoyle]

I find the bolt lock has more to do with the mag than the gun.. I have 16 mags.. some engage the bolt lock all the time .. some sometimes.. some never . I typically swap mags before empty anyway .. so I really have not experienced this little "idiosyncrasy" as a liability.

Originally Posted by Dart

OK this god damn thing is brand new and its already being a pain in the ass. No matter what I do the bolt lock won't work! I have tried every single fix on the internet and still nothing. I got it to lock back for about 3 times than it decided *oh fuck that I am working properly!*

WE scar
co2

Mods tried
Adding material to bolt lock
taking a little bit off the bolt lock well
weakening the spring on the bolt lock


It locks back when I manually charge it but when I fire... nothing. I don't get it, anyone?

[Dart]

so it catches when I have low fps * I think the co2 cap wasn't sealed properly* but as soon as I get some good hard shots it doesn't work again.

I wonder if these problems would all go away with green gas.

[m102404]

You know I can't really fix rifles over the Internet just by willing it to happen...right? JK

Sorry, no...I haven't used that part.

The positioning of the catch (most important, the height of it relative to the bolt) is a key factor. How far the bolt travels on a shot is critical as well.

Wear/tear, the position of the trigger unit in the lower, the fit of the upper to the lower, the position of the bolt in the upper, the recoil spring...can all affect the two parts working correctly together. It's one of those simple-complicated things. Tracking down what's off where isn't easy though.

If it'll lock back every time on an empty mag when you are manually racking it but not otherwise, then the bolt isn't traveling rearward enough on a shot. It can obviously absolutely travel enough (or else it wouldn't lock back when you manually rack it). That's also a good sign that the positioning of the trigger group and upper/lower receivers are ok.

The things that affect how much the bolt travels rearward are:
- oring seal on the nozzle to the inside of the cylinder (needs a drop or two of oil)...good seal = more pressure build up = faster rearward speed/more force
- compression length and strength of the recoil spring...if it won't compress enough with a normal shot then the bolt stop won't engage. If it's binding alot (lube it) then it'll slow down the bolt and might stop it from travelling far enough back
- "timing" of when the knocker retracts and stops feeding gas (that's really not adjustable...they're fixed parts)

How fast the bolt travels back...and how fast it travels forward...is affected by:
- the strength of the recoil spring...strong = slow back, fast forward...weaker = faster/further back, slower forward.
- the weight of the bolt + guide...heavy = slow to start recoil cycle and more gas use and more impact to rear hinge plate...light = more rearward speed and less impact force
- resistance from the guide's wheels...drag = slow bolt both ways
* bomber's super lightweight bolt is very light

First, try lubing all the bearing/contact surfaces...o-rings, etc... These guns like lube.

After that there's not much to do without modding/fitting parts, and that'd be hard to communicate in writting.

Best of luck.

***EDIT***
Brian M has a very good point about the mags. If the main knocker valve is stiff then it might not be dumping enough gas.

Lt is right too....I gotta do some work now
**********

[Dart]

alright thanks for the advice. One thing I did try is putting my finger under the bolt catch and firing, the bolt catch engages. So its not a matter of going back far enough, its like the catch doesn't have time to engage.... or its not up far enough.

[Dart]

well I had to snip a coil off the recoil spring, it doesn't slam the bolt shut anymore like it used to but it still cycles properly. pointing straight up the bolt does slide back just a little bit....

how ever the bolt catch functions properly now. Full auto is still usable as well *of course in bursts as with all GBBRs* Lets hope this fix holds.

[Dart]

yah so that didn't work. the spring must have compressed and now it doesn't go forward enough to let the sears catch and stops firing, so I guess the bolt catch on these were never ment to function. What a piss off. You would think if someone sells something like this "WE" they would make sure it actually functions on something as simple as a freaking bolt catch.

[ShelledPants]

Originally Posted by Dart

yah so that didn't work. the spring must have compressed and now it doesn't go forward enough to let the sears catch and stops firing, so I guess the bolt catch on these were never ment to function. What a piss off. You would think if someone sells something like this "WE" they would make sure it actually functions on something as simple as a freaking bolt catch.

The bolt catch on my WE Scar functioned properly for over 500 rounds (sold it last year). To the defense of the gun, you did a lot of drastic mods early on, when the problem may have been the magazine's bolt catch riser. :\

That being said, I don't believe in the WE Scar system, there are a lot of problems plaguing these rifles.