Roller Lock Problem

>>32591291
>Bought a used Century Arms C308

Found your problem right there.

>>32591291
>Bought a used Century Arms C308

Found your problem right there.

Have you taken it apart, or disassembled the bolt?

>>32591344
Yeah. Shit was pretty dirty when I got it. Cleaned everything up the best I can, lubed up the important bits. It has some minor carbon staining but nothing that should prevent it from working.

>>32591392
You may have put it back together incorrectly, which can cause the rollers to protrude unfavorably. Take it apart again and follow a video guide.

>>32591418
Done and done. I figured that the first video I watched was bullshit so I tried a few more. All the same. I'm positive everything is assembled right. Bolt has no issue going into battery when I drop it in during reassembly. Goes into battery just fine when I ease the bolt forward. It only does this when you release the bolt at full force.

>>32591418
This. Dunno what you've got experience with, but the way the bolt goes back together can be a little odd and frequently is borderline impossible to do without tool assistance to get you a mechanical advantage..

>>32591464
Find a video for a PTR, it will be the same internally. And try again.
If it's still fucking up look up how to measure the bolt gap.

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For reference, the rollers should not be protruding like that, which is probably your problem. NFC on the root cause.

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>>32591418
>>32591466
>>32591531
It's assembled correctly. I've been trying to get this working for days now. I've gone through at least half a dozen videos looking for anything I could have missed in the others. I've read up on bolt gap and it looks fine. Thanks for the suggestions but that's not the issue here.

>>32591615
Are the rollers protruding at all when the bcg is in that state?

>>32591544
I've noticed that the bolt takes very light pressure to push back into the carrier and engage the rollers, but a lot of force is required to pull it back out and contract the rollers.
>>32591624
No they are flush with the bolt.

>>32591638
That is normal, you should pull the bolt head forwards as far as it will go before putting it back in the receiver

>>32591638
Might need a new firing pin spring.
OR the little piece that holds the rollers in might be jacked up.Have you taken the rollers out before?

>>32591657
I'm aware. It goes back together just fine and has no issues going into battery correctly until the charging handle is released with full force. It's as if there's something in the way that causes the bolt to be pushed back as the carrier moves forward but that's not the case.

>>32591690
Can you feel the bolt rub in the receiver as its going into battery?

>>32591690
Have you tried replacing the recoil spring? The recoil springs on c308s are surplus, it seems like the bolt is going fast enough to accelerate over the force required to push in the rollers

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>>32591686
I haven't messed with the rollers but they seem fine
>>32591705
Not really. It's pretty smooth.
>>32591736
It's a little hard to believe the spring can push a bolt assembly THAT heavy so fast that it messes with the rollers, but at this point that makes the most sense.
I've figured that since it's an issue with the bolt coming back and engaging the rollers before going into battery, maybe it has to do with the bolt head locking lever or spring?

>>32591810
>I've figured that since it's an issue with the bolt coming back and engaging the rollers before going into battery, maybe it has to do with the bolt head locking lever or spring?
I have a PTR infront of me and if I ride it forward i can cause the same malfunction as you. If the bolt head was fucked you would see boltgap issues. Have you measured the bolt gap?

>>32591544
Your shit looks pristine anon. How old is it?

>>32591810
You probably need to take the bolt completely apart.

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>>32591843
Don't have any filler gauges, but no coin will fit in the gap so it must be less than 0.05". I can visually see a gap that's gotta be more than 0.01". Any household items you can think of for getting a better idea?

>>32591849
About a month. Still breaking it in so it still gets pampered after every mag.

>>32591951
0.05in is roughly the width of a dime or penny.

>>32591291
>C308
Problem identified. Slap yourself for buying a known shitter without testing it and sell it for scrap.

>>32591843
I guess all credit cards are .03" The gap must be less than that since it won't fit.

>>32592024
Your bolt gap should at least be between 0.004" and 0.020".

>>32591951
>taking pictures with a paper towel over the camera
Jesus make it stop

When you run the bolt home does the bolt head stay in the forward position? It sounds like it could be catching on something and being pulled backwards, which would force the rollers out.

>>32592101
Yeah I gotta get a new phone. Camera has been busted for over a year. Anyway that's what I thought. There's gotta be something pushing it to the rear while the carrier is moving forward, but I don't see anything that could be doing it.

>>32592145
Do you have any regular non-laminate copy paper laying around? Steal some from your printer tray and see how many folds you can fit into the gap, report back with that number.

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There should be more space between your bolt head carrier and bolt head.
Can't say what would cause that problem. I don't think the rollers should ever be able to come out in that position.

I will post pics of my C308 bolt.

>>32592168
Good thinking dude. I got 6 sheets.

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>>32592240

>>32592249
So with 6 sheets and about 0.004" thickness per sheet, your gap is about 0.024", which is slightly out of spec on the high side but shouldn't cause lockup fail like that. There's something else wrong with your gun.

Did you buy this from a pawn shop or what? Did you not get a chance to dry cycle the gun before you put money down?

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>>32592251

>>32592240
>>32592251
Keep your bolt open like in pic 1 and reach your finger in there and press the bolt back into the carrier. Does it go back at all, and if so, do the rollers come out slightly?

>>32592251
>>32592274
Century is using CETME bolt heads on these guns, not G3 pattern. Huh.

>>32592267
I dry cycled it and checked everything they would let me without taking it apart. I didn't slap the bolt from the locked position until after I bought it. Didn't notice this problem until I got home from work the next day.

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>>32592328
>I didn't slap the bolt from the locked position until after I bought it.

Field strip the upper receiver, take the bolt group apart, measure the rollers they installed (Check the tops for a "+number", if they're blank they're standard 8mm. (Unless Century doesn't mark, which is totally possible given their record of doing things.) Check the inside of the upper receiver for obstructions like metal debris.

>>32592283
No, the bolt head + carrier will move back like if I was using the charging handle.
I'm not OP, btw.

>>32591291
your rifle is fucked, like bulged receiver fucked

I don't have a cetme But I do have a HK93 clone, at no point should the rollers be able to protrude from the bolt EXCEPT when the bolt is locked.

>>32592648
How would a bulged receiver even affect the rollers? The carrier is much wider than the bolt head even with the rollers engaged. The issue must be the bolt head being able to walk back toward the carrier when it's not in battery. It could be anything from the locking lever to the firing pin/spring or the locking piece. It could even be the recoil spring as the guy mentioned before. It only happens when the carrier moves forward too fast.

>tfw you're able to do beginner tier googling and not get bamboozled into buying a shit tier g3 clone

>>32591291
it sounds like you barrel is a little too far in the trunnion. the bolt contacts the breech face of the barrel, stopping it's forward movement. the locking piece continues to move forward, pushing the rollers out and into the locking recesses.

if this is occurring too early, then the forward movement of the bolt is too soon or something else is out of spec.

check your bolt gap - it should be between 0.004" and 0.020". "service" range for guns that have seen use is 0.010" to 0.020". ideal gap is 0.014". if your gap is particularly small, then you may be on the edge of not locking the breech properly which is a safety issue. you can use larger rollers to increase this gap. also ensure your locking piece is the correct one (45* shoulders) and that you don't have a buffered carrier or something.