question for old timer smiths

[scgunsmith]

have a sweet 16 in the shop. everyting has been stripped form the reciever and reinserted part at a time. the gun locks up in the closed position when everything is installed. like the bolt lock is sticking, no burrs on anything nor nothing out of place... any ideas where to look next?

this one is about to make me say bad words !

[gunnut69]

Is the barrel extension free in the receiver? The locking block dragging on the inside top of the barrel extension. Bent or improperly installed strut. Locking block latch worn or improperly installed.  Likely none of the above but kinda working down the list.. Might check the amount the barrel extension protrudes from the receiver when assembled.. Check spring tube for bent/rusty or worn out spring.. If the action strut is worn or improperly installed it can cause major headaches.. Is the firing pin sticking in the bolt.   What must you do to free the bolt in the weapon?

[scgunsmith]

Hey gunnut, the firing pin is normal, nothing bent, it just takes a rteal heavy pull to open the bolt . it cocks and fires normal. but its a bear to open unfired. the barrel is almost flush as it should be, no burrs anywhere on any parts. like i say its about to cause bad words in the shop. I'm the 3rd smith , this guy has brought it to. he said the other two kept it a few weeks and found what I have found. Even talked to a cpl techs at brownells and basically they said to look for what I have already looked for.

[Judson]

I ran into this once and I am sure you already checked but look at the tube in which the recoil spring lives and also the plunger and "Arm" that all this depends on.    I ran into one a few years back that had the ribs broken off the locking bolt and it had burred up other things and given simular results.    One other thing you might check, is this the origional barrel as tight head space could cause the same problem.

[gunnut69]

Perhaps the links cam surface has worn or the operating handle is worn.   The cam on the operating rod allows the locking block to release when the bolt is drawn back by pulling the handle. The clearance between the operating rod handle and the locking block is crucial also. Be sure to check for burrs on the link where it contacts the operating rod.  Try moving the barrel/breachclock rearward a couple of inches by pulling on the barrel. Watch the lock block latch action as the block moves forward. It chould not unlock too soon. Remove the fire control group and watch the operating handle's action with the link. Might also check the action of the locking block in the bolt. It should move freely and not bind or jam. Be sure to check the semi circular half round the locking block runs on, in older guns this was thinner and prone to breaking or burring if the locking bolt to bolt body fit was poor.  My guess is a problem with the link/operating handle operation.

[scgunsmith]

took everything apart, stoned everything mirror smooth, still samething. everything works great until the long spring is installed, then it wants to bind in the closed position. I'm looking at the link between the bolt and the spring

[rebel49]

Check the one tang screw and make sure it isn't to long and is binding the recoil spring inside the spring tube. Had an A-5 do just that and sheer the tube. This was with an aftermarket synthetic stock, but over the years wood shrinks and guys tighten the screw down more and more till it binds the spring and op-rod making the whole works tough to open.
Just my .02 cents, but something to look at.
Rebel49

[scgunsmith]

yeah revel, that was first think I looked at. even with the wood off it binds up. I have a list of new bad words this thing has created in my vocabulary

[scgunsmith]

finally fixed this bugger, I took every part, nook and craniy and polish it so slick oil would not stick to it ! I mean everything got a major polish job !
sweet sixteen is sweet once again !

[Dee]

I was going to say check for corrision in the Chamber. Oh well,