This is Inland Manufacturing s/n 9001316. I received it as a replacement from Inland, replacing s/n 900698. Finally got out to the range with it yesterday.
At first, approximately 1 in 5 shots the bolt failed to rotate and lock completely during firing with the carbine failing to fire. After the first 50 rounds or so this increased to 1 in every 2 rounds. When the bolt did lock and and the carbine was fired, about 1 in 4 the bolt failed to cock the hammer for the next shot.
Attachment 67741 (click on the pics for an enlargement)
Checking the headspace with Clymer gauges, it wouldn't close on a No Go, but it failed to close on the Go gauge. Spring tension returning the bolt to the closed position during firing would sometimes force the bolt closed but at 1 in 2 firing was stopped and the headspace checked.
Attachment 67742
I replaced the Inland bolt with a GI bolt made by Inland during WWII. It headspaced correctly. During reassembly, fitting the right bolt lug into the cam cut in the slide was difficult. Cycling the action for firing the cam cut in the slide would not allow the GI bolt to rotate and lock into the closed position. This could be overcome with physical force but on the next cartridge the spring could not force the bolt into the closed position.
The GI bolt was removed and replaced with the newly manufactured Inland bolt. Surfaces of the bolt, slide, receiver and barrel that come in contact with one another were treated with Breakfree in an attempt to see if lubrication would help.
Firing the carbine, the same problem with the bolt failing to close and lock was encountered about 1 in 3. In addition, the bolt and slide now failed to move when the cartridge was fired.
The carbine was disassembled again and it was discovered the gas piston nut had rotated to the point it allowed the gas out of the gas chamber without enough pressure left to allow the piston to operate the action. Had firing been continued the gas piston nut would likely have unseated completely. Had this happened there would have been noting to restrain the piston from becoming the bullet.
Before going to the range I had visually inspected and cleaned the carbine. I had noted the gas piston nut had been staked in place.
Re-tightening the gas piston nut to very snug I found it rotated past the stake marks in the gas piston housing.
Attachment 67743
While the nut may not have been tightened fully before being staked, I do not possess the skill to check the gas piston housing dimensions or size of the gas hole. At this point I didn't assume. After I returned home I submitted a return request. I received a prompt reply that an RMA and shipping label for return would be forthcoming. As of the time I authored this post it hasn't been received but I expect it will come tomorrow.
An insufficient number of rounds could be fired for a break in period and to evaluate the right bolt lug to note improvements over the damage to the bolt in the first carbine.
Ammo used was factory new Aguila round nose and Lake City Arsenal ammo from the 70's in like new condition purchased from
CMP
.
Jim
Sleeplessnashadow 
Originally Posted by imntxs564
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