matthewdanger
12-06-08, 19:58
A friend of mine just bought his first rifle. He went out to shoot it for the first time today and had some nasty short stroking issues. I have not been able to see the rifle in person yet.
Here is what I know:
It is a 20" Colt barrel that has been cut back to 17" and some change (I know, I know, its a crime to go cutting on Colt barrels :) ). It has rifle gas. I am unsure of whether it has a 5.56 chamber or .223. The ammo used was a mix of Wolf 75 grain (steel case) and M855PD. It was about 20 degrees out when he was shooting.
The problem is that the rifle was short stroking each and every round. It was effectively a bolt action. It wouldn't eject the spent round, in fact he made it sound like it wouldn't even budge the case from the chamber on its own.
Here is what I have told him to check so far:
1. Check gas key.
2. It could be that the gas port was not opened up when the rifle was shortened which would cause shortstroking in the cold.
3. Check the brass for evidense of a rough chamber.
4. Check to make sure that the bolt moves relatively freely in the upper.
Can you guys think of anything else?
If I were a betting man, I would say it is because the barrel was cut back without opening the gas port. This is notorious for causing function problems. The person he bought the rifle from could not tell him whether or not the gas port was opened up but the cutting was done by a very well known place.
Thanks,
Matt
Here is what I know:
It is a 20" Colt barrel that has been cut back to 17" and some change (I know, I know, its a crime to go cutting on Colt barrels :) ). It has rifle gas. I am unsure of whether it has a 5.56 chamber or .223. The ammo used was a mix of Wolf 75 grain (steel case) and M855PD. It was about 20 degrees out when he was shooting.
The problem is that the rifle was short stroking each and every round. It was effectively a bolt action. It wouldn't eject the spent round, in fact he made it sound like it wouldn't even budge the case from the chamber on its own.
Here is what I have told him to check so far:
1. Check gas key.
2. It could be that the gas port was not opened up when the rifle was shortened which would cause shortstroking in the cold.
3. Check the brass for evidense of a rough chamber.
4. Check to make sure that the bolt moves relatively freely in the upper.
Can you guys think of anything else?
If I were a betting man, I would say it is because the barrel was cut back without opening the gas port. This is notorious for causing function problems. The person he bought the rifle from could not tell him whether or not the gas port was opened up but the cutting was done by a very well known place.
Thanks,
Matt