XCR Forum banner
21 - 27 of 27 Posts

·
Registered
Joined
·
41 Posts
Discussion Starter · #21 ·
Just as a friendly instruction/reminder, here:

If your OP-Rod Spring is worn-out/breaking, your OP-Rod and Bolt are not going to last much longer either.

They all work together as a unit and as they each wear-out they place additional stresses upon those other parts mentioned above.

Just so you know.

Best!

:)
 

·
Registered
Joined
·
1,128 Posts
Steve,
I have not had an opportunity to test the gas settings as of yet. I pulled out the two rifles yesterday and examined them. One setting was on 5 and the other on 3. That indicates to me that I did not adjust the system while sighting in the rifle (don't ask me why as I don't know, even though I know better!).

I then pulled out the manual I downloaded and printed. I read the gas adjustment section a couple of times. Here is what it says: The higher the number visible on top,the larger the volume of gas that is bledfrom the system and the lower amount ofenergy used to cycle the action.Conversely, the smaller the number ontop, the smaller the volume of gas bledfrom the gas system and the higher the amounts of energy availableto cycle the action.

If I am I reading this right, 5 is the least amount of gas cycling the system? The opposite process for the XCR? The rifle on "5" is still running 100% so a new spring is needed? I will have to test the rifle currently on "3".
I finally got my rifles out. The two M96's were set on five. They did not cycle properly with S&B steel cased ammo although they ran fine with PMC.

BAMA, do you still have any recoil springs?
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #23 ·
I finally got my rifles out. The two M96's were set on five. They did not cycle properly with S&B steel cased ammo although they ran fine with PMC.

BAMA, do you still have any recoil springs?
Col Maddog,

Yes, I still have a pile of springs available.

I suspect that the steel cased S&B ammo is under-powered where the PMC is on the hot-side.

Check your observations before proceeding further.

Best wishes,

Steve.
 

·
Registered
Joined
·
1,128 Posts
Bama, I suspect the same with the S&B steel case ammo. It does surprise me though as S&B brass case ammo usually runs warm. Anyway, I cleaned the rifles yesterday and paid attention to the internals while doing it. There is not much wear and I have put maybe 60 rounds through each myself, so not much. Springs were in excellent condition but I do worry about heavy wear on the other parts do to over gassing.

When you replaced the spring on yours did you get the gas adjustment you were hoping for? If replacing the springs with yours is preventative maintenance then I would like to get a couple and replace them now before excessive wear or damage. Thoughts?
 

·
Registered
Joined
·
41 Posts
Discussion Starter · #25 · (Edited)
Bama, I suspect the same with the S&B steel case ammo. It does surprise me though as S&B brass case ammo usually runs warm. Anyway, I cleaned the rifles yesterday and paid attention to the internals while doing it. There is not much wear and I have put maybe 60 rounds through each myself, so not much. Springs were in excellent condition but I do worry about heavy wear on the other parts do to over gassing.

When you replaced the spring on yours did you get the gas adjustment you were hoping for? If replacing the springs with yours is preventative maintenance then I would like to get a couple and replace them now before excessive wear or damage. Thoughts?
1. Set your gas to "3" for the S&B Steel cased ammo and test for function, set it lower by 1 click if it fails to operate reliably and repeating until it does run reliably.

2. The original springs' interior surface fully-contacts the OpRod and any carbon fouling of the OpRod will act like sand paper on the spring - eventually it will flatten the inside of the springs' surface thus reducing coil diameter which will weaken the spring and provide less recoil control and then as a result of this spring-wear will start to beat the bolt/carrier to death. Keep the spring & OpRod clean.

3. I never got the rifle to fail using my ammo even using the new springs that I designed on a gas setting of 5 - this indicates [to me] that my ammo is hot (in spec) and that the gas system adjustment design of the rifle could be in question, maybe not. (My bolt broke in 1/2 after around 9K rounds of in-spec brass ammo) so the system as designed and delivered is over-gassed, IMO which places violent forces that cannot be regulated upon the bolt/carriers action/components. The new spring is NOT a cure for this, it is just one small step in the right direction, IMO.

4. These new springs do not grab the OpRod and have some clearance so they will not wear out nearly as quickly as the original ones do. I will leave it up to you to decide if you want any of these new ones from me. I make no other claim than that they will be less prone to abrasive wear.

Best wishes and Merry Christmas, Sir.

/O

Steve.
 

·
Registered
Joined
·
1,128 Posts
Steve,
First of all, Merry Christmas to you sir!
Second, I have many guns to shoot so I doubt I will get to 9K rounds in my life time on either of my rifles. I guess I will have to wait and see. . . .
Jon
 

·
Registered
Joined
·
1 Posts
For those who need one.

It isn't easy to make and is time/tooling intensive - expensive; due to the material involved but it is available. (Turn your existing parts-kit into a functional/valuable rifle once again).

I have successfully made a replacement Op-rod using the existing piston-head and spring out of t304 SS rod and my rifle is now fully functional.

Details available to those paid/wanting one made for them.

Have a good day.

Steve.
My M96 operating rod sheared off at the rear of the notch that engages the bolt. I'm dead.
Robinson has been no help at all. I need to attain a replacement operating rod.
please proved details and contact information
thanx
 
21 - 27 of 27 Posts
Top