XCR-L break-in and recoil buffer damage?

What are the dimensions of this O-ring? Made from a rubberized plastic? There probably isn't any real need to custom make an O-ring when every variety already exists somewhere.
 
Xcr needs to be well lubed. What lube would you guys recommend?

Your favorite gun oil will work. Most of us have a favorite but it shouldn't make any difference. Grease is OK but I find it doesn't always stay on the wearing surfaces. WD40 is not a lubricant, but better than nothing at all, useful in artic conditions but dry graphite is better.

Engine oil will work if you have nothing else. I have resorted to using the grease and butter of my bacon sandwiches when I had left my range bag at home :) Diesel fuel will work in an emergency.

I like oil in a squrty bottle so I can spray it on the bolt and bolt carrier very generously and then just wipe of the surplus. Dapping oil on with a Q-tip is not enough.
 
What are the dimensions of this O-ring? Made from a rubberized plastic? There probably isn't any real need to custom make an O-ring when every variety already exists somewhere.

Very small and very difficult to measure. I will take a bolt carrier into my local "Piston Ring" store and see what they have.
 
It's roughly about this big around


ok-sign.jpg


Sorry I couldn't resist. I guess saying teenie tiny doesn't help either ?
 
All this talk of generous lubrication has me wondering why my manual says "Not much lubricant is needed on the moving parts after break in". Why the discrepancy?
 
You need to note if new or old style bolt catch.
I should also change the spare parts kit so that with the new bolt there is a spare firing pin retainer and firing pin retainer O ring, I haven't done this yet. Lose the O ring and you can lose the pin, lose the pin and your bolt will jam on the firing pin. If you only lose the O ring your rifle will still function but when you field strip the firing pin retaining pin could fall out. I just learnt this the hard way.

CORRECTION:
The L bolt is not fitted with an O ring at this time only the M bolt. I was confused. I have spoken to Rob Arms and they are looking into supplying O rings to use in the L bolt but they may have to be custom made/ordered. In the mean time please be aware that the firing pin retainer may fall out when field stripping.

We will be stocking spare retainer pins and will be getting some sample O rings to try.

LOL ME TOO!

Thanks a million to Brent for the great service getting me up and running quickly!!

Here is a pic of the M pin (with o ring) and the L pin (no o ring and no o ring groove).

 
So, about all this lube... Are you saying it will damage the rifle if it's too dry, or just compromise reliability?
And what about Froglube? It's my understanding that their directions are to apply the paste, let it soak into the metal, and then wipe it dry. That's what I've been doing and so far, it's been running like a dream (aside from American Eagle ammo which jams it up). Doesn't seem to be any excessive wear on any parts either.
 
So, about all this lube... Are you saying it will damage the rifle if it's too dry, or just compromise reliability?
And what about Froglube? It's my understanding that their directions are to apply the paste, let it soak into the metal, and then wipe it dry. That's what I've been doing and so far, it's been running like a dream (aside from American Eagle ammo which jams it up). Doesn't seem to be any excessive wear on any parts either.

Damage if too dry? Maybe not guaranteed to damage but it may and to dry can certainly cause excessive or premature wear. Too dry will often comprise reliability but not always.

I haven't used Frog Lube, if you are following the manufactures directions and the operation is good , I see no reason to change.

My whole point with lubrication is that it is far better to over lube than under lube.
 
semi related question.....
How can one tell an early version of the XCR-L compared to a current production version ?
Handled a XCR-L in a shop in my area and it seemed real heavy.
Barrel was about the same diameter as the brake/FH.
This must be an H-bar version and not the "keymod" version.
Any help or links you could forward me about this topic would be much appreciated.
Tank U,
Bod
 
semi related question.....
How can one tell an early version of the XCR-L compared to a current production version ?
Handled a XCR-L in a shop in my area and it seemed real heavy.
Barrel was about the same diameter as the brake/FH.
This must be an H-bar version and not the "keymod" version.
Any help or links you could forward me about this topic would be much appreciated.
Tank U,
Bod

If the receiver has four accessary rails it is clearly not a Keymod. The Keymod receiver only has a rail on the top. The weight difference is approx. 1/2 lb. Barrels can be light or heavy with either receiver, the vast majority of older guns will have heavy barrels and feel a little nose heavy. The Light weight barrel will save approx. 1 lb. and looks very skinny due to the length, the gun balances much better.


Top OD four rail heavy barrel
Middle white Keymod heavy barrel
Bottom DT Keymod light barrel
 
Last edited:
Thank you John.
The one I handled did have four rails which were partially covered by the plastic rail covers.
So I have to believe that is was not the "key-mod" version.

Closing question...........
Seen in various fourms that this lighter / thinner barrel is in fact lighter and has better balance like you said.
What about heat and accuracy between the H/bar and "keymod" barrel ?
If h/bar has tendency to stay more accurate, I could live with the extra 1 lb. as I am mainly interested in hunting yotes.
Plus that extra 1 lb. will give me a better cardio work out as I haul it around the woods :)

Again, thank you John.
Bod
 
Thank you John.
The one I handled did have four rails which were partially covered by the plastic rail covers.
So I have to believe that is was not the "key-mod" version.

Closing question...........
Seen in various fourms that this lighter / thinner barrel is in fact lighter and has better balance like you said.
What about heat and accuracy between the H/bar and "keymod" barrel ?
If h/bar has tendency to stay more accurate, I could live with the extra 1 lb. as I am mainly interested in hunting yotes.
Plus that extra 1 lb. will give me a better cardio work out as I haul it around the woods :)

Again, thank you John.
Bod
While it is generally accepted that heavy barrels will group tighter than light barrels once they heat up the accuracy will be similar and then the heavy barrels take longer to cool down. I am not looking for a work out so I would go with the lighter barrel in the Keymod stock. We haven't had customer feed back on the light verse the heavy as far as accuracy is concerned.

As for the Keymod versions been better manufactured: Like most manufactures, Rob Arms have continually worked at improving their products and QC, we see very few failures considering the large number that we have sold over the years. Personally I can't say that after serial # ###XX the quality was better, I believe the bugs were worked out a long time ago.
 
Back
Top Bottom