Too the three people whom are saying there XCR bolt release is letting go, I made a post outlining the problem is the XCR FAQ thread located here :
http://www.canadiangunnutz.com/foru...06-Robarms-XCR-FAQ-post&p=8621863#post8621863.
The problem is the magazine follower does not push the catch up high enough to make a large surface of contact on the bolt. It is not the fault of the magazine. if you loosen the screw on the bottom and give it 1/8" of play you can manually push it up to lock it and it locks great. the only problem is the follower wont push it that high to lock it on an empty mag. As soon as my XCR-M comes back from the machinist, my XCR-L is going in and he is building me a new bolt catch. It will be 1/8" longer so the tabs will hang down 1/8" lower than the trigger guard. It will also have the tab that the magazine follower pushes up on made into an L so it will hang 1/8" into the magwell. and subsequently be raised an 1/8" higher from the magazine follower. It wont be cheap... I figure it will cost me $350-$400 to have the one off part built. He is willing to do a "production run" but the price is still gunna be steep. my estimate would be about $150-$200 per piece. If anyone is interested I can get him to build the one off and I will demonstrate it with an actual confirmed price?
Describes the problem my -L is having. On further inspection manually pushing the catch up does lock the bolt tightly requiring a hard jar (one that hurts the hand) on the bottom of the handle to let go (as expected). Got a quote of $32 shipped to BC to get new bolt catch from WOLV. Looks like it won't fix the problem. $200 for new machined catch is kinda steep for my range toy.
Just too add on my XCR-M is there because I tried to remove the bolt and it spun the helicoil out about 1/6" then when I tightened it it would not tighten enough to hold the barrel. unknowing of this fact I tried to tighten it more and I ended up tearing out all the thread in the aluminum. The machinist is building a stainless tapered collate I designed, that will go from the inside out, it has a split pin to keep it from rotating when you tighten the bolt. and the force of the bolt pushing the collate out locks the collate in tight. this removes all chance of the aluminum stripping again. he figures $150 for that fix. If and when, I strip the XCR-L out I will do the same thing to it, threading into aluminum is a horrible technique and should be avoided.
Is there a best way to secure the barrel bolts? Locktite makes the bolt hard to turn for barrel changes. Grouping suddenly goes to hell, bolt is loose. No torque wrench so agree hand tightening a steel bolt onto aluminum is not preferable. EDIT: NVM, see the helicoil is a thread bushing
\\\Disclaimer For Flamers///
If anyone wants to judge my opinion on threading into aluminum, go right ahead and blame me for being an idiot and over tightening it, yes I did screw up. I'm a journeyman welder who has 3 years machine shop experience, I also have done very basic machining myself. NEVER have I seen a product built with threading into aluminum cause everyone knows its a disaster waiting to happen. tapered collates and or through bolt and nut set ups, are UN-officially the only way to fasten aluminum other than welding it... Products with tapped aluminum are purely poorly designed.