M14 and all of the variants/teach this guy about the M14 in general.

[Different]

LRB being CNC machined

J. V. Precision (Seymour, CT) uses a wire EDM machine, a horizontal CNC machining center and two other machine tools in five tool set-ups to machine each LRB Arms M14 receiver. The wire EDM machine is used to cut the magazine well. Even with that, some of the LRB receiver machining operations are finished with manually operated machine tools: drilling the bolt lock pin holes, final milling of the rear sight pocket and heel underside, cutting the receiver bridge primary firing pin retracting surface and cutting the receiver rear end firing pin recess.

References: My interviews with Lou Biancospino, LRB of Long Island, Inc. and the owner of J V Precision at the 2008 SHOT Show.

[Coleslaw]

I know J.V. Precision is doing the machining, and wire EDM is even better, but wherein does the problem(s) lie that Warbird is talking about? What is causing the problems? The few manually machined operations you list are causing LRB to sell questionable receivers?


Is this a Ford vs. Chevy argument between these two guys on the other forum?

[Different]

I know J.V. Precision is doing the machining, and wire EDM is even better, but wherein does the problem(s) lie that Warbird is talking about? What is causing the problems? The few manually machined operations you list are causing LRB to sell questionable receivers?

Is this a Ford vs. Chevy argument between these two guys on the other forum?

My post above was to clarify one narrow point in a broader discussion. LRB Arms M14 receiver machining is not entirely automated, that's all to my post.

I read the discussion thread across the street. I prefer not to comment on it.

[Coleslaw]

Ok. That raises the question, and I think I already know the answer, but isn't everyone's receiver machine work "not entirely automated"?

[Different]

Ok. That raises the question, and I think I already know the answer, but isn't everyone's receiver machine work "not entirely automated"?

That is correct. I'm being mindful of neophytes. There has never been a M14 receiver made entirely with automated machining. Armscorp and LRB have got real close. Even Federal Ordnance used a CNC machining center but they had to finish them by hand. Valley Ordnance (M1A rifles under 097XXX) made receivers totally on manually operated machine tools. The operations to cut the firing pin recess in the receiver heel and the left bolt lug recess have been difficult to automate. When Smith Enterprise, Inc. was manufacturing receivers in the 1980s and 1990s, it had two dedicated Bridgeport mills for cutting the receiver bolt lug recesses.

[MistWolf]

That is correct. I'm being mindful of neophytes. There has never been a M14 receiver made entirely with automated machining. Armscorp and LRB have got real close. Even Federal Ordnance used a CNC machining center but they had to finish them by hand. Valley Ordnance (M1A rifles under 097XXX) made receivers totally on manually operated machine tools. The operations to cut the firing pin recess in the receiver heel and the left bolt lug recess have been difficult to automate. When Smith Enterprise, Inc. was manufacturing receivers in the 1980s and 1990s, it had two dedicated Bridgeport mills for cutting the receiver bolt lug recesses.

I assume you're Different from TFL? If so, I know you're very knowledgeable about M14s. I've learned much from your posts on TFL- and from others- still, what I know is a drop in the bucket.

The way the thread turned out I provided the link for, it embarrasses me that I did so. At first, it was simply what Warbird found from his measurements.

Could you please take time to explain this timing problem that is supposed to arise from the safety bridge being out of spec? Being uninformed, I have no idea. Is it a concern? I have heard nothing but praise for LRB receivers and was surprised at this criticism

[Different]

I assume you're Different from TFL?

Could you please take time to explain this timing problem that is supposed to arise from the safety bridge being out of spec?

I am Different. I participate on many firearms dicussion boards.

The M14 firing pin floats within the bolt. When the safety bridge is located at its proper position in the receiver and its geometry is correctly formed, the firing pin will move at the proper time in relation to movement of the bolt. Otherwise, the firing pin may stick in the forward position as the bolt moves rearward. The retraction of the firing pin may be delayed. If it is delayed, the bolt is initially moving to the rear sooner than it should be. The firing pin could also cause a slam fire when the bolt is moving forward because it is not held back long enough by the bridge before lock up. The safety bridge is a critical area on the M14 receiver.

Not meeting the receiver drawing dimensional requirements is not necessarily a bad thing. It depends on what part of the receiver one is looking at. Many commercial brand receivers have extra wide operating rod rails. The extra steel allows for greater surface area contact with bedding material and it makes the receiver stronger.

[Coleslaw]

I read the discussion thread across the street. I prefer not to comment on it.

One thing I did glean from the "thread across the street" from some of the participants in the thread, is that it appears TFL is not a very friendly place that exhibits little tolerance from the owners/operators if you are not in lock step with them

[MistWolf]

I looked at an M14 after reading your post and understand the function better. Thank you for the explanation

[MistWolf]

One thing I did glean from the "thread across the street" from some of the participants in the thread, is that it appears TFL is not a very friendly place that exhibits little tolerance from the owners/operators if you are not in lock step with them

Not true. You don't have to be in lock step and you don't even have to agree. They are not unfriendly but you do need to be respectful on TFL. There is a wealth of knowledge there and many of the influential members are experienced warriors who fought hard battles with the M14. For me, it's like hanging out with my father and his old Marine Corps buddies