Trying my Hand at SR BR stock, but questions

[David Brooks Rifle Stocks]

I am looking at designing and making a SR BR stock or two, at first glance, the rules are very basic, and may actually be, but i start questioning myself when looking at where someone might place the action and how that effects the measurments to be legal. My question is, am i way over thinking this or is the angle of the Buttstock 84* that i calculated, or does this dimension change with action placement and Length of pull? These may be assinign questions, but ive been looking at this for 3 days straight and i think i may be turning myself in circles!! Let me know if there is a simple explanation to my overthought question.

Thank you,
David

 

[jackieschmidt]

You are correct in that the way the action is bedded in the stock can affect the angle tolerance of the butt stock.

If the angle of the butt stock is right on the minimum tolerance, , and a stocker beds the barreled action in with too much downward angle, it could render the barreled action/stock assembly in non compliance.

The reason being that the measurements are taken from the centerline of the barrel.

One other note, which you did not ask about but is of paramount importance is weight.
Two of NBRSA and IBS Classes are governed by a 10.5 pound weight limit.

With todays components, what ever you produce needs to not be over 26 ounces with bedding.

 

[AlNyhus]

David, no expert in this but having inletted a few , I always start with where I want the trigger to be. -Al

 

[AlNyhus]

You are correct in that the way the action is bedded in the stock can affect the angle tolerance of the butt stock.

If the angle of the butt stock is right on the minimum tolerance, , and a stocker beds the barreled action in with too much downward angle, it could render the barreled action/stock assembly in non compliance.

Yeah....gotta be carefull how much bias you give it. It's good to put the port cuts, etc. in after it's bedded. -Al

 

[Silo1616]

Here is the drawing to ponder:

 

[Jerry Wick]

Since the NBRSA doesn't specify a length of pull, the diagram is open to interpretation. The IBS specifies 13-1/4" so that nails down the minimum buttstock angle.

I think you'd be safe with either organization using the IBS dimensions. Personally, I'd make it a degree or two steeper to be safe. There isn't a real advantage unless it could be a truly flat buttstock like the long range stocks have. In short range, that's legal in Sporter class, but then you can't shoot it in any other varmint classes.

 

[David Brooks Rifle Stocks]

All of this feedback is great, and very much appreiciated. Following question, How were a Kelbly, Robertson, McMillan, or any of the others able to produce a Stock for this SR BR and know where the action will be inletted?, did they set the rear action screw and went off of that single point? Designing one of these is considerably different that the F-Open and FTR that i currently build. Just trying to figure out how to design a flatop SR BR stock that will be legal

 

[Rat Rifle]

Here is the drawing to ponder:
View attachment 1564413

What is the “intent“ of all these restrictive dimensions ?

 

[Fast14riot]

@BoydAllen has gone over the stock design rules a lot recently.

But, I seem to recall 7° from parallel to barrel is a safe number regardless of action placement. But don't quote me on that.

 

[Silo1616]

I took this diagram literal the first time I saw it. I'm told now the "A-B" line only establishes a minimum angle for the "keel" ie: the actual base of buttstock need not be 4" below bore centerline as long as the angle is preserved.