Action Rigidity with One or Two Piece Scope Base
- Thread starter pintopete
- Start date
You know, this is a good question. I've pondered it quite a bit myself lately. First I'll tell you what I did with my resent build, then I'll tell you what I think,my 2 cents). I recently put together a factory varminter. It's a Savage LRPV cambered in .204. I went with the single shot for "receiver rigidity", and opted for a one piece stainless steel base made by Near Manufacturing, again for weight and rigidity.,See image below) This thing is a true work of art, the fit and finish is immaculate. I got one with 10MOA, and twin screw stainless rings. I don't actually have the weight of them, but they are very heavy. Near supplies the US Navy, US Army, and the Canadian RCMP with bases, they are extremely expensive; three times that of benchrest quality Kelbly's. http://www.nearmfg.com/products.htm When I skim bedded the receiver to the stock with Devcon,the quality of fit between the receiver and aluminum bedding block was truly atrocious, it was resting on four tiny spots), I contemplated permanently joining the rail to the receiver with Devcon and decided it wasn't worth the work for such a light recoiling gun.
Now my 2 cents. Yes, the one piece stainless added some weight,bonus), and POSSIBLY some measure of rigidity as mentioned above. But, I think this is NEGLIGIBLE. I think that we collectively have placed to much emphasis on "receiver rigidity". It is promoted by manufacturers and talked about extensively. I believe that "rigidity", or the ability of a receiver to negate the effects of pressure and remain true, is more a factor of design and quality of fitted parts, as opposed to size of receiver and any rigidity offered by scope rails etc. I do believe that the size of receiver contributes to "rigidity", but not in terms of the size of the receiver itself. Think here a 700 vs. BAT. The amount of surface area available on larger receivers for a solid stress free bedding, is much more important than the size,or presumed rigidity) of the receiver. After all, the cartridge is already in the barrel chamber, not the receiver. The receiver and its relationship to the stock MUST NOT MOVE between shots, this is more a factor of surface area and bedding as opposed to the "rigidity" of the receiver.
There are just to many variables, such as barrel quality,a big one), brass prep etc., to believe that a more "rigid" receiver will contribute significantly to greater accuracy. Think of how many 20+lbs heavy guns with barrel blocks etc. get out shot by light guns. Read "NRBSA 600-yard Nationals - Are Maxi Heavy Guns Overkill at 600?" here: http://www.6mmbr.com/600nbrsa08.html
Now my 2 cents. Yes, the one piece stainless added some weight,bonus), and POSSIBLY some measure of rigidity as mentioned above. But, I think this is NEGLIGIBLE. I think that we collectively have placed to much emphasis on "receiver rigidity". It is promoted by manufacturers and talked about extensively. I believe that "rigidity", or the ability of a receiver to negate the effects of pressure and remain true, is more a factor of design and quality of fitted parts, as opposed to size of receiver and any rigidity offered by scope rails etc. I do believe that the size of receiver contributes to "rigidity", but not in terms of the size of the receiver itself. Think here a 700 vs. BAT. The amount of surface area available on larger receivers for a solid stress free bedding, is much more important than the size,or presumed rigidity) of the receiver. After all, the cartridge is already in the barrel chamber, not the receiver. The receiver and its relationship to the stock MUST NOT MOVE between shots, this is more a factor of surface area and bedding as opposed to the "rigidity" of the receiver.
There are just to many variables, such as barrel quality,a big one), brass prep etc., to believe that a more "rigid" receiver will contribute significantly to greater accuracy. Think of how many 20+lbs heavy guns with barrel blocks etc. get out shot by light guns. Read "NRBSA 600-yard Nationals - Are Maxi Heavy Guns Overkill at 600?" here: http://www.6mmbr.com/600nbrsa08.html
Pete, Awhile back there was a rather heated discussion on here about your question. There were several positive notes and several negative notes concerning the added strength or possible added strength. Some gave good sound information for both opinions. Personally, I don't see how on earth strapping a solid steel base across the top of the receiver could not help but the one thing that I remember about the issues was that the base could put undue stress on the action and cause distortion if the base did not lay perfectly flat such as bedding the base to the receiver. I hope this helps. Bill
That is a fine piece you got there man. How does it shoot?
That is a fine piece you got there man. How does it shoot?
Bill, your point about stress on the receiver from a one piece base is dually noted. I consciously installed the base to the receiver with Loctite BEFORE I bedded the action to the receiver, to negate any undue stress on the bedding.
About how this shoots... not so well... YET!. I'm averaging 3/4inch groups for 5 at 100yards with factory loaded 32gr Hornady's. My tube doesn't like'em, lots of flyer's and vertical. I'm shooting up 320 rounds of this stuff for brass,all the same lot #). I am pretty confident it will do under 1/2 with handloads, which I'm trying tomorrow.
About how this shoots... not so well... YET!. I'm averaging 3/4inch groups for 5 at 100yards with factory loaded 32gr Hornady's. My tube doesn't like'em, lots of flyer's and vertical. I'm shooting up 320 rounds of this stuff for brass,all the same lot #). I am pretty confident it will do under 1/2 with handloads, which I'm trying tomorrow.
Yea Man. I think your handloads will bring it on around. Very seldom have I ever owned a rifle that handloads did not shoot tighter. I hope it exceeds your expectations. I have not had a chance to shoot my .204 yet. Got to get busy and load some good ammo. Mine is on an AR platform. Sabre Defence upper on a RRA Varminter lower. Bill
CatShooter
Keep in mind that whatever base you use - one piece or two piece - the base,s) are held on with four little, itty bitty screws, who's strength is nada.
If you tap a base,either kind) with a light weight, plastic tipped hammer, the base will move
They add nothing to the strength or rigidity of an action.
.
If you tap a base,either kind) with a light weight, plastic tipped hammer, the base will move
They add nothing to the strength or rigidity of an action.
.
True enough
ronsroom1
Silver $$ Contributor
Catshooter hit the Screw on the Head. I'm not a Metalurgist, but the only way, I think, a steel base would add strength to the receiver is if it were welded on. I remember several years ago when the XXX Company,maker of steel bases) claimed extra receiver strength when using their bases. That claim disappeared quickely.
Catshooter,
Right on with the rigidity. It's nil as to adding action strength. Forgive me but if a scope base is screwed on with a 6-48/8-40 thread,4X),AND THE tapped HOLEs ARE SQUARE and on location) it is self centering due to its 90/82/60 degree angle of the mating screw head to base. IF THE HOLES ARE NOT DRILLED AND TAPPED SQUARE TO THE SURFACE, IT WILL MOVE DUE TO MISALIGNMENT. It there's enough torque holding the screws down, and again they are D&Tapped square they will not move. This self centering screw will also drag the base over and out of it's alignment with the other 3,or boreline) if the tapped holes are off location. These screws are designed to locate the part positively and the threads are used only to hold the mating part down. These screws are used so that you will not have to use a dowel as a locator. Now on the other hand, if a flat bottomed screw be used, it does NOT self center the mating part. You can knock these things around all day long and they'll never be in the same spot twice. This is written in stone to the tool/modelmaking industry. Maybe this is what you were referring to. Getting away from the main topic a little, I apologize. Thanx
Right on with the rigidity. It's nil as to adding action strength. Forgive me but if a scope base is screwed on with a 6-48/8-40 thread,4X),AND THE tapped HOLEs ARE SQUARE and on location) it is self centering due to its 90/82/60 degree angle of the mating screw head to base. IF THE HOLES ARE NOT DRILLED AND TAPPED SQUARE TO THE SURFACE, IT WILL MOVE DUE TO MISALIGNMENT. It there's enough torque holding the screws down, and again they are D&Tapped square they will not move. This self centering screw will also drag the base over and out of it's alignment with the other 3,or boreline) if the tapped holes are off location. These screws are designed to locate the part positively and the threads are used only to hold the mating part down. These screws are used so that you will not have to use a dowel as a locator. Now on the other hand, if a flat bottomed screw be used, it does NOT self center the mating part. You can knock these things around all day long and they'll never be in the same spot twice. This is written in stone to the tool/modelmaking industry. Maybe this is what you were referring to. Getting away from the main topic a little, I apologize. Thanx
CatShooter
Here's the thing about bases, and whether they add strength or not.
Aside form the little itty, bitty screws... the actions are not an exact fit, the holes in the bases are oversized, and so what do you have - a small piece of metal held on an action with two screws that will fail,that means snap off :, ) at ~2.5 foot pounds of torque
, and these screws are supposed to do something for an action who's tensile strength is measures in "lots of bunches of tons"...
Hello? Is there any intelligent life here. This is just plain silly.
Second - do you really want the screws to be stronger than the scope? The concept is called "Breakaway".
IF the scope gets "bonked", whether by accident or misfortune - do you want the scope to bend, or the screws to snap off?
I went rolled down a steep 50 grade with a rifle and a $1,300,street price) scope - the scope got shoved hard,but it was in a case), the screws took the force and the scope remained flawless.
Me... I'll sacrifice $1 worth of screws, any day.
If you need more strength in your action,WHY??), most of the action makers will make you an action the diameter of a sewer pipe if you throw money at them...
The down side to one piece bases is that if you get a fail to eject, it's a pain in the ass to get the case out during a match... when the clock is running against you. I have seen it so many times.
.
Aside form the little itty, bitty screws... the actions are not an exact fit, the holes in the bases are oversized, and so what do you have - a small piece of metal held on an action with two screws that will fail,that means snap off :, ) at ~2.5 foot pounds of torque
, and these screws are supposed to do something for an action who's tensile strength is measures in "lots of bunches of tons"...Hello? Is there any intelligent life here. This is just plain silly.
Second - do you really want the screws to be stronger than the scope? The concept is called "Breakaway".
IF the scope gets "bonked", whether by accident or misfortune - do you want the scope to bend, or the screws to snap off?
I went rolled down a steep 50 grade with a rifle and a $1,300,street price) scope - the scope got shoved hard,but it was in a case), the screws took the force and the scope remained flawless.
Me... I'll sacrifice $1 worth of screws, any day.
If you need more strength in your action,WHY??), most of the action makers will make you an action the diameter of a sewer pipe if you throw money at them...
The down side to one piece bases is that if you get a fail to eject, it's a pain in the ass to get the case out during a match... when the clock is running against you. I have seen it so many times.
.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.