Square Vs Round

[avidflyer]

Personally I like the square receivers more then round. Had a Panda and have a Viper. Also have / had plenty of rounds Rem of course Stillers and a coulple Defiance. With all that said I always thought / felt that a square had more surface area and bedded better. Lately was told to do the math and a round has more surface area to bed then a square action. FROM THE GUYS that do stock work whats your take and opinion on the square vs round

 

[JRS]

Lay a 2x4 (wide side down) and a piece of 4" pipe on a flat surface. Which has more surface contact?

 

[spife7980]

Lay a 2x4 (wide side down) and a piece of 4" pipe on a flat surface. Which has more surface contact?

So when you bed a round receiver you only have tangental contact with the bedding compound?

Really...

 

[Hoodoo]

So when you bed a round receiver you only have tangental contact with the bedding compound?

Really...

My thoughts lol.

 

[spife7980]

How about if we worry about the actual contact area.
A 1x1x6 block is 24 square inches (not including the ends), lets assume for easy math that its bedded half way deep, thats 12 square inches.

A 1x6 cylinder will be 18.85 square inches of lateral surface area, half of that is 9.43

However that doesnt account for the actual volumes, the block will have more volume than a cylinder with a radius equal to the blocks width. A 1x1x6 block has a volume of 6 cubic inches, the 1x6 cylinder will only have 4.7 cubic inches. If we increase the volumes to match the cylinder will have more surface area touching than the block. A diameter of 1.128 will get us a matching volume. The surface area in contact for that dimension will be 10.63.

So less but honestly it doesnt really matter. Bedding it to different depths will change the answer as well. Just so long as its not torquing on the receiver youll be fine.

 

[Stan Taylor]

I have one word to say which action has won the most of long range matches I have never shot short so I don't have a clue in short range.

 

[ridgeway]

Round vs Square vs Octagon vs Multiflat means diddly for accuracy.

 

[Alex Wheeler]

Bedded actions only sit on top of the pillars anyhow, especially if the pillar touch the action. Epoxy shrinks as it cures, and there is either touch or no touch. I do like the square actions if I have to do a regular bedding job as you can make the stock "hug" a square action if you want to bed it that way. Just glue and screw, then it wont matter plus it will shoot better.

 

[Depart123]

I was always under the impression that it wasn't just shear forces one need be concerned with, but resistance to torque also. It would seem to me that a square action would be superior in that respect. Just a thought, I could have wrong info.

 

[Alex Wheeler]

Thats true, but guys should be doing things to prevent the torquing effect from ending up on the screws. If the action is round and theres nothing to stop the twist you need to come up with something, there many things you can do. Aside from the obvious things bedding does is the transfer of vibrations/harmonics. To illustrate how important vibration management is touch your barrel in the middle of a group or shoot a group with the stock on something hard or just plain hold the rifle differently and see how this changes things. The harmonics that start in the barreled action need to be transferred out of the rifle through the stock and into the shooter and sand bags or bipod. The bedding interface has the job of transferring those vibrations consistently. Thats why an action moving in the stock shoots bigger groups, different contact in the stock is just like different contact to the shooter every shot. Holding the rifle differently every shot is similar to a poor bedding job. Thats why I glue 90% of the builds I do. The only way that interface is changing is if the epoxy breaks.

 

[Macropod]

What about HHE or CG Silent Bloc style bedding systems that absorb vibrations and harmonics? These use polyurethane bushings and strips to isolate vibration from the stock through a purpose built bedding block. Seen used in Australia and New Zealand in Fullbore (Palma) style shooting. The rifles just plain shoot well. I am currently building a rifle that uses that system. It will be interesting to see how it goes for F class.