| 3DogMike |
| (.400 member) |
| 17/02/25 04:30 AM |
|
Re: I just bought a Miller & Val Greiss what is the caliber?
|
Quote:
Sharps,
You have provided very good comments and experience. I like your load for the 500 BPE. I may try that when reloadfing for my 500 BPE.
My comment on the strength of doubles was based upon comments by people with geater knwledge than me and was that double rifles are not as strong as bolt action or drop block rifles. I agree that new doubles are chambered in higher pressure cartridges like 30/06.
Adding to thread drift….sorry!
One thing to keep in mind about the relative strength of double rifles (or any break open type action).
1) There is the strength of the barrels/chambers (maybe called hoop strength?) which would be comparable to any similar barrel on a single shot or bolt action rifle. Given good strong modern barrel steel this is not the limiting factor.
2) Then there is the strength of the actual action lockup. this is impacted by the (for lack of a better description) "bolt thrust" of the fired cartridge against the action face which acts on the locking surfaces and attempts to flex the action at the ~90º point between the breech face and action flats.
#2 is the weak point, and forces upon firing (call it bolt thrust) depend on the cartridge interior head dimensions and pressure.
this is (partly) why such higher pressure cartridges such as .30-06, 8mm's, etc. can be used in double rifles. Smaller diameter but higher pressure cartridges = less sq"/sq mm of area = relatively equal thrust on the action when compared to larger head diameter but lower pressure rounds like the .450's, .500's, etc.
All of this is of course resisted by the strength of the action lockup and quality/quantity of the steel in the action body.
Please forgive my layman's attempted explanation, I am not an engineer or physicist.
Suffice to say, I'm typically very careful to degrease the cartridges and chambers on my doubles which allows the cartridge cases to grip the sides of the chambers (the relatively strongest part of the rifle?) on firing and reduces or eliminates back thrust on the action face and thereby the stress on the action itself.
You can read about this phenomenon, that was published by PO Ackley, where he removed the locking lugs on a Winchester .30-30 lever action and then fired the rifle with degreased chambers & rounds with no ill effect. There was no thrust on the bolt , the entire pressure was contained by the cartridge case and chamber walls..
This of course was NOT using high pressure rimless rounds a la the .30-06 and similar.
- Mike