chamber pressures and bolt thrust

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hend238

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I'm considering installing a new barrel chambered in 7mm saum on my Savage 12 Fclass. The rifle currently is chambered in 6.5x284. I'm looking for insight regarding the increase in chamber pressure and bolt thrust the new cartridge will produce. Any concerns?
 
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I have had 5 precision F-Class rigs built in various chamberings and have never heard the term Bolt Thrust let alone be worried about such things.....
 
Bolt thrust is referring to the force applied to the lugs. Chamber swell is your concern, bolt thrust is ok with the wsm.
A large shank is the solution to chamber swell. If your into competition I would sugggest you use the large shank, depending on what rifle you have you may already have a large shank.
 
Thanks PEI Rob. I was about to comment, just because someone hasn't heard of a something doesn't mean it does not exist. So many self proclaimed experts. I never pretend to be and hence the reason for this thread. There is always something to learn. Moving on...The cartridge in question is a 7 saum not a wsm. At least that is my initial plan. I'm having problems downloading the saami specs or finding info on chamber pressure ratings to compare them to the 6.5x284. I'm not a Savage guy or at least have never built a rifle on a Savage action so I'm not up to speed on them. It's obvious that I will be installing a new barrel and bolt head for this project if I go ahead with it. I'm sure I have a large shank but I'll verify it. Thanks for your help as I never considered the small/large shank angle.
 
the same basic action has been used for decades with standard magnums and larger chamberings.

if the concern is whether the action can handle the RSAUM case, no problem. the WSM is already higher let alone a 7RM/300WM

Problem will be finding a new bolt head to work.

Jerry
 
Bolt thrust is something 'engineers' consider when designing a cartridge/action combination.

It is really of no concern to the gun owner when using modern actions and modern cartridges unless you try to do something extremely stupid. A high pressure cartridge on a correct size high pressure action is fine... excessively high pressures will result in hard bolt opening long before bolt thrust will become an issue.

The common denominator in all firearms is the weakest link - the brass case.
 
Unfortunately, we are seeing some not so happy affects on receivers when larger case heads magnums are installed. Although the DESIGN is sound, the actual parts are starting to fail with use.

So bolt thrust can have a profound affect on your receiver and bolt.

Sorry, not going to give details as it is being dealt with at the factory level.

Lilja has a really cool calculator on bolt thrust and lug shear strength. A small change in case head diameter does have a significant change on the bolt thrust. Modern receivers are designed to handle these loads without a fuss but sometimes things don't get made properly and you end up with a mess.

YMMV
Jerry
 
Thanks again Jerry. Many will say bolt thrust is a non issue and we don't know what we are talking about. Be that as it may. It's a topic I know nothing about and is the reason why I brought it up. Whether my question gets answered or not you have brought up some interesting points worth discussing and considering. That is the whole point of the forum and I'm happy to see the discussion move away from the intent of my original post.

May I ask which parts are failing or are those the details you don't want to elaborate on?
 
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By the look of it things don't start to get out of hand till your working with cartridges based on the 416 Rigby or 378 Weatherby. I guess a .50 BMG based on anything but an action sized for it is a very bad idea...
 
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