338?

Most gunsmiths will not chamber a stainless rem action to 338 Lapua if some do that is their issue. The poressure is not the issue it is rear thrust on the locking lugs not blowing the chamber apart, The stainless actions can set dack if people start to handload hot loads. As for the Norma case cost if they are that cheep that is great but still be wary of LApua sized cases on Rem Actions if pressures are keps sensable they are OK but if people try to push the boundaries their can be troubles especialy on a stainless action. Ask Shawn or Kirby im sure that they would be cautious of using a Stainless action in 338 lapua.

Anyway for the purpose asked for in this thread the ERdge or UltraMag would be the best options even if the others have a slightly better performance allowing a cheeper build and the ability to have a 7mm MAg and 338 on the same action using the same bolt.

Cheers Bill
 
I don't know where you get that "most" gunsmiths will not chamber to 338 Lapua on a Stainless action but there are plenty that will
 
JPW i dont know your information but i have facts with regard to this and dont want to get into a ****ing match but i do still stick by my advice on building a 338 Lapua on a Stainless Remington action it is just not the safest option contact remington and ask why they did not use a Stainless action with their 338 Lapua

Cheers Bill
 
Wild Bill,
Wondered if you new the working pressure of the 338 EDGE.I don't know what it is, but the max working pressure of the 300 RUM is 65,000, so lets say the 338 EDGE is similar, for arguments sake. So my question is why is it acceptable to build a rifle on a SS Rem action based on a 404 Jeffreys case with a base diameter of I think .55 @ max working pressure of 65,000, and not OK to build a rifle on a SS Rem action on a 416 Rigby case ( 338 Lapua, 338 Norma) with a base dia. of .584 and max working pressure of 63,500 ?
I am not a gunsmith, and maybe someone could chime in on this. Would like to know the answer to this question.
 
The extra diameter of the Lapua case is like the straw that broke the camels back. If the Lapua case is used and loaded to medium pressures they are OK but that.035" makes a large diference in surface area on the bolt face to make the rearward thrust above what is considered a safe margin for error in case their is a piece of grit down the bore creating excessive pressure their can be bad results. All actions are built with a safty factor in mind. Take a 223 they can be loaded to 6500psi but you can use them on an action with a 1/2" bolt diameter now im sure no one would ust an ultramag on a rifle with a 1/2" bolt diameter but arnt they the same pressure also some rifles in 223 have a 3/4" diameter thread tenon again not guun with a mag case.

It is not all about the cartrudges pressure i have used a 284Win on an Omark action they are designed for a 308 their is only 30thou diference in case diameter and when an Omark has an adaptor in it the lads 1/4" of the chamber is turned to 3/4" to clear the internals of the adaptor all quite safe when you go to a 284 case if you puss the pressures the base of the barrel at the back of the chamber springs and the cases require major sizing to get them back in but a 308 is fin again only 30 thou. their is a lot in the chambering of rifles and it is just best to place a Lapua based case on a larger action, Lawton makes their remington Clone for a 338 Lapua in Stainless but the lugs are larger the threads are also longer tha actions are made alot stronget than a rem action. Other gunsmiths recomend you use a .750 diameter bolt in a custom action over a .700 diameter action in any make they just like to have a safe margin for error. And i know that some people might chamber a stainless rem action to 338 Lapua but i will not shot one or recomend one to anyone else.

Cheers Bill
Australia
 
So my question is why is it acceptable to build a rifle on a SS Rem action based on a 404 Jeffreys case with a base diameter of I think .55 @ max working pressure of 65,000, and not OK to build a rifle on a SS Rem action on a 416 Rigby case ( 338 Lapua, 338 Norma) with a base dia. of .584 and max working pressure of 63,500 ?
I am not a gunsmith, and maybe someone could chime in on this. Would like to know the answer to this question.

FYI, I'm not a gunsmith. Being an engineer, I can answer this question:

The force against the face of the bolt, and therefore against the bolt lugs and lug recesses in the action, is a product of the pressure generated inside the cartridge, and the surface area of the cartridge case head (interior case head area). Take two cartridges fired under equal pressure, and the cartridge with the larger diameter case head will be thrust back against the bolt face with a greater force than a cartridge with a smaller diameter case head.

Technically (mathematically), it's the interior rear case head diameter that the pressure acts against which would be used to calculate the force thrust against the bolt face. In this discussion, we'll presume that the inner case head surface area increases as the outer case head diameter increases, which is almost certainly true.

I could throw some numbers out here for illustrative purposes, but I think you can understand the concept. Cartridge pressure (units of lbs/square inch) X surface area of the cartridge case head (units of square inches) = force acting against the bolt face (units of lbs).

Since the surface area of the cartridge case is calculated by multiplying (3.1416) X (case head diameter/2)^2, the case head diameter is really more critical than case pressure in determining the force acting against the bolt face, lugs, and lug recesses. For example, doubling the cartridge pressure simply doubles the force against the bolt face (2 times the force). On the other hand, doubling the diameter of the case head increases the force against the bolt by a factor of 4 (4 times the force).

So this explains why cartridges with larger diameter case heads create greater force and stress on the bolt, lugs, and the lug recesses.
 
I understand your explaination of surface area and exerted pressure on that area, but do you not assume that a .750 bolt has larger (thicker) lugs than a .700 bolt. I don't know if that is true, and if so , if you still use a 1.350 dia. receiver, how are you gaining anything? Why is it that BAT Model M action can use a .717 bolt on the 408 Chey-Tac case, is it due to the receiver being 1.450, and not related so much to the diameter of the bolt ? Also, would you concider a 338 Lapua a safer build on a custom action ,like Phoenix , with a .700 bolt than on a standard Rem action ?
 
Thanks for clarifying what i was saying about the pressures phorwath. As for the other custom actions a lot of them have larger lugs and they have a lot higher sheer strength than a standard Rem700. the Lawton 7000 for example has a lot stronger bolt and also the recoil lugs inside the action have a lot higher sheer strength even though both actions have 1.360" diameter and .700 diameter bolts the Lawton is a LOT stronger than the Remington. It all comes down to sher strength. As for the BAT actions i am unsure of the diameter of the bolt but i am sure it has much larger lugs inside the action and on the bolt. Also the Rem Bolts are 2 piece the boltheads are pinned to the bolt tube where most custom bolts are 1 piece making them stronger.

I understand why people think that two actions the same diameter same diameter bolts should be as strong as each other they just are not.

Cheers Bill
 
The greater the diameter of the case body the greater the rearward thrust, that is a given. But the fact remains there are plenty of the countries top gunsmiths that will build the 338 Lapua as well as 338/378, and 378 Wea, on a M-700 action even in SS

338LapuaBrassSolid005.jpg
 
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The following quote is by Dan Lilja

"Several years ago I wrote an article for Precision Shooting that determined bolt lug strength for a given bolt size and material strength. There was included in the article a computer code that also calculated bolt thrust developed from various cartridges. If we run the numbers through the program for our example here, the 378 Weatherby case and a standard Remington 700 action, we find that the bolt thrust value is about 12,760 pounds for a stiff handload (and whose aren't?) of 65,000 PSI. The lug strength value is greater (thankfully) at about 37,770."



I'd safety that's enough safety margin, of course the fact that there is a ot of 700's built in 338 Lapua and are working just fine must mean something, don't you think
 
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