338 lapua reciever question

[yobuck]

I was doing testing with 338 Lapua back around 2009. I put a barrel on a older single shot 112V J series. That one gun is my test rifle. I set it up with out the barrel nut so the breech diameter of the barrel at the receiver was 1.250” o.d and being a single shot it gave me more confidence with the bolt lug engagement vs. Rem. 700’s where you have to open up/rework the feed ramp which I don’t like. That makes that bottom lug area have less support.

I opened up a mag bolt face to 338 Lapua and polished the extractor so it would snap over the rim. It chambered and ejected empty cases with no issues.

When Savage came out with they’re factory rifle....yes it’s a large shank but the receiver o.d. And lug area is the same. So it’s not any stronger per say.

The large shank is 1.120 vs. the 1.055” thread on the small shank (which is only about .005” smaller than a Remington thread. If you use the factory Savage barrel nut even on a large shank that still limits you to a 1.120” breech diameter. By not using the barrel nut like I did at least I could go up to a 1.250” breech diameter. Heck you can even go up to 1.350” diameter on the barrel. I’ve done 1.3” before on a Savage.

That all being said it was for testing I did prior to PSR1. If I was going to have a dedicated 338 Lapua or Norma I’d build it on a bigger receiver.

Later, Frank
Bartlein Barrels

Interesting post.
I agree on the Rem action as for the larger cases, and it puzzles me as to why the cartridge designer of the 300/338 Norma chose to use a 700 action?
Explain large? As in custom? Or as in bolt diameter?

[Shortbox4x4]

Interesting post.
I agree on the Rem action as for the larger cases, and it puzzles me as to why the cartridge designer of the 300/338 Norma chose to use a 700 action?
Explain large? As in custom? Or as in bolt diameter?

No clue as to your question on why a cartridge designer of the 300/338 Norma and or Lapua cases would’ve used a 700 type action. If memory serves me right the first commercial type rifle chambered in 338 Lapua was the AI L115a3. I don’t recall the receiver/barrel thread specs off hand but I do know even the older AI rifles had bolt with larger body diameters than a Rem700 or a Savage 110 or Win.70. The AI bolt and again going off of memory has like a .775” or .800” bolt diameter. I’ll have to measure one to be sure but that is bigger then the .700” diameter of the Rem. Or Sav. Bolt body.

You have actions now a days with a larger receiver tenon thread like the Stillers Tac30, Surgeon XL etc...that use a 1.125” diameter thread. So usually the breech diameter of the barrel starts out at 1.3” to 1.350” and can usually go up a little more. The BAT Model M action has a 1.125” thread as well. My take on having a larger receiver/barrel thread gives you more meat (wall thickness) from the id to do of the bore to the barrel. Some actions with the larger tenon threads also ending up having a larger diameter to the bolt as well.

To me having this extra meat from the bore to od of the barrel and a bigger bolt diameter/bigger lugs gives you more surface area for strength. Also with the pressures that some of these rounds are running at with the larger case diameter....the larger barrel diameter to me gives/stretches less per say. So case/chamber expansion is less or per say equal to a standard caliber/action set up. This helps keep case expansion in check and to me helps reliability and you will see it at times when you reload/resize the cases.

Apply the same logic to reloading/sizing dies. When you start getting into the 338 Lapua and bigger cases the standard 7/8-14 threaded sizing dies are known to crack. Also the more problems with guys getting the cases stuck in the sizing die. It’s usually not if they will it’s when they will. It’s all stress and something has to give.

[yobuck]

No clue as to your question on why a cartridge designer of the 300/338 Norma and or Lapua cases would’ve used a 700 type action. If memory serves me right the first commercial type rifle chambered in 338 Lapua was the AI L115a3. I don’t recall the receiver/barrel thread specs off hand but I do know even the older AI rifles had bolt with larger body diameters than a Rem700 or a Savage 110 or Win.70. The AI bolt and again going off of memory has like a .775” or .800” bolt diameter. I’ll have to measure one to be sure but that is bigger then the .700” diameter of the Rem. Or Sav. Bolt body.

You have actions now a days with a larger receiver tenon thread like the Stillers Tac30, Surgeon XL etc...that use a 1.125” diameter thread. So usually the breech diameter of the barrel starts out at 1.3” to 1.350” and can usually go up a little more. The BAT Model M action has a 1.125” thread as well. My take on having a larger receiver/barrel thread gives you more meat (wall thickness) from the id to do of the bore to the barrel. Some actions with the larger tenon threads also ending up having a larger diameter to the bolt as well.

To me having this extra meat from the bore to od of the barrel and a bigger bolt diameter/bigger lugs gives you more surface area for strength. Also with the pressures that some of these rounds are running at with the larger case diameter....the larger barrel diameter to me gives/stretches less per say. So case/chamber expansion is less or per say equal to a standard caliber/action set up. This helps keep case expansion in check and to me helps reliability and you will see it at times when you reload/resize the cases.

Apply the same logic to reloading/sizing dies. When you start getting into the 338 Lapua and bigger cases the standard 7/8-14 threaded sizing dies are known to crack. Also the more problems with guys getting the cases stuck in the sizing die. It’s usually not if they will it’s when they will. It’s all stress and something has to give.

Which also means a new larger loading press, $250 custom dies, new trimmer, new hand priming tool, not to mention the brass cost for a real 338.
And count on about 3 loads at peak performance before chucking the brass anyway
But then you wont need good eyes to see the difference between 2850 and 3250 with 300 grains at 1500 or more either if your into that stuff.
It’s a shame that everybody wanting a long range gun cant go watch them fly first, before they commit to buying one.

[efm77]

All good points. My point about the large shank is not that it makes it any stronger at the receiver ring. My thought is that Savage did it be able to keep the barrel nut and still have thicker chamber walls for that portion that extends beyond the receiver ring. I agree that a larger action overall would be the better option. However, I've seen quite a few Savages in 338 Lapua (their factory action designed for the Lapua that is) with quite a number of rounds through them with zero issues. Something makes me think that if people are having issues with lug setback etc, (when using the actions that came from the factory made for the Lapua, not putting a Lapua barrel on a regular Savage action) are using over loaded rounds, or have oil in their chamber restricting the brass from gripping the chamber, etc. I say that because I can't imagine Savage continuing to make them and not recalling them if it was found to be inherently dangerous.

As kind of a side note, does anyone know the dimensions of the RPR that's chambered for the Lapua in comparison to the Savage? I'm curious because I've thought about getting one of them too and haven't heard of any issues with them and Ruger has always been know for building stout actions.