338 Lapua...loads...info etc.

[Mike375]

From the reamer dimensions on Clymer it would appear that the 338 Lapua would be somewhere between the 338 Ultra and 338/378 in case capacity. Is this correct.

Anyone done any loading of the 338 Lapua and if so, what sort of velocities did you get with 250s or other bullet weights.

The 338 Lapua looks like an idal caliber for rebarrel of CZ 550 in 416 Rigby or one of the Wby Mark Vs that has been on the 378 case

Thanks,

Mike

 

[308 Hawg]

A friend has both and has told me that the .338 Lapua and tht .338 U'mag are very close in capacity. He questions why anybody would bother with the natural Lapua. His is an improved, just short chambered with his .338-4l6 Rigby Imp. reamer.

 

[chris matthews]

If you pick up the latest Hornady or VhitaVuori reloading manuals they both have info on the Lapua or drop me an email at [email protected] and I'll be glad ti give you some more info. As you mentioned the CZ action is a perfect choice- as soon as my barrel and stock arrive I'll be building my Lapua on that very action. Love the set trigger! If you need any more help just let me know.
Chris

 

[Mike375]

Chris,

What mounts are you going to use on the CZ. I see Talley now makes mounts for the CZ.

I have seem the Vithavouri data. Do you know the apacity of the 338 Lapaua compared to the 338 Ultra and 338/378 Wby. Thanks.

Mike

 

[Brent]

308 Hawg,
what is the distance to the shoulder on the improved 338 Lapua of your friends and how much neck length is left after fireformed?

Does his reamer have a seperate throater?

If so is he looking to sell it possibly?

The 338 RUM has a ways to go to match the Lapua and farther the Lapua Improved. Each seperated by a hundred FPS or several hundred FPS easily.

For the average person the RUM is close enough, the others, there is only the fastest using good brass to boot.

We just crono'd my friend's 338 RUM with 250 SGK's at 2920 fps. It was with ejector marks and sticky bolt lift too so it "ain't" that fast.

I used to get 3000fps out of my Ruger 338wm with 250 X bullets and 73gr H4350 but that was pushin it too. Bolt was never sticky and no extractor marks either. Primers were getting pretty hammered though and the Federal High Energy brass was unable to load a fourth time from loose pockets.

 

[chris matthews]

I will use CZ rings as they are now making them in 30mm. Can't help you with the total case capacity of the other two 338s- the closest I could come would be to compare the max charge of a powder that they all have in common.
Chris

 

[BrianW]

Hello Mike375,

Don't tell anyone here, but it's me "BW" from the 24HourCampfire board.

Anyhow, as you may recall I'm also interested in a "super" .338 cartridge. Here's what I've found concerning case capacities (water) of several .338 cartridges...

338 RUM 113.8
338 Laupa 122.9
338 Win Mag 88.3
338-378Weatherby 134.7
338 A-Square 129.0
338 Hawk 74.9

I'd love to get more data on the Laupa version using a barrel in the 26' range.

Brian

 

[Mike375]

Brian,

Thanks for that.

I think the 338 Lapua is much easier thing to do than the 33/404 if you are happy to go with either CZ or Wby Mark V.

The interesting thing with the Mark V is that they do not use the actions rails for feeding so with maagzine box and follower you could swap around between the H&H case, 404 case and Rigby/378 case.

I will get a chance soon to see if 300 Ultra will feed from the inline magazine of a 416 Wby and I am betting they will.

With a bit of work on the extractor and how it rests on the bolt I suspect you could use the dame bolt for both the 404 case head and Rigby/Lapua/378 case head.

We poor people have to imporovise

Mike

 

[jhendri2]

Mike375,

I have a 338 Lapua and a 330 Dakota and just sold a 338 RUM.

I have gotten 3000fps from a 250 and 3500 from a 180 from the Lapua. I never chrono'd the Rum. In the Dakota, I have gotten 2875 from a 250. What other infromation are you looking for?

Jim

 

[BrianW]

338Lapua,

Do you have any velocities with 210gr Barnes X bullets, in any of those .338's?

Thanks

BW

 

[Steve Shelp]

Brian,
In regard to your listing of H2O water capacity, the 338 Lapua (which I assume is a std 338 Lapua??) is way off. A std 338 Lapua is very close to the 338 RUM at 113gr of H2O. I shoot a 338 Yogi (Dave Tooleys version of a 338 Lapua Improved) and I get 120.6gr of H2O on that so the parent case can't be bigger. I've measured the 338 RUM, std 338 Lapua, my 338 Yogi, and 338/378 cases personally and I agree with your numbers for these cases except of the 338 Lapua. It's almost neck in neck to the RUM case right around the 113+gr H2O capacity area.

FYI: Lapua brand 338 brass has about 1gr more water capacity over Norma brand 338 Lapua brass.

Steve

[ 07-14-2002: Message edited by: Steve Shelp ]

 

[BrianW]

Steve,

That would explain a few things.

Most notably, the lack of extra velocity out of the Lapua version as compared to the RUM.

My data came from a relatively new reloading software program. To be fair, the version I have is a "beta" version, and the data may be correct in the final version. I'll e-mail the program writer and let him know.

Thanks again.

BW

 

[Brent]

So Steve, what would you guess a 338 RUM's capacity would be if using the full length 300 RUM case and necking down to be? More than the Lapua, but not as much as the Yogi that has the good brass? My father is considering the 338 RUM Imp. for a LH Rem 700 action I have.

 

[Steve Shelp]

Brian,
No problem. Good luck with your program and whatever caliber you decide to build.

Brent,
How's it going? Sure hope your over your M1A experience ok. That was scary!! anyway without having actually measured a 300 RUM myself, I would have to say based on the known outside dimensions of that case, that would be a pretty fair assumption to say it would be right in between the 2. Should make a nice hunting rifle..... especially in a lefty version! A rifle built the "right" way.

Steve