.338 Lapua Magnum 'Improved'

[Curious]

Guys,

Can anyone help me to locate a reamer print for the .338 Lapua Magnum Improved with 40 degree shoulder?

 

[dkhunt14]

Look at Dave Kiffs site. Pacific tool. I believe I saw it there. Matt

 

[Curious]

The PTG website was the first place I looked, I can't see any reamer prints.

 

[Gottschall]

The PTG website was the first place I looked, I can't see any reamer prints.

Call Dave, He has them. Jeff

 

[ELR Researcher]

There are multiple chamber reamers identified as "338 LM Improved" (or ".338 fill-in-the-blank") that might be based on the .338 LM and have a 40 degree shoulder. Parent case and shoulder angle only address two of the "features" of a cartridge. There is the 338 LM AI (Ackley Improved), the .338 Allen Xpress, and the .338 Yogi (A to Y), just to name three. Different reamer houses may have different reamer details for the same cartridge name. IF you want the 338 LM AI, specify that to PTG and that is what you'll (probably) get (since there is a specific set of features that define an "Ackley Improved" cartridge). PTG's AI is at http://pacifictoolandgauge.com/309-...r-reamers/3612-338-lapua-ackley-improved.html

PTG has NO ".338 LM Imp" reamer listed on their site but they do have:

".338 (Order any OAL, Freebore, Neck)" - http://pacifictoolandgauge.com/309-...rs/10631-338-order-any-oal-freebore-neck.html

".338 Lapua (Order any OAL, Freebore, Neck)" - http://pacifictoolandgauge.com/309-...19-338-lapua-order-any-oal-freebore-neck.html

"Just" changing the freebore makes a new "variant" - which might then be identified the .338 John Smith or .338 Suzy Q. Also note that the two above "open spec" designs could be an "improved" version depending on the individual reamer drawing details/specs when compared to the parent case (PTG and other reamer houses include "parent case" on the reamer print). And there is no definition for what constitutes an "improved" design.

The "issues" proceed from the name and associated reamer print details to the associated dies. Unless you have the reamer print that was used to set the specs for the dies, and the chamber reamer print, you may no way to compare. When pursuing an "improved" (and many "wildcat") dies, you'll want to send the chamber reamer print to the die house to have them verify that their dies match.

Welcome to the wild and wooly world of "improved" cartridge designs.

 

[LA50SHOOTER]

Guys,

Can anyone help me to locate a reamer print for the .338 Lapua Magnum Improved with 40 degree shoulder?

Send me a PM if your interested in the one I have if you want to. - Here's how it was developed - And I used JGS as my supplier as I feel that I get better services from them over some of the others - I purchased my brass first - Lapua Blue box, did the neck measurements on several random cases so that I'd know what I was working with for min. neck thickness as I wanted (and have) neck turning, but only to the point to where I'm cleaning up the necks to get rid of variations. - I then neck turned a couple of samples & created a "dummy round" - then I "marked up" the JGS version of the drawing to get their approval on my dimensions. The JGS drawing was for a .338 Lapua Improved 40 degree which is what I wanted, but I wanted to run a tighter neck and tighter tolerances in the neck. Also I wanted the throat & leade set up for the 300 gr. Berger Hybrid bullet so that the bullet body bearing surface was above the neck/shoulder junction (deadly-doughnut area)and only the boat-tail portion hangs down into the shoulder area. - If my memory serves me correctly the OAL (bullet tip to case head) is approx. 3.975" as I'm running this in single shot actions. - I purchased an inexpensive .338 Lapua mag bullet seating die to build my dummy round when I started the initial project. - The cases after being neck-turned still maintained enough neck tension to hold the seated bullet (and I super-glued it when I established the seating depth). - I provided JGS the dummy round so that they could provide me the final version of the drawing (which I'm providing to you) which I approved for production. I then had JGS supply me the reamer & a "GO" head-space gauge. - I supplied the reamer, gauge, drawing, dummy-round & barrel blanks along with the BAT action to my Gunsmith who chambered my 3 barrels. - I like this cartridge a lot, it is a "true" Ackley type design in that the head-space dimension is .004 under measured from the case head to the datum on the shoulder. This is the way P.O. Ackley "wild-catted" most of his cartridges. It makes it so that a "Standard / Factory" (SAAMI spec) round will chamber (with "feel") in the Ackley chamber. - The caming power of the bolt will close on the factory brass - no trouble & worrying about excessive head-space isn't a worry. - After I fired a good stiff "Standard" .338 Lapua load in the Improved chamber, the brass formed out quite nice using Reloader 33 & the 300 gr. Berger. - In a 34" Benchmark 1-9 twist barrel the velocity was in the high 2700 fps range 9approx 2785 - 2800 fps). - I forgot to mention Improved reloading dies but will now. - I pursued this in 2 ways. - When I had my Gunsmith chamber my barrels I provided a Wilson .338 caliber straight-line bullet seating BLANK die. - I had him chamber this die with my reamer, making up a very nice and tight tolerance bullet seater. - Also, I had him provide a Newlon Shoulder-Bump Bushing style sizer die using the same reamer. - For a Full-Length Sizing die I provided 3 Fire-Formed pieces of brass to Whidden Gunworks and had him build me a F/L sizer (bushing style) & also another bullet seater just because it was a good deal & completed the die set.
- Running around 102 - 104 gr. of Reloader 33 & the 300 grain Berger Hybrid in a 34" Benchmark barrel I'm at 2960 fps with great accuracy with these bullets .012 off the lands. - I do believe that the load can come up a few grains but I have not pushed it & I feel that at the present load my brass will last +20 firings & I don't really see the benefit of pushing it to gain the extra 50-80 fps & loosing accuracy. - I like this design enough that I took a Savage Model 112 (Single-shot Long target action) rifle & had it re-barreled with a 28" finished length Bartlein barrel & used a Holland's brake on it for a Tactical/Sporter with a Bi-Pod mount as well, using the same chambering reamer. - It is a little slower than the 34" barrel(s) I'm running on the BAT gun but it's a decent set-up and not a lot went into it to get it up to an "improved" 338 Lapua & I can use the same dies as well.

If you contact JGS & give them the reamer drawing number they can provide you this reamer.

Kind Regards, Ron

 

[germanlongbow]

I used a PT&G 338 AI and throated mine for the 277gr Cutting Edge over Retumbo. BAT M action, Tooley MBR stock, Krieger 1.450 x 32 tube 5R. Shoots mid 0.150-0.200 three shot 100 yards. Velocity is 3080 fps with single digit Sd. Weighs in at 30 pounds with scope and can. This is my second 338 lapua, first factory Dakota Arms and now BAT. Built a buddies with same reamer on a Surgeon 1581XL with similar results with berger 300 gr bullets and Reloader 33. Its a cool round and stupid easy to load for. Good luck with your rifle. It look amazing. Scott