338 LAPUA IMPROVED

[Sling]

Which version you running? I had a 338 Excaliber but had sticky bolt with A-Square brass so I had Jamison make me some. Same problem. I wasnt running it hot, just mild loads. 300gr Berger @3070fps. After talking to some knowledgeable people, we all agreed on that there wasnt enough case taper and once pressure got around 60,000, I had premature extraction issues. I dont want to reinvent the wheel and design a new improved case, just trying to see which version is working great. I know that custom dies will be needed, no problem. I have come to the conclusion that a big, long case needs at least .012 or so of case taper per inch to fix this problem. I have been looking at the 338 YOGI. My goal is 3000fps with 300gr bullet.

Thanks,

 

[Dirtball]

I am running one I designed, it has .016 total body taper, if I keep the chamber and the brass CLEAN, anneal every 3-5 firings and don't load too hot, I do not have any problems with extraction. Remember with an improved version there is no need to push chamber pressures over 60K, that last 40FPS you get by pushing it is NOT worth the potential problems that can come with it, IMHO.
If you have not tried RL33 in the 338LM IMP you need to give it a try, you should get 75 to 150 FPS increase over Retumbo/RL25/H1000, depending on your barrel length.

Dave

 

[xswanted]

I think the guys at Gunwerks have one they were using called the 338 Allen Express. I don't know much about it but it said it was an improved 338 Lapua. They were shooting the 300 Berger around 3000.

 

[jimbires]

Kirby Allen should be the 338 Allen Express inventor . here is his web page .

http://www.apsrifles.com/

 

[dkhunt14]

Maybe you could check reamer drawings on Dave Kiffs site. I have one of Kiffs but not sure which one. Hit 3137 with 300 Sierra and us 869. Very slow burn and very dirty. Hard to ignite when it gets really cold. I want to try RE33 when i can get some. Kirbys 338 is supposed to be fast. A lot of difference could be in the throat.

 

[Rockfish Dave]

From what I have gathered from Kirby's posts on the 375/338 AX:

- The taper for his express is: a minimum of .010 per inch and a max of .012 per inch.

- The OAL is 3.820" for the seekins bottom metal/magazines so the throat freebore length is 0.200" set up for the 350 gr SMK

Dealing with Dave Kiff at PTG:

- The Kiff throat for single feed is: lead of .223" and throat of .239"


For my current project I was trying to get the improved case to feed from a CID length magazine (3.74") and found I would have to compromise too much on case capacity. Ultimately I went with the single feed...

I think I will be able to load the Barnes 300gr tsx for a magazine, but ELR plinking will be a single feed proposition.

 

[montana_native]

From what I have gathered from Kirby's posts on the 375/338 AX:

- The taper for his express is: a minimum of .010 per inch and a max of .012 per inch.

- The OAL is 3.820" for the seekins bottom metal/magazines so the throat freebore length is 0.200" set up for the 350 gr SMK

Dealing with Dave Kiff at PTG:

- The Kiff throat for single feed is: lead of .223" and throat of .239"


For my current project I was trying to get the improved case to feed from a CID length magazine (3.74") and found I would have to compromise too much on case capacity. Ultimately I went with the single feed...

I think I will be able to load the Barnes 300gr tsx for a magazine, but ELR plinking will be a single feed proposition.

Why not the Seekins 338LM bottom metal? I can get 3.930" in mine.

 

[Rockfish Dave]

From what I have gathered from Kirby's posts on the 375/338 AX:

- The taper for his express is: a minimum of .010 per inch and a max of .012 per inch.

- The OAL is 3.820" for the seekins bottom metal/magazines so the throat freebore length is 0.200" set up for the 350 gr SMK

Dealing with Dave Kiff at PTG:

- The Kiff throat for single feed is: lead of .223" and throat of .239"


For my current project I was trying to get the improved case to feed from a CID length magazine (3.74") and found I would have to compromise too much on case capacity. Ultimately I went with the single feed...

I think I will be able to load the Barnes 300gr tsx for a magazine, but ELR plinking will be a single feed proposition.

Why not the Seekins 338LM bottom metal? I can get 3.930" in mine.

Couldn't find one anywhere. If I could I would!

 

[montana_native]

From what I have gathered from Kirby's posts on the 375/338 AX:

- The taper for his express is: a minimum of .010 per inch and a max of .012 per inch.

- The OAL is 3.820" for the seekins bottom metal/magazines so the throat freebore length is 0.200" set up for the 350 gr SMK

Dealing with Dave Kiff at PTG:

- The Kiff throat for single feed is: lead of .223" and throat of .239"


For my current project I was trying to get the improved case to feed from a CID length magazine (3.74") and found I would have to compromise too much on case capacity. Ultimately I went with the single feed...

I think I will be able to load the Barnes 300gr tsx for a magazine, but ELR plinking will be a single feed proposition.

Why not the Seekins 338LM bottom metal? I can get 3.930" in mine.

Couldn't find one anywhere. If I could I would!

Gotcha. I got mine well before all of the pandemonium. Even though I've got it, I find it's not necessary at all for the type of shooting I do with the rifle.

 

[Rockfish Dave]

Gotcha. I got mine well before all of the pandemonium. Even though I've got it, I find it's not necessary at all for the type of shooting I do with the rifle.

Just got off the phone and nope it will be a while...

When something is this hard to get a hold of I'll just stick with what is readily available and make due.

 

[338 Mollett]

My case loads the 300g berger to 3.550 oal and well above the donut ,with the same case capacity as the 338 lapua.It is shorter and fatter than the 338 norma with a 30 degree shoulder and a .370 long neck.

 

[Sling]

My case loads the 300g berger to 3.550 oal and well above the donut ,with the same case capacity as the 338 lapua.It is shorter and fatter than the 338 norma with a 30 degree shoulder and a .370 long neck.

If your case is fatter than the Norma & Lapua, i`m guessing you used either the Cheytac case shortened or the 585 case necked down & shortened right?

 

[338 Mollett]

I used a 408 cheytac rebated the rim blew out the body a little. Short fat and sweet,might be the most efficient 338 designed .Cases are a pain to make,takes two days to make 50.

 

[Sling]

I used a 408 cheytac rebated the rim blew out the body a little. Short fat and sweet,might be the most efficient 338 designed .Cases are a pain to make,takes two days to make 50.
[/quote

PM sent

 

[Rockfish Dave]

I used a 408 cheytac rebated the rim blew out the body a little. Short fat and sweet,might be the most efficient 338 designed .Cases are a pain to make,takes two days to make 50.

I'd love to learn more about this.

 

[338 Mollett]

I will post pictures as soon as I figure out how .