.338 lapua improved or 338-378 wby improved

[300spanker]

Folks,
considering one of the two for my next build. would like to push 300 grain sierra at 3000 fps with 30 inch barrel. would like any opinions or experience concerning the two including brass and accuracy and velocity difference, will use a 40 degree shoulder on both. i am considering a stiller action or defiance machine action for this build. I want to keep gun as light as possible, this will be my long range hunter, so any other recommendations on a good lightweight action would be appreciated. I will be putting on ABS carbon barrel, and a light weight stock.
thanks,gun)

 

[RDM416]

300,

I have 2 338 Khan's which is a 338/378 improved. One is built on a WBY MK IV action with a 27" Lilja, the other is built on a Nesika Bay action with a 30" Lilja.

You will have no trouble getting 3000 fps with the 300 SMK and a 30" barrel. I have been shooting 250 SMKs out of the Nesika at 3350. This hunting season I have been using the WBY action Kahn loaded with 300 grain Bergers. It easily pushes the Bergers to 2875 which is where I have been loading them to due to the "nose slump" problem when pushed too fast. I was getting around 3130 to 3150 out of them before that issue came up and I throttled them back. Both my Khan's are very accurate (1/4 moa) and both were built by Kirby Allen (Fiftydriver). My rifles are quite heavy compared to what you are wanting to build, both coming it at over 16 lbs (with scope). As light as you are trying to go, be sure to use a brake or recoil will be a bear.

Now, as far as the Lapua improved....... I have no experience with it although from what I have seen, the performance should be about the same as the 338/378 Imp. Brass will be expensive for both so no advantage one way or the other there. However, the Lapua brass is a harder alloy and may give you more loadings if you are going to be pushing things to the limit. I can get up to 10 loadings from my brass if I take it easy on it (like my current 2875 load with the 300 Bergers). If I start pushing the limits the primer pockets will get too lose to use after about 3 loadings. Normal, middle of the road loads will give me about 5 or 6 loads. This is true for either WBY or Norma brass, both of which are known to be quite soft.

 

[300spanker]

RDM,
thanks for the reply, i imagine you have shot the 300smk also. i did hear that berger fixed the nose slump, is that true and also do you think the new hornady 285 will be a winner, it sounds like the kahn and lapua improved produce similar velocities, and lapua has a little harder brass. just trying to stay away from chey-tac case. i will have muzzle break and gun shoud weigh in around 9.5lbs., i have watched my brother shoot two mule deer with the 300smk at 800 yards and they don't move much, maybe 30 inches down.
gun)

 

[RDM416]

I have shot the 300 SMKs but it has been a while and I don't have my log book handy to look up, but I am certain you can easily beat 3000 fps with the 338/378 imp. and probably the Lapua imp. also.

I have heard the nose slump problem is fixed on the Bergers. I bought a box of 250 early on and worked up the load for my WBY that runs them at 2875 and they shoot so well I have just kept shooting them rather than sending them back for replacement. I have killed several critters with them at ranges from over 900 to as short as 50 and the bullets have performed great.

I expect the 285 Hornady will be a good bullet. It will give us 338 guys a heavy bullet with a good bc (I hope) that is actually made for hunting. Some question the use of match bullets for hunting but I have not had any terminal performance problems with them. I am sure I will try the Hornady's when they become available.

One option to consider if you are leaning toward the Lapua imp. is the round Kirby Allen developed called the 338 AX (Allen Express). It is an improved Lapua and Kirby is able to supply new Lapua brass for it with the proper headstamp so there is no fireforming of brass required. Kirby has built several rifles for me and they all perform great....... I have 338 AM (chey-tac case) on order from him now.