30-338Lapua / 30-338Lapua Imp

[300Wildcat]

What is best way to make cases -> 338Lapua to 30-338Lapua ? Is it much harder work if you have ack imp chamber? Possible to do without fireforming? lightbulb

 

[Elk Hunter 338]

They can be made with a hydro form die through whidden gunwerks, and I think hornady will make them also although they will not be fully formed and will still need to be shot through rifle for final forming. that's about the only way without putting some sort of fire to it. The ones I've delt with will shoot pretty dam good while fire forming and are very usable loads for long distance shooting/practice.

 

[RockyMtnMT]

What is best way to make cases -> 338Lapua to 30-338Lapua ? Is it much harder work if you have ack imp chamber? Possible to do without fireforming? lightbulb

I full length size, prime, load 3/4 case bullseye with piece of cotton in the end to hold the powder. Go outside and pull the trigger. I have to neck turn mine before I can load them because neck is tight and the brass gets thicker when sized down. My chamber is slightly shorter than the parent cartridge so it gives a crush fit when virgin brass is chambered so there is no head space issue.

I think I am going to change to the cream of wheat method in the future. I think it works better and less pressure on the brass. Much more mess though. The bullseye method has worked well on the lapua brass and very easy. Used this method on rum brass and seemed to be a little too much pressure.

Steve

 

[300Wildcat]

How about differences between "normal" vs Ack Imp chambers?? I know if i choose ack imp chamber its better to do fire/hydro forming. But how about basic 30-338 Lapua (Actually 300LapuaMagnum) is it possible neck to down only with sleeves??

 

[RockyMtnMT]

How about differences between "normal" vs Ack Imp chambers?? I know if i choose ack imp chamber its better to do fire/hydro forming. But how about basic 30-338 Lapua (Actually 300LapuaMagnum) is it possible neck to down only with sleeves??

If the neck is the only diff in the chamber you would be good to go. May still have to neck turn if the chamber neck is tight.

FWIW I really enjoy my improved version. A true hot rod.

Steve

 

[RockyMtnMT]

We just got a reamer to do a .264 version improved. Tried it with the rum last summer and the brass was the weak link so using the 338 lap now.

Steve

 

[300Wildcat]

How about twist rate? Plan is shoot Berger 230 hybrids fast and accuracy. Maybe it need tighter than 10"? Anyone tested?lightbulb

 

[IdahoCTD]

Mine shoots 230's just fine in a 10 twist at 3350fps. I do have a 33" barrel though.

 

[300Wildcat]

Mine shoots 230's just fine in a 10 twist at 3350fps. I do have a 33" barrel though.

How about accuracy? Moa or better? How about stability on real long shots? I mean over 1400yard accuracy. 10" twist is correct for 215Hybrid include ovet 1400y shots but how about 230Hybrid???

 

[IdahoCTD]

I haven't shot it much at long range. It will shoot around 1/2 moa with that load and I haven't really work with any other powders. A case of too many rifles and not enough time.

 

[300Wildcat]

I haven't shot it much at long range. It will shoot around 1/2 moa with that load and I haven't really work with any other powders. A case of too many rifles and not enough time.

If i can ask what is that load and powder? Do you have imp chamber or basic? Any problems with coppers/cleaning?

 

[bigngreen]

At 0 ft elevation you may want to run a 9.5 twist per Berger twist rate calculator but a little elevation and your good. I've been back and forth as well on a barrel do my 30-338 LAI, this is an excellent round to stress the heck out of jackets but their are some 240 gr bullets to shoot as well as some very good monos which would need twisted up.

 

[RockyMtnMT]

At 0 ft elevation you may want to run a 9.5 twist per Berger twist rate calculator but a little elevation and your good. I've been back and forth as well on a barrel do my 30-338 LAI, this is an excellent round to stress the heck out of jackets but their are some 240 gr bullets to shoot as well as some very good monos which would need twisted up.

A 9 twist opens the world. Should never hurt you, and you will be able to shoot long bullets that we will be seeing more and more of. As bc's go up so does the length of the bullet.

Steve

 

[IdahoCTD]

If i can ask what is that load and powder? Do you have imp chamber or basic? Any problems with coppers/cleaning?

Mine is a 35 degree shoulder improved version. The load is 112grs of WC872 with a CCI250. I should probably try Fed215's in it.

I don't think a 9 or 9.5 twist would hurt either. Compared to most other calibers the .308 caliber cartridges and big bullet don't need super fast twist. All my .30 magnums except a X-caliber barreled 30-338 Norma Imp. are 10 twist and I haven't had any problems stabilizing bullets. I have a 10 twist Bartlein 30-338 Norma Imp. that shoots 230 Bergers in the .1's for 3 shots and around .250" for 5 shots at 100yds. It's not as fast as the Lapua case (3045fps) but I think it's more accurate.