.338 Lapua mag improved

[ARMECA]

Hello,

I plan to rechamber my .338 LM in the 40° imp. version, because I need some more speed with the .300 grs bullets.

Do you know what the velocity gain will be ? ( 28" barrel )

Also, where can I buy a full lenght sizing die ?

Thanks for the infos.

Bruno.

 

[rman1]

Re: .338 Lapua mag improved

You will be able to launch a 300 grain SMK at 3000 fps. Redding makes dies based on the reamer from Dave Manson. It is a 40 degree shoulder with a 1 degree body taper. Hope this helps.

R.

 

[guther]

Re: .338 Lapua mag improved

You can get 3000 fps with a Sierra match king. I have a 1:10 twist and mine lost accuracy at that speed. What powder are you using?
Guther

 

[rman1]

Re: .338 Lapua mag improved

Hodgdon US869.

R.

 

[rommelj]

Re: .338 Lapua mag improved

My barrel twist is 9.3 so I kept my velocity around 2900 fps using 95 grains of Retumbo.

I use Hornady Match grade Dimension dies and .369 Redding Titanium Nitride bushing.

 

[desertHK]

Re: .338 Lapua mag improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ARMECA</div><div class="ubbcode-body">Hello,

I plan to rechamber my .338 LM in the 40° imp. version, <span style="text-decoration: underline"><span style="font-weight: bold">because I need some more speed with the .300 grs bullets.</span></span>
Do you know what the velocity gain will be ? ( 28" barrel )

Also, where can I buy a full lenght sizing die ?

Thanks for the infos.

Bruno. </div></div>

how fast are you driving it now? and how much faster are you looking to push it? Have you consider the 338 Edge?

 

[264win]

Re: .338 Lapua mag improved

cant rechamber a lapua to edge[short of cutting the barrel down] as edge uses smaller diameter case . im also interested to how much velocity can be gained by the imp.

 

[guther]

Re: .338 Lapua mag improved

I am shooting 92gr of H1000 getting 2700 fps. I know that is not fast but it is accurate. Is that the only bullet you have or are going to try? What kind of accuracy are you looking for say at 500 or 1000 yards?
Guther

 

[ARMECA]

Re: .338 Lapua mag improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DesertHK</div><div class="ubbcode-body">how fast are you driving it now? and how much faster are you looking to push it ? Have you consider the 338 Edge? </div></div>

Actually, I push them to 2700 fps, with superb accuracy out to 1000 yards. ( within 1/2 MOA )

But after that range, I begin to have too much droop ( I only have a 30 MOA base on my Surgeon ), and the NXS go out of elevation at 1800 yards approximatively...
Also have some vertical stringing at the longer ranges due to bad ES.


I've had a .338 Edge for 2 years, and with the same powder capacity, I've been able to send those 300 grs to 2850 fps without problems... ( I use VV N 170 in either caliber )

If I could reach 2950-3000 fps and a better ES with the AI,it will be perfect !

Thanks again for your help.

 

[guther]

Re: .338 Lapua mag improved

That is exactly what I found. I can push it to 3000fps but lost accuracy. I lowed it down to 2700 and it shoots like you discribe. 5 inches a 1000yds. I have a 40 min base on my rifle and I can go a little further out. But like you I would love to have the speed up some.
Guther

 

[Goin'Hot]

Re: .338 Lapua mag improved

Does anyone know where the next accuracy node for the 300 SMK is? I'm at 2800 with an edge and get excellent accuracy out of a 9.4 twist. Ballistics look so much better at 2900 but if the accuracy isn't there whats the use?

 

[desertHK]

Re: .338 Lapua mag improved

Chasing the speed demon are you? Have you considered a different type of projos that gives better BC and therefore less drop?

 

[guther]

Re: .338 Lapua mag improved

I have tried Barnes and 250gr Nosler. Neither gave me the accuracy that I wanted. So I went with the next best thing, heavy and accurate. Any suggestions? I am willing to experiment more with load development if I can keep the groups tight.
Guther

 

[Goin'Hot]

Re: .338 Lapua mag improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Guther</div><div class="ubbcode-body">I have tried Barnes and 250gr Nosler. Neither gave me the accuracy that I wanted. So I went with the next best thing, heavy and accurate. Any suggestions? I am willing to experiment more with load development if I can keep the groups tight.
Guther </div></div>

What are you asking?

 

[guther]

Re: .338 Lapua mag improved

Sorry about being unclear. I was replying to DesertHK's comment about trying different projectiles that give a better BC. Any suggestions?
Guther

 

[264win]

Re: .338 Lapua mag improved

anyone tried the lapua scenars ? only a little better than the smk , but might have a higher acc. point.

 

[ARMECA]

Re: .338 Lapua mag improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 264win</div><div class="ubbcode-body">anyone tried the lapua scenars ? only a little better than the smk , but might have a higher acc. point. </div></div>

The 300 grs I shoot are Lapua Scenar. They are as accurate as the SMK, the BC is just a little higher, but they are way more available in France !

I've tried the 232 grs GSC, and last week, the 245 grs Lehight, but none are as accurate as the Scenar.