Rifle?? 6.5-338 Lapua

[Whit]

I found a caliber that I never heard of and wandering if anyone has heard of or seen a rifle chambered in it? The cartridge is 6.5-338 Lapua. It launches a 139gr scenar at 3780 FPS. Here is the link and its at the bottom of the page under "High Velocity 6.5mm". Its interesting to see how it performs. Even the 300 Lapua Magnum is interesting to see also.


http://www.lapua.com/en/story-of--338-lapua-magnum.html

 

[ranger1183]

Re: Rifle?? 6.5-338 Lapua

sounds as useful as the 6.5 STW. Sure you can hunt with it, but you might as well buy replacement barrels by the dozen.

 

[stalski]

Re: Rifle?? 6.5-338 Lapua

Good luck with that... Wonder what the pressure is

 

[Tyler Kemp]

Re: Rifle?? 6.5-338 Lapua

There's no reason the pressure would be any higher?

 

[RobertB]

Re: Rifle?? 6.5-338 Lapua

Up there where you at in Ohio Tom Sarver at thunder valley precision has a shortend and improved case off of the 338LM. The 300 hulk. He has also necked it down to 7mm (7mm HULK). Fast Boolits

 

[TGagnon]

Re: Rifle?? 6.5-338 Lapua

It would be much easier to run a 6.5 RUM as the brass is easier to neck down for starters and you would have less inclination to use a larger action than just the standard 700LA. Plus you would need one hell of a barrel to get it up to those velocities without profuse amounts of powder burn after bullet clears barrel. I played around with it a bit in quickload a while back and there just isn't a great reason for it unless you have to have a 6.5 hunting rifle that shoots 140 class bullets past 3500fps.

 

[blksno]

Re: Rifle?? 6.5-338 Lapua

The 6.5 is interesting, but I don't see any advantage over the 7mm Hulk. If you're going for that big bad case, there isn't much reason to try hot rodding 6.5 bullet when a 7mm bullet has it out-classed.

 

[RobertB]

Re: Rifle?? 6.5-338 Lapua

Sounds like there is no reason to get anything bigger than a 264wm or (STW, Ultra mag) really. Your just going crazy past that point.Can you really do much better?, in the future with different powder and bullets something might could be used more effectively. My thoughts

 

[Cacciatore]

Re: Rifle?? 6.5-338 Lapua

Whats next 6.5-50? These ideas are cool on paper but have no practical purpose other than finding out how fast you can burn a barrel.

 

[Whit]

Re: Rifle?? 6.5-338 Lapua

I just thought it was interesting to see the 6.5-338 Lapua. I didn't say it was perfect. I have never heard of a 6.5 bullet being launched at over 3700 FPS.

 

[bohem]

Re: Rifle?? 6.5-338 Lapua

Yowza, that's incredibly fast. My concern is how do the bullets survive launch and for how many rounds?

In an 8tw my 6.5-06 load had to be toned back from 3250fps because the 140 Bergers had a disintegration issue.

 

[105amatt]

Re: Rifle?? 6.5-338 Lapua

Im guessing a slower twist is in order. I don't know how to do the math for that kind of thing, anyone?

 

[Gray]

Re: Rifle?? 6.5-338 Lapua

http://www.apsrifles.com/Allen_Magnum_Wildcats.html

Here is your builder if you won't something like that...

 

[bohem]

Re: Rifle?? 6.5-338 Lapua

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 105amatt</div><div class="ubbcode-body">Im guessing a slower twist is in order. I don't know how to do the math for that kind of thing, anyone? </div></div>

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

This is a pretty good estimator that runs off the Miller Stability estimation.

Also a good thing to look at is the exit RPM on the muzzle velocity.

MV*720 / twist (inches per turn)

So a 12 twist 308 shooting a bullet at 2500fps is:

2500*720/12 = 150,000 rpm

I found the Berger 140's and the Amax's to have issues as they approached 290-300 krpm which is around 3250-3300fps from an 8tw

 

[leadbullet]

Re: Rifle?? 6.5-338 Lapua

talk about useless, cool but useless to me anyway.

 

[fw707]

Re: Rifle?? 6.5-338 Lapua

Sounds like a good idea to me, but I'll stick with my 17-BMG.
It'll do about everything I need.

 

[stalski]

Re: Rifle?? 6.5-338 Lapua

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tyler Kemp</div><div class="ubbcode-body">There's no reason the pressure would be any higher? </div></div>

please correct me if I'm wrong, but much more powder (more powder from 338 case) in the same barrel diameter would lead to higher pressure inside the barrel behind the screaming bullet after ignition than when using a regular 6.5 case.

no?

 

[Whit]

Re: Rifle?? 6.5-338 Lapua

I didn't say it was perfect. I just ran across it and wandered about it.

 

[wadebrown]

Re: Rifle?? 6.5-338 Lapua

I built a 6.5 WSM about the time the WSM rounds came out and it was a great round up until 550 rounds and then the accuracy went away and never came back. I could easily get 3,250 fps with SMK 142, but the only thing they did different than the 3,100 fps 142's out if my 6.5x55AI was burn the barrel out faster.

wade

 

[Cacciatore]

Re: Rifle?? 6.5-338 Lapua

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fw707</div><div class="ubbcode-body">Sounds like a good idea to me, but I'll stick with my 17-BMG.
It'll do about everything I need.

</div></div>

EPIC.

 

[trentcwwilson]

Re: Rifle?? 6.5-338 Lapua

Yowza, that's incredibly fast. My concern is how do the bullets survive launch and for how many rounds?

In an 8tw my 6.5-06 load had to be toned back from 3250fps because the 140 Bergers had a disintegration issue.

You're only getting 3250? Rechamber that to a 260 Dingo. I'm getting 3900 with q00 grain bullets. Hell, change to 240 Dingo. We're slinging 60 grainers at 4525 and still going up. Aiming to beat Ackley's 4600fps mark and were doing it with more bullet and less powder.

Sent from my SM-G950U using Tapatalk

 

[Supersubes]

I know of a guy who did that. I believe he got approx 120 rounds out of the barrel before bullets started to explode.

 

[BurnOut]

'bout the time you got a load worked up, it'd be time for a new tube.

 

[dannySH]

You're only getting 3250? Rechamber that to a 260 Dingo. I'm getting 3900 with q00 grain bullets. Hell, change to 240 Dingo. We're slinging 60 grainers at 4525 and still going up. Aiming to beat Ackley's 4600fps mark and were doing it with more bullet and less powder.

Sent from my SM-G950U using Tapatalk

Necrothread. If you read well that is a 5 years old post.