My New Defensive Edge LRKM

[Kiwi Greg]

Kirby, and or Greg, Two part question, Kirby pointed out how the BC and velocity of a super 338 can make ELR shots easier. I want to bring that back up and say I can tell you this is a real eye opener to me with the addition of 400 fps over my old 338.

So, I am and have been keeping an eye on the development of the 375's with new bullet offerings. It would be assumed that the larger bore would have a better barrel life too?? Or would the added 30 gr of powder to get the bullets to 3300 keep it close to the super 338's? I feel maybe a little more life from the 375?


Second part, bare with me,... Ok to rebarrel my 338 lets assume the going rate of $250 for thread and chamber and $400 for a tube..= $650. if a 338 terminator round loaded is $1.50 `$1.75 (less brass) what is the cost of a loaded 375 round with a good LR bullet (less brass)? I am trying to figure how much more it will cost to shoot a 375 and include barrel maintenance compared to a super 388 like the Terminator.

Thanks for any info.

Jeff

ps: but then we really have to also think about what it takes to replace all the loading equipment like presses and dies for the big gun.

How do you feel all this weighs out? I know, back to the "Speed Cost Money, How Fast do You Want to Go" thing right..

Hi Jeff.

My 375 Terminator gets along pretty well, basically the same case dimensions as your 338, just in 375, pushes the 350-425s nicely with around 115 grains of powder.

The only real difference is the cost of the projectile.

The 375 barrels will last longer.

The new Lazer CEBs will transform the terminal performace of the solid projectiles.

I do know it is much easier to shoot my 375 DCM than the 338 DCM at distance, the further you want to shoot the easier it is to hit with the 375, the more difficult the conditions the easier it is to hit with the 375.

Ballistic calculations only tell part of the story, IMHO the bigger projectiles "hold" better at distance than the smaller ones even though the calculater says there is very little difference.

The 425s are easier to shoot at distance than the 350s even though they are both very accurate all the way.

PS by at distance I mean a mile +

 

[Fiftydriver]

Looking back on my notes looking at different powders and the amount of each powder that the 338 Lapua Improved design holds when filled to the case mouth, from your numbers N-570 is a pretty dense powder.

Here are the capacities for my 338 AX when filled to the mouth with each of the following powders:

VV 20N29..............114.5 gr
Retumbo................116.3 gr
H-50BMG...............117.3 gr
WC-872.................122.5 gr
RL50......................123.1 gr
WC-860.................123.3 gr
WC-857.................123.4 gr
H-US869................130.1 gr

As you can see, VV N-570 is nearly identical to RL50, WC-860 and WC-857 which makes it a very dense for volume powder.

It always amazed me to see how dense RL50 powder is for being a very large kernal stick powder, yet is has a weight to volume ratio nearly identical to the ultra slow burning surplus ball powders.

Putting N-570 in this same class makes it clear how it can produce some added velocity as it fits a significant amount more weight in a given volume compared to other powders.

I have not measured H-1000. I have never used it in my 338 AX mainly because its to easy to pressure out with that powder in that case volume. It can certainly be used if one wanted to work up a load and be careful watching your pressures but I like a powder that prevents us from getting ourselves into to much trouble with pressure, especially when using the ultra strong Lapua case.

 

[MT4XFore]

Jeff and Kirby: It is really nice to see some intelligent discussion between a couple of experienced LRH'ers. Seems like old times on this forum now. Thanks a lot.

Jim

 

[MontanaRifleman]

Hi Jeff.

My 375 Terminator gets along pretty well, basically the same case dimensions as your 338, just in 375, pushes the 350-425s nicely with around 115 grains of powder.

The only real difference is the cost of the projectile.

The 375 barrels will last longer.

The new Lazer CEBs will transform the terminal performace of the solid projectiles.

I do know it is much easier to shoot my 375 DCM than the 338 DCM at distance, the further you want to shoot the easier it is to hit with the 375, the more difficult the conditions the easier it is to hit with the 375.

Ballistic calculations only tell part of the story, IMHO the bigger projectiles "hold" better at distance than the smaller ones even though the calculater says there is very little difference.

The 425s are easier to shoot at distance than the 350s even though they are both very accurate all the way.

PS by at distance I mean a mile +

Greg,

I am watching this thread with some great interest... concerning the CEB's. If you convince Broz to go the copper mono bullet route you will have made him a new born man ...

... and I will gladly call your local beverage distributor with my card number and buy you a case of your favorite wheat/barley based beverage

Jeff,

The monos are king in the big boys gun)

 

[Broz]

Thanks Kirby and Greg for that info.


Greg, with 115 gr of what powder and what velocity are we talking if a 1.0 moa bullet is used?

MT4XFore, I am enjoying this conversation too. To say I am a tad excited with my new rifle would be an understatement. So all this is fresh on my brain.

Jeff

 

[Kiwi Greg]

Thanks Kirby and Greg for that info.


Greg, with 115 gr of what powder and what velocity are we talking if a 1.0 moa bullet is used?

MT4XFore, I am enjoying this conversation too. To say I am a tad excited with my new rifle would be an understatement. So all this is fresh on my brain.

Jeff

Hi Jeff.

The 115 is an average charge weight for 330-425 grain CE projectiles.

The 425 has around 0.98-1.0 at 2800+ in my Terminator

With 111 of Retumbo giving 2824, 2826, 2827fps according to my data for a group I shot last year, obviously I don't have to mention work up to this, this is a big action with a little case in it & a long barrel.

I don't use it much now I have the 408 cased DCM

My case holds 125 grains of water to the top.

A bit more info here

375 Terminator

Cheers Greg.

 

[Broz]

Greg That is a cool round. But when I go 375 I will probably go with the big cased offering.

Thanks!
Jeff

 

[Kiwi Greg]

Greg That is a cool round. But when I go 375 I will probably go with the big cased offering.

Thanks!
Jeff

I would too Jeff.

I just suggested it because the 375 Terminator will go in your LRKM

The 375 CT imp is the way to go lightbulb

 

[Fiftydriver]

Well hell, might as well throw a teaser out there. If things go as planned with my 300 and 338 Raptor projects, there will very likely be a 375 Raptor as well. In comparision with the 338 Lapua Improved chamberings, using Retumbo filled to the base of the neck, the Lapua Improved will hold 109.0 gr, the Raptor will hold 134 gr and the 338 AM will hold 158 gr.

basically the Raptor case will split the difference between the Improved Lapua and the Improved Cheytac and still function in a Lapua class receiver but will need to be a single shot.

That said, this is all dreams at this point. As long as it has taken to get this Raptor project off the ground, who knows how long it will be before the 300 and 338 Raptors are main stream and ready to start the next adventure. Many times in this project, over the past 10 months I have about said, screw it, the 338 Lapua Improved is plenty!!!

Your excitement about your new rifle is well justified, we are all excited to see you stretch her out!!!

 

[Kiwi Greg]

Well hell, might as well throw a teaser out there. If things go as planned with my 300 and 338 Raptor projects, there will very likely be a 375 Raptor as well. In comparision with the 338 Lapua Improved chamberings, using Retumbo filled to the base of the neck, the Lapua Improved will hold 109.0 gr, the Raptor will hold 134 gr and the 338 AM will hold 158 gr.

basically the Raptor case will split the difference between the Improved Lapua and the Improved Cheytac and still function in a Lapua class receiver but will need to be a single shot.

That said, this is all dreams at this point. As long as it has taken to get this Raptor project off the ground, who knows how long it will be before the 300 and 338 Raptors are main stream and ready to start the next adventure. Many times in this project, over the past 10 months I have about said, screw it, the 338 Lapua Improved is plenty!!!

Your excitement about your new rifle is well justified, we are all excited to see you stretch her out!!!

Kirby it is fun playing with new things, but it takes plenty of time & money....

I have been playing with a long case about the same capacity as your Raptor, man they go lightbulb

I have 300, 340 & 380 Terminator as their names, just waiting patiently for others to do their bit.....

 

[royinidaho]

I'm liking this thread!

Puts excitement back in LR.

When the window opened to get the rig of my dreams I'm pleased that I went with the 375 AM over the 338 AM.. No more scheming to go bigger is easier on the brain.

Y'all got me thinking about those solids, big time!

Greg, your suggestion for a projectile in a chey I improved 375 w/ 10 twist would be?


Also, because I'm po, tight and cheap is there a way to get, from the bullet maker, a sample few for tearing?

 

[Fiftydriver]

Kirby it is fun playing with new things, but it takes plenty of time & money....

I have been playing with a long case about the same capacity as your Raptor, man they go lightbulb

I have 300, 340 & 380 Terminator as their names, just waiting patiently for others to do their bit.....

It takes as much patients as money when bringing something new to the market!!!

 

[Kiwi Greg]

I'm liking this thread!

Puts excitement back in LR.

When the window opened to get the rig of my dreams I'm pleased that I went with the 375 AM over the 338 AM.. No more scheming to go bigger is easier on the brain.

Y'all got me thinking about those solids, big time!

Greg, your suggestion for a projectile in a chey I improved 375 w/ 10 twist would be?


Also, because I'm po, tight and cheap is there a way to get, from the bullet maker, a sample few for tearing?

I would try the CEB 350 or the 375,

The 350 SMKs are pretty good but mighty hard & I haven't been able to get much terminal performance data,

The CEB Lazer projectiles should be great for terminal performance, my tipped ones are possibly a little over zealous

 

[Fiftydriver]

I have just never been dramatically impressed with the CE bullets. Nothing really wrong with them but the ones I have tested in 7mm, 30 cal and 338 really left me wondering one major question after I developed loads for them, what am I really gaining here????

The reason I ask that is three fold.

1. Mainly cost. I can get conventional cup jacketed lead core bullets that are more consistant over a wider range of bore diameters and more forgiving in seating depth and load and do so with prices that are 1/3 to 1/2 less then the CE bullets.

2. They can be a real pain in the rear to find that sweet spot in seating depth, in fact a few rifles I have never found it and gave up.

3. Terminal performance. There is no doubt that at closer ranges they do extremely well but at long range, like the TSX, TTSX and LRX bullets from Barnes, they thrive on speed but as range increases, terminal performance can really drop off as with all solid copper or alloy designs, even HP designs.

Now in the 375, they may have some merit simply because of the lack of options out there but for all other calibers, I see them as an option but just can not justify the extreme cost over more conventional bullets which will offer at least as high of a BC, be more forgiving from bore to bore and generally better terminally over a wider range of distances. Just my throughts.

Again, have no problem with these bullets, just do not really see the justification to charge what they do for what you get in most calibers.