My New Defensive Edge LRKM

[Fiftydriver]

Got turned onto your post on the new rifle and set down today and read all the way through it. Congrats on a fine weapon system and great shooting. I am sure you will have a load of fun with that rig.

Wanted to make a couple points however, some reading this that do not know better may believe that its simply the throat design that is resulting in the added 200 fps over a standard improved version of the 338 Lapua when in fact it is a combination of many things put together and allowed to work together to get the end result your seeing.

The throat design is one of many things that are allowing the performance increase. Other things are:

1. Long barrel length
2. Krieger barrels tend to run on the fast side of average
3. VERY long OAL in the ammo resulting in dramatic usible case capacity increase over standard length throats.
4. Berger bullet which is proven to be 50-70 fps faster then the SMK for same chamber pressures(shorter baring surface)
5. Lapua case that will easily take 70,000 psi or more without showing pressure signs
6. High energy powder that will on average give a 30-40 fps boost in velocity with similar pressure to more easily attainable powders such as Retumbo
7. Last but not least, the +P throat design which flattens the pressure curve and allows the use of more powder under a give bullet weight. This results in more pressure under the bullet for a longer period of time which results in higher performance.

Just wanted to add my two cents for those that are reading this and thinking, ****, I can just put a special throat in my rifle and get another 200 fps, that is really not the case. Its a combination of every one of the above factors that add up to an additional 200 fps so for those reading this, realize its a combination of things that need to be put together correctly to get these results.

The OAL of your ammo is just as huge as the throat design, all you have to do is measure the volume of a cylinder that is 0.338" in diameter and 0.400" in length and you can see the dramatic increase in usible case volume compared to a standard 338 Lapua Improved with a conventional 3.650" OAL.

Certainly not taking ANYTHING away from Shawns research, his rifles, your loading and shooting ability or anything else, truly impressive results but just wanted to throw a bit of education out there as well for those new to this type of technology.

Now I just hope your throat will hold up long enough to give you some good use out of the rifle. I know in my testing of my Hybrid throat design which is very similar to Shawns +P throat. Velocity gains were dramatic but barrel life was also measurably shortened compared to a conventional throat.

I think the jury is still out on how N-570 treats a throat. Many say its easier on throats, just as many say its harder on throats then more conventional powders. I have not burned enough to be able to say either way. I still believe the biggest factory to barrel life is making sure not to overheat the barrel and keeping it clean. That said, in testing my Hybrid throat in my 7mm AM and 300 AX, I got a bit rushed in doing some ballistic testing and got the barrels a bit warmer then I should and it made a big difference in throat life.

Now, both of those are significantly to DRAMATICALLY harder on a throat then the 338 Lapua Improved designs so hopefully if you keep that barrel cool, you will see decent barrel life. With that long of a throat, you do not have much room to chase the lands!!!

Have fun, keep us posted with your extreme range results. Would love to hear about your case life as you get some life on those brass. Ya got to kick Shawn in the rear and tell him to start offering formed brass for you guys!!! LOL

Looks like my new 338 Raptor has some pretty serious numbers to compete against. We will see how she does here in a week or so with a conventional throat compared to the +P throat design that Shawn is using.

Again, great looking stick and fine shooting, have fun!!!

 

[Broz]

Kirby, I agree with the entire combo being the result, I think it is a good combo too and that was exactly what we set out to build with the LRKM .338 Terminator +P. Back when I raced and tuned Nitro engines we had a saying, "speed cost money, how fast do you want to go" When I compare barrel life to replacing a crank every 20 runs, ring and pinions in sometimes 12 runs, aluminum rods regularly, and referring to pistons as fuses, replacing a barrel on this hot rod is not so bad. However, knowing what we did to keep the pistons alive and from liquefying under severe heat, and comparing this to the +P design chamber, I am optimistic for a usable barrel life. It could be that spreading the pressure spike out, and removing tall thin areas where heat will erode first, has a positive effect. That said, I am also being careful not to abuse the rifle with excessive heat. This is not the kind of rifle you set down over a prairie dog town with. No more than you would take a supercharged nitro engine on summer vacation. I have been holding back to 2 shot groups with some cooling after.

The performance of this rifle combination is stunning. To get an idea you have to look far beyond the horsepower and the extra 200 fps. There is a beauty that lies in the chassis of the LRKM as well. Back in the race car days when I got a cars chassis to preform this smooth I referred to it as "free Horse Power" That meaning I didn't have to lean on the engine as hard to get the performance level to win races. This is how I feel now that I have fired several rounds through the LRKM. Last weekend my son (Young-Gun) and I were out shooting. We took his 300 win to a mile with some good results. My son is a good shot, if he levels off on an antelope or deer under 1000 it is not looking too good for the critter. But he has little to no experience shooting past a mile. I dialed in the Terminator +P for a shot on a 1 moa rock at 2422 yards. With my son spotting we both watched the first round impact the rock. Then I sent another and my son seen chips fly off the rock. We gave her a little cooling time and then my son got behind the LRKM. He too put a round right on the 1 moa rock at 2422 yards. If my memory is correct, this was either the first or second shot he had ever taken with the LRKM design. In the end we each had put 2 or 3 rounds on the rock with only one miss when a bag slipped and the round went slightly over the top. My point is, this rifle makes shots that are amazing, a lot easier to obtain. Just like a good race car does with winning races. A solid platform that is efficient and consistent is a winning combination, with or with out the bonus 200 fps. If the barrel life is too much for the regular maintenance schedule to bear, then I will fall back on the performance of the total LRKM .338 Terminator +P package. A little de-tuning with a little less boost and I will still have a winner. But for now I am happily enjoying having it all at my finger tip.

Thanks for your post, I always enjoy you opinions.

Jeff

 

[Broz]

Kirby I was just thinking. We reside pretty close to each other. I would like to extend an open invitation to you. When you have the 338 Raptor up and running maybe we could do a day of shooting here at my favorite shooting spots. Now, I ain't looking for a drag race or any competition. Those days are behind me. But a friendly day in the field with a couple good ELR rifles. Heck maybe we could even pry Shawn away from work to join in. He could bring a LRKM in 338 EDGE +P and we would have some of the finest iron I know of here to shoot. Might make for an interesting story we could write up. Or if not, at least a darn good time. I have guest rooms so over night would be fine too.

Jeff

 

[Fiftydriver]

I could not agree more. Performance is a huge benefit to hitting small targets at extreme range but quality rifle design along with the performance is what really makes things special.

Never been one to believe in overkill for long range hunting. When most see the size of my 338 Allen Magnum the first comment is generally, does that thing blow up the animals when you hit them??? Then when they line one up at a mile or 2K and compare it to what they have been shooting, they quickly realize that a 300 gr berger at 3400 fps makes it pretty darn easy to hit small targets at extreme range.

As far as your barrel life goes, I am pretty confident that you know very well how to care for a barrel properly and I also fully agree, replacing a barrel on a precision rifle is a very small investment compared to the original price of the entire rifle. Generally, for the cost of what you would pay for a factory Rem 700 Sendero rifle these days, you can have a brand new pipe and complete installation. Pretty reasonable to be back in business for all intent and purpose with a brand new rifle!!!

I like your comparision to high performance cars. I am a sucker for high performance cars as well, not for racing but just for stout street rides. My current project is a 2010 Camaro SSRS that is about finished and will be putting out around 850 hp . Certainly nothing like the level that you were working with but I will be able to take my family to town for dinner and a movie in the Camaro!!!

I use cars as comparision to this class of performance all the time to those that have some understanding of cars. In my opinion, case volume is very similar to engine displacement. You can get a lot of performance out of a smaller capacity chambering but the larger case capacities just make bigger power more easily and with less stress on the engine, just like a big case volume makes more power and with less stress on the case and rifle system.

These special throat designs, Shawns +P and my Hybrid are in my mind like the supercharger or turbo systems. They allow a larger charge of fuel and air to be forced into the same space as a conventional volume to get more performance.

The way these throats change the pressure curve is simply amazing but do need some understanding to make them work properly and there is no doubt Shawn understands these designs as well as anyone out there. I like to think that I know a little about them but Shawn has really pushed the development of these designs and I have focused more on cubic inches to produce performance. Same result, different designs to get there. Both work great.

Now to combine the two and perhaps we will see +3500 fps with a 300 gr Berger in our near future........ Just a prediction.

Will be curious to see how your extreme range testing goes with your LRKM. Have only found one combo that was consistently accurate at +3000 yards and that was with the old Wildcat 265 gr AT RBBT with their .92 BC and driving them to 3550 fps out of my XHS in 338 AM. On three different occasions I was able to put three consecutive shots on my 20" round gong at a measured 3010 yards. That's 3/4 moa at +3000 yards.

That said, there were several outing that I never got a bullet on steel at that range because of mirage and air conditions, not to mention slight winds.

Still, this is the only combo I have ever tested that got anywhere near 3K yards with consistency. At my elevation, the 300 gr SMK launched at just shy of 3400 fps would make it to just over 2700 yards but ANYTHING over that and they went to hell fast. Seems the 300 gr SMK DOES NOT like the trans sonic stage. I have not tested the 300 gr Berger to its limits yet but it should add a bit to this. We will see how it handles the transonic velocities. Hopefully better then the SMK but often, the longer the bullet, the more its effected at this stage of flight. Not written in stone so maybe we will get lucky.

Anyway you look at it, your set up will take you easily to 2500 yards with no problem at all. As long as you stay supersonic, you should never have any accuracy or consistency issues. Past that, that will be the interesting testing!!!

Keep us posted and congrats to Shawn for the LRKM platform and you for your help with further development. I know my customers have helped me TREMENDOUSLY in the development of all my wildcats and have been invaluable to me. I know for a fact that Shawn feels the same about his customers. You guys really do make us look good!!!!

Have fun!!

 

[Broz]

Kirby, for what ever it worth I have taken the 300 Berger through the sub-sonic transition as well as the 300 SMK on several occasions. In slower rifles of the same twist. Once side by side with Shawn he shooting a 338 EDGE and I with a std. 338 LM. We were pretty darn impressed as to how well the Berger did. The SMK's just hated it, but the Berger's have held 1 moa after the transition on a few tests for me.

With the Terminator platform and the drag model I am using now (model was on at 2422) it looks like I can stay above the transition to 2600+. The amazing thing, and I am sure you know this, is it only looses another 100 fps on out to 3000 yds.

Anyway, something to shoot for.

Jeff

 

[fmajor]

Thanks guys for all the amazing info on these hot-rod 338s!

I'm a good bit out from putting my order in on one of these, but the LRKM is an absolutely amazing platform - well done! It's revolutionary in thinking and looks expertly executed.

That said, I'd prefer the LRKM chambered in Kirby's 338 Raptor cartridge design (easily attaining 3,200 fps with a 300gr is my personal criteria for a LR 338 stomper).

 

[Fiftydriver]

Kirby, for what ever it worth I have taken the 300 Berger through the sub-sonic transition as well as the 300 SMK on several occasions. In slower rifles of the same twist. Once side by side with Shawn he shooting a 338 EDGE and I with a std. 338 LM. We were pretty darn impressed as to how well the Berger did. The SMK's just hated it, but the Berger's have held 1 moa after the transition on a few tests for me.

With the Terminator platform and the drag model I am using now (model was on at 2422) it looks like I can stay above the transition to 2600+. The amazing thing, and I am sure you know this, is it only looses another 100 fps on out to 3000 yds.

Anyway, something to shoot for.

Jeff

That is certainly very good news and sounds like the Bergers are doing better then the SMK which from what I have seen fall on their faces dropping out of supersonic velocity.

If those Bergers are holding 1 moa after dropping out of supersonic velocity, then with the range you have with your rifle, it should make 3K shooting very interesting!!!!

Next question, bullet performance........

When Berger redesigned their 300 gr Hybrid bullet, Eric sent me a supply with the sole purpose to TRY to destroy them out of my 338 AM. I loaded them to some VERY hot pressures, in fact hot enough that cases were only good for two firings at these levels. I will not even state the velocities I was getting with them in a 32" barrel length because I DO NOT want anyone trying to duplicate that performance level in any way. This was simply a test to push the limits of this bullet as far as integrity and surviving extreme launch velocities.

In this test, rounds were fired one, every 10-15 seconds for a total of 20 shots fired down range. Again, this is something I would NEVER recommend doing but again, this barrel was donated to the cause of testing this bullet. I Each shot past the 7-8 shot was probably putting wear on the throat comparible to 50 rounds down the bore of normal use. Not good.

The reason for this torture test was simple. In the bast, Berger bullets had proven to be a bit sensitive to bore temps, especially the very long VLD style bullets driven at high velocity. The longer the bullet, the more sensitive the old style VLD were to excessive bore heat.

This test on the current 300 gr Hybrid was two fold.

A. Find the velocity limits of this bullet if possible.

B. See how this bullet would handle very hot barrels.

Concerning A, I tested at 1000 yards shooting at my 20" round gong. Certainly not a challenge to hit and I will be honest, I was not shooting BR quality as I was worried more about getting shots off in a timely manner. Still, all 20 shots EASILY landed on the gong for a total group of slightly under 12". Again, I will not state what the exact velocity was but it was far in excess of anything I would recommend for my 32" barreled 338 AMs and I generally recommend a 3300 fps accuracy load and 3350-3400 fps absolute max load in that platform. These bullets obviously handled the high velocity very well

Concerning B, slightly over 1 moa group is not great but remember that once I got to 7-8 firings, the barrel on my XHS was so hot I could not hold it. After 20 shots, I could smell the McMillan stock from the barrel heat. Took 45 minutes before I could even put my hand on the barrel and keep it there. Still, these new bullets shot close to 1 moa on that torture test. Dramatically better then the old design. I do not believe I have ever gotten a single shot, bolt action barrel that hot ever before!!!

This brings me back to the comment about seeing how they will perform terminally for you at extreme range. I have had many customers use these new bullets on big game in chamberings such as the 338 RUM, 338 Edge, 338 Lapua and 338 AX. Out to 1/2 mile or so, nothing but great results. From there out to 1000-1100 yards, results have been mixed with some claiming good terminal performance, others reporting pin holing through big game animals. This obviously greatly dependant on bullet impact location of course. Now these examples had muzzle velocited in the 2650 to 3050 fps range.

I have also had customers use these bullets out of my 338 AM on big game and have absolutely no problems with terminal performance at all out to even 1500 yards. These were launched at 3290 to 3380 fps so a significant boost in performance.

I suspect that at your performance level, which is right between these two levels, terminal performance may start to drop off at that 1400-1500 yard mark on soft impacts such as clean chest shots. On hard impacts, i.e. high shoulder, shoulder knuckle, you will likely see good expansion out as far as you are capable of shooting which I know is a FAIR POKE!!!

I believe that your combo certainly produces velocity levels that have to be classified in the "Super 338" category right there at the bottom rung of the 338-408 CT class level so you will likely see much better terminal performance out of the Berger. Course, you have to report all the details when you let her feed on some meat!!!!

Got to get to the shop and get some work done, take care!

 

[Broz]

We have not had any that didn't expand in game from a std LM or Edge at 1000 or so with the 300 OTM's. MV's were in the 2800 range. I took a few yotes either side of 1200 with the same set up and got expansion. That is all the first hand info I have, so I will use it I guess. Impact velocities were around 1700. There ain't much in the rib cage of a yote to aid expansion I figure. I know at some point expansion will be an issue. But I know of no other bullet that will equal the 300 OTM in BC, accuracy and terminal performance. 1700 fps with the 338 Terminator +P comes in just under a mile. That should cove my hunting for a while. Unless we are talking wolves, then it's game on at any distance.

Jeff

 

[Fiftydriver]

Amen on the wolves!!!

 

[Kiwi Greg]

That is certainly very good news and sounds like the Bergers are doing better then the SMK which from what I have seen fall on their faces dropping out of supersonic velocity.

If those Bergers are holding 1 moa after dropping out of supersonic velocity, then with the range you have with your rifle, it should make 3K shooting very interesting!!!!

Next question, bullet performance........

When Berger redesigned their 300 gr Hybrid bullet, Eric sent me a supply with the sole purpose to TRY to destroy them out of my 338 AM. I loaded them to some VERY hot pressures, in fact hot enough that cases were only good for two firings at these levels. I will not even state the velocities I was getting with them in a 32" barrel length because I DO NOT want anyone trying to duplicate that performance level in any way. This was simply a test to push the limits of this bullet as far as integrity and surviving extreme launch velocities.

In this test, rounds were fired one, every 10-15 seconds for a total of 20 shots fired down range. Again, this is something I would NEVER recommend doing but again, this barrel was donated to the cause of testing this bullet. I Each shot past the 7-8 shot was probably putting wear on the throat comparible to 50 rounds down the bore of normal use. Not good.

The reason for this torture test was simple. In the bast, Berger bullets had proven to be a bit sensitive to bore temps, especially the very long VLD style bullets driven at high velocity. The longer the bullet, the more sensitive the old style VLD were to excessive bore heat.

This test on the current 300 gr Hybrid was two fold.

A. Find the velocity limits of this bullet if possible.

B. See how this bullet would handle very hot barrels.

Concerning A, I tested at 1000 yards shooting at my 20" round gong. Certainly not a challenge to hit and I will be honest, I was not shooting BR quality as I was worried more about getting shots off in a timely manner. Still, all 20 shots EASILY landed on the gong for a total group of slightly under 12". Again, I will not state what the exact velocity was but it was far in excess of anything I would recommend for my 32" barreled 338 AMs and I generally recommend a 3300 fps accuracy load and 3350-3400 fps absolute max load in that platform. These bullets obviously handled the high velocity very well

Concerning B, slightly over 1 moa group is not great but remember that once I got to 7-8 firings, the barrel on my XHS was so hot I could not hold it. After 20 shots, I could smell the McMillan stock from the barrel heat. Took 45 minutes before I could even put my hand on the barrel and keep it there. Still, these new bullets shot close to 1 moa on that torture test. Dramatically better then the old design. I do not believe I have ever gotten a single shot, bolt action barrel that hot ever before!!!

This brings me back to the comment about seeing how they will perform terminally for you at extreme range. I have had many customers use these new bullets on big game in chamberings such as the 338 RUM, 338 Edge, 338 Lapua and 338 AX. Out to 1/2 mile or so, nothing but great results. From there out to 1000-1100 yards, results have been mixed with some claiming good terminal performance, others reporting pin holing through big game animals. This obviously greatly dependant on bullet impact location of course. Now these examples had muzzle velocited in the 2650 to 3050 fps range.

I have also had customers use these bullets out of my 338 AM on big game and have absolutely no problems with terminal performance at all out to even 1500 yards. These were launched at 3290 to 3380 fps so a significant boost in performance.

I suspect that at your performance level, which is right between these two levels, terminal performance may start to drop off at that 1400-1500 yard mark on soft impacts such as clean chest shots. On hard impacts, i.e. high shoulder, shoulder knuckle, you will likely see good expansion out as far as you are capable of shooting which I know is a FAIR POKE!!!

I believe that your combo certainly produces velocity levels that have to be classified in the "Super 338" category right there at the bottom rung of the 338-408 CT class level so you will likely see much better terminal performance out of the Berger. Course, you have to report all the details when you let her feed on some meat!!!!

Got to get to the shop and get some work done, take care!

Kirby.
I assume you are talking about the 300 OTMs ?
Have you done any testing with the 300 Elite Hunters ?
I have shot them in my 36" 338 DCM at 3400+ with no issues so far with accuracy etc, I haven't tested terminal performance yet.
Myself & other locals have had issues with terminal performance with the 300 OTMs at normal velocities 28-2900.
I have had several problems with the OTMs out of my 338 Terminator, Lapua improved at 3050 with a 1-10 SG barrel, the bore/throat is probably very easy on the jacket which could be the problem with lack of expansion ?
Cheers Greg.

 

[Fiftydriver]

OTMs are what I am throwing right now.

Seeing similar results as you are with the lower velocity levels but bumping things up over 3300 fps seems to dramatically improve expansion consistency.

 

[Fiftydriver]

[QUOTE

The case is off of a 338 Lapua, reduced taper and increased shoulder angle as well as the shoulder moved forward a bit. No loss of neck length though. Pumps it up to about 124 gr capacity. That and the new Defensive Edge +P design throat makes it a pretty sweet .338. It is what I choose over all of them anyway.

Jeff[/QUOTE]

You mention that the Terminator has 124 gr of capacity, is that total case capacity filled to the mouth or to the base of the neck? Is that water volume or measured with some other method? Just curious for comparision sake.

 

[Broz]

You mention that the Terminator has 124 gr of capacity, is that total case capacity filled to the mouth or to the base of the neck? Is that water volume or measured with some other method? Just curious for comparision sake.

A fire formed, once fired case, with water flat at the top of the neck is 123.7 gr.

Same case filled to top of neck with N-570 is 121.2 gr

Probably would hold a few more grains of H-1000, but that is a guess due to the large kernels of N-570 compared to H-1000

I feel the cases will form a bit more too with a second firing. But again that is just a theory.

Jeff

 

[Broz]

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..