Seeking education on the .338 LM for ELR?

[Wannashootit]

A couple of years ago, started gathering components for a .388 LM build. Doing things bass-ackwards, I purchased brass, dies, and had a custom shellplate holder made first. Before getting to the iron, the range we frequented (Manatee in FL) shut down temporarily and when they eventually reopened, their 1,000 yard line was gone forever. Put it on the back burner for "some day" as who needs a .338 for 600 yards...

Anyway, appears a new facility will be opening next spring that will have up to 2,000 yards available- so it's time to start planning the shit that matters.

I'm pretty ignorant on the wildcats based off this case, but given that the rifle will now be able to reach out twice the distance originally anticipated I'm wondering if I should be considering any of them. The range is still a good distance away, and I've got limited time for load development and "tweaking"- so I'm ruling out anything that's crazy sensitive on that end. Wondering if overbore is worth it, maybe .30 cal? I'd like to be able to get at least 1K rounds out the barrel.

I was also considering building this off an "atypical" receiver rather than the usual suspects- for no reason other than "because I can"- but don't want to be stupid about it. Weatherby MKV, maybe even an old P14 action...curious if anyone's ever done this (I;ll be doing the work, so I could true the action- I also have a stock duplicator so it'll be in custom wood). Not going to be a competition gun, but of course it needs to shoot and if I can do it somewhat uniquely that would be a plus. If I'm nutz. say so and I'll probably go with a Defiance or other standard-bearer.

So...2000 yards, based off the .338 LM case, not-overly sensitive on load development and 1K round barrel life. What would you do?

 

[THEIS]

Hi,

IMO, for 2k yards; do not over complicate the cartridge side of things. Just go 338NM and be done with the cartridge side of the equation. That will give you more time to dedicate and focus on the environmental and shooting fundamental sides of the ELR triangle.

Sincerely,
Theis

 

[White Mamba]

Stick with Defiance or other well known recievers, they will hold their value better and you know you will get a quality product. Your 338lm will be excellent for 2k

 

[j-huskey]

All known data on p14 actions refer to max pressure of 50k cup.

Lapua is rated at 60k cup, so 60k cartridge in a 50k action isnt a risk most of us would take.
Then, there is the feeding issues trying to modify feed rails so it mag feeds, and being a controlled round feed action, this is a detail to consider. Popping the extractor over the rim isn't recommended for functional longevity of the extractor. Parts arent readily available when u break p14 stuff.

And long loading heavy bullets to get the 2k range pretty much begs single loading. Getting a unfired long loaded round out of a crf rifle like the p14 will try your patience.

Any modern action for the 338 is a better choice.

Wildcatting a 338 case is a lot of work when there are factory offerings like 338nm that are plug and play. Wildcatting can get expensive versus plug and play cartridges, in the long run you can get more bang for the buck avoiding wildcatting, and have a lot more shooting time.

And when you get tired of the hassle and headaches that pop up with wildcatting, selling a plug and play cartridge is much easier.

Others' mileage may vary, but a modern action in 338lap is hard to beat, equally so the 338nm. Best to you in this deal.

 

[Wannashootit]

Consensus in three is all the advice I need- thanks guys.
Should I also not worry about throating to a particular bullet and seating depth, and just use a SAAMI spec finish reamer and see what it ends up liking?
Is a 28" barrel generally optimal- or would 30" be better (10 twist) ?

 

[j-huskey]

30" will give you the velocity bump with the right slow powders to keep you in the game at 2k.
My 26" isnt a 2k rifle, the 28" is but, can be edgy with factory lapua ammo. The 30 to me is what I wish I'd done on both for long range.
I will when I burn the two current barrels out.

 

[THEIS]

Hi,

As much thought that goes into your rifle build I would suggest that same amount into your ammunition build too because it can change your barrel specs.
For example:
Have you given any thought as to if you intend to shoot jacketed or solids?
Have you given any thought as to if you intend to go back and forth between jacketed and solids?

Also--side topic:
Have you began narrowing down which support equipment you want for this ELR journey? The support equipment can make and most of the time break whether successful ELR engagements are not.

Sincerely,
Theis

 

[bjay]

Why not 300nm less recoil never worry about stretching OAL using cip mags.. at long range accuracy with skills is the key .and i still think 300nm has the edge vs 338lm when comes to accuracy

 

[THEIS]

Hi,
So I have more time and off my phone so I can reply in more detail

If you intend to shoot monolithics then I suggest a 7P twist from Schneider to finish at 30".
If you intend to shoot jacketed then I suggest a 9.4 twist from Bartlein to finish at 30".

Support Equipment:
Elite Iron Bipod

Best Rangefinder you can afford (The +/- error allowances of rangefinders can put you over/under your target)...my recommendation is probably a little to "over the top" for casual shooting lol

Coldbore Ballistic Program..run on whatever phone, tablet, rugged laptop you desire. (You can get some good toughbook prices on Ebay).

Nightforce ATACR 7-35F1

Suppressor of your choice. This will help in not developing a "recoil" flinch but the flinch often referred to in this situation is really towards to blast and not the recoil in itself.

I prefer an aluminum chassis system just to reduce the number of parts in the equation.

Sincerely,
Theis

 

[Wannashootit]

Thanks again to all.
Theis,
Had never even given a thought to monolithic boolits, so that's another area I need to gain some knowledge. The build is for my son, capable shooter of about my skill level- meaning we both will need substantial trigger time getting better at doping wind at range- and actual ranging because all of our shooting heretofore has been known ranges - before 2k is realistic on anything but a reasonably calm and consistent day. Seems different twists due to weight/length are needed, so I'll probably be shooting jacketed boolits and will go with the slower twist on this one.

Haven't gotten as far as mount/optic...but I'm impressed with what I see in Ivey's adjustable mount.

Sending in for my 02 on Jan.1, and I've started talking to a national distributor for suppressor lines already to gain some much needed knowledge in this area. I'm thinking that 30" of heavy contour barrel in a hefty chunk of lumber will help control felt recoil enough to make the can a preferable choice over a brake.

Still think I'll go with a custom stock and not a chassis, it'll make it unique and one-of-a-kind as a gift. Plenty of beef and epoxy bedding... just torn between a wild-colored laminate or hardwood...maybe a beautiful hunk of figured walnut or curly maple. I mean, everyone (including me) has chassis systems...but how many have a boomer in hardwood ?

 

[towerofpower93]

Not to thread jack, but in the spirit of 338LM for beyond 1K...what to do with a short throated barrel?

Stiller Tac338 action with an MPA 10 twist apparently set up for the 250gr SMK.

Measured OAL and CBTO with a modified Hornady case and came up with 2.750” CBTO for both the 285gr ELD-M and 250gr Berger OTM. OAL of the Hornady is 3.595” and the Berger is at 3.645” in the lands.

Loaded up a single round velocity ladder with RL33, but backing the rounds .010” off the lands lead to the below pic and following OALs. Seem pretty short, and wondering if getting the chamber reamed a bit deeper would be worth it for a local mile shoot.

Hornady 285gr ELD-M
CBTO: 2.740”
OAL: 3.595”

Berger 250gr OTM
CBTO: 2.740”
OAL: 3.635”

With both the 285gr ELD-M and 250gr OTM, the ogive is just above the case mouth, per a Giraud 338 ogive/headspace comparator.

I presume the 250gr SMK was just an upsized 168gr .30 SMK, so maybe this is why the older chamber was cut so short?

I'm crunching powder in the last third of my loads, but nothing which sounded or felt ridiculous. Ran the ladder at 1.0gr increments from 94-103 for the 285 ELD-M and 95-104 for the 250gr Berger OTM.

Seem like I'm eating up way too much case capacitybwith the bullet seated that far? I can run 3.850" CIP mag length in the MPA chassis, but the loaded rounds for this barrel are way back from that, obviously.

 

[j-huskey]

Mine are throated longer so I have options in loading for long range.
Both were built by G.A. Precision and shot match grade from day 1 with a variety of bullets and factory ammunition.
I bought a throater and had a closer smith throat them for longer seating.
I had no loss of accuracy.
One has its second barrel now, and began long throated. Cant tell any difference in the groups with any ammunition.

I, would have no problem throating the rifle you have, if it were mine.

But, that's totally up to you if you are going to shoot say 90% close range and are satisfied with the results and 10% long range, and if you were unlucky, throating hurt your close range accuracy. There is a certain amount of risk.

Other people's mileage may have varied.
Be interesting to see their comments.

 

[THEIS]

Hi,

I personally would have it throated too....

Would be a shame if you got out to shooting spot and forgot your ammo (YES it happens lol) but your buddy had his 300gr or some of the longer monos and you had to watch him shoot because you would possibly be "jamming" them into lands..but then again depending on what COAL he loaded to it may not.

Sincerely,
Theis

 

[CJS-6.5]

One of the reasons Savage rifles have gained an accuracy reputation is that they are often short throated. So mag compatible factory rounds often shoot well in them. As in typical hunting bullets. A short throat becomes detrimental in an underbore rifle that is trying to be used at long range. The deep seated bullets use up valuable powder space. There is many other variables based on infinite configurations but those are 2 simple ones.

 

[CJS-6.5]

I guess what I'm saying is that if you have the choice, just throat it to suit you.

 

[towerofpower93]

Thanks for the confirmation bias, haha.

Think I'll break the rounds already loaded past the LabRadar, within safe reason, just to see what I get and (probably) have the barrel reamed deeper for yet newer/longer bullets over the winter.

As an aside, and since we seem to have some 338LM afficianados in attendance, what freebore are you looking for to use the 285 ELD-M or 250gr OTM and stay within 3.850" CIP mag length?

 

[j-huskey]

Mine start std Saami cip.
That way, any factory ammo should work in any temperature, and with added field dirty.
Secondary, it allows higher velocities 95% of the time over tight match chambers when loading for long range.

I cant give you the oal numbers right now, but I load a 300 grain scenar where only the boat tail is below the neck, and the bullet is no more than .010 off the lands to start on new chambers.

It has worked well for me for the last 10 years.
And again, other people's mileage may have varied, and always curious to their experience and comments.

 

[ZiaHunter]

Had a 338LM built specifically for ELR and went with a Defiance action with a Bartlein 1:10 26" heavy palma. When I rebarrel will most likely go with a 28" 1:9.4. Used the rifle twice at the Gunsite XLR class and was able to engage targets out to 2200 but it was a stretch. Tried the 300 OTM's but had better results with the 285 ELD-M's with 91.0 gr of Retumbo. Went with CIP over SAAMI when having the rifle chambered. Shooting solids is a big step up in cost and bullets are very sensitive to bore and groove dimensions as well as generally requiring more freebore. Having a can on the rifle makes the rifle much more pleasant to shoot. As mentioned above, having a LRF capable of accurately pinging ELR targets is critical. I have both Coldbore and FFS and when we did a head to head test out to 2200 there solutions were basically identical.

 

[Alpine 338]

Rifle pictured is a custom 30 Nosler built to my spec by Jon Beanland. He also built the same rifle as this in 338LM for me previously. I shoot the 30 Nosler more, and it outperforms the 338LM in distance and accuracy, with less powder and recoil.

338LM is a good cartridge if you just want to run factory ammo, but since you said you would consider a .30, I would highly recommend the 30 Nosler if you reload.

 

[LastShot300]

Wildcatting a 338 case is a lot of work when there are factory offerings like 338nm that are plug and play. Wildcatting can get expensive versus plug and play cartridges, in the long run you can get more bang for the buck avoiding wildcatting, and have a lot more shooting time.

And when you get tired of the hassle and headaches that pop up with wildcatting, selling a plug and play cartridge is much easier.

Others' mileage may vary, but a modern action in 338lap is hard to beat, equally so the 338nm. Best to you in this deal.

Wouldn't you consider the .338 AI? It's no big deal and the extra performance is there to spare.

 

[j-huskey]

Wouldn't you consider the .338 AI? It's no big deal and the extra performance is there to spare.

Almost did it.. might one day. Its the first option for me wildcatting a 338.

Off topic, kinda, I absolutely despise my last 338 semi wildcat, the 338Xtreme.... it's on it's way to becoming 375#2...

 

[THEIS]

Hi,

LOLOL the Xtreme is/was a comical joke.

It was birthed purely due to some purchase order disputes between company A, B, and C.

Each thought their "part" was payment for the other companies "parts".

Not to mention the exact copy action knockoff of the Lawton 8000, along with knocking off chassis system.

Convert it to a 37XC ?

Sincerely,
Theis

 

[j-huskey]

Hi,

LOLOL the Xtreme is/was a comical joke.

It was birthed purely due to some purchase order disputes between company A, B, and C.

Each thought their "part" was payment for the other companies "parts".

Not to mention the exact copy action knockoff of the Lawton 8000, along with knocking off chassis system.

Convert it to a 37XC ?

Sincerely,
Theis

My other 375 is a lawton... ?
The Xtreme is proof some abortions live on past the DNC... ??

 

[towerofpower93]

Not to thread jack, but in the spirit of 338LM for beyond 1K...what to do with a short throated barrel?

Stiller Tac338 action with an MPA 10 twist apparently set up for the 250gr SMK.

Measured OAL and CBTO with a modified Hornady case and came up with 2.750” CBTO for both the 285gr ELD-M and 250gr Berger OTM. OAL of the Hornady is 3.595” and the Berger is at 3.645” in the lands.

Loaded up a single round velocity ladder with RL33, but backing the rounds .010” off the lands lead to the below pic and following OALs. Seem pretty short, and wondering if getting the chamber reamed a bit deeper would be worth it for a local mile shoot.

Hornady 285gr ELD-M
CBTO: 2.740”
OAL: 3.595”

Berger 250gr OTM
CBTO: 2.740”
OAL: 3.635”

With both the 285gr ELD-M and 250gr OTM, the ogive is just above the case mouth, per a Giraud 338 ogive/headspace comparator.

I presume the 250gr SMK was just an upsized 168gr .30 SMK, so maybe this is why the older chamber was cut so short?

I'm crunching powder in the last third of my loads, but nothing which sounded or felt ridiculous. Ran the ladder at 1.0gr increments from 94-103 for the 285 ELD-M and 95-104 for the 250gr Berger OTM.

Seem like I'm eating up way too much case capacitybwith the bullet seated that far? I can run 3.850" CIP mag length in the MPA chassis, but the loaded rounds for this barrel are way back from that, obviously.

Well, I didn’t blow myself or the gun up today, haha. First time shooting a magnum caliber rifle as was pleasantly surprised with the recoil, or lack thereof. Never put it on a scale, but the Titan-Ti, MPA chassis, and Razor Gen 2 all pack on the pounds to an already beefy 26” pipe on a Stiller TAC338 action.

Saw no pressure signs and bolt life was the same, butter smooth motion from first to last shot.

02DEC2018
MPA 338LM w Titan-Ti
Win LRM
Virgin Lapua w .002-.003” neck tension

LabRadar series: 111

Hornady 285gr ELD-M
CBTO: 2.740”
OAL: 3.595”

RL33:

94.0: 2452
95.0: 2542
96.0: 2583
97.0: 2672
98.0: 2685
99.0: 2702
100.0: 2751
101.0: failed to read
102.0: 2788
103.0: 2816

Berger 250gr OTM
CBTO: 2.740”
OAL: 3.635”

RL33:

95.0: 2624
96.0: 2640
97.0: 2689
98.0: 2717
99.0: 2751
100.0: 2774
101.0: 2788
102.0: 2855
103.0: 2872
104.0: 2894

To be honest, I’m at a loss for next steps. Not seeing a clear plateau where three charges cover ~20fps like I did with my 6.5x47L.

I guess I see one for the 285gr ELD-M between 100-102, with 101gr not being read, unfortunately. Also kinda have one covering 97-99gr, but a 2700fps load isn’t going to make it worthwhile.

On the 250gr Berger OTM I think 102-103gr might be something, but I’m wondering if I can/should go up in one grain increments another 3gr for both bullets.

Having never dealt with magnum sized cases and their associated powder charges, does this sound like a viable idea to find my own max as well as to see if an honest 2800 or 2900 is doable with the 285 or 250?

 

[j-huskey]

Please look very seriously at Retumbo....

None of us in my neighborhood have been successful with RL 33. Got speeds, but 50-75fps es... and crap vertical at distance.

Had single digit es with retumbo... 2900 very easy with rt and 250 scenar.

 

[towerofpower93]

Have a pound of Retumbo I was going to do a velocity ladder with in the next couple of weeks, depending on how the RL 33 did.

Planned charges are:

285gr ELD-M

Retumbo: 86, 87, 88, 89, 90, 91, 92, 93, 94, 95


250gr Berger

Retumbo: 86, 87, 88, 89, 90, 91, 92, 93, 94, 95

 

[j-huskey]

Found joy in the 94 range with 250.
Found joy in the 95 range with 225 for hunting load.
Still shooting vv570 w 300's. Never worked up ret with 300, even though friend with TRG is is getting 2900 with ret and 300 Berger.