338LM handloading questions

[towerofpower93]

Got a used (200rds) MPA barreled action on the way with a 26" 1:10 twist barrel that I'll eventually be mating up with an MPA chassis.

Will be handloading for this from the start and would like to avoid any known pitfalls this particular cartridge holds.

Plan is to get a Redding S type FL die with carbide button and competition seater along with the competition shellholder set.

Looking at what others have used for brass, Lapua is an obvious choice, but have read a few things about the brass offered by Peterson as well. Any consensus as to "the best" at this point? Is there another manufacturer I've missed?

As for bullets, I'll try a few, but thinking I'll get a 100 of the Hornady 285gr ELD-M and Berger 250gr Hybrid for ladder testing. Not interested in running solids at this point, but am I missing another bullet I should also give a nod to?

Powder seems to be where the roads diverge some. Retumbo and H1000 seem to get mentioned more than others for 250+gr bullets in the 338LM, but RL33 seems to get noted a bit and have higher velocities from same length barrels to boot. Am I missing the downside to RL33 or is it just a newer/better/faster powder for this cartridge and bullet weight?

Will likely go with Fed 215M primers.

Any other tips, tricks, or gotcha moments I should be tracking for the 338LM? Been handloading for a number of years, and doing so for long-range shooting for the past couple, but never messed with a big bore slinging this much lead and burning this much powder, so any advice is greatly appreciated.

Thanks

Eric

 

[lash]

I cannot answer your questions with absolute certainty, since I have not tried all of the options you list. I can however offer my experiences so far.

For .338, I've only used Lapua brass, since Peterson's brass was not out when I started and my 200 pieces of brass are still going strong after 5-6 loadings of pretty stout loads. I have heard good things about the Peterson brass though, just have no experience with it.

Of the two projectiles, I've only shot the .285s and those were not in the ELD-M flavor. I still have too many boxes of Amax left to change at this time. My 26" barrel loves the .285s over H1000 and seems to do better than with them than the 300s I tried. You will find that quite a few people prefer the 300 bergers over retumbo, I'm just not one of them. Your barrel will tell you what it likes.

I happen to be using Winchester WLRM primers, since at the time I wanted to get going, the Federal 215s weren't readily available. They are working fine for me, with mid to low SDs, so I've found no reason to change yet.

I chose H1000 due to it's ready availability and have wanted to try RL33, but it is only now easily available from most places and I don't love load development. I've read good things about RL33, just haven't tried it.

 

[lash]

A couple additions.

Since you already have been loading for long range, you may already know that there are some things that begin to make more of a difference once you really start reaching out there. In my opinion, those things include weighing your brass, weighing your bullets and measuring your bullets before you start. I then create batches of brass and bullets based upon grain weights. I've found that if I weigh 100-200 pieces of either brass or bullets, there will be a normal distribution curve that fits the results. What this means in layman's terms is that most of the results will be within +/- 0.2g-0.4g with outliers on both the low and high ends. This is typical, fits within the manufacturer's tolerance requirements and shows capability of their process.

The bergers I weighed did have a smaller variation total across the spread, but I still separate them into 0.2g batches. The real outliers are used for things like new scope sight in's and the occasional times when I'm shooting within 1000 yards, where the variances matter little/less.

As always, brass prep is key, with consistency in process and neck tension being the two big ones for me. Anything that can reduce variation will be better for your results.

Good luck and good shooting!

 

[towerofpower93]

Thanks for the personal data.

Been weight sorting 6.5 bullets by 0.2gr lots and figured I'd do the same for this.

Never used the Redding FL bushing dies, but thinking I might for this caliber, based on the cost of brass. Figure anything I can do to get more loads out of each piece makes sense.

 

[lash]

Oh yeah, and I anneal every other time. I'd probably do so every time if I had a nice annealer, but doing them by hand is a bit time consuming so....

 

[towerofpower93]

I have a Giraud annealer so I'll be doing every firing.

 

[M47Patton]

Just got started with 338LM myself. As far reloading procedures, its the same as all my other chambers, just a lot more powder.

I came into some 285gr amax for very cheap and used them to break the barrel in. I'm just now starting load development. I have 285 elds and 265gr nosler ablr's. The 265gr nosler are relativily cheap at about ~.60 per round. Nosler updated the BC information on the entire ablr line, now the BCs look more realistic (.731 g1). If the BC holds true and I can get the velocity over 2900fps, and it groups well it should be a nice round.

As for RL-33, the biggest negative I see is that it isn't a temp stable powder. I'm going to try it out anyway. I've already used H1000 with the 285amax's and it shot great so if RL-33 doesn't work I'll probably just stick with H1000.

For brass I'm using peterson. So far very happy with it but I only have 3 reloads per case. We'll see how it holds up.

 

[BurnOut]

I just put ran a handful of the Berger 250s through mine the other day... literally only 11 rounds. That said, I was fire-forming (mine is an AI chamber), and I found that 85.0 gr of H4831 got me right at 2800 FPS out of a 30" barrel. It seemed to shoot well, though... sub-MOA with virtually no effort on my part as the shooter. I'm running once-fired Lapua brass.

At this point, I'm basically just burning the Berger 250s, since they won't work in my 338 WM and I plan on running the Berger 300s out of my 338 LM.

 

[towerofpower93]

Picked up a Redding FL bushing, comp seater, and comp shell holder set last night along with 100pcs of Lapua brass, 100 of the 250gr Hybrids, and 50 of the 285gr ELD-Ms.

Going to look for a cheap box of 338 bullets to get one firing on the brass before I prep it and start load dev.

 

[Juggerxxx]

Picked up a Redding FL bushing, comp seater, and comp shell holder set last night along with 100pcs of Lapua brass, 100 of the 250gr Hybrids, and 50 of the 285gr ELD-Ms.

Going to look for a cheap box of 338 bullets to get one firing on the brass before I prep it and start load dev.

You can grab a 100 count box of 230ELDx bullets for $38.00. That’s what I used for break in but found that I like them. Can push them 3100fps with a mild load.

 

[towerofpower93]

Thanks for the heads up. Think I got the 285gr ELD-M for that same price from Brownells last night.

Bullets.com is shuttering their reloading side of things so I might see what they have collecting dust and pick up on the cheap for fireforming.

 

[Diver160651]

If you are using Hornady bullets it is best to sort them one additional way base to ogive. Of course like everything doing it fast and easy is a trick. Hoovers meplat trimmer, is on of the fastest and easiest comparators http://bullettipping.com/products/meplat-trimmer You are not trimming with it, so all you need is the body and stand. Use your calipers in the rear caliper slot. http://bullettipping.com/products/meplat-trimmer/measuring-bullet-bearing-surface-length/ You can do a box of bullets in just a couple of minutes. I have tried benchrest dial set ups etc.. nothing is a repeatable or as fast.

The base to ogive sorting will help with the proper case volume and lower your SD's -

Seat everything very slowly and choke-up on your press so you can feel any differences in the seating pressure. Try to organize them by seating pressure.

 

[M47Patton]

Thanks for the heads up. Think I got the 285gr ELD-M for that same price from Brownells last night.

Bullets.com is shuttering their reloading side of things so I might see what they have collecting dust and pick up on the cheap for fireforming.

The 285s you bought from Brownells is a box of 50, not 100. The 230 eldx's are a box of 100

 

[towerofpower93]

Doh!

You are correct. Not a huge deal as I got them for actual load dev tests vice fireforming, but good catch nonetheless.

Will look at the 230s for fireforming if bullets.com doesn't have anything super cheap.

 

[ZiaHunter]

+1 on what Diver stated. Favorite load for the 338LM is Lapua brass, 215M primers, 285 ELD-M and 91gr of Retumbo which gives me apprx. 2830 fps out of a Bart 26" 5R 1:10 bbl. Since I only use this rifle for ELR pretty anal about loading and process is basically the same as for my F Class rifles with exception of me plat trimming and seating with an arbor press. Necks turned during initial case prep and anneal after every firing. Don't weigh bullets but measure and sort bullets by base to ogive using Hoover trimmer. Charge weights are measured to the kernel on a Sartorius scale. Type S die with expander removed. Been able to achieve mid single digit SD's which translates to less vertical dispersion. Last lot of 300 285's when measured were generally within .0015 which surprised me with there consistency.

 

[ManOfAction]

This is a velocity workup I did with H1000 and the 285 ELD-Ms out of a 30" barrel. 70 degrees F, with Federal Match primers.

 

[Steel head]

This is a velocity workup I did with H1000 and the 285 ELD-Ms out of a 30" barrel. 70 degrees F, with Federal Match primers.

Brand new barrel?

 

[ManOfAction]

Brand new barrel?

Yes

 

[lash]

Any pressure signs? I’m getting 2780 from a short-throated 26” barrel using 91.4 gr H1000.

 

[towerofpower93]

Guess I never updated my own thread.
Here’s an 11rd string from Dec 2019 during the last mile match I shot with the LR accelerometer trigger on the gun during the final string at the 1730yd target.

Chamber was cut for the 250gr SMK, so 285-300gr bullets hit the lands really early for the available mag space. This load is only jumping 10 thou.

26” MPA 338LM w Titan-Ti
Win LRM
Retumbo 96.0gr
2xfired Lapua w .002-.003” neck tension
Headspace: 2.270”
Hornady 285gr ELD-M lot #2181455
CBTO: 2.740”
OAL: 3.600”

11rds chrono’d

Lo: 2880
Hi: 2908
Avg: 2892
ES: 28
SD: 8.0