338 Lapua Retumbo loads

[.375Mojave]

I have a lot of Retumbo powder for my 375 Chey Tac and am about to start load development on a 338 LM Savage I just picked up with a 1:9 twist. I would like to hear about specific experiences and load testing with Retumbo in this caliber and if there was a consensus (thats usually hard to find around here I know) on that powder and 250gr vs 300gr projectiles.

With the 9 twist I can go either way on weight and a drop chart doesn't seem to lean toward one or the other that much.

I would like to get some feedback on velocities and group consistency experience with Retumbo.

Thanks for the input.

 

[cali_tz]

Re: 338 Lapua Retumbo loads

I used a bunch of Retumbo on my Rem 700 338LM with 250 and 300 Scenars. Regarding accuracy/precision, I don't think Retumbo is any better/worse than other options. I switched to N570 for my Steyr 338LM, and am getting two results:
1) lower recoil (maybe due to the slower burn, or a better muzzle brake on the Steyr)
2) better MVs without pressure signs that Retumbo gave me on lower MVs. Again probably due to slower burning.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

Thanks for the info.

 

[cali_tz]

Re: 338 Lapua Retumbo loads

also the Steyr is a couple pounds heavier than the Rem 700. But I suspect the slower burning powder creates less of a peak impulse and helps to reduce recoil in addition to heavier rifle and more efficient muzzle brake.

 

[SVG308]

Re: 338 Lapua Retumbo loads

Retumbo should work great w/ the 300g bullets. It typically produces better velocity than H1000 but may sacrifice some consistency/ES. I have 8lb jugs of each that I will be working with once my build is done. I will use the 300 SMK and 300 Bergers.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

I have almost 15 lbs of Retumbo on hand so I am hoping it will be suitable. I have a feeling it may be slightly better with the 250 SMK vs 300 gr but that is strictly a hunch.

I have limited load development experience in my 375 CT with it and it is too early to tell if that load with 350 SMK's is going to be consistent.

I am hearing that RL22 and RL25 are both good 338 LM choices and do not know the burn rate on those relative to Retumbo. If anything, I think the Retumbo may be slightly faster burning than ideal for my 26" tube. I might get higher velocities/lower pressures before i hit the limit with something a little slower burning. Just an educated guess based on some scattered data.

Again, I appreciate any and all insights provided. Thanks.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

FYI, further research shows US869 getting higher velocities ina 24" barrell vs the 26" on my Savage.

Any experiences there?

 

[cav has been]

Re: 338 Lapua Retumbo loads

My pet load in 338LM is;
HSM or Lapua brass
250 Scenar,hbn coated
99 gr of Retumbo
Win. mag primers
I started at 91 gr and worked up through 101 gr.
My uncoated load was 97 gr.
As with any load development, reduce starting loads and use god given intelligence when increasing powder charge.

 

[cali_tz]

Re: 338 Lapua Retumbo loads

I recommend you 338LM shooters to check out N570... with 92.0 grains only, I get 2730 fps with a 27.14" barrel, 300 gn Scenar, Fed 215M. No pressure signs whatsoever. Yeah it is more expensive I think than Retumbo, but since you use less powder, then we'd have to do the math to see if it actually saves you or costs you.

 

[Beale338]

Re: 338 Lapua Retumbo loads

I use Retumbo with 300gr SMK's out of a 28" barrel, with 88.5gr of Retumbo @ 2740fps. I get pressure signs around 92gr.

 

[cali_tz]

Re: 338 Lapua Retumbo loads

That's interesting... if I used that little Retumbo (88 grains) on my 26" Rem 700, I'd get like 2500-2600fps.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

Any indications of the accuracy of your Retumbo loads when compared to other powder types?

I routinely see the reloading manuals (Sierra etc) designate their max accuracy load with an "A" or asterisk.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

I am looking at the VV powder options.

It is pretty expensive but, assuming they use their powder in their factory ammo, you are hard pressed to hear anyone say a bad word about the accuracy of the ammo.

 

[zac_c]

Re: 338 Lapua Retumbo loads

I just got my 338 lapua rogue and I am using retumbo for fireforming I am using. 96.5 grains with 300 gr smk and jaming them and no signs of pressure I was up to 99 grains with no real sign of pressure it is shooting at 2900 fps and the groups are in the 3s hope this helps I have a thirty inch barrel

 

[cali_tz]

Re: 338 Lapua Retumbo loads

30" barrel would explain it. To get 2900fps out of a 26" barrel would require my Rem 700 chamber to definitely overpressure my brass.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

I won't likely get the 2900 FPS you are out of my 26" barrel but it is good input just the same.

I will likely start my loads at about 89 gr as I have seen some reports that the Savage chamber may run a little tight and in some cases it seems a little over 90 gr is seeing pressure signs in some weapons.

I will do a load development ladder with a .3 gr increment. If I load 20 rounds with the .3 gr increment starting at 89 I will run to 95 gr. That may be my upper pressure limit.

If not I will re-start a new ladder a a couple grains higher noting sweet spots along the way.

Thanks,

 

[SVG308]

Re: 338 Lapua Retumbo loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">30" barrel would explain it. To get 2900fps out of a 26" barrel would require my Rem 700 chamber to definitely overpressure my brass. </div></div>

He is getting 2900 due to having an "improved" version of the case in addition to the 30" barrel. I bet once fireformed this combo will push 3,000fps.

 

[Beale338]

Re: 338 Lapua Retumbo loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: .375Mojave</div><div class="ubbcode-body">I won't likely get the 2900 FPS you are out of my 26" barrel but it is good input just the same.

I will likely start my loads at about 89 gr as I have seen some reports that the Savage chamber may run a little tight and in some cases it seems a little over 90 gr is seeing pressure signs in some weapons.

I will do a load development ladder with a .3 gr increment. If I load 20 rounds with the .3 gr increment starting at 89 I will run to 95 gr. That may be my upper pressure limit.

If not I will re-start a new ladder a a couple grains higher noting sweet spots along the way.

Thanks, </div></div>

If your rifle has a tight chamber I would start your load development even lower, around 87gr.
I ran into this problem and found my accuracy load to be 88.5gr which was below what my initial starting point was.

 

[bas402]

Re: 338 Lapua Retumbo loads

I have tried the 250gr pills and they shoot ok with H4831SC but my Savage 110BA likes the 300gr Sceaners better. I have loads worked up with 88.5gr Retumbo, 82.5gr N560, and yesterday tested N570 and tested up to 94gr without any pressure signs. Don't have chrono results yet but 93grs shot the best. Retumbo burned dirty for me and was not as consistant as the VV powders. I'm guessing along with my Q/L data the 93gr N570 will be about 2760fps but will chrono this week end to verify.
Sully

 

[zac_c]

Re: 338 Lapua Retumbo loads

My goal is to get over 3000 fps I don't think it will be to hard. I just hope I find a accuracy node.

 

[mdmp5]

Re: 338 Lapua Retumbo loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">I recommend you 338LM shooters to check out N570... with 92.0 grains only, I get 2730 fps with a 27.14" barrel, 300 gn Scenar, Fed 215M. No pressure signs whatsoever. Yeah it is more expensive I think than Retumbo, but since you use less powder, then we'd have to do the math to see if it actually saves you or costs you.</div></div>

I get 2835 with 93 of H1000 out of a 27" barrel. You will not save anything using VV powder; it is pricey.

 

[cali_tz]

Re: 338 Lapua Retumbo loads

is your 2835 on a 300 Scenar? I'd love to get that additional 100fps on a 300 Scenar. But the max load on VV's guide is 94.0 grains of N570. And I am already at 92.0 grains to get 2730. I should try another two grains and see what I can push it to.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

Really dont know if the chamber is tight but point well taken. I may just drop down to 87 gr and work up to 93 gr with a ladder. If I seem to have some freeboard on the pressure issue I will do a re-start at something a little higher.

Just picked up a mic that reads in .0001 increments so I can measure the first case head expansion. I am hearing that an expansion of the case head of .0003 is a much more reliable indicator than brass flow or sticky extraction.

Seems logical. If i can get the accuracy and velocity I am looking for with no case head expansion I can stick to neck sizing only and get better case life along with better accuracy potential.

I get some components and will get back in the reloading room in the next week or so. I will post some results when I have them.

 

[Sendero_Man]

Re: 338 Lapua Retumbo loads

I used 95 of Retumbo with the 250 Scenars.. very accurate load

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

I appreciate thie input. Looks like I have a lot of bullet options. It is a magazine fed weapon so some of these may have to be run through single shot but that's OK too.

Sendero Man, how much jump are you seating these for.

 

[Sendero_Man]

Re: 338 Lapua Retumbo loads

3.685 COAL which is 10 thou off

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

Did you experiment with different jumps and this was the best result or it produced good results right off so you didnt look further?

In the past I have had some loads respond better to just off the lands but on magnum loads I am seeing a lot of people holding .005 to .010 for best results.

 

[normbal]

Re: 338 Lapua Retumbo loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">That's interesting... if I used that little Retumbo (88 grains) on my 26" Rem 700, I'd get like 2500-2600fps.</div></div>

Just starting with reloading this round, With a single trial of 94 grains of Retumbo (300 gr Scenars, CCI mag primers, Hornady Brass), I'm getting about 2722 fps without pressure signs.

Savage 110 BA with a 1/9 26" barrel.

H1000 only gets me to 2670 with 92 grain loads.

FWIW.

 

[snipedogg]

Re: 338 Lapua Retumbo loads

This is good to know about the Savage. I just picked up the FCP HS version and I'm on the fence with Retumbo and H1000 with the 300 gr SMK and Berger OTM. Also think I'm gonna try some N170 and possibly try a faster powder when I get a chance due to such extreme weather changes down here it may be the trick to consistency. Anybody have a good less temperature sensitive load that's worked for them? We'll typically see a 20-30 degree temperature rise during the course of a match so it is my largest variable by far.

 

[.375Mojave]

Re: 338 Lapua Retumbo loads

I have used Retumbo in Vegas with wide temp swings and it does not seem overly affected. Ballistics change as usual but MV seems reasonably consistent but I admit I have only tried a couple powders for 375 CT.

 

[cali_tz]

reviving this thread, as I am going back to Retumbo since VV powders have proved impossible to get from anywhere for many months now. AFAIAC, VV is out of business.
Back to Hogdgon and IMR choices.

The problem now is I have to invest in finding a doggone accuracy node with Retumbo ... I spent so much time on this with VV N570 sucks having to start over.

From now, as much possible USA made.

 

[mtang45]

The rumor mill has it that Lapua bought VV, so it may be back...soon.

 

[RHunter]

From now, as much possible USA made.

Then you better give up on Retumbo as well because it is made in Australia by ADI as is ALL of the extreme line of powders. All the IMR is made in Canada by General Dynamics.

Pyrodex, Triple Seven, White Hots muzzleloading propellants are made in Kansas. All Winchester, Herco, Bullseye, Unique, 2400, and the three "Dots", and Hodgdon ball/spherical powders are made in Florida. All other non extreme extruded Hodgdon powders are made outside the United States.

So if you want to stick to American made powder for 338 Lapua, you better learn to love US869 which is actually a good powder for 338 Lap.

A shipment of VV did arrive recently, unfortunately it did not have any 5 series powders, all 1 series. The date of manufacture on the N160 I got was late 2013... There is HOPE.

 

[Tristian19]

The problem now is I have to invest in finding a doggone accuracy node with Retumbo ...

I just got my .338 Lapua less than two months ago and still going through load development. I have just over 16 pounds of Retumbo so that is where I started.

285 Hornady over Retumbo inside of Lapua sparked by 215M.
* Node areas for me appeared to be 89.8, 92.0 and 93.7.
I have not narrowed down nodes using .1 grain as of yet followed by seating depth.

Chrony results:
91.8 ~ 2755 (2760, 2760, 2743, 2754)
94.0 ~ 2855 (2855, 2855, missed)
94.3 ~ 2874 (2892, 2873, 2873)
* No signs of Pressure at all in my BTA

05.02.14
Temp: 64F
DALT: 1016-1119
Alt: 515'
Pressure: 29.19
HUM: 38.4
DPOIN: 40.0-40.2
WETB: 52.0
MOST CLOUDY

I also have rounds made up for 300 SMK's and 300 Bergers using all mentioned components. Trying to get back to range as soon as I can.

I did shoot 91.8 of Retumbo with the 300 SMK's and was pleased with four shot group but you know that does not mean much without further testing.

 

[Tristian19]

Then you better give up on Retumbo as well because it is made in Australia by ADI as is ALL of the extreme line of powders. All the IMR is made in Canada by General Dynamics.

Pyrodex, Triple Seven, White Hots muzzleloading propellants are made in Kansas. All Winchester, Herco, Bullseye, Unique, 2400, and the three "Dots", and Hodgdon ball/spherical powders are made in Florida. All other non extreme extruded Hodgdon powders are made outside the United States.

So if you want to stick to American made powder for 338 Lapua, you better learn to love US869 which is actually a good powder for 338 Lap.

A shipment of VV did arrive recently, unfortunately it did not have any 5 series powders, all 1 series. The date of manufacture on the N160 I got was late 2013... There is HOPE.

Just a quick FYI: I have seen Retumbo in 8 lbs at least twice over the past seven plus days. Last time was Recobs just two days ago or so. Also saw H1000 8 lbs once and 1lb about three times within past seven plus as well. Recobs, and two other sites. Precision might have been one...

No big deal.

 

[Tristian19]

300 SMK & Retumbo Load Development...

Just sharing some data...

This resulted in a 92.1 grain Load my rig really likes...

 

[Ishallbie O'Cullkillin]

Hey Tristian19, What barrel length is that Krieger Heavy Palma? Is it 31"?

 

[Tristian19]

Hey Tristian19, What barrel length is that Krieger Heavy Palma? Is it 31"?

28 inch barrel.

sent via Tapatalk

 

[RHunter]

Just a quick FYI: I have seen Retumbo in 8 lbs at least twice over the past seven plus days. Last time was Recobs just two days ago or so. Also saw H1000 8 lbs once and 1lb about three times within past seven plus as well. Recobs, and two other sites. Precision might have been one...

No big deal.

My reply was directed at this post:::

reviving this thread, as I am going back to Retumbo since VV powders have proved impossible to get from anywhere for many months now. AFAIAC, VV is out of business.
Back to Hogdgon and IMR choices.

The problem now is I have to invest in finding a doggone accuracy node with Retumbo ... I spent so much time on this with VV N570 sucks having to start over.

From now, as much possible USA made.

It had nothing to do with availability, it had everything to do with where the powders were made.

If you want to stick to a powder you can usually find ALL THE TIME and it is American made, US869 is your best option for a 338 powder. It, and H50BMG are the two powders that were always available during this "shortage". Not once since the Newtown BS was I wanting a powder for my 338 or my Barret 50.

Then you better give up on Retumbo as well because it is made in Australia by ADI as is ALL of the extreme line of powders. All the IMR is made in Canada by General Dynamics.

Pyrodex, Triple Seven, White Hots muzzleloading propellants are made in Kansas. All Winchester, Herco, Bullseye, Unique, 2400, and the three "Dots", and Hodgdon ball/spherical powders are made in Florida. All other non extreme extruded Hodgdon powders are made outside the United States.

So if you want to stick to American made powder for 338 Lapua, you better learn to love US869 which is actually a good powder for 338 Lap.

A shipment of VV did arrive recently, unfortunately it did not have any 5 series powders, all 1 series. The date of manufacture on the N160 I got was late 2013... There is HOPE.

 

[Capt Academy]

Interesting

 

[Tristian19]

My reply was directed at this post:::



It had nothing to do with availability, it had everything to do with where the powders were made.

If you want to stick to a powder you can usually find ALL THE TIME and it is American made, US869 is your best option for a 338 powder. It, and H50BMG are the two powders that were always available during this "shortage". Not once since the Newtown BS was I wanting a powder for my 338 or my Barret 50.

I now see your point indeed. I also clearly recall seeing US869 and H50BMG mostly available during time you mention. I was thinking of trying out US869 for my 110 BA 338 LM during this same time period but without getting into a long story I stopped shooting her and ordered a custom 338 LM.