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It is a 3 shot group.
The rifle is a GA Precision built rifle.
26 inch rock creek barrel with badger ordnance brake
Lawton 7500 action with Shilens trigger
Bedded in a McMillan a5 stock.
Scope is an Athlon Ares BTR 4.5-27 in Seekins rings.
Anybody try n565 with their lapua and 300gr bullets? Looking for a retumbo backup and I have 8-16lbs of n565 available.
I know it will work fine, more so looking for reloading data and numbers to compare to.
I know it will work fine, more so looking for reloading data and numbers to compare to.
Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori
Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.
www.vihtavuori.com
I enclose a quick screenshoot from their app with selection of N565 and 300gn bullets.
Sorry, measures are metrics,col in mm and speed in meters per second.
I hope it could help.
Attachments
I have been running N570 under the 300 Grain Elite Hunters. 91.5grains .085 jump is my load but I have brought it up to 94 before and got just a hint of heavy bolt. Lapua brass and WLRM primers. Other loads were 101 of RL33, shot the fastest but too dirty and smoky. 105gr of US869 gave better groups and same speed as 88-89 grains of retumbo. I think I was able to replicate the Berger factory ammo with around 91 Grains of H1000.
Do you have LRT loads with any other bullets, I can’t seem to get Bergers 300 OTM to group with LRT worth a damn….
I tried out some 300 gr SMKs on Friday with LRT. 95 and 96 gr both shot just under MOA groups. COL was 3.685. Id have to look in my notes, but I believe they were around 2650 fps.
Ok, I have a new barrel on my .338LM. Since Retumbo is unobtainium these days, I’ve decided on using N570 powder. (Mostly because I found a nice supply of it.) The bullet is the 300gr SMK, brass is Lapua, and primers are Federal 215m magnum. The new barrel is finished at 31”, and is a 1:9” twist. This rifle is used only for extreme long range (1500 metres and beyond). And I single load, so mag length is moot here. (In other words, I load ‘em long.)
On the Hodgdon site, it notes charge weights between 68 to 76 grains of the N570 powder With a 300gr projectile. I would like to see speeds in the range of 2800 to 2900fps. I was getting 2880fps with the old 26” barrel and 93.6gr of Retumbo. Which was a pretty hot load. It was very accurate and I had great success to the mile and out to 1900 metres. I will maintain a .010” jump for seating depth, like I did with the first barrel. Since it seems the reamer that was used has given me the exact same CBTO with the 300gr SMK bullet As the first barrel (talk about luck!).
I‘m thinking I don’t need to go that stout since I have 5 more inches length on the barrel. (To try and at least maintain that speed of around 2900fps.)
Who has tried a 300gr bullet with N570? What charge weights did you try? Barrel length? Jump? What were your results?
I am leaning towards starting out around 70gr and working up. What say you?
Andy 6MT
On the Hodgdon site, it notes charge weights between 68 to 76 grains of the N570 powder With a 300gr projectile. I would like to see speeds in the range of 2800 to 2900fps. I was getting 2880fps with the old 26” barrel and 93.6gr of Retumbo. Which was a pretty hot load. It was very accurate and I had great success to the mile and out to 1900 metres. I will maintain a .010” jump for seating depth, like I did with the first barrel. Since it seems the reamer that was used has given me the exact same CBTO with the 300gr SMK bullet As the first barrel (talk about luck!).
I‘m thinking I don’t need to go that stout since I have 5 more inches length on the barrel. (To try and at least maintain that speed of around 2900fps.)
Who has tried a 300gr bullet with N570? What charge weights did you try? Barrel length? Jump? What were your results?
I am leaning towards starting out around 70gr and working up. What say you?
Andy 6MT
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Thanks! H1000 and Retumbo have not been available in Canada for almost two years. Thats why I chose IMR4831.
Anyone else?
Anyone else?
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4831 is too fast for 300 gr. I only use it in 250gr smk which around 1/2 moa at 100 yards. You can try 250~260gr solid which will fly flatter and higher speed. I tried Retumbo, H1000 and N570. The N570 gave me the most speed @2920fps 91gr with 285eldm. At 2920 gave me a little stiff bolt lift but not too bad. My bbl is 27” 1/9 twist
Yeah, I know Dave. It is probably too fast burning for the 300gr bullet. And velocity will suffer, even with the longer barrel. At maximum charge weight, the 4831 will be hard pressed to reach 2800fps IMHO.
So I managed to find some N570. I will have to wait a couple of months to get it (early May delivery). But that's just the nature of the beast up here in Canada. The only good thing is that it's still cold up here. I had not planned on doing load development until temperatures rose above 50deg anyways. And for those of us above 53°, that's usually late April or early May.
Thanks for the input!
So I managed to find some N570. I will have to wait a couple of months to get it (early May delivery). But that's just the nature of the beast up here in Canada. The only good thing is that it's still cold up here. I had not planned on doing load development until temperatures rose above 50deg anyways. And for those of us above 53°, that's usually late April or early May.
Thanks for the input!
Just a reminder, the n570 does burn up your barrel throat much faster, u have to measure your throat every 100 rounds. Since my 338lm bbl was done, I rebarrel to 338nm. I’m using 255gr solid with 88.2 RL26 @ 2950 fps w/8 ES over 20 rounds data. I still have room to push it to 3100 ish, but I’m happy with 2950. Just a reminder some caliber/barrel once it reaches certain length, you won’t get extra 30 fps per inch. It might decease to 5-10 fps per inch.
Well, I'm not looking for anywhere near 3100 with the 300gr. I would be very pleased to get around 2850 to 2875fps with this combo. That's the same area of performance I was getting with the old barrel. It was accurate out to 1900 metres, and that's all I'm looking for again.
I have been running N570 in mine pretty much since new pushing 300gr Bergers. I tried a few others, (Retumbo, H1000, RL33, US869) and 570 has been the best of them all. After about 450 rounds I have seen a .015 growth in throat from beginning measurement. I would attribute a little of that to break in. after 150-200 rounds I have been able to back off a grain of powder to keep my node and speeds the same as well.
It’s not like R26 is any nicer on barrels than N570.
If you want barrel friendly try N165 or 170.
Me?
I’m perfectly happy with the extra 100ish fps R26 and N570 gets me.
Your gonna spend a bare minimum of $2500 in ammunition to burn out a 338 barrel.
Worrying about barrel life at that level is silly.
The last ELR match I shot there was a guy shooting a 7mm-338LM Improved. I forget what weight the bullet was, but it was pushing 3800fps and took something like 12 mils to get to 2000 yards @ 3000' alt. The problem was that the barrels lasted around 800 rounds tops, so yeah...consumables.
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I can hear the conversation now.......
so, I love my 220 swift... I want to do the same thing with my 7mm..
to keep post on subject
A person can slow the 300 gr bullet down, to Mil spec 2640 fps and get a projected 3,000 plus rounds (per the MRAD site)
or make it go super fast, and you have a barrel burner
edit: > technical term.. 'throat erosion'
Like car racing, how fast you want to go, how much you want to spend
I’m shocked he’s getting 800
338 snipetac barrel life is pretty interesting
A smith I shoot a local mile match with ran a 7mm Hulk (338LMI necked down to 7mm) and said he got ~800rds out of it.
I'm sure there are a few variations on the 7/338LM IMP out in the wild, but I suspect they're all sub-1,000rd barrel life if pushing the bullet to their max potential. Doesn't mean I don't want one though
I hear 'ya. But above the 49th parallel in Canada, the real life facts of having to wait for a barrel, makes changing them difficult. I just waited 11 months for the Hawk hill barrel I just got for my .338LM.
I'm at the point now where I'm pretty committed to .338LM Improved 40 and .300NM for my ELR shooting that I just order new barrels when fresh ones arrive.
This is correct. Smoked my 375 cheytac barrel in 500 rounds; gladly Retumbo shot better in my 338 so I didn't burn much in that barrel
I haven’t yet, but know a few who do use them, including a few who compete in ELR. Let’s just say that they get a nod. I do want to try them out but access to distance has become expensive for me and it will likely be a while.
i use badland precision icbm bullet. Very easy to tune.
I bit closer than I usually start with cup/core
5-10 off the lands is where I start my jump test.
just to clarify for my own sanity.
you mean .5 to .1 off the lands...... or .05 to .01 off the lands
in inches
Getting ready to load some 338lm and started doing research on loads and came across this.
and this in the same thread..
So yeah I have a box of berger 300 but i also have some 250 and a box of 285. So forget about the 300s?
285 is a pretty good bullet all around and Frank has said you can't beat the Hornady 285 box ammo, IIRC. Why they don't make a 275 I dunno.
With one of the "go-to" loads (92.5 Retumbo, Lapua Brass) I get almost 2950 but it's a 32" barrel. I'm guessing 2875 with a 26" barrel, which IIRC is pretty close to what I was getting with the Factory Hornady ammo; I'm pretty sure they have 94 grains of Retumbo in there, Hornady brass, loaded pretty short too. (I know it's 100 fps faster than advertised for the factory ammo, but that's what it got for me.)
With one of the "go-to" loads (92.5 Retumbo, Lapua Brass) I get almost 2950 but it's a 32" barrel. I'm guessing 2875 with a 26" barrel, which IIRC is pretty close to what I was getting with the Factory Hornady ammo; I'm pretty sure they have 94 grains of Retumbo in there, Hornady brass, loaded pretty short too. (I know it's 100 fps faster than advertised for the factory ammo, but that's what it got for me.)
300s are fine, but I think the point is that 285s are better optimized to the common .338LM setups with 26”-ish barrels. 300s are very well suited for long 30”+ barrels with an Improved chamber though.
I run the 300s right around that 2750-2800 fps line. 27" barrel and about 300ft elevation. I could push them harder but I lose my node. I have seen 2900 before but that really is the limit on an unimproved lapua. I take what everyone says online about as seriously as April 1st. I am sure for him and his setup it works, and I am sure there is some validity to the threshold where speed overcomes energy with every weight bullet. For me to run 250s at 3kfps I give up an extra 300ftlbs at 1k yards. I want the momentum down range, I can always add a little more dope in.
I'm running the 285gr Hornady ELD-M over 96gr of Retumbo in a short throated 26" barrel and getting ~2890fps
Indeed it does. The barrel was throated for the 250gr SMK, so I load to CBTO: 2.740” / OAL: 3.600” to get a 20thou jump.
No stiffness in the bolt, flattening of primers, or ejector marks on the Lapua brass.
Not sure if I just have an "off" keg of Retumbo that let me get that high with zero signs of pressure, but I'll take it
I've loaded for my TRG-42 1:12" since 1/06, so I have a bit of experience. I also was part of the SH/Berger 250gr Hybrid/OTM testing. We're going back to 2013, but I think that Frank was of the opinion that the then Hornady 285s and the various 250s were sufficient, absent some specialty applications, like a mile plus.
The Finnish army snippers did their T/E with the 250 Scenars at 2000m and were getting good results.
Chris
what was your load for your TRG on the 250's?
Edit - I think I found it on post #77
"Pet load is H-4831sc at between 88gr-89gr under 250gr Scenars, LockBase, Berger OTMs and SMKs, for about 2875-2950ish fps"
what are the specs on your pet load? COAL, group size, ES, SD?
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