338 Lapua Velocities
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Fiftydriver
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That seems pretty high for a 25" barrel length. The Lapua case can take some serious pressure. What load are you using to get those velocities. Not saying your over pressured, just above average in my opinion.
I generally see around 3050-3075 with the 250s.
I generally see around 3050-3075 with the 250s.
Long Time Long Ranger
Well-Known Member
I use winchester wmr in mine and get 5-8 fps extreme vel spreads. The 200 AB tops out at 3400 fps and the 250 AB tops out at 3125 fps. These are the two I have with 26" barrels. Virually identical to my 338-300 ultramags with 28" barrels and about 75 fps faster than my 340 Weatherby with a 28" barrel.
edward hogan
Well-Known Member
Wondering if your rifles all share the same receiver-magazine oal, LTLR?
How much better performance can/could you obtain if you were seating your bullets in the smaller capacity cases to the same oal your .338LM allows? Have you looked at the .338 Norma which is supposed to be in the same ballpark as all others you mention, including the LM and 338-378; but being several tenths shorter enable optimum seating flexibilty?
With the super-mag cases, you lose much seating variability, unless your receiver has a 4" magazine oal. The Sako TRG42 or TRG-S with M995 action has 3.75". I'm not familiar with Lawton or Stiller super-mag sized actions but how many are using them with anything but the largest cartridges anyway? Ultra Mag and 340 Weatherby are all standard magnum functional.
My point is without having to stuff half the bullet below the case neck, likely you would get same neighborhood performance as the lapua and do so while burning less powder or using those with less than slowest burn rates.
Just happen to have the Accurate Arms #2 by the desk and it shows in a .338RUM that a 250gr Grand Slam driven by 79gr of xmr4350 yields almost 2800fps, while same bullet w/104gr of their 8700 yields 25fps LESS! Not debating that there aren't more energy producing powders, but if you had an extra .25" (or more) to move the bullet forward, freeing up additional capacity, should be able to boost those velocities.
The same load of xmr4350 in the .340wby yields the same velocity as the .338rum according to AA, but at only 61000psi. With another .15" of seating depth and throat optimized for it, in the .340wby, and going up to 65kpsi you could be in the same ballpark as the Lapua but with 20gr less powder...
Just some thoughts.
Now I will shamelessly plug the .338/300 win mag which I've embraced because it allows more flexibility than any large magnum. From 65gr of xmr4350 to 79gr with a 250gr bullet; plus oal case length of 2.62" which allows seating your bullet almost flush with the neck. About the same performance as the .340wby, but with wider variety of brass and lower expense.
I understand about Lapua brass, and they no longer make win mag brass, but in a 14lb field rifle such as a .338/300 win TRG42 you won't "need" a brake. With more mid-sized ctg case you don't need the 28-30" barrel to burn all that slowest burning powder.
Of course the .338LM really needs a 4" minimum oal magazine to get all its horsepower and torque working for you. Yet, those actions are really heavy, or I would expect them to be, and the military shoot factory loads to specs anyway so the magazine oal is not valued.
Custom rifles, chambers, wildcats and handloading variables are what this a most fascinating pursuit. When it comes to the power element of highpower rifles, nothing can do as much as a .338 bullet.
Casscade
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Sorry on the 25 inch bbl, should have said 26 inch bbl. Using rl25 for the most part, seemes to put out the most for me. I am around 3.78 oal btw. This is not a one shot deal btw, these are all reloadable. Just filled up a lapua case last night with H870 and gor 116 to the top of mouth. Some have stated quicklaod calls for a water cap. of 108, don't get that one.
Fiftydriver
Official LRH Sponsor
Casscade,
Do not go on primer pocket tightness as a judgment of pressure when using the lapua case. The Lapua 338 case will take 65 to 68,000 psi all day long and never show any sign of primer pocket loosening.
Believe me, I have pushed this case developing all of my wildcats based on it and can say I have yet to really loosen a primer pocket on one of these cases. If you do see any primer pocket loosening, your WAY over pressured.
Again, primer pocket tightness is just not a good indicator of pressure with the Lapua case.
Do not go on primer pocket tightness as a judgment of pressure when using the lapua case. The Lapua 338 case will take 65 to 68,000 psi all day long and never show any sign of primer pocket loosening.
Believe me, I have pushed this case developing all of my wildcats based on it and can say I have yet to really loosen a primer pocket on one of these cases. If you do see any primer pocket loosening, your WAY over pressured.
Again, primer pocket tightness is just not a good indicator of pressure with the Lapua case.
Fiftydriver
Official LRH Sponsor
Casscade,
It does depend on barrels. I generally use Lilja barrels which run tight in bore diameter and will be a bit slower in velocity but their accuracy is great so I live with it. Still, I have used all the top barrel makers enough to say that in a 26" barrel length+3000 fps is an upper pressure load. What does that mean, well, it does not mean its a dangerous load.
I looked through some of the current load data sources On average, they list the 338 Lapua to get around 2950-3050 fps with a 225 gr bullet weight and 2750 to 2850 fps with 250 gr bullet weights.
Now this is rather anemic and I completely believe this as most will say the 338 Lapua will get 2650 fps with a 300 gr SMK....... We all know that is incorrect.
I do not know why they load the 338 Lapua to this level but most recommend this. Personally, I think the 338 Lapua can be safely loaded to roughly 100 fps higher then what most load manuals recommend.
So how do you read pressures..... Primer pocket tightness is not a reliable judge as your well over pressured if your loosening primers pockets. If you have a factory rifle, bolt lift can be an indicator. If the force to lift the bolt increases at all, your likely over where you should be with the Lapua in a factory rifle.
If your rifle is a custom rifle with a custom or accurized receiver, bolt lift can be very inaccurate for judging pressure. I had a customer come into the shop screaming at me because be blew the primer pockets out of nearly 100 257 STW brass he had loaded up. He said that the bolt could be opened with one finger so he said it must be a problem with the rifle. Shot one of his loads over the chrono and he was ripping a 100 gr bullet out at 4000 fps!!!! About 200 fps over where he should be and yes the bolt lift was effortless as was extraction. Keep that in mind.
So how do we do it....
Chronograph is about the very best way to know where your pressures are. I would personally tell you to shoot over a chrono, load from 3000 to 3100 fps with 250 gr bullets and see where the rifle shoots best and be happy with that.
It does depend on barrels. I generally use Lilja barrels which run tight in bore diameter and will be a bit slower in velocity but their accuracy is great so I live with it. Still, I have used all the top barrel makers enough to say that in a 26" barrel length+3000 fps is an upper pressure load. What does that mean, well, it does not mean its a dangerous load.
I looked through some of the current load data sources On average, they list the 338 Lapua to get around 2950-3050 fps with a 225 gr bullet weight and 2750 to 2850 fps with 250 gr bullet weights.
Now this is rather anemic and I completely believe this as most will say the 338 Lapua will get 2650 fps with a 300 gr SMK....... We all know that is incorrect.
I do not know why they load the 338 Lapua to this level but most recommend this. Personally, I think the 338 Lapua can be safely loaded to roughly 100 fps higher then what most load manuals recommend.
So how do you read pressures..... Primer pocket tightness is not a reliable judge as your well over pressured if your loosening primers pockets. If you have a factory rifle, bolt lift can be an indicator. If the force to lift the bolt increases at all, your likely over where you should be with the Lapua in a factory rifle.
If your rifle is a custom rifle with a custom or accurized receiver, bolt lift can be very inaccurate for judging pressure. I had a customer come into the shop screaming at me because be blew the primer pockets out of nearly 100 257 STW brass he had loaded up. He said that the bolt could be opened with one finger so he said it must be a problem with the rifle. Shot one of his loads over the chrono and he was ripping a 100 gr bullet out at 4000 fps!!!! About 200 fps over where he should be and yes the bolt lift was effortless as was extraction. Keep that in mind.
So how do we do it....
Chronograph is about the very best way to know where your pressures are. I would personally tell you to shoot over a chrono, load from 3000 to 3100 fps with 250 gr bullets and see where the rifle shoots best and be happy with that.
Long Time Long Ranger
Well-Known Member
The 338 lapua loads are seated to touch the lands. The 200 grain bullet is 3.703 and the 250 is 3.623. Just depends on the ogive of the bullet but most hit from 3.62-3.72 in my rifles. The fastest load I had in my lapua rifles listed was 3157 fps with the 250 but no accuracy so I settled at the 3125 fps load. The accuracy loads in my 338-300 ultramags run high 3000's to right at 3100 fps with the 250 and 3325 fps with the 200. The top accuracy loads in my 340 weatherby averages 3057 fps with the 250 gameking and 3284fps with the 215 gameking. I have used those loads for 30 years. The Lazzeroni Titans I chronographed fell right in this range also with max loads. There is just not enough difference between any of these that you would notice while hunting and taking game.
edward hogan
Well-Known Member
If chasing max velocities, why not run a Molyed bullet?
Understand the arguments about moly, and never being able to completely clean a molyed bore, but so what if your barrel life is under 800 rds anyway? Pretty hard to deny the velocity boost moly enables, and if you have an optimum velocity value, it should enable you to achieve that velocity with reduced powder charges. Better barrel life with less friction and reduced powder burning. Just an idea...
As far as any modern magnum goes, seems 65,000psi is the SAAMI spec, Lapua cases are for sure about the highest quality. Maybe to determine pressure from "signs" like primer pocket looseness, try your loads in Hornady brass? I do seem to recall a magnum specified at 68k or 70k PSI? Might have been the .408 Chey-Tac in the preliminary look-see done in Tactical Shooter back in 2000/01...
Maybe using moly disturbs bullet flight once the projectile enters the transitory velocity phase? I still don't buy that concept as critical or even important. Funny how the PALMA shooters manage fairly well with those 155gr .308 bullets arriving on target at 1000yds going about 1100fps at their destination. And then there's the Dominion Rifle Club of Canada article with 2.5" vertical dispersion at 1000yds for 15-20rd .223Rem groups fired with 90gr JLK bullets. Maybe a .22-250AI with 6.5 twist will outshoot them all? Of course, there's that pesky transition velocity stuff... Evidently nobody told those 90gr JLK's they weren't supposed to stay .25moa or better all the way to 1000yds...
Link below to DRC issue w/90gr JLK testing results:
Winter/Spring 2008 ....Inthis issue
Understand the arguments about moly, and never being able to completely clean a molyed bore, but so what if your barrel life is under 800 rds anyway? Pretty hard to deny the velocity boost moly enables, and if you have an optimum velocity value, it should enable you to achieve that velocity with reduced powder charges. Better barrel life with less friction and reduced powder burning. Just an idea...
As far as any modern magnum goes, seems 65,000psi is the SAAMI spec, Lapua cases are for sure about the highest quality. Maybe to determine pressure from "signs" like primer pocket looseness, try your loads in Hornady brass? I do seem to recall a magnum specified at 68k or 70k PSI? Might have been the .408 Chey-Tac in the preliminary look-see done in Tactical Shooter back in 2000/01...
Maybe using moly disturbs bullet flight once the projectile enters the transitory velocity phase? I still don't buy that concept as critical or even important. Funny how the PALMA shooters manage fairly well with those 155gr .308 bullets arriving on target at 1000yds going about 1100fps at their destination. And then there's the Dominion Rifle Club of Canada article with 2.5" vertical dispersion at 1000yds for 15-20rd .223Rem groups fired with 90gr JLK bullets. Maybe a .22-250AI with 6.5 twist will outshoot them all? Of course, there's that pesky transition velocity stuff... Evidently nobody told those 90gr JLK's they weren't supposed to stay .25moa or better all the way to 1000yds...
Link below to DRC issue w/90gr JLK testing results:
Winter/Spring 2008 ....Inthis issue
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Fiftydriver
Official LRH Sponsor
Edward,
You offer a great bit of information and something I had forgotten. When I was doing load development for my 7mm AM, 300 AX and 338 AX, I did use Norma 338 Lapua brass for exactly the reasons you state. The Norma brass is quite soft, in fact a bit softer then Remington RUM brass on average. I would do load development until the primer pockets would just begin to loosen up and then back off a couple grains and measure muzzle velocity.
I would then switch over to the Lapua brass and adjust the load as needed to match velocity. This told me that I was in the 65-68,000 psi load range, right where any modern loaded magnum should be for proper powder burn.
Again, great tip!!!
You offer a great bit of information and something I had forgotten. When I was doing load development for my 7mm AM, 300 AX and 338 AX, I did use Norma 338 Lapua brass for exactly the reasons you state. The Norma brass is quite soft, in fact a bit softer then Remington RUM brass on average. I would do load development until the primer pockets would just begin to loosen up and then back off a couple grains and measure muzzle velocity.
I would then switch over to the Lapua brass and adjust the load as needed to match velocity. This told me that I was in the 65-68,000 psi load range, right where any modern loaded magnum should be for proper powder burn.
Again, great tip!!!
edward hogan
Well-Known Member
Thanks for the compliment. Too kind...
Why not use moly coated bullets though? Or is this already assumed and factored in?
I sold my .30-378wby and .338rum, .300rum rifles just because could not see any real advantage once I discovered the .338/300win. Also have a .275gr NEI flatpoint mold in .338. My .454 casull w/345gr Lyman flying pie plate bullet penetrated 27" of cottonwood timber in a staight WheelWeight alloy. The .338/300win at 2200 fps should really deliver the goods. Just couldn't convince myself the .338rum was as versatile...
Anyone shooting the Barnes 160gr bullet? They may not even be in production anymore for all I know, but a 160 at 3600 or 3700fps is comparable to a 52gr from a .22-250. Not my idea for varminting, but..
If I keep mouthing off here, I will have to buy a chrony and some 300gr smks and report some results...
Why not use moly coated bullets though? Or is this already assumed and factored in?
I sold my .30-378wby and .338rum, .300rum rifles just because could not see any real advantage once I discovered the .338/300win. Also have a .275gr NEI flatpoint mold in .338. My .454 casull w/345gr Lyman flying pie plate bullet penetrated 27" of cottonwood timber in a staight WheelWeight alloy. The .338/300win at 2200 fps should really deliver the goods. Just couldn't convince myself the .338rum was as versatile...
Anyone shooting the Barnes 160gr bullet? They may not even be in production anymore for all I know, but a 160 at 3600 or 3700fps is comparable to a 52gr from a .22-250. Not my idea for varminting, but..
If I keep mouthing off here, I will have to buy a chrony and some 300gr smks and report some results...
Fiftydriver
Official LRH Sponsor
I really do not have an opinion on moly bullets. To be honest, in a custom barrel that is broken in properly, there is really no need for it from a copper fouling standpoint.
As far as velocity gains, yes there is something to that, not dramatic as many advertise it is but there is the ability to increase powder charges and gain a bit of velocity.
I have used Moly bullets, still use some, no real opinion either way. As with everything there are advantages and disadvantages.....
As far as velocity gains, yes there is something to that, not dramatic as many advertise it is but there is the ability to increase powder charges and gain a bit of velocity.
I have used Moly bullets, still use some, no real opinion either way. As with everything there are advantages and disadvantages.....
87grs of RL25 gives me 2780fps with the 300 SMK out of a 30" ABS/Rock barrel.
Wayne aka WAMBO
Wayne aka WAMBO
