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How hot should I go...

n/an/a Member Posts: 168,427
Varget and a 70 Grain Nosler BT do not seem to be the optimum combination for my Weatherby SVM in .243. My best group at 100 yards was 11/16" at 40 grains of powder, but the groups seemed to tighten back up at 42 grains which is the maximum load in the book (3/4" group). I saw NO pressure signs whatsoever and my velocities were running very consistant with the books published velocities (mine were just slightly higher all the way up the scale). I think I can safely run this up a little hotter to see if the groups tighten back up some. What increments do you guys use when exceeding maximum published loads? If I'm showing no pressure signs, do you think it would be safe to jump up .5 grains?...or should I back it off to .2 or .3 grains? Varget was the most accurate powder tested for Nosler, but I'm not having much luck with it. Their most accurate load was 42 grains which is also their max load. My groups tightend back up at 42 grains and I think there may be some potential with going a little hotter. I'd like to play with it a little more before moving on to another powder... These are the first 70 grainers that I've worked on with this rifle. Thanks for the input!![8D]

Comments

  • bpostbpost Member Posts: 32,669 ✭✭✭✭
    edited November -1
    If you are going to exceed the lawyer proof loads I would go up .3 for five rounds and then if everything is OK .2 from there. I'd stop and back off at the first hint of pressure.
  • JustCJustC Member Posts: 16,056 ✭✭✭
    edited November -1
    shot a factory class match for the past 2 days with a guy who was using varget in a 223 under a 55gr v-max and he was well over 2gr over max (thrown to the top of the neck). I doubt varget will get too hot in your case.
  • BHAVINBHAVIN Member Posts: 3,490 ✭✭
    edited November -1
    For my rifle (Remington 700) I have the best accuracy with 41.5g Varget using a 70g BT. I have shot up to 42.5 and didn't have any signs of pressure at all. The way they lawyer the load manuals now you are probably safe but I would go with bpost1958 ideas on increasing. The 70g Nosler BT does great on coyotes[}:)]
  • sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    Eric,

    It depends a lot on the caliber when reloading as to how far I will move up. Anything in a book for a Mauser based cartridge I will start at max... and usually, look at the case and move up a grain. With newer cartridges I start lower and move up in the .2-.5 range depending on how my case looks. Either way when I see signs of pressure I work in the .1 to .2 (max) range. Go a little over then come back. Check it again, but usually don't as far as the first time.

    Varget, I have found can fill a .223 case. What I found my rifle likes best is XMR2015. behind 60 gr. Sierra's. 24 gr's. I worked all the way up to 24.5 and just got hotter pressures and got a little more speed but no better accuracy. Different rifles have different likes too. If you get great groups with the higher volume shoot that..if it's safe. Then adjust as necessary when your barrel wears down a little bit.
  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    ECC,

    Your 42.0 gr. load is nearly at the top of the Varget/.243 Win. combination but the case is only filled to approximately 88% of capacity. You will probably get away with the 0.5 gr. increase just fine but I would approach any greater loads with care. Remember that the Weatherby leade (freebore) is having some effect here and maybe they cut a decent chamber which is holding back some of the pressure signs. No matter how you slice it, you should be at the top end of the usefulness of the Varget with the 70 gr. Ballistic Tip.

    I suggest a switch to the 87 gr. Hornady VMAX in order to better balance the relationship between the bullet weight, case capacity and the bore volume. They perform superbly at longer ranges on things like prairie dogs and ground hogs and step right up for some fun paper punching. The 70 gr. bullets are a bit too light for the case capacity of the .243 Win. and Varget.

    Best.
  • JustCJustC Member Posts: 16,056 ✭✭✭
    edited November -1
    Eric,..throw a few bucks at a chronograph if you don't have one,..even a cheap one. They can be the next best thing to a strain guage attached to the chamber exterior. Mine has told me to back off quite a few times when NO pressure signs were present. I had run a 140gr a-max out of a 26" 1:8 tube in 6.5-06AI to 3208fps and the chrono was the tool that told me I had made an error in judgement regarding RL22 in that case[B)] Upon removing the rest of them, the fired cases had to be tossed due to the primer pockets being wasted. imagine if I ran that ladder all the way up without the chrono to tell me that[V]
  • n/an/a Member Posts: 168,427
    edited November -1
    quote:Originally posted by nononsense
    ECC,

    Your 42.0 gr. load is nearly at the top of the Varget/.243 Win. combination but the case is only filled to approximately 88% of capacity. You will probably get away with the 0.5 gr. increase just fine but I would approach any greater loads with care. Remember that the Weatherby leade (freebore) is having some effect here and maybe they cut a decent chamber which is holding back some of the pressure signs. No matter how you slice it, you should be at the top end of the usefulness of the Varget with the 70 gr. Ballistic Tip.

    I suggest a switch to the 87 gr. Hornady VMAX in order to better balance the relationship between the bullet weight, case capacity and the bore volume. They perform superbly at longer ranges on things like prairie dogs and ground hogs and step right up for some fun paper punching. The 70 gr. bullets are a bit too light for the case capacity of the .243 Win. and Varget.

    Best.




    NN...in your opinion, what would be the optimum powder for the 70 grainers? I've got a few hundred of them to use up... RL-22 performed better than the Varget with my 90 grain pills...maybe this rifle does not like Varget.?.? One more question: I thought the Weatherby Leade only applied to Weatherby calibers??? I did not think they used their leade in standard chamberings??? My pills are seated .005 off the lands. Thanks!
  • n/an/a Member Posts: 168,427
    edited November -1
    quote:Originally posted by JustC
    Eric,..throw a few bucks at a chronograph if you don't have one,..even a cheap one. They can be the next best thing to a strain guage attached to the chamber exterior. Mine has told me to back off quite a few times when NO pressure signs were present. I had run a 140gr a-max out of a 26" 1:8 tube in 6.5-06AI to 3208fps and the chrono was the tool that told me I had made an error in judgement regarding RL22 in that case[B)] Upon removing the rest of them, the fired cases had to be tossed due to the primer pockets being wasted. imagine if I ran that ladder all the way up without the chrono to tell me that[V]


    JustC...I chrono'ed these loads. I've heard quite a few folks talk about using a chronograph to know when pressures were getting too high. How exactly do you do this? I tested these loads in .5 grain increments and I noticed that my velocities jumped approximately 40-60 fps per .5 grain increment. My top load of 42 grains had an average velocity of 3634 fps, which is just slightly higher than book. Actually, all of my loads were just slightly higher velocities than the published velocity. Am I just looking for a huge jump in velocity, and if so, what constitutes a huge jump? Thanks!

    Here are my velocity changes:

    38.5 gr to 39.5 gr: 106 fps 3405 fps

    39.5 gr to 40.0 gr: 60 fps 3465 fps

    40.0 gr to 40.5gr: 36 fps 3501 fps

    40.5 gr to 41.0 gr: 40 fps 3541 fps

    41.0 gr to 41.5 gr: 39 fps 3580 fps

    41.5 gr to 42.0 gr: 54 fps 3634 fps
  • JAKEJRJAKEJR Member Posts: 24 ✭✭
    edited November -1
    ECC- You can keep easing up on the powder until you get very small increases in velocity. Then back off to your last load that gave you a significnt vel. increase. I use Varget in a 6mm Rem with a 70 gr Sierra. It does the job on prarie dogs way out in the wind, also works on coyotes. I've always been a Nosler man, but these Sierras are more accurate. May just be my rifle {26 in Douglas, 1in14 twist, just for light bullets and max vel.} Now, can you tell me some new tricks to reduce extreme spread?? Bl-C{2} is working well in my 204; avg vel better than factory, accuracy very good at 100 yds, but extreme spread over 100 fps. Accuracy not real good at 250-300. Benchmark gave the lowest e.s., but not enough speed. what do you think??
  • n/an/a Member Posts: 168,427
    edited November -1
    quote:Originally posted by JAKEJR
    ECC- You can keep easing up on the powder until you get very small increases in velocity. Then back off to your last load that gave you a significnt vel. increase. I use Varget in a 6mm Rem with a 70 gr Sierra. It does the job on prarie dogs way out in the wind, also works on coyotes. I've always been a Nosler man, but these Sierras are more accurate. May just be my rifle {26 in Douglas, 1in14 twist, just for light bullets and max vel.} Now, can you tell me some new tricks to reduce extreme spread?? Bl-C{2} is working well in my 204; avg vel better than factory, accuracy very good at 100 yds, but extreme spread over 100 fps. Accuracy not real good at 250-300. Benchmark gave the lowest e.s., but not enough speed. what do you think??


    A buddy is using BLC-2 in his .204. We shot that yesterday as well. He is also getting a very wide spread in velocities. We attributed it to his electronic scale. He still hand meters, but weighs on an electronic scale. My loads seem to be much more consistant than his and I sitll use the old balance beam scale. Perhaps it's the powder and not the scale.?.? He was having extreme spreads (over 100 fps) as well. I'm not sure what to tell you, but I'm sure someone here can weigh in on this...
  • RCrosbyRCrosby Member Posts: 3,808 ✭✭✭
    edited November -1
    A word of, likely not necessary, caution.
    Once you start playing around with max-plus loads the potential for problems with any change increases; sometimes more than you'd think.
    Higher ambient temperatures, different primer, seating depth, etc.
    So have fun, but be careful.
    Enjoy.
  • JAKEJRJAKEJR Member Posts: 24 ✭✭
    edited November -1
    There is a little more info about this on loaddata.com/articles. click on the article titled "
    Safe loads with your chronograph"
  • JustCJustC Member Posts: 16,056 ✭✭✭
    edited November -1
    Eric, once you exceed a book max velocity (taking into account barrel length differences) you are likely at max anyway. The info given about the small velocity jumps between say 2-3loads shows that that is THE max for your rifle. If you beat the book by a hundred FPS, I would say you are now venturing into uncharted territory. There are formulas that can be searched that work backwords from the MV and powder charge and bullet weight, and the result of the calculation is chamber pressure. I can't remember where I saw those though.

    As to wide spreads,..neck tension or variance of such can cause this as well as deteriorating powder, bad or too hot primers, gun just doesn't like that powder etc. If the spreads are that large, I would look at my components and maybe pull down and reweigh some of the charges. if they checked out on a digital, I would say they are correct,..but that is assuming the scale isn't defective. Reweigh them on your scale beside his scale to determine this.

    Also, I have found that I either need to have a small jump to the lands or be into the lands. The "at" the lands seating requires sorting bullets by bearing surface lengths to assure the same distance each time. Some that sit closer will leave faster, and those that were shorter will leave differently. I get vertical when I try to be exactly "at" the lands do to this. Even match pills are quite often sorted by bearing surface length to avoid this.
  • n/an/a Member Posts: 168,427
    edited November -1
    quote:Originally posted by JustC
    Eric, once you exceed a book max velocity (taking into account barrel length differences) you are likely at max anyway. The info given about the small velocity jumps between say 2-3loads shows that that is THE max for your rifle. If you beat the book by a hundred FPS, I would say you are now venturing into uncharted territory. There are formulas that can be searched that work backwords from the MV and powder charge and bullet weight, and the result of the calculation is chamber pressure. I can't remember where I saw those though.

    As to wide spreads,..neck tension or variance of such can cause this as well as deteriorating powder, bad or too hot primers, gun just doesn't like that powder etc. If the spreads are that large, I would look at my components and maybe pull down and reweigh some of the charges. if they checked out on a digital, I would say they are correct,..but that is assuming the scale isn't defective. Reweigh them on your scale beside his scale to determine this.

    Also, I have found that I either need to have a small jump to the lands or be into the lands. The "at" the lands seating requires sorting bullets by bearing surface lengths to assure the same distance each time. Some that sit closer will leave faster, and those that were shorter will leave differently. I get vertical when I try to be exactly "at" the lands do to this. Even match pills are quite often sorted by bearing surface length to avoid this.


    JustC...I'm not sure I understand your explanation. I had consistant jumps in velocity all the way through my last load...anywhere from 36-60 fps...with the last load being 54 fps. Am I looking for a large jump in velocity???...or as someone else stated, a decreased jump in velocity??? When you reach the max for your rifle, do the velocities decrease or increase greatly? I'm showing no real signs of pressure with my cases. I'm just interested in knowing how to use the chronograph to recognize when you are getting too hot. Thanks again!!![8D]
  • JustCJustC Member Posts: 16,056 ✭✭✭
    edited November -1
    Well the MV is a direct result of Pressure. So,..as the load jumps past book max loads, you can plan on being at maybe 60-63K PSI. Traditional pressure signs show up at 70K+ psi, so you are already far past optimum operating parameters (adding in a safety feature). Some types of rifling or match barrels may offer a jump in MV due to gas seal tolerances and lapped surfaces, but the PSI is what makes the MV. I start with a load a couple of maybe 3grs under max and work my ladders from there. I rather take the mid-range harmonic than the max harmonic just for barrel life if not for a safety cushion.

    The chrono lets you know about when you have gotten to a max load that is not approaching the 70K psi range that will show the pressure signs on the cases.

    The jumps were, as explained and as you understand, smaller when you are reaching a max load. The extra powder isn't doing anything. Think of it like this,..why can you burn almost 2x the powder in a 22-250 that you do in a 223 at close to max loads?? When you only have "X" volume to work with it only takes "Y" amount of propellant to make "Z" MV. So,..ifin ya have "2X" volume, then you would need roughly "2Y" propellant to make a proportionately lesser increase in "Z" (MV). The variable that controls that is the bore diameter. You can only physically fit so much expanding gas through a given dia. Once you start seeing small jumps, you space in which that particular propellant burns, is not increasing at a rate that allows similar velocity jumps as before. The load with THAT powder, in that chamber, in that barrel, is now inefficient on the high side, and is not building more MV, only a sharper pressure curve with high peak pressures. Remember, you can only fit so much of a given burn rate propellant out of a given bore dia and case dia, so the result is the higher peak pressures and lower noticeable exterior increases.
  • n/an/a Member Posts: 168,427
    edited November -1
    Thank you for the explanation...now I have a better understanding of how and why it works that way.[8D]
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