Drop in Velocity?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by bcraft1111, Jan 20, 2005.

  1. bcraft1111

    bcraft1111 Well-Known Member

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    Hello everyone, I am new to the Forum lots of good info on here . I was hoping to get some good advice. I got this virus called 30-378 itus ( I had to have a super gun ) 3 years ago. I knew nothing about reloading or custom guns. I did know that I wanted to be able to shoot deer as far as I coud see. In reasearching what caliber I wanted I ordered a Lazzeroni 7.82 Warbind model 2000 not the TRG-S. It has a 27 inch barrell 1-12 twist. I thought the faster the better. I read everything I could about reloading and started trying to work up a load for my new gun. My best load was 103.5 gr. IMR 7828 FED 215M primers Lazzeroni 150 gr. Coated X bullett AOL 3.575 This would shoot 3729 averaged over 50 shots with ES. of 22 FPS. It would shoot 1moa groups I thought that was great ( until I found this sight everyone here shoots 1/2 or 1/4 moa) so to get to my question I have taken deer with this rifle out to 536 yards with 1 shot kills. The other day at my farm I missed a doe at 527 yards. I did not come close she never even moved so I went to the range the next morning . I was shooting low. So I broke out the Chronograph. My shots were around 400 fps. slower, same temperature,same loads ,so I cleaned my barrell and made sure the copper fowling was out and tried again my next shots were 3261 fps and went up every shot 6 shots later I was at 3493. I think it is time for a new barrel. I have shot the gun about + or - 800 times. What do you think. Any other Ideas. If so who can I send it to to have a new barel chambered and installed in the same caliber. Also is there something about running these bullets out so fast that makes them not as accurate as other calibers. Like I said my gun shoots 1moa with every thing I try I cant get them any better even 168 match bullets shoot 1moa. Help /ubbthreads/images/graemlins/confused.gif
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bcraft1111,


    Fist off, welcome to LRH. Good to have you with us /ubbthreads/images/graemlins/smile.gif.

    Well, I am not a huge fan of the Lazzeroni rounds as a hole, on paper performance numbers are pretty impressive but unless you use his rifles and bullets, you will not reach these levels.

    In your case you are using his rifle and loads. I have always found case tolerances to loose with the Lazzeroni brass to produce consistant results at long range. While some has been very good others have been very bad and you never know what you will get from one box to the other and for +$2.00 per case, that is simply not acceptible in my opinion.

    As far as your velocity lose, its hard to say for sure, loosing 400 fps is a dramatic velocity loss for sure.

    The problem with some barrels and using Moly coated bullets or any other coated bullets for that matter is that sometimes it take a few shots for the velocity to stabilize and get consistant. This is one reason I do not like coated bullets except for rounds like the 50 BMG where controling copper fouling is a must.

    I would say there are several areas to look at.

    First off, with 800 rounds down the tube, you may or may not have a throat erosion problem. Really depends on how those 800 shots were fired. IF you kept the barrel relatively cool during shooting, I would be suprised if you were even half way to the end of your barrel life.

    Course with a case this size, if the barrel did get heated up, and was still shot when hot, the throat may be eroaded quite badly.

    This is the most obvious reason for velocity loss of this degree but it does not happen all at once.

    Some other factors that may be in play are:

    -Are you using a different lot of IMR-7828 then when you developed your first loads? If so this can often change velocity a significant amount in a case this large.

    -Are your X bullets being seated to the same depth as your first load. Not measured with Over All Length but at the full diameter of the bullet at the beginning of the ogive.

    The X bullet is extremely sensitive to seating depth, any solid bullet is. Even a change of .020" can dramatically drop or raise velocity(pressure). Another reason I do not use the X bullet, they are simply to finicky to shoot.

    Lot to lot variations in bullet shank length are common to a small degree, this can effect the distance from the full diameter of the bullet to the origins of the rifling, changing pressures from one pot of bullets to another.

    In my honest opinion, using a 150 gr bullet in a 30 cal magnum case with a case capacity of +100 grains is really a waste of alot of horsepower. Sure over 500 yards they are flat shooting as hell but past that they really start to drop off.

    If I were you, before I did anything as far as rebarreling the rifle, I would get a box of 180 gr Accubond bullets and test them with H-Retumbo. My brother has the Sako in the Warbird and with this powder and bullet was able to hit +3500 fps with groups ranging from the 1/2 to 3/4 moa range with great consistancy.

    Big cases are quite pissy with light bullets driven very fast. It seems anything of a weak link is magnified dramatically with a light bullet driven to very high velocities.

    Whereas the heavier bullets can be driven to very good velocities and just seem to settle the big cases down as far as an accuracy standpoint is concerned.

    I have never found the X bullets to be accurate enough and consistant enough for me to recommend them to my customers for use in the rifles I build for them.

    For a rifle like yours that cost what it did to only shoot in the 1 moa range would just about make a guy sick. This is not a shot at you at all but are you being effected by the recoil and blast of this big 30 magnum? Does teh rifle have a brake fitted to the muzzle?

    All of the things I have listed would probably not equal a 400 fps loss in velocity but the drop is just over 200 fps from your 3493 fps to your 3729 fps average to start with. This could easily be a result of a combination of the above listing.

    To be honest and you probably do not want to hear this but personally, if you rebarrel the rifle, I would drop the Warbird adn go with something else. Even the 30-378 Wby or a 30-338 Lapua Improved which is basically a 7.82 Warbird would provide much better consistany from a brass stand point and its cheaper to buy as well.

    Still before you do anything I would highly recommend dropping the X bullet and testing some Accubonds or something on that line. Load them off the lands about 0.010" to 0.015" to start with and then you can adjust the seating depth from there to see how they respond on target.

    You will not get the screaming velocity with this bullet weight but if your rifle did not hit 3550 fps I would be suprised using Retumbo. Also, if your rifle does not shoot them inthe 3/4 moa or less range I would say its time for a change in barrel.

    Couse if your rifle has never shot better then 1 moa, it may need to be torn down adn rebuilt with a quality accurizing job.

    The cheapest step is to try a new bullet, then go from there is that does not work.

    If it comes to rebarreling the rifle, find a smith that builds extreme accuracy rifles for a living. There are several on the board alone that do this including myself.

    I assure you, that if you ordered one of my rifles it would not leave the shop until it was cutting 1/2 moa groups and I know that is teh standard from the other smiths on this board as well. You should not have to settle for 1 moa groups from a rifle that cost that much money. We could build one for much less that would shoot far better I assure you.

    Good Shooting!!!

    Kirby Allen(50)
     

  3. bcraft1111

    bcraft1111 Well-Known Member

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    Fiftydriver, Thanks for info

    When you say the case tolerances are to loose do you mean in case weight.

    You are correct about the Moly coated bullets. My first shots after cleaning the barrel were 2 inches high every time and then they would come down to the point of aim after 3 or 4 shots this always bothered me.

    While we are talking new barrel, I spoke with Gary Schneider today who made the original barrell on the gun and he said that the #5 barrel I have on the gun may be " a little whippy" he sugested that if I did not mind the weight on my gun He would put the largest barrel the Mcmillian stock would hold. He also suggested shooting the non coated bullets.He thought that may be a problem with the 1moa groups.

    I found some 180 Accubonds today but no Retumbo.
    I also have no load data for the retumbo. But here is what I do have
    Max Load data from Lazzeroni
    180 Grain Nosler Partition 3.600 O.A.L. @ 70ºF

    DuPont Min Max F.P.S. P.S.I.
    IMR 7828 90GR 98.5GR 3464 66,100
    Alliant
    Reloader 25 94GR 104GR 3560 66,400
    Accurate
    8700 108GR 118GR 3481 66,700

    Can anyone use this to give me a starting point for Retumbo

    As far as the aol for that load If I use a fired case and tighten up the neck and insert the case in the chamber I come up with 3.760 with the accubond but I dont think any aol over about 3.650 will fit in the mag.

    The rifle has a break. I shot it the 1st 300 rounds without the break screwed on because I thought it would affect the accuraacy. Then I shot it with the break and you do not have to wory about me shooting without the break anymore.WHAT A DIFFERENCE A BREAK MAKES. Do not get me wrong when I say it shoots 1moa I have shot 3 shot groups with it less than 1/2 moa and my best group is less than 1/2 inch at 300 yards but the next group will be 3 inches at 300 yards. It just does not seem to be consistant.Maby it is the Coated X bullet.

    Again thanks for taking the time to help me with my problem.

    PS. If I deside to keep the warbird do you have a reamer to chamber the rifle.
     
  4. brian b

    brian b Well-Known Member

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    After reading Fiftydrivers post I agree with him on almost every point,if you do have to re-barrel get as far away from lazzeroni chambers and brass as you can,the first thing to trash can is Barnes x bullets (I live only 7 miles away from Barnes and wish I could support a local company but every time I have used there product I have been disappointed)
    the only point I disagree with Fiftydriver on is if you have to re-barrel he suggested a 30-378wby, I think even a 30-378wby is too much powder capacity for a 26" barrel. I have seen several 300RUM's that shoot faster than a 30-378 with far less powder. personally I will stick with my dirty old school 300wm.
    On this topic one thing I find fascinating is that I have several shooting friends that shoot the lazzeroni warbird and they have all been convinced (or brain-washed)to shoot 150gr bullets in this cartridge, I see no logic to it at all it would be like shooting a 200gr flat base in a 50bmg wasting all that powder going so fast with no B.C.
    If some one has a logical answer I'm listening
    B
     
  5. bcraft1111

    bcraft1111 Well-Known Member

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    Well here is mine. Not a very good one.

    Lazzeroni suggest the 150 x bullet and because I purchased a gun from them I thought they would know there guns better than anyone else. I thought that the 1-12 twist barrell was better suited for bullets under 168. Also the 150 had less recoil than the 180,s.


    /ubbthreads/images/graemlins/crazy.gif
     
  6. brian b

    brian b Well-Known Member

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    bcraft1111,
    Your 12" twist is perfect for a .308 win to shoot 150-168gr. bullets fast and efficient for the case size, a Lazzeroni warbird is a waste with these size bullets, it would be like sending Rosie O'Donnell into Mc Donald's for a 79cent hamburger, this girl needs a double quarter pounder with cheese (180,200+ gr)
    lazzeroni missed the boat but people buy into the leading edge hype like this and carbon fiber fluff barrels.
    have a good weekend B
     
  7. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bcraft1111,

    What I was referring to as far as loose tolerances in the brass really is not the weight of each case, or the volume. They seemed to be acceptible in consistancy for this large of a case, suprisingly.

    What I was referring to was body wall and case neck thickness. Some Lazzeroni brass I have measured in the case wall thickness just ahead of the solid case head varied by as much as 0.020" from one side of the case to the other. This is impressively bad consistance.

    Others would be identical but there were enough bad ones in the lot of brass I measured to show the true colors of the brass quality. About 15% would be off by this much.

    Case neck thickness also varied by up to 0.001" from side to side. Again, some was very consistant, others were pathetic in quality.

    When you drop that kind of money on each case, they better be quality, all of them!!!

    Schneider barrels are surely quality barrel, only bad thing the barrel is only as good as the machining in the rifle. I have not looked at enough Lazzeroni rifles to determine the quality of the machining in their rifles but this sounds like a mechanical problem to me.

    Gary does have a point to the barrel whip issue but at only 27" of barrel length, a #5 contour is a pretty stiff barrel espeically when using 150 gr class bullets.

    I use Lilja #6 contour 30" stainless barrels on my Extreme Sporters chambered for my Allen Magnum rifles and they print sub 1/2 moa consistantly and in the 1.5" range at 500 yards. True these are slightly smaller case capacities but they are longer barrels as well. I also totally free float the full barrel length and never have a problem with barrel whip, even in the 270 AM with the 130 gr bullets loaded to 3850 fps.

    I also use Lilja #5 contours on my conventional sporters for rounds such as the 300 RUM which is only about 50 to 75 fps if that behind the Warbird in equal length barrels, never had a problem.

    I will get you some load data from my brother that he developed in his Warbird with the 180 gr Accubond. He is getting some great groups out of his Sako.

    Of the powders you list, RL-25 would be the best, IMR-7828 can be temp sensitive and 8700 can be a little dirty until top pressures are reached. Rl-25 is relatively temp resistant and will produce good velocities.

    Retumbo will perform better then any of them in consistancy and top velocity and also temp resistant.

    How close are you seating the X bullet to the origins of the rifling? Unfortunately, I would not recommend getting any closer then 0.050" off the lands for safety sake.

    Your rifle obviously has a pretty long throat if the Accubond can be seated out to 3.760 on the shorter then full length Warbird case. Unfortunately this will effect accuracy unless the throat is cut to tight specs which by the sounds of it it is not.

    For curiousity sake though, I would seat the Accubonds as long as possible and feed them single shot and see how they shoot. IF your groups shrink dramatically, you may want to look into having a longer mag box fitted if possible.

    I do not have a Warbird reamer in shop but if you wanted a barrel chambered I would get one in.

    If your barrel will shoot well at times and not at others, I would say we are dealing with either a mechanical vibration consistancy problem or a load dimension problem such as bullet seating depth away from the rifling.

    Again, get a know accurate bullet and full test that first. The Accubonds already have a much better accuracy reputation then the X bullet ever will.

    I would also like to warn you about that load data you listed, When we were developing loads in my brothers Warbird, Retumbo was not yet released and RL-25 was the powder for this round. Well, he was blowing primer pockets out at 102 gr and only 3450 fps with RL-25. Sure this was in the Sako rifle but I would be cautious about using Lazzeronis top loads.

    HE lists his Warbird as faster then the 30-378 Wby which is about 15 gr larger in capacity then his case, physics are physics, this ain't possible without higher pressures.

    I will get you some safe load data to start with the 180 gr Accubond and Retumbo.

    Good Shooting!!

    Kirby Allen(50)
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Brian B,

    My comment about the 30-378 was only referring to the price of brass and what you get for your money. The 30-378 will outperform the Warbird and do it with slightly cheaper brass but my point was, much better quality Norma brass.

    I totally agree that in a 26" barrel, anything including the 300 RUM and larger is really to much case for the appropriate powders to be used. Now bump up to a 28" barrel and the RUM and Warbird will start running hard, as will the 30-338 Lapua. Get a 30" barrel and the 30-378 comes into its own as it can actually put that 120 gr case capacity to use.

    I have run my old 300 RUM side by side to a 30-378 Sako, both with 26" barrels. Both loaded to top acceptible pressure levels meaning that the addition of two more grains would start openin gup primer pockets on each load.

    Both used the 180 gr Ballistic Silvetip. The 30-378 churned up 3490 fps, the 300 RUM hit 3420 fps. That was like you said with 15 grains less powder.

    Velocity, like sex, SELLS!!!

    Lazzeroni knows this very well, thats the only reason he is in business still.

    I see this nearly every day taking with customers about my Allen Magnums. Especially the 257 AM. I tell them that it will drive the 130 gr Bonded Core FBHP with its B.C. of .550 to an honest 3650 fps and they just look at you.

    Tell them it will drive a 115 gr ballistic tip to 3800 or a 100 gr BCFBHP to near 4100 fps and they light up like a christmas tree.

    I will show them the pencil length 156 gr ULD rebated boattails for teh 257 AM with their B.C. of .820 and they simply ask how fast will it go. When I reply in the 3200 to 3300 fps range they just look at me and reply big deal, my 300 Win Mag will drive a 150 gr pill faster then that.

    At that point I know if they are going to compare a .820 B.C. bullet at 3300 fps to a .420 B.C. bullet at the same velocity, it will just be a waste of their time and mine as well to try to show them the advantages of a fast moving extremely high B.C. bullet.

    Again, velocity sells like hotcakes and out to 500 yards extreme velocity does work well I will admit as long as the bullet will handle the strains. Problem is, many extreme velocity rounds will not reach the grade for extreme range accuracy.

    I am with you, far to many get hung up on velocity these days.

    Good Shooting!!!

    Kirby Allen(50)
     
  9. bcraft1111

    bcraft1111 Well-Known Member

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    Thanks again for taking time to help me with this.

    I looked back in my journal and my aol for the X bullet was 3.632 I found the most consistant ES was at 3.575 AOL. at 3729 FPS.

    By the way I do not understand ( on the shorter then full length Warbird case ) What do you mean. I trim my brass to 2.790. Maximum case length is 2.810 is this what you are talking about.

    I have also seen some post about tightning the action bolts to 65# when I take my actioned barrel out of the stock should it be tightned to a specific torque when I place it back in the stock.

    Brian was talking about the heavier bullets. If I were going to rebarrel my rifle would you change the twist rate to something other than a 12 twist.to shoot the 180 grain at 3550 fps. And what if I used a 30 in barrel.

    I loved the Rosie thing Point taken. Thanks Brian
     
  10. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bcraft1111,

    What I ment by "shorter then standard" is that a standard full length magnum runs 2.850" in case length. The big magnums like the 30-378 and Rigby will run 2.910" long.

    I did not realize the Warbird was actually 2.800" long. Still it is shorter then the standard 2.850" standard magnum length brass allowing even more room in a conventional length Mag box.

    The X bullets generally need to get a run at the rifling to have any consistancy at all. Most often an X bullet seated to close to the rifling will result in pressure variations that show up in velocity spreads.

    This is really the opposite compared to a conventional bullet design. Unfortunately, while the velocity spreads may decrease with a longer jump to the rifling with the X bullet, often the group size increases.

    For a pillar bedded rifle, 65 in/lbs is the correct torque. For some composite stocks this is to much and they will get springy.

    This is far to much for a traditional wood stock, even a properly glass bedded stock as this amount of pressure will compress the wood significantly.

    I would recommend contacting Lazzeroni and finding out what torque specs they recommend for their rifle. If it is pillar bedded, I would use 65 in/lbs.

    If you do decide to rebarrel, the 1-12 twist will actually stabilize a 200 gr Accubond, I have seen it at 200 yards. The rifle was printing 1 1/4" groups at 200 yards. Not great but not bad either.

    Still, I would go with the standard 1-10 twist simply because it give so much great flexibility in which bullets you can use. There is no doubt the 1-10 twist barrels would stabilize any bullets up to a 220 gr Sierra MK or 210 gr Berger VLD even in the coldest temps.

    They also shoot the lighter bullets extremely well if you choose to do so. I am in total agreement with Brian about the use of heavy bullets in this class of round. Once you get to the point where you can get 100 gr of powder under a 30 caliber bullet, there is no point in using anything less then 180 gr bullets and yes, the 200 gr bullets are even a better balance for the Warbirds case capacity.

    My brothers rifle shot the 200 gr Accubonds very well with Retumbo and topped 3200 fps easily with this bullet. I believe he was puching 3300 fps with top safe loads.

    As far as barrel length, that is a personal preference. I like long barrels on my big game rifles and especiially my extreme range rifles. But I hunt in very wide open big country here in central Montana where a long barrel is more of an advantage then a disadvantage.

    If I were building myseld a rifle like around the Warbird, I would use a #7 contour Lilja 3 groove, 1-10" barrel and flute it with the large diameter .312" 50 BMG style flutes with a finish length of 30".

    This would give me the stiffness of a .825" diameter muzzle but with the weight of a relatively slim #6 contour. Properly set up I would imagine you would be getting +3600 fps with the 180 gr Accubond and groups would be in the 1/2 moa range or less.

    Better yet, you could drive the 200 gr Accubonds to 3400 fps and with a quality brake such as the Holland Quick Discharge brake, recoil would feel about like a 308 Win in a heavy rifle.

    That is just what I would do but again I like the feel of a 30" sporter rifle as all my shots are off bipods or bags. No offhanding for this kid.

    Have a good one,

    Kirby Allen(50)
     
  11. bcraft1111

    bcraft1111 Well-Known Member

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    I thought I understood that in the magnum calibers that every inch you add or take off a barrel takes or adds 50 fps, So where does it stop being efficient. why not a 32 in barrell or even 34.

    I called Jarret and talked to Jay Jarret and he said that in there signature rifle in 300 jarret they only use a 25 in barrel and that used all the powder and got all the velocity they could get out of it 3450 with a 165 grain. I do not quite understand this. Is there a trade off somewhere in this approach to barrel length.

    Oh by the way I did call Lazzeroni about 3 months ago about the action screws and they said just tighten them up. I asked if the needed to be tightened to a certian torque and the answer was " just make sure they are tight" I was just getting a second oppnion.

    Thanks for the Info.
     
  12. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bcraft1111,

    From teh testing I have done, what I have witnessed from actual velocity testing with the same load in different barrel lengths is that a round of this size will generally gain around 20 to 22 fps per inch of barrel added after 24" out to around 28". From there on out you will gain about 18 fps per inch.

    In a round like the 257 STW and my 257 Allen Magnum which have case capacities in the 85 gr and 100 gr range on the very small .257" bore, you will see around 35 to 40 fps gained goign from a 26" barrel out to 30".

    It simply has to do with the expansion ratio of the round and the length of barrel you are using. A round like the 257 AM has a very low expansion ratio so it will gain more velocity per inch of barrel then say a 257 Wby with its higher expansion ratio.

    Your Warbird has a pretty low expansion ratio but not exceptionally low for a 30 cal round. For thsi reason this round will not get a huge velocity gain per inch of barrel.

    The big 338 mags are even worse in this aspect. They will generally only gain 20 fps or so at the most per inch of added barrel.

    Heavier bullets will gain more velocity in long barrels then light bullets will, simply because they use slower burning powder.

    I certainly will not question anything that one of the Jarrets say about their rifles but I will say that by todays standards the 300 Jarret is a relatively small 30 cal magnum. Basically identical to the 300 Wby with its 85 to 90 gr capacity compared to the RUM with its 100 to gr capacity, the Warbird with its 105 gr and the 30-378 with its 120 gr capacity.

    SO of all these it will gain the least amount of velocity per barrel inch and it is far better suited to a 25" barrel then either of the others.

    These numbers are not a given by any means, more like an average. Some barrels will produce slightly more, others slightly less per inch.

    If your looking to gain 50 fps per inch of barrel you will be disappointed I am afraid.

    The way I look at it, the 300 RUM and the Warbird, in real world rifles using real world bullets are damn near ballistic twins when each are loaded to the same chamber pressure in same length barrels. They also will gain about the same velocity per inch of increased barrel length.

    I assure you that if you took a 300 Jarret and chambered it in a 38" barrel, you would most assurely gain anywhere from 75 to 100 fps over the 25" barrel length so, yes, they will keep gaining velocity, even out to 36" or so of barrel length.

    Jarret rifles are built for extreme accuracy, well all custom rifles are built for this but the best way to get extreme accuracy is with the stiffest barrel you can use. That translates into either a shorter barrel or a heavier contoured barrel. The Jarret rifles are designed to be relatively light weight and as such they use shorter barrels to get keep their barrels stiff.

    Again, accuracy is far more important then extreme velocity.

    Good Shooting!!!

    Kirby Allen(50)
     
  13. bcraft1111

    bcraft1111 Well-Known Member

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    Fiftydriver

    I was wondering if you were able to find the recipie for the 180 accubond and retumbo for the warbird.

    Thanks for your help.
     
  14. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Bcraft1111,

    I dod not forget, my brother has been out of town the last couple days. Supposed to be back tomorrow. I have a message for him to contact me with his load data.

    I will get it to you as soon as I get it.

    Sorry for the wait.

    Kirby Allen(50)