338 ulta verses 338 kt mag

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by gary brezinski, Sep 4, 2001.

  1. gary brezinski

    gary brezinski Member

    Messages:
    23
    Joined:
    Jul 7, 2001
    sir,
    what is the difference between these when using 250 and 225 grain bullets.
    elmer keith said th kt delivered a ton or so energy to 600 yds using 26 in barrels.
    can i do the same with the 338 ultra?
    what king of acc can i expect from a factory ultra in the 338 cal?
    gary b
     
  2. Guest

    Guest Guest

    Gary,
    I just received a new Remington 700 Sendero with a 26" barrel in the 338 Ultra Mag. I have tried three different powders to date Rel 25, H1000 and H870 with the Sierra 300 grain MK. The average high velocities from safe loads have been from 2565 fps with H870 to 2688 fps with both Rl25 and H1000. These are not hot loads in this rifle. All three powders have shot the 300 MK into groups from .458" to .800" at 100 yards. This rifle is very accurate but it does have heavy recoil. This weekend I will work up loads with the 250 Sierra and the 210 Nosler.

    My son and I shot accross the canyon out to 910 yards with the 338 Ultra this past Sunday. Ranges were from 620 to 910 yards with the 300 MK. The 338 Ultra hits a whole lot harder than my 300 Win Mag. The 338 Ultra had no problem at these distances using the ballistic data spreadsheet that Peter Crohelm (sp?) and Dave King have developed. This spreadsheet calculates that the 300 MK with a BC of .768 and started at 2650 fps, at an altitude of 8800', has 2408 lbs/ft of energy at 1000 yards.

    I am not familiar with the 338 kt so I can't comment on the comparision between the two. I am happy with the 338 Ultra. Hope this helped you a little.
     
  3. Darryl Cassel

    Darryl Cassel Well-Known Member

    Messages:
    1,757
    Joined:
    May 7, 2001
    Guy
    Run the ballistics for the 300 Sierra MK at .800 BC.
    It will work out much closer to your drop charts at the speed you are running the bullet.
    We are driving the 300 gr much faster from our 37 1/2" to 40" barrels and found that the drop charts were off when using the lower BC.
    Oehler reports the 300 gr 338 MK at .800 BC.
    A 300 gr will most certanly hit harder then the 30 cal coming from a 300 Win mag.

    You have a great place to reach the new 338 out. We go through that part of Colorado on Rt 70 on our way to the Aspen-Glenwood Springs area every year.

    Later
    Darryl Cassel

    [ 09-05-2001: Message edited by: Darryl Cassel ]
     
  4. Guest

    Guest Guest

    Darryl,
    Thank you for your input. I had read your previous posts and Dan Lilja's comments concerning the actual BC of the 300 MK. We used .798 to compute our drop chart for the 338 Ultra and it matched the actual shooting data we collected last Sunday. Peter's and Dave's excel spreadsheet is the most accurate cacluator that I have used. The price was right too, thanks again to them.
    I do have a question that maybe you could share some insights on. I think the rifle is dumping rounds to the right at longer ranges. We are shooting from bags and we have a scope level. We zeroed the rifle for the 300 MK at 100 yds and checked the velocity of the load (90.0 gns/H1000/Fed 215GM/once fired-neck sized cases for av-2688 fps & S/D of 24). At 620 yds the bullets were impacting 3" right. We had to progressively add more left adjustment into the scope as the ranges increased. The farthest distance that we shot was 1610 yards. With the scope set at 50 1/2 moa up and 0 windage, the bullet impact was right on for elevation but 24" and 36" right for two rounds. It was an absolute calm day with no wind and all ranges fired showed the same horizonal dispersion. What should I check for in the rifle/scope system? And what about the load? Or is this normal behavior from a factory rifle and barrel?
    Thanks for the compliments about Colorado. I feel very fortunate to live here with all the outdoor activities that abound, especially elk hunting. You were probably refering to the Loveland ski area on I70 from my signature. We live in Loveland (the town) north of Denver. My wife and I (the kids too...) own land a few miles north of Rocky Mountain Natl Park. This is where my son and I hang out and shoot. Great hunting and fishing and it's our backyard.

    Thanks in advance for any thoughts.
     
  5. Darryl Cassel

    Darryl Cassel Well-Known Member

    Messages:
    1,757
    Joined:
    May 7, 2001
    Hello

    Thats normal for the twist rate of the rifle and you should figure it into the scope setting when ready to fire at the extended ranges.

    That's another reason we shoot a sighter round either in front 100 yards or behind 100 yards or over the animal to make the correctins of wind and rifle twist variations.
    I'll bet your son makes a good spotter on the long shots?

    My wife and I are getting the gear ready for the trip out your way at the end of October.

    Yake care
    Darryl Cassel
     
  6. Dave King

    Dave King Well-Known Member

    Messages:
    2,362
    Joined:
    May 3, 2001
    Guy

    Bullets impacting right... If you're sure of your data and shooting what (theoretically) you may be seeing is Magnus Effect/Force or I believe it's also called 'spin drift' and perhaps some Coriolis. Coriolis could easily be several inches at 1000 yards to a fairly larger value at 1600 yards.

    Coriolis can be calculated based on time-of-flight, location on the planet, and direction of projectile travel.

    Spin Drift is something I don't know how to calculate.

    There are ballistics experts that frequent this site and perhaps they can tell us how to calculate spin drift.

    There are huge debates about these effects and it nearly always makes for a lively discussion.
     
  7. Guest

    Guest Guest

    Darryl and Dave,

    I will input this info into our "real data" drop chart based upon your thoughts. I am assuming to add the correct windage moa to adjust for the bullet impacting right first, then add to that setting the ammount of moa nesessary to correct for the current wind value. We will re-verify this data on Saturday. If we do try LR hunting this November, we will fire spoter round(s) first. Thank you for sharing your knowledge.

    My son is a good spotter AND he shoots much better than I [​IMG] . Dang kids.....

    Good luck next month.
     
  8. the444shooter

    the444shooter Well-Known Member

    Messages:
    445
    Joined:
    May 8, 2001
    Guy:
    Any luck with the 210 Nosler yet? I just bought my .338 Ultra in the BDL custom setup, and chose the 180gr Nosler Ballistic Tip for Antelope and Deer (can't go wrong with a 180gr pill going 3500fps) and the 210gr Partition for Elk. I decided to go with the 210gr because I'm hoping for more dramatic impact results because of the higher velocities...sometimes the heavier partitions hold up TOO well, almost acting like FMJs. I will be sighting mine in this weekend, and taking it out for antelope on Sunday with the Ballistic Tips...I'll let you guys know how they turn out. In the mean time, Guy, and everyone else, if you have any experiences with the 210, 225, or 250gr Partitions, please share them.
     
  9. Guest

    Guest Guest

    Ben - I have only fired the 210 Nosler Partition and the 180 Nosler BT with Reloader 22 to find the approximate pressure/velocity levels (one round at one grain intervals). The 210 went 3205 fps with no pressure signs while the 180 BT went 3375 fps with an ejector mark on the case. Accuracy with both bullets was a little less than 1 moa@100 yds. I don't think I can get close to 3400 fps with the 180 BT in my Sendero w/ a 26" barrel, so 3500 fps may be too optimistic for that bullet. But I don't know that for sure. You can find more info at www.accuratereloading.com. Look under Forums, Big Game Hunting, 338 Ultra? for the data that I posted.
    My family and friends all hunt with various 338's and we all use the 210 Nosler Partition for deer and elk. It's penetration was more than adequate on the larger bulls that we have killed, plus, on deer it doesn't seem to do too much damage to the meat - for a 338 caliber bullet. Through the years we have all tried the 250 Nosler on elk and the performance was excellent also. We just prefer the 210's for elk. IMHO on game larger than elk I would bump up to the 250 Nosler in my 340 Wby.
    I am interested in what your loads work out to be in your 338 RUM. Please post some info including your fun with antelope this coming weekend. A friend called me this morning and told me that he took a 14 3/4" antelope this past weekend. That is a pretty good antelope for Colorado.

    Good luck this weekend
     
  10. the444shooter

    the444shooter Well-Known Member

    Messages:
    445
    Joined:
    May 8, 2001
    Guy,
    Nosler posted load data on their website for the 180-200gr Ballistic Tips and 210-225-250gr Partitions. With RL22, the 180gr was screaming out at 3500+fps. Max load with RL25 had the 250gr Partition pushing 3000fps. The 210-225gr partitions were hovering between 3200-3100fps respectively.
     
  11. Guest

    Guest Guest

    Just looking at Nosler's data singed my eyebrows! Pretty fast velocities for the 180 BT. I don't think I can reach that velocity with my rifle. I was using 97.0 gns of Rl22 for 3375 fps and that was showing pressure signs. Maybe I should take a closer look at the 180 again.
     
  12. wannabee

    wannabee Active Member

    Messages:
    40
    Joined:
    Oct 19, 2001
    guy, how did the shooting go w/ the 210 AND 225 gr bullets.I can't make up my mind between a Sako TRG-S in 338 Lapua and the Rem sendero that you mentioned. Case capacities are very similar, the two guns cost about the same, accuracy is the only variable I'm yet to get info on. Thanks SC
     
  13. Guest

    Guest Guest

    wannabe - we have not been out shooting since my last post. The 210 Nosler might in my 338 RUM might better my 340 WBY velocities by 100 fps or around 3200 fps w/ RL22. Accuracy was under 1 moa. I use an excel spreadsheet for logging my load data. I input group size (when available) into the load data info and let excel track the averages. So far the rifle is still shooting in the 1/2 moa range at 100 yds for all the loads we have fired through it. All we have done to the rifle is to lighten the trigger to 2 1/2 lbs.
    We have not used any 225 grain bullets yet.