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Thread: 30BR vertical

  1. #1
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    30BR vertical

    Fellas i have been shooting my BAT 3 lug Robertson's stock Krieger 18 twist 30 br the last couple days and im a bit discouraged. .3's is about as good as i can muster at this time. Im seeing a bullets worth of vertical in just about every group. I am using 4198 and i have went from 32.5gr all the way up through 34.8gr using 118 and 112 bibs. I have tried 3 different seating depths but it doesnt seem to change much. I have seated at full jam 10 off full jam and 20 off full jam, even a group at 28 off full jam. ( I call jam the max length before bullet to lands push back) Im trying not to do to much at once. I started going through the powder charges with the same seating depth. then i change seating depth and go again. The rifle will put a few bullets into the same hole on occasion but the final result is a bullet of vertical not much more. Its not real bad but i think this rifle should shoot low .2's rather than mid .3's. the winds were a little tricky but manageable. Not real sure what to try next. maybe a different powder? Im using lot 4757 of 4198.
    Today was a bit better as i increased the powder charge to 34.8 after seeing so much vertical yesterday. So far the best i can tell from the two days of shooting is that the rifle shooters better with the 34.8 and the 118 bullet back about 25 off full jam. Do you think the bullet is still in the lands at 25 back?
    I know its hard to suggest anything by all this, i just thought it might make good conversation. Ill get it figured out!! I did shoot a 1 and a low 2 today so it is looking up, i just wish i could get the vertical out. You know and maybe its that the 30cal bullets make the groups look like there's more vertical than there really is?? All in all i think a low .2 agg is reasonable, but im not there yet. Thanks fellas!! Lee

  2. #2
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    Smile Lee ...

    Quote Originally Posted by skeetlee View Post
    Im seeing a bullets worth of vertical in just about every group. I am using 4198 and I have went from 32.5gr all the way up through 34.8gr using 118 and 112 bibs. I have tried 3 different seating depths but it doesn't seem to change much. I'm trying not to do to much at once. I started going through the powder charges with the same seating depth. Then I change seating depth and go again. The rifle will put a few bullets into the same hole on occasion but the final result is a bullet of vertical not much more.

    Not real sure what to try next. Lee
    You didn't say anything about which BUSHING you were using for NECK TENSION.

    Are you using a .326, 325, .324, or a .323? I suggest trying the .325 and the .324. [The 30BR likes a lot of neck tension.]

    When I was getting small cloverleafs with the .325, Randy Robinett suggested I try the .324. When I did, everything tightened up real nice.

  3. #3
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    Vertical

    I don't know if you're shooting off a bipod or rest or free recoil, etc. but it may not be your load* but shoulder pressure or a too hard front bag (something mechanical).
    *What is the extreme spread in fps of your loads? If you don't have pressure yet try going up a little more, since you said your last increase was an improvement. You should go from vertical to horizontal when you pass the node. Just thoughts. - nhk

  4. #4
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    X 2 re: neck tension. Mine always liked a lot of jam and a case full of N130 or Re7 with a .325 bush but REALLY started to work when i went to a .324 bushing. Hard to believe that such a small change would have such an obvious effect, but it did.

    Darren

  5. #5
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    I guess neck tension preference is something that varies among shooters. With my 30BR, (you know how it shoots), I use a rather light neck tension. Actually, it amounts to just a tad over .001.The bullets are probably .005 into the lands. The die has no bushing, measures about .326.

    I have no idea why I get away with such a light neck tension, both the 17 and 18 twist barrels shoot equally well in the Rifle.

    One thing you might check is the firing pin spring fall. Action builders seem to like a light spring, mainly so the actions will open with just a fip of the finger, and everybody will marvel at the smoothness. But, that is a source of erractic ignition, I would use no less than 22 pounds............jackie
    Last edited by jackie schmidt; 08-01-2010 at 07:51 PM.

  6. #6
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    If you are using anything over 34.5 grains of H4198 and not jamming your bullets, you are cramming the base against the powder column, and that will change each OAL. A larger bushing only makes it worse. I am using a .323 bushing and if I load more than about 2 days before a match, the OAL's differ. I jam my Euber 118's .013 and that works for me. No vertical.

  7. #7
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    Thanks fellas there is a couple good thoughts here. I am using a .325 as its the only one i have. i will buy a .324 and try that. Also i may be still fighting this rifle a little. I have a NF 42 power scope and the darn thing keeps hitting my eyebrow if i dont put the proper shoulder into it. The rifle is set up for the weight of the NF and tom glued the pad on so im not real sure if i can change it and still have the proper balance, but i am going to look into that. I love the scope but the eye relief is just to short for the recoil this rifle has. I will say that i was being very carefull and really paying attention to how much or how little shoulder i was putting into the rifle while shooting. I was also keeping my head still and really trying to shoot good groups.
    Just about everyone says the 30BR like a lot of jam so maybe i need to try that as well. Im my mind to much Jam is stress on the cartridge so i dont like to do it, plus i have found that all the ppc barrels i have had like the bullets about 5 to 10 off full jam. Maybe im not thinking about all that the way i should? I figure if the action doesnt need any stress then why would the cartridge what stress on it?? Lets see what else? Oh, Im already at 34.8gr of powder should i try to get 35gr in the case? Seems like a lot, but i havent had any pressure signs, now i think about it. The load would definitely be compressed. We will get it figured out one way or another! Thanks a bunch! Lee

  8. #8
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    I would also suggest trying to jam deeper into the lands. The 3 30br's that I have shot all liked a .025-0.030 jam with a .324 bushing. I got some good input from Al Nyhus and Randy, and tried that recipe in each of those guns with good success. I was very recoil sensitive and had to go to the Past recoil pad and a pin style of shooting and have had some success with it. It will induce some vertical if I am not careful with my technique, but my scores/groups have become much more consistent since I switched styles.
    Mike
    Last edited by savet06; 08-01-2010 at 07:50 PM.

  9. #9
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    Some barrels won't let ya reduce the vertical. One that I had would do no better than a bullet of vertical until I had a tuner installed. I was easily able to take the vertical out with the tuner while using the same load paramaters.

    It has been my experience that the majority of my 30 cal barrels shoot best at .006 into the lands. That .006 is measured from where one can barely see land marks on the bullet. I manitain that one is simply lucky finding a tune if they just jam their bullets in without knowing precicely where the bullets are positioned.

  10. #10
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    I have read a lot of different post were fellas talk about jamming bullets. I always wonder what there definition of jam really is. The same goes here on this post. To me jam is the max length i can seat a bullet before the rifling pushes the bullet deeper into the case. At least thats what i think happens?? When someone suggest to jam 30 thou what does that mean? Does that mean your placing your bullet 30 thou past push back length?? You know maybe im not even thinking about any of this in the proper way. Is it true that you can only seat a bullet so far out before the rifling pushes the bullet deeper into the case, or can you actually (with enough neck tension) push that bullet farther forward into the rifling?? I guess i figure that i have about .030 of land contact point before i am completely backed out of the lands and i have found on all my rifles that somewhere with in that .030 (approx) area is where the rifle shoots best. I have been shooting some of George Ulrich little uglies BT bullets in my ppc and they like to be in the lands about .005 and it also seems to me this 30BR is about the same?
    I have a real good friend here that i talk to on the phone quite regularly and after talking all this over with him, im first going to move my scope forward (so i dont keep getting hit) and im going to move the front/rest bag back down the stock further. I may also try a softer front bag. I may have an issue with the stock acting in a spring board type situation. One other thing i discovered was that i was really putting the squeeze on the sides of the stock to try and slow the recoil down, and that could cause some vertical as well. So i have a few things to try. I appreciate everything you fellas do for me, and im glad to be a part of all this. Have a safe week, and i will post after i get a chance to go shoot again! Lee

  11. #11
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    Smile Lee ...

    I shoot my 13.5 lb Heavy Varmint 30BR ... Free Recoil ... just as I do my LV 6PPC. Both have provided excellent results with this method.

    When you hold your 30BR, how do you measure your shoulder pressure? How much pressure do you vary between holds?

    That's the problem with holding. I was never good at judging hold pressure so I've always used Free Recoil. Much easier. More consistent.

    Here's something to look at for more vertical solutions: http://www.6mmbr.com/verticaltips.html.

  12. #12
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    The bbl on my Metal Mayhem was bought used. I used my split case as shown below to locate the lands. Then I set the seater to put the bullet app .008" into the lands. .325 bushing. I use 33.8 gr of H4198 as this load shoots great in my other 30BR. I use 112 Cheeks bullets. The first time this combo was ever fired was in a group match back in March. I was low on 2 targets and 2nd on 3 more [ 100/200 group match ]. I anneal the cases after about 5 or 6 firings.


  13. #13
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    Skeet, if you are having trouble getting the powder in the case so that it does not push the bullet back out, just get a 8 inch drop tube and trickle slow. I get my 35+ grn load in my cases with no problem. And that is not a hot load. I have cases that have been fired 30+ times, with no problems.

    There are a lot of ideas here, but the simple truth is you probably do not have the Rifle tuned as of yet. Both of my barrels, (1-17, 1-18), shoot at just over 3000 fps with the 112 BIB. 30's do stay in tune quite well when you finally find the sweet spot, but you do have to find it.

    Many score shooters get lulled into thinking that their 30's are shooting really great because they can hit 18 X's, when the truth is they are actually sitting on a .280 tune. You are doing it the right way. Until you see a sub .200 agging capability, it isn't right.

    There is probably nothing wrong with your bags, your Rifle handling, or any of the other things that shooters blame poor performance on, when the reality is the Rifle is simply not quite there yet............jackie

  14. #14
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    Rifle dynamics

    Lee,
    It could be that the dynamics of your rifle need tuning. A ladder test would determine if this is a problem. Load two sets of rounds from say 33 gr to 35 gr in 0.2 gr increments. Shoot each round at a separate bull to make it easy to measure its vertical position. (Two sets allow you to see if the results are repeatable.) If you get a graph like below, you are in luck. Use a load in the middle of the range that minimizes vertical, like 33.8 gr or 34.6 gr in this graph.

    If you don't find any flat "steps" in the ladder, first try varying how much the forend overhangs the front rest and how close the rear bag is to the toe. If these don't work, then try moving weight around. Try moving weight from high in the butt to low in the butt. Try weight in the forend. Try a DanH "possum belly." (I'll let Dan explain this innovation.) Try heavier or lighter scope and rings.

    To put rifle dynamics in perspective, consider that an ES of 50 fps would be pretty good for a 25 shot match. A 50 fps difference will cause 0.1" of vertical at 100 yards for typical 30BR ballistics if the barrel is stationary. If the barrel is swinging up at the right speed when the bullet exits, this vertical can be essentially eliminated. If the barrel is moving the wrong way, the vertical could be doubled or tripled. The ladder test is a good tool to see whether the dynamics of your rifle are working for you or against you.

    Cheers,
    Keith
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  15. #15
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    Smile Jackie ...

    Quote Originally Posted by jackie schmidt View Post
    Skeet, if you are having trouble getting the powder in the case so that it does not push the bullet back out, just get a 8 inch drop tube and trickle slow. I get my 35+ grn load in my cases with no problem. And that is not a hot load. ... jackie
    In addition to the long drop tube,

    isn't a good part of the reason you're able to get more powder into your cases is because you blow your case necks out and forward when fire forming [instead of mechanically necking them up which shortens them]???

    And, with this method, and a longer reamer that provides a chamber length of 1.550" and hence a longer trim-to length, you arrive at a finished case that provides more powder capacity???

    Last edited by abintx; 08-02-2010 at 01:00 PM.

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