Lands vs. magazine length, browning A bolt 270

Discussion in 'Long Range Hunting & Shooting' started by fireworks, Aug 18, 2013.

  1. fireworks

    fireworks Member

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    Hello, I' m new to the forums here and need some input. I Lucked out and stumbled onto a most coveted box of 150 gr. Nosler ablr's. Anyhow, i've burned up 1/2 of it trying to find the sweet spot. Powder is rare in these parts so I am working lmr 7828. I discovered with these bullets my lands ( 3.454 verified 3 times, i know. Sounds way deep) is longer than my magazine capacity of 3.386. I fear the magic COAL may be longer than my mag. Anyone have any experience with these in an A bolt? I am thinking of switching to berger150 vld because of future availability. Hunting season is a little over a month out and I want to order a turret from leupold which has a 20 day turnaround. Any shortcuts with the 270 browning a bolt ( srainless synthetic stalker 22 barrel with boss ) would be appriciated.
     
  2. cohunter14

    cohunter14 Well-Known Member

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    What you are talking about is something that everyone has to deal with. If you load a round at or near the lands, chances are it is not going to fit in your magazine. So you just have to make a personal decision on what is more important, being able to load in the magazine, or being able to load them out towards the lands, which sometimes gives a little added velocity and/or accuracy. If you go to the Bergers, chances are you will be dealing with the same issues as those tend to like being out closer to the lands.

    Bottom line, if you want them to fit in the magazine, just load them to that max length and try to find an accurate load with decent velocity. If it's not important, then load out past that point. Good luck!
     

  3. MudRunner2005

    MudRunner2005 Well-Known Member

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    With my A-Bolt II 7mm Rem Mag I seat mine 0.005" to 0.010" shy of the magazine's max internal length. Then I adjusted my powder charges from there to find a good one that shot great with my rifle adjusted where everything is. You're is not a magnum, but Reloder 19 would be a good powder to try, as well.

    So far, I've found great loads with Alliant Reloder 19, 22, and H1000.

    I have heard excellent things about IMR 7828, and have a pound of 7828 SSC on my bench, but haven't used it yet. I will use it when I finish my current build.
     
  4. HuntFarther

    HuntFarther Well-Known Member

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    I have dealt with your problem a lot in the abolts. It usually is pretty easy to fix if you are handy at all with a dremel. Take your magazine out, slide the bottom plate off and pull the spring and follower out if did not already come. Then with a dremel and a high speed cutter, router out each side of the rivet in front of your magazine. There is a big spacer you will see what I am talking about. Usually can gain .200-.300 pretty easy.
     
  5. fireworks

    fireworks Member

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    Hunt the distance thanks for the tip. I assume you need to mill down the back of the spacer and re install so they glide?
    I loaded 3 rounds at 0.005 off, 0.010, 0.015 and 0.020 with 56 grains imr 7838. Low velocity all around but 57 grains will fill to the neck so I'm thinking the ssc may be the ticket. Forget any others, rl 22, 4831...4350... a snowballs chance in getting those but the imr 7828 in both forms are available in my area. Here's my trouble, no matter the seat, I can put two of three inside a dime but the 3rd is in left field, off 2 to 3 inches and it is not just the first or "cold shot". I clean after ever 3 round group. Two so tight you smile... one in siberia. I' m using standard remington lg. Primers due to area availability. Do mag primers such as federal 215 make that much difference? I've ran 70 rounds of a 100 round box and I fear I may not be able to luck onto another even IF I figure this out.
    I load every round by hand weighing with a didgital scale and use a lee handloader and caliper every load precise. Even went so far as to check my scope to see if it's taking recoil.
    Frustrated! At this point I'm thinking of switching to berger 150 VLD. Any further pointers are appreciated.
     
  6. theEMP

    theEMP Well-Known Member

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    I would go longer between cleanings. In my rifle (300 win mag model 70) it takes 3-5 rounds of fouling to get my velocity and groupings to settle down. Now I only clean every 50 rounds or so.
     
  7. fireworks

    fireworks Member

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    Tried the bergers by following the info on the sticky about seating. It likes them much better with the IMR 7828. But I think the seating will ultimately be between 0.015 and 0.020 which the reccomenfdations say to skip. They bounce from 0.010 to 0.050. Getting low to mid 2800's at 56 gr. with all seating reccomendations on the sticky so we'll see....

    Going to try the 7828 SSC at 0.015 and 0.020 and go with the 210 or 215 primer provided I can find any. With a little luck and some fine tuning on the brake I may just like these berger VLD's. I've heard of 3000fps out from the ssc in the .270, but the short barrel may be a shortcoming in achieving that, but I always felt that brake is a bit of an equalizer.
     
  8. HuntFarther

    HuntFarther Well-Known Member

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    No you dont have to take it out. Just be careful with your dremel and get the high speed cutters that will fit as good as you can along side the rivet. I most of the time end up taking off part of the sides of the rivets before things are done. One thing also to think of is you will need two cutter. They will eventually fill with the aluminum and quit cutting. With two you can switch and keep them cool to prevent this. All you need is two verticle channels one on each side of the rivets. It is not to tough to get it smooth, and works great.
     
  9. drbill

    drbill Well-Known Member

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    The brownings I have worked with all start flying after the 3rd shot. Maybe some don't but the ones I have dealt with all do. I would be happy with the 3. I used to be consumed with 5 shots on big guns.
     
  10. fireworks

    fireworks Member

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    Well I think I dialed it in. This gun likes the berger vld 150 gr. at 56.5 gr. Imr 7828 ssc at 0.020 off. 3 shots at 100 yds. You can can cover with a dime. One shot was actually partially inside one of the others. Not bad using a prone position bi pod. When I added up the three chrono's and devided by 3 the mean FPS was 2912 with a 22 inch barrel. I tried bumping to 57 grains and it started to separate and the mean FPS was not much better. Then I tried the 150 gr. Nosler ABLR. Ironically. The lands are virtually the same as the bergers so I went with 0.020 off as well but since they are a longer bullet I backed off to 56.0 grains. The group could be covered with a quarter but the wind was also picking up. Couple that with the fact I was again shooting prone off my bi pod I figured good enough. Here is the real irony... mean average FPS three shot group? 2912 same as the bergers? Go figure. I believe I could mess around with the charge and the BOSS brake and get the magical 3000 FPS but I don't see much point. This I feel is very good considering the 22'' barrel. Time to send the data and scope to leupold.