1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

patterns and chokes

Discussion in 'Shooting Related Threads' started by slayer, Jul 28, 2011.

Thread Status:
Not open for further replies.
  1. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,934
    Location:
    beautiful northern michigan
    The other day I was out patterning my shotguns and something came to light that made me scratch my head some. My new Browning bt threw a 28 inch pattern at 35 yds with the stock full choke. Next I shot a Beretta 390 with the new trap barrel [thanks Brad] and full choke. This pattern was approx 21 inches. Can't manufacturers get a little closer to the same diameter with these chokes? I'm using a modified choke on the Beretta to get about the same pattern as a Browning full. Can anyone let me know the reason for this disparity? thanks Bill Wheeler
     
  2. Bob Hawkes

    Bob Hawkes Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    3,916
    Bill, You are now a good candidate for a bore guage from Gary. Even then there are things that don't make sense, but you'll have a better idea of what you are really putting your shells through. You will probably be surprised when you compare the two guns and choke relationship. Have fun, Bob
     
  3. BAD 303

    BAD 303 Active Member

    Joined:
    Apr 13, 2006
    Messages:
    3,550
    Bill in my experience what you are finding is also what i have found many times. The tighter bore Italian barrels just seem to pattern tighter than the over bore barrels and they seem to also hold that tighter pattern at longer ranges. Also without a bore mic you really don't know what constrictions you are comparing on those two barrels. Just because a choke says full does not tell you how full. In other words one company may sell full chokes as .30 and another may sell .40 as full choke. The chokes need to be miced and compared to the bore diameter to really know for sure what your findings mean. If i recall that barrel was a .725 bore diameter.
     
  4. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    Heck, I have Full chokes with .030" constriction and Full chokes with .035" constriction.

    You don't need measuring tool to tell you what you have... just give your gun what it likes. Measurements are only one aspect of choke performance.

    MK
     
  5. miketmx

    miketmx Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,971
    The answer is simple: Browning rates their screw in chokes by the resulting pattern in a 30" circle and their Fixed chokes are rated by constriction the same as every other manufacturer. There is nothing wrong with Browning chokes provided you understand this difference.
     
  6. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,934
    Location:
    beautiful northern michigan
    I understand about chokes and constriction differences. My question is: why can't these manufacturers operate upon some kind universal standard? What's the purpose of some of them being so different from others as far as diameter?
    The average gun buyer shouldn't have to pattern his gun just to see what he's throwing out there. IMHO Bill Wheeler
     
  7. cunninmp

    cunninmp Member

    Joined:
    Nov 15, 2008
    Messages:
    639
    Bill,

    The nominal size for your later BT 99 is .742. Now here's the glitch----

    Browning says .742 + or - .005. So, just like Bad 303 said, without a

    bore mic you really don't know what you have. In another thread I stated what

    I found with all my Browning chokes. Out of a dozen of them, only one was

    within spec. Terrible patterns. All of them were more open then marked

    on the tube.

    To give you a starting point you'll need to have a dial caliper to measure

    the inside diameter of your chokes. We'll assume you have a .742 bore.

    You should get the following measurements:

    Full = .707

    Lt Full = .712

    Imp Mod = .717

    Mod = .722

    Lt Mod = .727

    Remember, without knowing your exact bore size, this will just get you

    in the ballpark. I solved pattern problems with my BT 99 Golden Clays by

    going to all extended Angle Port chokes, but any very good after market

    choke probably would have given me the same results. Now on paper it

    produces very nice patterns.

    My Caesar Guerini, like Bad 303 said, patterns much better then my BT.

    It has a .735 bore with about a four inch forcing cone. BT has about

    3/4 to 1" forcing cone.

    I could write about this for hours but am out of time.

    Remember what I have given you is only a starting point. Nothing takes

    the place of spending some quality time on the pattern board. Whatever

    you decide to do, as long as the bird breaks, thats what we're all after.

    Mike C.
     
  8. Twinbirds

    Twinbirds TS Member

    Joined:
    Jan 29, 1998
    Messages:
    1,144
    question is why should they? differences in guns is what it is all about. bascially it comes down to percentage of choke to bore ratio, smaller bores need less constriction larger bores need more. what you see on the pattern board can be deceiving and is never the same shot to shot. Shotgunners play the percentage game. Without seeing what you have going, I'd buy a Briley I/M and shoot it anywhere on the concrete.
     
  9. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    <blockquote>"...My question is: why can't these manufacturers operate upon some kind universal standard? ..."</blockquote>Why should they?? The government isn't involved and the market is small.

    It's a free market. There's no business advantage to be gained by the manufacturers complicating their lives by imposing restrictions and standards on themselves that won't boost their bottom lines. And there's definitely no advantage in everyone making the same thing!

    Besides, most gun makers will tell you the bore diameter of your gun and most choke manufacturers do or will tell you either the bore size or constriction of their chokes. Since there's more to the performance of a choke tube than the size of the hole, that's still not all there is to finding the choke that gives you the performance you want from your gun/ammo combination.

    MK
     
  10. JerryP

    JerryP Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,753
    slayer, how are you arriving at the size of these patterns? You can't be including every pellet.

    "The nominal size for your later BT 99 is .742"
    mine measures .737 3 inches from the choke. lots of variables.
     
  11. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,934
    Location:
    beautiful northern michigan
    As I mentioned in a previous thread, I patterned the guns at 35 yds and started measuring when I had at lest two pellet holes near each other. I didn't measure the "fliers". An interesting side note: My midas grade extended full choke didn't pattern nearly as well as the flush full in the Browning.
     
  12. W.P.T.

    W.P.T. TS Member

    Joined:
    Jan 29, 1998
    Messages:
    8,371
    I have found over the years that many guns (chokes) will throw totally different patterns just by shooting different shells or shot in them ... I have 2 Model 12's that are almost identical when you measure the barrel dimensions but pattern like day and night ... The one likes Heavy 7 1/2s and the other seems to like Heavy 8's based on what the patterns are showing ... I'm not a fan of shooting multiple patterns and pretty much take it for what I see the first time and go from there ... The Static pattern is only going to tell you so much as opposed to a multi dimensional pattern anyway so at some point it all becomes guess work or should I say Educated guess work anyway ... I firmly believe no two shells are going to pattern alike because they are much like snowflakes and there are no two shells exactly alike and the pattern differences prove that point ... WPT ... (YAC) ...
     
  13. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    <blockquote>"My midas grade extended full choke didn't pattern nearly as well as the flush full in the Browning."</blockquote>How many times have you tested the 2 chokes?

    Are you using factory ammo or reloads? <UL><LI>Factory<ul><li>How many brands have you tried?<LI>Different shot loads?<LI>Different shot sizes</UL><li>Reloads<UL><LI>Shot loads?<LI>Wads?</ul></UL>Each difference has its own effect. You may well find that changes in components will reverse the results you saw previously.

    MK
     
  14. cunninmp

    cunninmp Member

    Joined:
    Nov 15, 2008
    Messages:
    639
    Slayer,

    Interesting about your Midas choke. They used to be made by Briley.

    I have one in Lt Mod and it throws great patterns.

    Got me curious, are you using the same type shell for your observations??

    Mike
     
  15. hmb

    hmb Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,442
    It's all about quality control, some manufactuers have very little. HMB
     
  16. Steve W

    Steve W Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    5,118
    Location:
    Los Angeles
    Every gun shoots differently with different loads. Even from the same manufacture.

    This creates a market for barrelsmith, they charge you a fee sometimes more than a cheap barrel's worth to make your factory barrel pattern well.
     
  17. W.P.T.

    W.P.T. TS Member

    Joined:
    Jan 29, 1998
    Messages:
    8,371
    The inconsistancies are not only the gun but the ammo also, once you have fired a shell you may of shot the only perfect shell you may ever have or ever get so why waste it on a pattern sheet ..? The very next shell out of the same box will not pattern even close to the privious one ... Think about it ... WPT ... (YAC) ...
     
  18. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,934
    Location:
    beautiful northern michigan
    I'm using a AA hull, w209 primer, claybuster wad, 18 grains of red dot and 1 1/8oz of magnum 8 shot for every pattern.
     
  19. JerryP

    JerryP Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,753
    "started measuring when I had at lest two pellet holes near each other."

    slayer, that is meaningless. tells you nothing. Draw a 30 inch circle around the densest part of the pattern on each of the two patterns you mentioned. Count the holes in each and that will give you an idea of which choke it tighter. Even then you will need to shoot more than a couple to see an average.

    wpt, are you saying you deduced that one gun likes heavy 8's better than 7 1/2's after one pattern?
     
  20. W.P.T.

    W.P.T. TS Member

    Joined:
    Jan 29, 1998
    Messages:
    8,371
    JerryP,

    It was actually several patterns even though I was convinced after about 5 of them, I continued to try to prove that it couldn't be ... Now, I didn't lay them down and count every pellet but eyeballing it seemed to be good enough ... I'm not a big fan of patterning guns for anything other than point of impact compared to point of aim ... WPT ... (YAC) ...
     
Thread Status:
Not open for further replies.