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Perazzi barrel bore diameters

Discussion in 'Shooting Related Threads' started by mette56, Mar 31, 2013.

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  1. mette56

    mette56 Well-Known Member

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    For ALL MX and TM barrels (including older and newer models) with less than a .740 bore...can these barrels be opened up to a .740 bore?

    milt
     
  2. W.P.T.

    W.P.T. TS Member

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    I got to think Wilkinson would be one of the professionals to ask about that ... Mine were .735 and opened to .740 and .032 choke (restriction) smokes targets from long yardage, just not enough of them ... I know its not me, thats for sure ...

    I looked at the paper work that came from the factory on my Perazzi, it said the chokes in all barrels are .736 ... I measured them with my bore gauge and they measure .736 in the over/under and .740 in the single barrel which has been work on by Wilkinson, now it measures .740 with .032 restriction ... WPT ... (YAC) ...
     
  3. drgondog

    drgondog Member

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    Short answer - yes. Longer answer is that if you were ever in Italy with an over bored barrel larger than 18.4 or 18.7 they would force you to reproof it.

    When you lengthen forcing cones you are opening up the barrel at its weakest point/highest pressures - that would also cause a re-proof in Italy.

    Both are done all the time - taht doesn't make it sound engineering..
     
  4. miketmx

    miketmx Well-Known Member

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    18.4 mm equates to .724 bore and personally I would not go over .735 or .010 but that is just my opinion. I still get very nice patterns with 18.4 barrels and I am not sold on the overbore idea.
     
  5. drgondog

    drgondog Member

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    I'm with you Mike.
     
  6. semperfi909

    semperfi909 Well-Known Member

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    There is no documented evidence that big bore bbls do anything different than a standard sized barrel.

    Just consider that a 12ga is a way overbored 16ga and how much better is that in terms of patterns?

    There were "chamberless" .800 bore 12ga guns at the turn of the 19th Century. Wonder why that never caught on?
     
  7. zzt

    zzt Well-Known Member

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    Milt, the answer is that many Perazzi (and other) barrels should not be opened up to .740 or larger, because the wall thickness is not sufficient. I once owned a barrel modified by a very prominent smith where after 25 rounds the barrel warmed up and changed POI.

    My current Perazzi barrels were tuned by Kerry Allor. He does have a minimum wall thickness that he will not go under no matter what. Evidently there was more than enough meat in my barrels because the O/U bores ended up at .740 and the unsingle ended up at .745. I have many thousands of rounds through them and they are stable and consistent. I am quite happy.

    If you are considering barrel work, I'd suggest you talk to your potential smith so that you understand everything about the process.
     
  8. bossbasl

    bossbasl Well-Known Member

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    Reputable Perazzi folks (e.g., Giacomo) will not lengthen forcing cones or overbore Perazzi barrels. Most common reason given is concern for mid ribs loosening and the barrels as delivered by Perazzi are designed to function best as delivered.
     
  9. Barry C. Roach

    Barry C. Roach Well-Known Member

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    Milty. Having a single barrel power honed will not be a problem as their ribs are silver soldered. The "side ribbed" OU's are soft soldered and the honing can loosen from the heat.
     
  10. mette56

    mette56 Well-Known Member

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    Some great info...thanks! Should have added that my only reason and concern has to do with recoil. Since P has produced factory .740 bores...does that mean those barrels had more wall thicknes than say the .724's?

    Thanks again...

    milt
     
  11. semperfi909

    semperfi909 Well-Known Member

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    Bore diameter has NOTHING to do with recoil. A nine lb 20ga shooting a 1200fs 1oz load recoils JUST like a nine lb 12ga shooting a 1200fs 1oz load. It is only otherwise when calculated with Hogwarts Physics.

    Bore jobs are hype jobs and Perazzi was just responding to market hype with the bigger bores. Just like all the other makers that did the same thing. I refer you to the rise and fall of porting as an example.

    Latest I've noticed is that FWB's (my new shorthand for F'd With Barrels haha)are not the most sought after. I could be wrong on that but more adverts seem to be interested in UnFWB's.

    besta luck
     
  12. Steve W

    Steve W Well-Known Member

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    milt, yes, Perazzi factory big bore (18.7 & 18.8 mm) barrels have bigger OD.
     
  13. Avaldes

    Avaldes Well-Known Member

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    ...meaning the wall thickness remains constant. So when the bore diameter increases, so does the outer diameter.
     
  14. zzt

    zzt Well-Known Member

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    I'm not so sure that enlarging the bore does not make for a softer shooting gun. I'm not sure if it's the larger diameter per se, or the fact the larger diameter automatically made the forcing cone less deep. I don't have enough evidence to say for sure, but my experience with 9 trap barrels bears that out.
     
  15. Dr.Longshot

    Dr.Longshot Banned Banned

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    I prefer .740 Bbls on all my guns, I tried ther Kolar .750 and did not like it, was getting bloopers and I am not changing my re-loads to take care of it.

    Al Ljutic said years ago the the.740 bore was the optimum bore.

    The new Antonio Z-Trap has the old style bore of approx .724, when they realize they need a .740 bore their sales will increase, I love the fact they will shoot 125% patterns, they have a good weight system going for them,

    I would try one with a .740 bore.They have a nice factory adjustable comb designed for the Maximum High Rib Rt or Lh.


    Gary Bryant
    Dr.longshot
     
  16. vhntr1

    vhntr1 Member

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    Kerry Allor just did a perazzi for my daughter ,it ended up at .740 bore softer shooting and it flat smokes targets she is a happy camper!
     
  17. globe fish

    globe fish Member

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  18. JLSO5

    JLSO5 Member

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    I have a new P gun ordered with fixed chokes and am going to have Wilkinson work them. He told me to order 18.7 barrels.
     
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