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Could you please quote Burrard on muzzle flip. I think you and Joe are using "Muzzle Flip" when you mean "muzzle rise". "Muzzle flip" is a dynamic by which the barrels bend downward from the initial recoil, and shoot low. Garwood wrote of this phenomenon and that is how I remember he described it. He said that long barreled sub bores were more susceptible to it because the barrels were not as stiff along in the vertical plane since they were of a smaller diameter. I would dig it out of Garwood's books but since I am debating several of you I am at a time disadvantage. So I request the favor a you, asking you to dig out Burrad's definition of muzzle flip.

At any rate when I used the phrase of "muzzle flip" I meant it in the meaning I described above.




By definition all Parker two-frames have to have the same distance between the centerline of the bores at the breech. By definition the muzzles touch on all Parkers. The amount of convergence needed in any barrel set is determined by the MOI of the gun (everything else being equal). Suppose I make a shotgun out of carbon fiber and aluminum with identical dimensions to a 26" Parker two frame. I mean same stock dimensions, same spacing of the bore centerlines at the breech and at the muzzle. Suppose when I get done building it it has half the MOI of the real Parker two-frame 26". That carbon fiber gun will need much more convergence than the real Parker because, as the shot goes down the barrel, the barrels will rotate much more before the shot leaves the barrel because the carbon fiber gun has a much lower MOI. If the carbon fiber gun had the same convergence as the real Parker AND the tubes were straight the carbon fiber gun's right barrel would shoot way to the right of Joe's dove perched on the barbwire. The left barrel would shoot way left. But wait a minute! I can't give that straight barreled carbon fiber gun more convergence because the barrels will cross each other at the muzzle. So, instead of putting the bananas back to back I turn each banana over and they curve out from each other in the middle but join at the muzzle and breech. The muzzle end has a higher convergence than straight barrels and the carbon fiber gun can shoot straight.

Miller I make the same request of you that I made of Stan. I request that for just a little while we keep the discussion on two-frame Parkers. By doing that I think we can broaden our areas of agreement and gain a more exact understanding of our differences. Or course it is up to you.



I go back to the lamp. The light is not piped in through a fiber optics cable. Electrons going through wires to the filament cause it to emit photons. I have never seen an electron. No body else has either. But we have to have electrons to explain the physics of our world. I certainly am not offended by your statement. We are arguing facts and physics. I would much appreciate a more detailed explanation of your disagreement with my Parker post.



Your belief that the tubes are always intended to be straight is the reason I keep focusing on two-frame Parkers. If you give the length of a factory orginal set of two-frame Parker barrels AND if the tubes are straight as you contend I can calculate the convergence. And it is amazing that the convergence rate and the MOI just happen to work out that those straight tube Parker two-frames shoot straight, whether they have 26", 28", 30", 32", 34" or 36" barrels.

Thanks for clarifying barrel flip, but I'm glad you noted that the barrels do rise. Maybe, for the same amount of rise, the s x s will hit a bit lower than the o/u.

Possibly, on a free hanging line on a gun with no cast you may get an even rotational recoil right and left. Maybe, decent, or not so, gun fit will not allow a comparable rotation to the left for a right handed shooter because of different hand grips on the wrist and forearm, and cheek contact in an uneven manner on the stock. I've noticed gun fit can be given quite a bit of importance on affecting point of impact.

Also, I don't believe a flat rib necessarily lines up divergent to the horizontal [lane of the bores. They're on different planes, but I bet it's pretty likely to see the line of the rib converge with the plane the bores are on. Wouldn't you want bores to point a bit up from the aim since the shot may 'flip' down.

I'd still suspect it's more likely to limit muzzle rise on a longer barrel gun, but the longer a shot column is in a barrel, the more it can be affected by any movement. Probably wouldn't matter though as much as on a s x s rifle.

I find all this pretty interesting,, but I have forgotten most of these 4 pages..
I would have to believe Gunman...he worked at Webley n Scott, or just Webley, in his younger years, it seems,what ever..he seems to me to be a real hands on gunmaker, I'd have to go with what he said,as the rest of the stuff said here is just opinion, not hands on work by real gunmakers...???
I',m sure he is telling the truth,though whether you can understand him or not is a different matter.
Not many posts from real gun makers apart from him.
What would old crossed chisels say???
Talking of David, is he ok, hasn't posted in a good while?
No harm meant, but, these people might just know more than you all..?
Franc

I have been convinced I was wrong about the curved tubes. Joe had a conversation with Kirk Merrington. Joe relayed as best he was able what Kirk said in a thirty minute conversation to me.

This is my understanding of what Joe's understanding of what Kirk said. The third wife bit all over but I felt I needed to explain what changed my mind.

The gunmakers intended for the tubes were to be straight in the barrels as per Miller, Stan, Shotgunlover and others. If jigged up properly and with straight tubes they both tubes would shoot to a point. Each tube needed a convergence of about six thousandths per inch of bore which is .012" for both tubes which is the number Miller has been giving out for his Smiths I believe. The .072" difference at the muzzle in a two frame Parker 26" and two frame Parker 32" gun was made up by the flat that was filed on the flat filed on each tube at the muzzle.

Parker barrels made before 1900 were made with straight tubes as described above. After 1900 something changed in their method. After they were brazed together at the breech but before they were soldered at the muzzle they drove wedge in between the barrels. The wedge was driven in just downstream of the hook. They drove the wedge in until the flat surface filed on the outside of the barrel at each muzzle touched at the right angle. This new process created a bow in Parker barrels made after about 1900.

I am unclear if Kirk said regulating the tubes to have the same POI by filing the chokes was normal for the top tier guns. He said the Birmingham makers did not do that.

I hope Joe will post a more detailed account.

I repeat: I was wrong, Miller, Stan, ShotgunLover, Craig, and others were right. The competent makers did not intentionally install curved tubes in their SxS. Thanks for the interesting discussion.

Thanks for that post, Mike. Now, if I could only convince you the eye can discern a few thousandths "out of straight" in a barrel, by light rings and shadow lines. Oh well, we'll save that for another time.

Sunflowers are up!!! High hopes for another great dove season! First Saturday in September, 117 days. Man, that seems like a long ways off.

SRH

Well Mike, all I can say is that was a pretty classy admission on your part. You are a gentleman! Everybody pretty much knowed you was wrong but you made a cogent argument anyhow...Geo

Thank You Mike;
I was just getting ready to add the Only reason I have not included a #2 frame Parker in my discussion was that at the present time I do not own a Parker of any frame size. Any Parker I have owned was long gone before I became interested in this aspect of gun making. I could only speak of that which I had personal knowledge. Sorry for any friction that may have arisen over this topic & still perfectly willing to consider you as a "Friend". I will say your point on MOI using the carbon fiber barrel I feel certain was quite valid & would be correct. I would add one more little bit here for your consideration. While I do not know what the actual spacing on a #2 frame Parker is it seems obvious that if you build both a 26' barrel & a 32" barrel on this same frame the 26" ones have a lesser MOI than the 32" ones.
Now this next is "Pure Speculation" on my part. It would however seem valid to me that with the coupling of the lessened MOI & the shorter barrel time of the 26" barrels they would Need more convergence than the 32" ones.
As to the barrel flip Burrard was saying the same thing as Garwood. I was not disputing that, only stating it was not totally Confined to the smaller bores. When I stated he said a longer barrel had more Flip Vertically, I thought I had made this plain. He did not compare a 12 ga with a small bore, only a longer barrel with a shorter one in a 12ga. His reasoning on the flip was for a downward flexing brought on by the rise of recoil exactly as you stated. His contention was of course a longer barrel fitted to the same frame, stock etc would hit lower. The reasoning that a smaller bored barrel is more flexible certainly seems sound to me. I would think that a 30 barreled 28ga for instance would need a straighter stock than a 30" barreled 12ga to compensate. However a 30" barreled 12ga would still have more Flip than a 26" barreled one & would need a slightly straighter stock, but not to the same extent as the 28ga. I actually did think that on this point I had Agreed with you.

Hi Miller:

It greatly pleases me that you consider me your friend. I certainly consider you my friend.

Sorry I missed the meaning of your original Burrard post. I should have read more carefully.

I did point out a few posts back that the lower MOI of the 26" barreled two-frame would work to counteract the (incorrectly assumed by me) greater angle of convergence of the 26" barrels. But, at that time, I was doubtful that it would just happen to offset it. As it turns out it the Parker two-framed 26" barreled gun had the same angle of convergence as the 32" gun. But yes, I agree with you that if the 26" gun had a higher rate of convergence it would be at least partially offset or perfectly offset by the lower MOI of the 26" gun, everything else being equal.

I view you as one of the most knowledgeable contributors here, perhaps the most knowledgeable.

Your Friend,

Mike

George thank you for the kind words. And classy admissions are the kind of admissions classy guys make. I completely agree with you. I still don't understand why my physics were wrong.

Stan is saddens me that you are looking forward to murdering those wonderful little songbirds. May I suggest you shoot clays instead? Clays don't bleed.

Yep. When I read your post I immediately started thinking about what gun I would use opening day. Right now I am thinking the Parker two-frame with the 32" barrels choked really tight and super tight. I shot it at trap Saturday. 7-1/2 pounds of avian lethality. But if we shoot over decoyed dove I may use the 5-1/4 pound Parker Reproduction with 28" barrels. But it is so expensive shooting decoyed dove as my shooting student Joe Wood winds up shooting all the MoJo decoys at $30 per.

When we have more time I will disabuse you of your delusion that you can see a thousandth of an inch bend in a 30" tube.

I get my share of clays, Mike, but there is no substitution for the little grey rockets we call doves. They haunt my dreams even in May. It is a sad, sad thing (to most of the world, not to me ) to be so consumed with something, as I am with shooting doves.

SRH