Barrels in your loft?

[Hamster]

I ask again Hamster, when was the last time you shot OT?

As mentioned already, you have yet to grasp the question. The OP mentions OT as an example, it could be any number of different types of Trap games, even DTL could require different POI between top and bottom barrel. I recall reading articles on the very subject in fact where O/U POI differences were discussed, it makes no difference to you and I but don't assume that means everyone.

 

[jwpzx9r]

I am going out on a limb here and saying this POI issue is total tosh. The average club shooter changes their POI nearly every time the mount their gun because of a poor and inconsistent gun mount and head lifting. There is no merit in the argument whatsoever that a OT shooter will miss over and below at certain distances due to some perceived change in POI due to barrel alignment. How many shotgun shooters allow for fall of shot in their shooting under normal conditions out to 50 m ... that right ...nobody and windage anybody that right again nobody??!  Will anybody answer the question as to why the very best makers of shotguns have constructed their barrel to be convergent when they could very easily make them parallel ? Don't tell me it is easier to do it that way because that would be total bullcrap!

edit

If there is any truth in this shoite then the hedge swingers must be driven to distraction with their selective triggers!!!!!!!!!!!

 

[timps]

I am going out on a limb here and saying this POI issue is total tosh. The average club shooter changes their POI nearly every time the mount their gun because of a poor and inconsistent gun mount and head lifting. There is no merit in the argument whatsoever that a OT shooter will miss over and below at certain distances due to some perceived change in POI due to barrel alignment. How many shotgun shooters allow for fall of shot in their shooting under normal conditions out to 50 m ... that right ...nobody and windage anybody that right again nobody??!  Will anybody answer the question as to why the very best makers of shotguns have constructed their barrel to be convergent when they could very easily make them parallel ? Don't tell me it is easier to do it that way because that would be total bullcrap!

edit

If there is any truth in this shoite then the hedge swingers must be driven to distraction with their selective triggers!!!!!!!!!!!

Quite simply it’s for all those that spend hours at the pattern plate.

If a parallel barrel shoots 2 cm apart regardless of range you are always 2 cm apart.

If the same barrel is then set to converge at 40 yards then simplistically every 20 yards from your gun your POI from each barrel comes 1 cm closer together then after 40 yards 1 cm further apart every 20 yards .

So it makes a lovely pretty perfect 0 on top of each other at 40, and only 0.5 cm out at 30 and 50 which means it’s infinitely better at the pattern plate at 30, 40 and 50 yards than the woefully inadequate parallel  barrel, which is a whole 2 cm out consistently.  (sarcastic smiley).

Then you have the top barrel wanting to muzzle flip more than the bottom so with convergence you can tailor in dealing with that phenomena better than with parallel  barrels.

Now back in the real world away from marketing men, pattern your gun and find there is a 5” difference between bottom and top at 40 yards complain to your importer and ask for a new gun.

You will be greeted with the response “it’s within manufacturing tolerances”  :spiteful:

 

[ips]

I am going out on a limb here and saying this POI issue is total tosh. The average club shooter changes their POI nearly every time the mount their gun because of a poor and inconsistent gun mount and head lifting. There is no merit in the argument whatsoever that a OT shooter will miss over and below at certain distances due to some perceived change in POI due to barrel alignment. How many shotgun shooters allow for fall of shot in their shooting under normal conditions out to 50 m ... that right ...nobody and windage anybody that right again nobody??! Will anybody answer the question as to why the very best makers of shotguns have constructed their barrel to be convergent when they could very easily make them parallel ? Don't tell me it is easier to do it that way because that would be total bullcrap!

edit

If there is any truth in this shoite then the hedge swingers must be driven to distraction with their selective triggers!!!!!!!!!!!

The interesting thing is. If there is no benefit of converging barrels and assuming that Beretta and perazzi etc make them that way it begs the question why, one assumes it's easier and cheaper to make them parallel ?

 

[jwpzx9r]

My guess is there is some perceived advantage on having the barrels convergent, whey would you go to the trouble of undertaking an operation like that if it is not required because as you say Ian I think it would be easier making them parallel than having a long taper.

 

[Wonko the Sane]

The reason is simple - having the muzzles separated the same distance as the chambers is ugly and serves no purpose as converging barrels provide a perfectly acceptable scheme for shotguns and make for more attractive lines for the barrels.

And that muzzle flip crap affecting POI is simple BS too.   More Hogwarts Physics.

 

[jwpzx9r]

Charlie I read an article by an American, I am afraid, expressing the opinion that the best gun to shoot any discipline or hunt with is a good old single barrel semi auto because there is no shift in POI between shots! Not trying to cause any upset here but it just highlights there are believers ... I am not one of them.

 

[Wonko the Sane]

The world abounds with the mis-informed and mentally defective.  That affects every aspect of life.  To expect it to not be in evidence among shooters would be just as mis-informed.

I try to find amusement in the crap, but it is sometimes difficult I have to admit.  The intuitive view of the cosmos has about as much validity as the intuitive assessment of the suitability of a particular woman for a life partner.  Best of luck at any of it 

Just because you think it doesn't make it real

Just because you believe it doesn't make it true

 

[Gavin]

I'm with Wonko on this, poi there's better things to worry about, and the amount of people shooting high adjustable ribs worrying about poi when there mount is canted,

 

[schmokinn]

i seem to miss over the top regularly...will bending my barrels down improve my scores? :crazy:

 

[timps]

Like I said above the benefits are at the pattern plate.

Convergent barrels are going to have the point of impact of both barrels closer together from 0 yards up to  double the distance of where the barrels converge over parallel barrels.  

So a gun  setup for 40 yards will beat or equal a parallel gun from 0 to 80 yards at the pattern plate with the 40 yard mark being perfect.

This is a marketing man’s dream and the reason why they go to the trouble, it's provable on paper and most decent gun fitting involves a pattern plate which is probably set up at the manufacturers ideal convergence distance hence why they do it.

So in answer to the question there is a provable benefit but only very small one.

The problem is we don’t compete in static pattern plate shooting so is there any benefit  when out on the clays and swinging a gun.

My view is nope there is not, I have shot a semi auto at skeet and sporting and cannot see any benefit to it over a O/U.

My gun flip comment was my tongue in cheek at the marketing men not meant as my opinion.

My back in the real world comment was they sell you a gun claiming all sorts but try and get a new gun out of them if it doesn’t pattern as advertised at x amount of yards. I know they strangely then have quite a big + or – manufacturing tolerance when someone complains so it cannot be that important.  

 

[Darkside]

As mentioned already, you have yet to grasp the question. The OP mentions OT as an example, it could be any number of different types of Trap games, even DTL could require different POI between top and bottom barrel. I recall reading articles on the very subject in fact where O/U POI differences were discussed, it makes no difference to you and I but don't assume that means everyone.

So, your not going to answer the question, "When was the last time you shot OT?"

I'm going to guess you haven't shot it, I wasn't asking if you'd shot OT for the reasons you probably thought I was asking B)

Think about it this way Hamster, OT targets are all just teal on full spring, coming from below your feet variations...from flat hard going away to the left or right to straight away climbing!!! Low ones are going faster, with more spring so as to reach the minimum distance traveled (correct me if I'm wrong trap guys) and some of the climbing/straight away birds apear slower and you seem to be able to pick them up very fast and fire quickly with the first barrel. Due to angle, some can be second barrelled much closer than others, the straight away is sooo easy to shoot over the top of first barrel, then miss with a dead gun underneath second barrel just like any straight, flat, fast real on a sporting layout, sometimes looks like it's not moving, but it is moving and needs shot with a moving gun. (As you know) The point is, the distance your the clay has traveled by the time you fire the second barrel will be different depending on what teal variant you get. Well, this is what I've concluded after shooting a couple of registered OT comps. Lose your rythme or concentration a tiny bit at OT and you will drop 10 clays easy per line!!! It's unforgiving that way...

 

[jwpzx9r]

Well I am not the most experienced OT shooter there are many more on here better qualified to comment but I think the targets are thrown at almost the same distance + or -  regardless of angle and trajectory. An experienced shooter may well be able to recall all the angles and trajectories for each of the three traps at each of the stations if you practice enough I dare say it would be possible... but you do not know which trap will be sprung. That is besides the point anyway I think even as a complete novice I can say that the POI for each individual barrel will not cause a miss due to the distance at which the shot is taken and these shots are typically taken at 32m and 37m ish distance travelled by the target. Also remember this is a gun up discipline but even so for most shooters there will be far greater chance of POI changed due to gun mount and head lifting issues.

 

[ips]

One thing I will say re poi. Ever noticed the amount of rib you see after the shot is rarely the same as what you saw during the mount. This is why imo comb height (within certain restraints) is in many ways academic.

I wonder what renato lamera's poi is when he shoots from the hip or over his head gun upside down. I wonder how often he adjusts his comb to ensure perfect gun / hip alignment?

Just a thought.

 

[ips]

Ps

The only time miniscule poi / comb height adjustment would be THAT critical is if one was conciously using the bead as an aiming device. And apparently we do not do that so why do people who say they are never aware of the bead or barrel spend so much time with adjustable combs or bits of cardboard and gaffer tape ?

 

[Dug]

So after 93 replies to my enquiry, I have accurate information about one manufacturer, Longthorne, whose barrels are designed to be parallel to each other. Very interesting, but I want to know about other makes too. I'll go first. My MK38's 32" barrels are at 25mm centres at the blunt end and 20mm centres at the sharp end. Quite a bit away being parallel...suggests convergence at 3 - 4 yards...that can't be right, can it?

Keen to know in particular measurements for MX8, Beretta DT's and SO's, Gamba, Guerini, and Krieghoff. And, are sporter barrels any different to trap barrels?

Apologies in advance for prolonging this shoite.

 

[ips]

Yes but if rib tapers down at muzzle ?

 

[jwpzx9r]

WUM !

 

[Hamster]

So after 93 replies to my enquiry, I have accurate information about one manufacturer, Longthorne, whose barrels are designed to be parallel to each other. Very interesting, but I want to know about other makes too. I'll go first. My MK38's 32" barrels are at 25mm centres at the blunt end and 20mm centres at the sharp end. Quite a bit away being parallel...suggests convergence at 3 - 4 yards...that can't be right, can it?

Keen to know in particular measurements for MX8, Beretta DT's and SO's, Gamba, Guerini, and Krieghoff. And, are sporter barrels any different to trap barrels?

Apologies in advance for prolonging this shoite.

Dug,

The measured differences between makes won't in themselves be that meaningful, this is because all will have different ergonomics anyway. The thickness of the chamber ends will vary as will the distance between the barrels because some are designed as what we refer to as shallow action (Blaser, Beretta and Perazzi) and others less so such as (Browning & Miroku).

I don't know for sure but the Blaser looks to me as though they have gone the parallel route judging by the distance between barrels at the business end. 

 

[Skeet UK]

Dear Technoid,

I was interested in your response to Steve (“Barrel Convergence Woes”) because I had just that evening re-read Brindle’s book “Shotgun Shooting”. On page 173 he writes, “However, the barrels of many over-and-under guns intended for trapshooting are purposely converged to shoot to different heights. Traditionally they have been set so that the lower barrel shoots a good deal higher than the upper one (adjustably so on an increasing number of models) but this is reversed in some newer models. A difference of six to 12 inches at 40 yards is usual. For most shooters this makes such guns more useful for doubles shooting as well as International Trap.”

Brindle goes on to explain in detail why this is advantageous.

Keep up the good work!

Dave

Dear David,

While I normally take everything Brindle wrote as Gospel writ in stone, I can’t agree with this one. The very design of the O/U “wants” to throw the top barrel high because it recoils above the main axis of the gun. I can’t tell you how many O/Us I have owned or tested which shot the top barrel higher than the bottom. I have never owned or tested an O/U, as it came from the factory, which shot the bottom barrel higher than the top.

That isn’t to say that it wouldn’t be a good idea. I am sure that some people would love to have that bottom barrel high and top barrel flat. I remember a Perazzi trap gun which had a non selective trigger set to fire the top barrel first. As this is not ideal for recoil purposes, I always felt that it was an effort to get the first barrel high and the second one flat with out actually going to the expense of barrel regulating.

I set my International Trap guns up to shoot dead on both barrels. I find it easier to build in the right vertical lead mentally just as long as I know where the gun will shoot. Even with a high shooting first barrel, the leads on a flat bird are very different from those on a vertical rocket. I am too busy correcting for that the bird is doing to also be trying to remember that my barrels shoot to different points of impact. Clearly, ATA-style American trap is a different game with a fixed vertical component where it definitely does pay to have a high shooting gun so that you don’t have to cover the bird and shoot blind. ATA trap and Olympic bunker trap are very different sports. I have no experience with the new Olympic double trap, so I don’t know what is needed there.

Regulating barrel impact on medium priced shotguns is usually what turns them into high priced shotguns. I have personally owned both Belgian Brownings and Perazzis which shot the top barrel so high that I sold the guns once I discovered it. One Perazzi’s top barrel shot over a full pattern high at 40 yards. They just never took the time to test the point of impact before they boxed it up and shipped it off.

Changing point of impact of one barrel can be a real pain. You can recut the choke on a bias (I had this done to a Parker Repro with a left barrel which shot way left) or install eccentric screw chokes. Of course, it is never best to have your shot take a right hand turn just before it exits the barrel, but a little tinkering for a modest change isn’t too bad. Everyone does it.

The proper way to correct a bad convergence problem is to unsolder the barrels, realign them, test, realign again, test and final solder. It is expensive to do and that is why even some expensive guns aren’t regulated properly. One of the big advantages to the Krieghoff K-80 (other than the fact that you get free-weight exercise every time you hoist one) is that they have interchangeable barrel hangers so that you can adjust your own barrel convergence. Very handy.

That’s it. I’m out of ink.

Best regards,

Bruce Buck

The Technoid writing for Shotgun Report, LLC

Just out of interest...