Big Bore Needs Less Constriction

Chatting with a gunsmith a few days ago and he implied my 745 barrel would need less choke. I said I previsously had tm1 that had 42 points constriction and he said 42 points in a large bore was extremely rare.

 

Did he show you some evidence? I've extensively tested many of them and found no evidence for that very common assertion. This is one test of larger bores vs smaller



This result if more to the point of your question.



All the guns had constrictions around 0.040"".

N1H1

 

Dr. Longshot regularly preaches the gospel of tight chokes. He goes for Extra Full and smoke. Says it makes a better break and a better shooter.

 

I am not sure 732 is a big bore at least not like a 745.

 

My .750 barrel shoots almost identical persentages in a 30 inch circle at 40 yards with .025 and .035 restrictions. The core being hotter with the .035 and the pattern being more even with the .025.

 

I had a Baker Big Bore chamber size .800 bore from chamber to barrel exit with choke tubes. This was not a good barrel to shoot in the winter unless the shells were warm. The fps was faster than a barrel with a .730 b0re.
We took 3 shells that my friend reloaded and 3 shells that I reloaded shot them thru his barrel then took another 3 shells he reloaded and 3 shells that I reloaded and shot them thru the Big Bore. All shells shot thru the Big Bore barrel as shot over a chronograph were 45 to 55 FPS faster than thru the .730 bore barrel. The Big Bore barrel required less choke for a tight pattern than a regular barrel and was soft shooting. The tightest choke I had for the Big Bore barrel measured .o4o and had a very hot centre pattern. A .020 restriction choke tube would crush targets from 27 yds. There is in my opinion merit in larger bore barrels. For your information.

 

Olde, how, specifically, did you analyze your patterns? Did you keep your data? I ask because I have some of my own and I'd like to compare our results.

N1H1

 

And Michael, I have the same general question for you. How did you analyze the patterns and can you share your data? I don't doubt that your 0.025 and 0.035 tubes shot about the same;

here are three Wilkinson chokes in a TM9-X Perazzi shooting shells bought at the 2012 Grand American in Sparta:








By the way, the relative rankings of shells often changes from one Grand American to the next. But for that year, I think if one shell is better, that's the one to use.

These data underline what I have most-often seen. Differences in patterns can be gun-based or shell based or both and to accept just one as the "cause" of differences without enough data is as likely to mislead you as help you. But all these shells are just fine, of course. But once you know something, does it make any sense to ignore it?

Yours in Sport,

N1H1

 

N1H1,
I used no program to analyze my patterns. I counted the pellets in 20 new STS and marked each shell, then marked off 40 yards and shot 10 large papers with each choke, marking on the paper which choke was used and the pellet count of the shell used. I brought the paper sheets home and as I had time drew a 30 inch circle around the center of the patterns and counted the holes. The pellet count averages between the two chokes varied very little. Actually the .025 choke had very few flyers outside the circle but still left many pellets unaccounted for. A case of too much time on my hands, I guess. Most of my better handicap scores shot with this gun was when I used the .025 Choke, so I suspected the performance of these tubes to be close. I am a mid yardage shooter who most often averages around 90 in handicap. Not trying to prove any theories or prove anyone wrong. I do use a .035 choke when I shoot non registered targets from the 27. Just trying to tell cook about my limited experiance with a Kolar .750 barrel which is actually .747! Your milage may vary.

 

Very thorough. That's the only way to know for sure what your pattern is.

 

N1H1
I did not keep any data, as I recall we counted pellets in each reload ( each load had identical number) we then drew a 25" circle ( yes 25") and counted pellets inside each circle very little variation with the BigBore some with the standard barrel. The speed variation and this information sticks in my mind and I really don't know why after these years. Just something that I remembered when the thread of larger bore barrels came up.