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Will an increase in velocity effect the pattern. Does the pattern open up more with an increase in velocity? I've gone from loading 1145 FPS to 1200 FPS. Does this effect the pattern. Do I need to use a tighter choke? I didn't think it made any difference but, I'm told that it does. I've searched but, I haven’t been able to find anything on the internet.
 

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Shoot paper with both loads and different chokes to see what combination patterns the best at the yardage you are breaking the bird. Everything is speculation until you do the testing with your own gun, chokes and loads.
 

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Neil Winston tested this often-told gun club porch wisdom, and found that for the typical ranges of velocities of ATA shells, patterns don't change enough to notice.

If you go really slow, they tend to tighten up, but that's below 1100 fps.
 

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There is a good article on Mullerchokes.com that speaks to this question under the advise section. The article mentions that the best patterning loads are in the 1145 - 1250 range, and the worst exceed 1350. So for ATA speeds and targets, there is little difference. Neil proved this. My question has always been how much faster does a 1200 fps load reach a target at 40 yard break point than a 1145 load, and is the difference worth the extra recoil? My limited math skills tell me the difference is negligible, but I am still curious.
 

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Yes, in long-yardage handicap and perhaps (or perhaps not) in the second shot of doubles. But speed is not the only difference; pellet energy is in play too. I shoot 8's for the second shot of doubles (and sometimes handicap too) and I need all the energy I can get.

The 40-yard difference between 1200 and "handicap" shells is only 0.003 seconds and a lot of stars opt for the faster ones over the comfort of the slower, but I don't. Handicaps just barely exceed my tolerance for discomfort, generally speaking.

Neil
 

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There is a good article on Mullerchokes.com that speaks to this question under the advise section. The article mentions that the best patterning loads are in the 1145 - 1250 range, and the worst exceed 1350. So for ATA speeds and targets, there is little difference. Neil proved this. My question has always been how much faster does a 1200 fps load reach a target at 40 yard break point than a 1145 load, and is the difference worth the extra recoil? My limited math skills tell me the difference is negligible, but I am still curious.
Rather than give you the answer (0.005 seconds) - here's the math should you run into it again (with limited math skills):

(40 yards x 3 ft./yard)
----------------------------- = 0.100 flight time (seconds)
1200 ft./sec.


(40 yards x 3 ft./yard)
----------------------------- = 0.105 flight time (seconds)
1145 ft./sec.

(Delta) difference = 0.105 minus 0.100 = 0.005 seconds
 

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I don't understand that, DC. I used Ed Lowry's Shotgun Insight for Windows and get the same difference but our times differ by 1/3, mine being 0.146 seconds vs 0.141 seconds.

Neil
 

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Neil, do you know what the difference in kinetic energy between two premium factory trap shells from the same manufacturer with 1 1/8 oz. of #7.5 shot at 40 yards? One shell with a muzzle velocity of 1145 fps and the other with a muzzle velocity of 1200 fps.
 

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Garry, I know the faster ones have more. The variables in whether a pellet will break a bird are so numerous, inter-related, inter-contrasted, and untested (except by Dr, Jones) that further analysis of what amounts to guesswork is, in my opinion, futile.

Neil
 

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As it happens, I have a spreadsheet full of data from Ed Lowry's Shotgun Ballistics for Windows program.

Time of flight of #8 shot fired through an Improved Modified choke is 0.1496 seconds if launched at 1150fps, and 0.1452 if at 1200fps.

ToF for #7.5 for the same velocities and choke is 0.1469 and 0.1425 seconds. Retained energy at 40 yards is 1.02 ft/lbs for 1150 and 1.07 ft/lbs for 1200fps.
 

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Gary, I personally use 0.6 ft/lbs of retained energy as my benchmark. That puts the effective range of 8 shot launched at 1150fps at 50.5 yards. For 7.5 shot that extends to 52 yards. If you went up to Nitro 27s with 7.5 it would be 62 yards. I don't shoot anymore because of retina problems, but when I did everything except bunker loads was at either 1135fps or 1150fps.

To answer the OP's question, it depends on the quality of the shot you are using. Using first rate, round, hard shot you will see no meaningful difference if pattern efficiency between 1100 and 1325 fps. Under 1000 fps, the pattern is noticeably, measurably tighter. My bunker load was 24g #8 WCM shot at 1300 or 1325 fps. It patterned beautiful and destroyed targets. Everything I used for ATA Trap was at 1150fps. For Skeet is was 1135. I tried faster loads and the only thing it got me was a sorer shoulder.
 

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DC, the figures you use for velocity are taken at 3' from the muzzle. The muzzle velocity is much, much higher.

A velocity of 1150fps 3' from the muzzle will not remain at that velocity out to 40 yards. It will slow significantly, and that accounts for the extra flight time.
 

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Neil and Tim... what about high velocity shells, while not related to trap, I'm interested in what happens with those SC shells that are in the upper 1300's to mid 1400's in fps.

Also have you had the chance to doing any testing with Gamebore/Kent "diamond shot"? I would love to see some information and not just opinions. The rumor is that it has excellent patterns and is very hard.
 

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Percula, I think that there are enough sporting clays shooters to get testing of the shot they use done by some of its participants.

I have a Gamebore box and I remember the shot being very shiny but that's about all. I still have plenty of Grand-sourced shell-brands (12) to test but once that's done I'll try to find the Gamebores and get back to you.

Neil
 

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