Diffusion Choke

[Wap wap]

shoot a lot of doubles in skeet and then theres the shoot off--- use reloads and skeet chokes in the 4 gauges but would like to try one in .410. Sometimes the light is really bad at some ranges ( or bad at some stations on particular ranges) and the shot is almost instinct, if it worked the choke would be good for a few situtations.

[EkuJustice]

The 410 just dosent have enough shot to fill the entire pattern you are looking for uniformly. On the 410 your looking for uniform pattern in the useable pattern(without the fringe). If you talk the pellets out of the middle(which dosent have a ton to spare) and try to cover a larger area you get holes in the pattern. I know how the bad lights go. Masters(when it was in savannah) first squad out station 1 and low 8 were awful for the sun which is one reason people tried to get the rotation which never had it. The shootoffs were also awful especially for the 20 ga which got started in the twilight every year. On the poor lights, a set of clear glasses helps a little but not much.

[Sean Gaines]

True on the chips. No doubt. I am from the school of a chip is still dead! I did have some amigos that liked powder..

For 3 gun though, a chip usually causes the clay to fall, which is all we need.

Cheers.

M

Thats all that matters in the 3gun world

[EkuJustice]

Only problem I see with the single pellet hit is often it wont break the clay in 3gun especially if rabits are used. It would get seen in scoring that it was hit and counts but I like to see the clays break in 3gun especially in bennings scoring where a miss is very costly time wise. It takes more to break a stationaty target than a moving spinning target. If I don't see it break, its hard to leave it and hope there is a pellet hole in it.

[Wap wap]

1/2 oz 9 same number as 7/8 oz 71/2 20 ga. pattern just as uniform in my guns. But I can run straight with a 12, 20 or 28. , Sometimes drop 2-3 with the .410. In my case the reloading techniques of 410, especially crimping, give too high of ES in velocities. Still would like to try this choke in .410 for the light issue, (who knows maybe it would average the ES more) but if it isn't made. ----

[MarkCO]

So I decided I needed to test this Diffusion choke since no one had posted any pattern size or density data. Ordered one up from Sean for the 1100 and took it to the range for some testing with the Casanova's. We shot onto a pattern board with a dirt berm about another 10 yards behind the board. Here is the data:

Gun was Rem 1100 tactical with a 22" barrel.

Winchester Universal 7.5, 1 1/8 ounce, 1200 fps'

Fiocchi Interceptor Spreader, 9, 1 ounce, 1300 fps

B&P Dispersante (Spreader) 7, 1 1/6 ounce, 1330 fps

Modified Choke

Win 10 yards: 6" pattern with a tight center

Win 25 yards: 14" pattern with even dispersal

Fio 10 yards: 14" pattern with even dispersal

Fio 25 yards: 32" pattern with even dispersal

B&P 10 yards: 13" pattern with uneven dispersal

B&P 25 yards: Off the board (over 3 feet)

Diffusion Choke

Win 10 yards: 11" with spotty pattern

Win 25 yards: 28" pattern very open and spotty

Fio 10 yards: 16" with even dispersal

B&P 10 yards: 16" with even dispersal

The spreaders through the Diffusion with spreaders at 25 yards was not even worth recording. We could see the pattern on the berm which was well over 4 feet at 20 yards. I then shot slugs at 50 yards with 3 different slugs and the groups were about the same, but the POI rose about 2" with the diffusion choke versus the modified choke.

Using the Winchester, the Diffusion patterns were pretty poor. The patterns do open up closer, but they keep opening up. There was no indication that they held some sort of unchanging pattern for any distance at all. Both of the spreaders produced a larger, and more uniform pattern at 10 yards with a modified choke than the diffusion produced with the Win loads. When at 10 yards, we could see the berm hits at 20, and when at 25, berm hits at 35. All the loads, with both chokes produced cones of shot, no cylinders!

I will try some more loads on the pattern board in the future, but for now, I don't see a large benefit. Clays to about 15 yards or so even if on edge, should be okay, a full clay target, maybe out to 30 yards, but you might have to live with a wobble and hoping it is chipped. A stage with close clays and far slugs would be the ticket for the Diffusion. If you use the Diffusion AND spreaders on a stage with close clays, you should be able to pick up some time as well.

[outerlimits]

Mark-the win universals contain some of the cheapest shell components money can buy. I think you'll notice a difference testing a better shell like AA or STS.

[Sean Gaines]

So I decided I needed to test this Diffusion choke since no one had posted any pattern size or density data. Ordered one up from Sean for the 1100 and took it to the range for some testing with the Casanova's. We shot onto a pattern board with a dirt berm about another 10 yards behind the board. Here is the data:

Gun was Rem 1100 tactical with a 22" barrel.

Winchester Universal 7.5, 1 1/8 ounce, 1200 fps'

Fiocchi Interceptor Spreader, 9, 1 ounce, 1300 fps

B&P Dispersante (Spreader) 7, 1 1/6 ounce, 1330 fps

Modified Choke

Win 10 yards: 6" pattern with a tight center

Win 25 yards: 14" pattern with even dispersal

Fio 10 yards: 14" pattern with even dispersal

Fio 25 yards: 32" pattern with even dispersal

B&P 10 yards: 13" pattern with uneven dispersal

B&P 25 yards: Off the board (over 3 feet)

Diffusion Choke

Win 10 yards: 11" with spotty pattern

Win 25 yards: 28" pattern very open and spotty

Fio 10 yards: 16" with even dispersal

B&P 10 yards: 16" with even dispersal

The spreaders through the Diffusion with spreaders at 25 yards was not even worth recording. We could see the pattern on the berm which was well over 4 feet at 20 yards. I then shot slugs at 50 yards with 3 different slugs and the groups were about the same, but the POI rose about 2" with the diffusion choke versus the modified choke.

Using the Winchester, the Diffusion patterns were pretty poor. The patterns do open up closer, but they keep opening up. There was no indication that they held some sort of unchanging pattern for any distance at all. Both of the spreaders produced a larger, and more uniform pattern at 10 yards with a modified choke than the diffusion produced with the Win loads. When at 10 yards, we could see the berm hits at 20, and when at 25, berm hits at 35. All the loads, with both chokes produced cones of shot, no cylinders!

I will try some more loads on the pattern board in the future, but for now, I don't see a large benefit. Clays to about 15 yards or so even if on edge, should be okay, a full clay target, maybe out to 30 yards, but you might have to live with a wobble and hoping it is chipped. A stage with close clays and far slugs would be the ticket for the Diffusion. If you use the Diffusion AND spreaders on a stage with close clays, you should be able to pick up some time as well.

Thanks for your analysis Mark, the only problem is there is quite a bit of constriction difference between a modified and a diffusion choke. When you goto the range you ought to try a skeet choke and compare it to a diffusion choke, as they are the same constriction. There will be some applications were the diffusion choke will prove to be dominate.

Here is a handy constriction chart:

http://www.briley.com/2009/chokeconstrictions.html

[MarkCO]

Mark-the win universals contain some of the cheapest shell components money can buy. I think you'll notice a difference testing a better shell like AA or STS.

You are correct, but I got them just for this test since a lot of folks use them. I will test more.

[MarkCO]

Thanks for your analysis Mark, the only problem is there is quite a bit of constriction difference between a modified and a diffusion choke. When you goto the range you ought to try a skeet choke and compare it to a diffusion choke, as they are the same constriction. There will be some applications were the diffusion choke will prove to be dominate.

Here is a handy constriction chart:

http://www.briley.com/2009/chokeconstrictions.html

Sean, I do have a skeet, and I took it, but I got cold and I had some surgery on my right cheek right where the cheek weld was and it was starting to hurt a tad. What I was looking for in this first test was a comparison between what I used all of 2010, and the Difussion. I'll get out next Friday and do some more testing.

I am going to shoot some Federal, Win AAs, use skeet choke. Any other requests or recomendations I can accomodate, I will.

[Kyle O]

Thanks for posting mark! You miight consider federal bulk as well for any future testing.

[AustinT]

Deleted.

Edited January 10, 2011 by Spiff034

[MarkCO]

Gun was Rem 1100 tactical with a 22" barrel.

Winchester Universal 7.5, 1 1/8 ounce, 1200 fps'

Fiocchi Interceptor Spreader, 9, 1 ounce, 1300 fps

B&P Dispersante (Spreader) 7, 1 1/6 ounce, 1330 fps

Diffusion Choke

Win 10 yards: 11" with spotty pattern

Win 25 yards: 28" pattern very open and spotty

Fio 10 yards: 16" with even dispersal

B&P 10 yards: 16" with even dispersal

I was able to get to the range twice this week for some more testing. I shot 1 ounce #8 loads of Federal Bulk pak, Winchester SuperX, Remington STS and AA with the Modified and Diffusion chokes at some old Christmas wrapping. Generally, the patterns were about the same size, (all within an inch) with less dense patterns. Ran out of time to finish, so I got back this afternoon on the pattern board. Same gun, but with some different loads and chokes. I used Winchester SuperX 1 1/8 ounce 7.5 and Federal Tactical 00 buckshot.

Briley Skeet Choke

Win 10 yards: 11" pattern with even dispersal

Win 25 yards: 21" pattern with a few small holes

Fed 20 yards: 6" even dispersal

Briley Diffusion Choke

Win 10 yards: 14" with even dispersal

Win 25 yards: 36" with clumped and open pattern

Fed 20 yards: 15" with uneven dispersal

The "better" quality Winchester did produce slightly larger patterns at close distances, however they also deteriorated more at the further distances. As compared to the skeet, it more than doubled the pattern of the buckshot. Maybe if there is shotgun speed shoot with very close clays and buckshot inside of 20 yards it would be of benefit. The most practical use on a 3 gun stage appears to be one with close clays and slugs. There was no deterioration in slug performance, but this same gun shoots slugs patterns at twice or more with a skeet choke as compared to the Diffusion choke. Using the Diffusion choke on poppers is too risky for me. There might be a stage a match where it could be of benefit. On the pattern boards, the spreaders through the modified choke definately had a better pattern. Anyway, I've given some data that should be sufficient for you to decide if you want to try it.

Edited January 15, 2011 by MarkCO

[Sean Gaines]

Gun was Rem 1100 tactical with a 22" barrel.

Winchester Universal 7.5, 1 1/8 ounce, 1200 fps'

Fiocchi Interceptor Spreader, 9, 1 ounce, 1300 fps

B&P Dispersante (Spreader) 7, 1 1/6 ounce, 1330 fps

Diffusion Choke

Win 10 yards: 11" with spotty pattern

Win 25 yards: 28" pattern very open and spotty

Fio 10 yards: 16" with even dispersal

B&P 10 yards: 16" with even dispersal

I was able to get to the range twice this week for some more testing. I shot 1 ounce #8 loads of Federal Bulk pak, Winchester SuperX, Remington STS and AA with the Modified and Diffusion chokes at some old Christmas wrapping. Generally, the patterns were about the same size, (all within an inch) with less dense patterns. Ran out of time to finish, so I got back this afternoon on the pattern board. Same gun, but with some different loads and chokes. I used Winchester SuperX 1 1/8 ounce 7.5 and Federal Tactical 00 buckshot.

Briley Skeet Choke

Win 10 yards: 11" pattern with even dispersal

Win 25 yards: 21" pattern with a few small holes

Fed 20 yards: 6" even dispersal

Briley Diffusion Choke

Win 10 yards: 14" with even dispersal

Win 25 yards: 36" with clumped and open pattern

Fed 20 yards: 15" with uneven dispersal

The "better" quality Winchester did produce slightly larger patterns at close distances, however they also deteriorated more at the further distances. As compared to the skeet, it more than doubled the pattern of the buckshot. Maybe if there is shotgun speed shoot with very close clays and buckshot inside of 20 yards it would be of benefit. The most practical use on a 3 gun stage appears to be one with close clays and slugs. There was no deterioration in slug performance, but this same gun shoots slugs patterns at twice or more with a skeet choke as compared to the Diffusion choke. Using the Diffusion choke on poppers is too risky for me. There might be a stage a match where it could be of benefit. On the pattern boards, the spreaders through the modified choke definately had a better pattern. Anyway, I've given some data that should be sufficient for you to decide if you want to try it.

Seems to me that the diffusion rifeling adds somewhere from 40 to 50% more coverage than the same choke without the rifeling. So the choke is not smoke and mirrors, there is some merit to its design. I do agree that shooting heavy poppers with it is a no go, but for clay targets and slug targets its wonderful. thanks Mark for the analysis!

[AlamoShooter]

delete

[SMSI]

a new diffusion choke on 24" and 21" BEnellis will bust a clay very well at 25 yds but steel falls very slow if at all. at 15 yds all is good, and the plates come right off the Texas star. However, not all Texas stars are created equal, so YMMD. also, I am not talking about super heavy steel, like you might find at TAC-2 or Knob Creek.

[MarkCO]

a new diffusion choke on 24" and 21" BEnellis will bust a clay very well at 25 yds but steel falls very slow if at all.

I was using a "new" diffusion choke on a 22" barrel and frankly, the data says it will not reliably break clays at 25 yards. There were holes in the pattern so big you could put at least 6 or 7 clays inside the pattern and they would have not even a "golden" pellet. There very well may be some circumstances that this choke is well suited to, however, it is not a universal 3 gun choke, nor a 25 yard choke, it is a specialty choke.

[AlamoShooter]

OK I saw one land in a lake before at a sporting clays event ..... granted the guy only had to throw it 30 yards.

Just not for every one on every thing:roflol:

[SMSI]

when i say a new diffusion choke, i mean new to me. i used the Brileys from Power Factor. i had no misses on the clays at 25 yds today, and shot probably at least 10 - 15 at that distance. all were busted, not just nicked. Like I say the steel was another story until i got closer. I put a few on paper and they were very dispersed but pretty consistent. anecdotal, but convincing to me.