Beretta 20 Bore Barrels, 0.630" (16mm) - Choke?

[wymberley]

I've been OK up to now but age/infirmity is such that I really need to act it. The 12 can stay where it is choke-wise, but I could do with opening up the 20. I can't find any info' regarding choke diameters for the barrel diameter as per the Title. Could anyone kindly give me the  ballpark figures for, say, Imp and !/2 as an opening gambit for a discussion with the 'smith?

[oldypigeonpopper]

Hello, What chokes are there now and what is your go to cartridge, and what is your main type of shooting ??

Edited October 21, 2024 by oldypigeonpopper

[wymberley]

18 minutes ago, oldypigeonpopper said:

Hello, What chokes are there now and what is your go to cartridge, and what is your main type of shooting ??

Don't know as I can't find figures for .630" but the restrictions are 18 and 24 thou which would be c3/4 and Full for .615".

Supreme Game 7s 25g but the pellets are - or would be - 7&1/4s if there was such a thing of which I probably have sufficient to see me out.

Pigeon.

No need to be too pedantic and am thinking that c8 and c16 thou will do.

[oldypigeonpopper]

1 hour ago, wymberley said:

Don't know as I can't find figures for .630" but the restrictions are 18 and 24 thou which would be c3/4 and Full for .615".

Supreme Game 7s 25g but the pellets are - or would be - 7&1/4s if there was such a thing of which I probably have sufficient to see me out.

Pigeon.

No need to be too pedantic and am thinking that c8 and c16 thou will do.

Hello, It was the old rule of thumb , Improved and half would be the go to chokes using Eley 6s , 30 yard for improved, 35 yard for half choke but i think today with modern powders etc and 7s 7.5s i would go 1/4 3/4 , That is only my suggestion

[JohnfromUK]

It may be worth considering that Beretta barrels are (usually I think) internally chromed. 

Whilst this doesn't prevent opening chokes, I assume that if the chrome is removed, there will be a reduced resistance to corrosion?

[wymberley]

1 hour ago, JohnfromUK said:

It may be worth considering that Beretta barrels are (usually I think) internally chromed. 

Whilst this doesn't prevent opening chokes, I assume that if the chrome is removed, there will be a reduced resistance to corrosion?

 Good point. This one is an S56E from '77 - not so much a sleeper, more like a coma for most of the time. Over to the 'smith methinks.

[JohnfromUK]

11 minutes ago, wymberley said:

 Good point. This one is an S56E from '77 - not so much a sleeper, more like a coma for most of the time. Over to the 'smith methinks.

I have a S57EL which I think is also around 50 years old and came (second hand) with 2 sets barrels (Skeet + Skeet and 1/4 + 1/2).  I'm not 100% sure it is chromed, but many Berettas are.  Mine has also largely been a 'sleeper' for the last 30 years, but it has been 100% reliable and travelled to Central America with me shooting back in the 1980s.

Edited October 21, 2024 by JohnfromUK

[wymberley]

2 hours ago, oldypigeonpopper said:

Hello, It was the old rule of thumb , Improved and half would be the go to chokes using Eley 6s , 30 yard for improved, 35 yard for half choke but i think today with modern powders etc and 7s 7.5s i would go 1/4 3/4 , That is only my suggestion

This is one of those rare occasions when energy fails before pattern so Imp x 1/2 is plenty.

[Fil]

On 21/10/2024 at 10:28, wymberley said:

I've been OK up to now but age/infirmity is such that I really need to act it. The 12 can stay where it is choke-wise, but I could do with opening up the 20. I can't find any info' regarding choke diameters for the barrel diameter as per the Title. Could anyone kindly give me the  ballpark figures for, say, Imp and !/2 as an opening gambit for a discussion with the 'smith?

Hi there,

Imp/Cyl on a 20 bore is .004 thou of restriction and 1/2 is .016 thou. As for choke diameter that depends on the bore size. A Beretta 20 is usually quite large internally (around .624 - .626) so Imp/Cyl choke would be .620 if the bore was .624. So you need to measure the bore to work it out. But the important thing is the restriction in relation to the bore which will be .004 (imp/cyl) - & .016 (1/2). Hope that makes sense. 

 

[wymberley]

23 minutes ago, Fil said:

Hi there,

Imp/Cyl on a 20 bore is .004 thou of restriction and 1/2 is .016 thou. As for choke diameter that depends on the bore size. A Beretta 20 is usually quite large internally (around .624 - .626) so Imp/Cyl choke would be .620 if the bore was .624. So you need to measure the bore to work it out. But the important thing is the restriction in relation to the bore which will be .004 (imp/cyl) - & .016 (1/2). Hope that makes sense. 

 

Cheers.

I don't have the correct bore gauge but do know how to use a telescopic gauge (long reach obviously) and a micrometer reasonably accurately hence the up and coming visit to the 'smith and now also re the bore material ( had a look and don't think it's lined). While allowing for my possible inaccuracies, I make the bottom barrel (9") .632 and its choke restriction 18 thou' and the top .630 and 24 thou'. Both barrels are stamped 16 (mm). The figures you gave are for .615 barrels. The restriction figures figures for a 12 bore are somewhat more. So to cater for this 20 bore oversize, but mainly because you can take it out but you can't .............., I thought I'd hedge my bets a little.

[Fil]

17 minutes ago, wymberley said:

Cheers.

I don't have the correct bore gauge but do know how to use a telescopic gauge (long reach obviously) and a micrometer reasonably accurately hence the up and coming visit to the 'smith and now also re the bore material ( had a look and don't think it's lined). While allowing for my possible inaccuracies, I make the bottom barrel (9") .632 and its choke restriction 18 thou' and the top .630 and 24 thou'. Both barrels are stamped 16 (mm). The figures you gave are for .615 barrels. The restriction figures figures for a 12 bore are somewhat more. So to cater for this 20 bore oversize, but mainly because you can take it out but you can't .............., I thought I'd hedge my bets a little.

Hi. Your bottom barrel measures a slightly tight 1/2 (.016 being 1/2)  and your top barrel measures 3/4 (.024)

 .004 (imp/cyl) - & .016 (1/2) is for a twenty bore regardless of the internal bore measurement. If a bore is .615 the chokes are that. If they measure .626 the restriction would still be .004 (imp/cyl) - & .016 (1/2). I grant you the pattern may be differ slightly hence why boring chokes on a gun of that bore patterning is recommended.