Give me a heads up how tight the pattern

[nathan]

would be using modified choke ?

I have a new Remington 870 Express Magnum 12 g birdgun with 28 inch barrel and modified choke. At 25 yds what s the estimated grp size using birdshots, 00 buck and slugs ? I havent had the chance to shoot this shotgun , so just for the sake of discussion .

 

[RNB65]

A shotgun pattern is measured as a percentage, not as a size. It's the percentage of shot that falls inside a 30" circle using a given choke. Patterning is usually done at 40 yards, so a modified choke at 25 yards is going to be a very tight pattern with a high percentage of shot in the 30" circle. The only way to know for sure is to put up some large sheets of paper and check it for yourself.

http://www.chuckhawks.com/pattern_shotgun.htm

While patterning may traditionally be done at 40 yards, you should always pattern your shotgun at the typical distance you expect to use it. I shoot sporting clays and the average shot on the sporting clays range is around 25 yards, so that's the distance that I use when I pattern my shotguns.

Another important thing you learn when you pattern a shotgun is whether the point of impact is true. If the shot string isn't going where you think it is, it's really hard to hit anything!
-

 

[Fred Fuller]

It depends on the gun and the load. Only patterning the gun and load you want to know about on paper can tell you for sure.

With birdshot, you should be getting patterns ranging from almost too tight to about optimum, depending on the load you're shooting.

With buckshot a whole lot depends on the load. With the cheap stuff (S&B, Rio Royal etc) I wouldn't be surprised to see you lose pellets off a standard silhouette target at 25 yards. With the medium priced stuff (name brand buckshot like Remington Express etc) it should give pretty decent patterns. With the premium stuff (FliteControl), a MOD choke is probably going to be too much choke and will actually result in more open patterns than a CYL or ImpCyl choke.

And with slugs you get groups - unless you're a really bad shot .