Do long chambers affect patterns

[njc110381]

I've kind of asked this one before, but as a passing subject rather than a topic on its own. I really like the idea of having a gun that is proofed for 3.5" steel loads, but I wont be using them much. I have just found a silver pigeon steel in the Beretta catalogue which can handle these rounds, and is very similar to the other models except for the chamber length. Would having chambers this long effect the pattern when using lighter (24/28g) skeet cartridges at the clay club? Also, how much do you gain by having an extra half inch of pellets/powder (the standard silver pigeon is a 3" magnum)? Would I want to fire a load like this through a sub 7lb O/U gun or would it hurt my shoulder?

[Lord Geordie]

For Pattern there should be NO difference using a 2 & 3/4" cartridge in a 3 or 3 &1/2" chamber

 

And the 3" cart will pack a bit of a thump but not too bad. You should try a 66g 3 & 1/2 cart :blink:

 

The thump on your pocket can be worse than the one on your shoulder when it comes to 3 & 1/2" carts though

 

LG

[njc110381]

To be honest I prefer to ask you chaps first, as you don't want to take my money and are quite clever on the subject! It's an O/U gun, so the round cycling isn't an issue. What I'm really wondering, is whether I even need the extra power? A 3" magnum (standard proof for a silver pigeon game gun) with 50 odd grams of shot is a pretty powerful round, so I may not need the specialist version. Seeing as I will only be shooting the odd fox or goose with it now and again maybe the standard gun may be more than capable for what I need anyway?

[Lord Geordie]

A 3" mag version should be fine for goose and a Fox can be dispatched with BB or SG from a standard 2 & 3/4" cartridge.

 

Of course the 3" has a greater load but i think thats about it. Mainly they carry more shot so generally more powder also but that doesn't always mean more power.

 

You can get a 2 &3/4" shell to produce around 1500 FPS

 

OR a 3 & 1/2" up to around 1700 FPS

 

I beleive it depends on the Powders used and load weights?

 

LG

[henry d]

Of course the 3" has a greater load but i think thats about it. Mainly they carry more shot so generally more powder also but that doesn't always mean more power.

 

You can get a 2 &3/4" shell to produce around 1500 FPS

 

OR a 3 & 1/2" up to around 1700 FPS

 

I beleive it depends on the Powders used and load weights?

 

LG

Think you may find this the other way round,as your pellet load goes up you need a more progressive powder(slower burning) and the muzzle velocity will be reduced too.This will save your gun exploding

 

If my memory serves me right most 10 bore 3 1/2" loads are around the 980 - 1050 F/S range so I would expect that a lot of the 12 bore 3 1/2" to be in a similar ballpark figure.

[Lord Geordie]

Of course the 3" has a greater load but i think thats about it. Mainly they carry more shot so generally more powder also but that doesn't always mean more power.

 

You can get a 2 &3/4" shell to produce around 1500 FPS

 

OR a 3 & 1/2" up to around 1700 FPS

 

I beleive it depends on the Powders used and load weights?

 

LG

Think you may find this the other way round,as your pellet load goes up you need a more progressive powder(slower burning) and the muzzle velocity will be reduced too.This will save your gun exploding

 

If my memory serves me right most 10 bore 3 1/2" loads are around the 980 - 1050 F/S range so I would expect that a lot of the 12 bore 3 1/2" to be in a similar ballpark figure.

 

 

My appology Henry it's the 3" that is 1700FPS not the 3 & 1/2"

 

Here is a link i used to get the figures

 

link

 

LG

[mry716]

Since it is the cone that will affect patterns more than anything else the gap between the end of a short case and the cone may have a detrimental effect, even if only because it will help add additional plastic fouling from the wads. All you can do is try another gun similar to the one you want to buy and see how it fares with the ammo you will likely be using.

[Lord Geordie]

I thought it was the chokes that affected the pattern?

 

I use a 3 & 1/2" mag version of the Escort and the pattern for a 2 & 3/4" shell similar other than the obvious extra shot from the 3 and 1/2" inch cartridge.

 

They both pattern well on the board with good density depending on Chokes used

 

LG

[mry716]

Chokes affect the amount of shot put within a specific sized circle at a specific distance - say a 30" circle at 30yds. The cones will affect how the shot is patterned within the circle - ie in groups or evenly overall. In the 'Old' days the cones were often 'scraped' to improve patterns.

The fact that there is a gap between the end of the case and the cone start allows the shot ( even within a plastic wad ) to expand slightly and is then re constricted. This bunches the shot and could even 'weld' pellets together into larger lumps so destroying the overall coverage of the pattern at any given range.

[Lord Geordie]

Food for thought then indeed

 

LG

[the last engineer]

therefore many target guns have lengthend forcing cones to reduce the stress put on the shot cup when entering the cone, the longer cone will allow the shot to "relax" in the cup giving a more even pattern, and as explained earlier reduce the amount of shot weld or deformed shot in the cup.

 

Martin

[chippy18]

therefore many target guns have lengthend forcing cones to reduce the stress put on the shot cup when entering the cone, the longer cone will allow the shot to "relax" in the cup giving a more even pattern, and as explained earlier reduce the amount of shot weld or deformed shot in the cup.

 

Martin

Hi all

 

on page 98 of the December issue of Sporting Shooter, there is an article by Tim Woodhouse all about how the length of your cartridge in relation to your chamber size, can muck up the pattern before the shot has traveled a couple of inches from the cartridge.

 

[njc110381]

I think I'll stick with the 3" then. No point risking the patterns of 99% of my shooting just so I can let go a few heavy loads for fun sometimes! 3" magnums can take 50g plus of shot from what I've read. That should be enough to get a decent pattern when using BBs I would have thought?

[lurcherboy]

I think I'll stick with the 3" then. No point risking the patterns of 99% of my shooting just so I can let go a few heavy loads for fun sometimes! 3" magnums can take 50g plus of shot from what I've read. That should be enough to get a decent pattern when using BBs I would have thought?

 

 

I am using 67mm carts on a pump action that handles 3.5" They hit hard enough today

 

 

LB