[pijonsmasher]

I really need to go shoot I have been thinking way to much!!!!

I am wondering about the wad seal and how much blow by there is. Say an overbored 12 gague lengthend forcing cones and 3" chambers. I would not expect much if it were 2 3/4" chamber.

So what do you think? How much blow by? and will it effect the Speed, pattern greatly???

I am looking at a new gun and know I want 2 3/4" chambers, just so many out there have 3" chambers.

Thank yall

 

[bopper]

I think you are worrying too much. In all of my reloading and chronographing experience, I've never noticed a difference between 3" overbored barrels and 2-3/4" tight barrels.

For example, I ran ten shells of my preferred target load over my chronograph with a Browning Citori. This gun has 3" chambers and .739 bores. Average velocity for the string was 1223 FPS. I ran ten more shells through another one of my guns with 2-3/4" chambers and .724 bores. Average velocity: 1228 FPS. The 5 FPS difference is well within the standard deviation for all 20 shots combined or either of the 10 shot strings. In other words, in this case there is no difference.

 

[Case]

It's a nonissue. Just get the gun that fits both you and your budget.

 

[UltraMag]

The mossberg 835 is a 12ga 3.5" gun with a 10ga bore on it, it shoots on average 50fps faster than a nominally bored 2 3/4" gun.
I've looked at wads that were shot out of mine, and they compress and completely fill up the 10ga bore, and the increased velocity is due to less friction.does the wad seal? yes, very well.

 

[Burnt Powder]

Shotguns are NOT rifles. The wad will seal, the shot will be fine. IF you get loads that have a deviation of only 5 fps average between guns, THAT is remarkable! I'd expect more than that from the SAME gun shot to shot, and string to string. My compliments to the guy who loaded the ammo! OUTSTANDING job. Either that or the chronograph isn't working right! :roll:

BP

 

[pijonsmasher]

Thanks

You really eased my mind about that one! That was totally not what I expected.. I just got a few more gremlins to get out of my mind before the next shoot.

Thanks again and happy shooting

 

[bopper]

Shotguns are NOT rifles. The wad will seal, the shot will be fine. IF you get loads that have a deviation of only 5 fps average between guns, THAT is remarkable! I'd expect more than that from the SAME gun shot to shot, and string to string.

There is more than 5 FPS deviation shot to shot but the averages of the two strings were only 5 FPS off. For example, in the string out of the Browning, the slowest shell was 1193 and the fastest was 1262.

Remember the more data points you have in each string, the more dependable the data. So, the fact that the averages of the two strings are close together shows that the load is consistent overall. It does not mean that the load is consistent from shot to shot.

 

[TexasTon]

i kinda look at it like----there is, say 450 grains of shot in front that wants to go anywhere other than where it is going, and around 10k pounds pressure saying it will. the overpowder cup is pliable enough to move/stretch by hand. you can bet if it is within the limits of the plastic---it will be forced against the cone/barrel walls and seal.

 

[GordonWood421]

Stan Baker , GRHS, pioneered BIG BORE barrels in the 0.800 dia regime --- that is essentially a chamber that extends the length of the barrel . Having never heard anyone ***** about problems related to by-pass in one of his barrels , I believe you can increase your level of comfort with most stuff available to most of us .

421