20 ga. Chamber length

[Heff]

Bruce,
Based on 2 3/4" shells in a 2 3/8" chambered 20 gauge not being an issue, would you or others also say a 3" shell with 1 1/8 oz and 3 dre load would be acceptable to shoot in a 2 3/4" Parker with 2 5/8" chambers?

[Bruce Day]

No. Wall thickness.

Why would I shoot a load that far exceeds the published service load max and exceeds what Parker recommended ? I urge people to take the effort to find out what Parker said.

[Heff]

Ok, now I'm confused. The load I referenced, 1 1/8 @ 3 dre is what was referenced in an earlier post as recommended service load. The only difference in my question was about using this same load in a shell that is 3/8" longer than the actual chamber length. This is basically what we were discussing with using a 2 3/4" shell in a 2 3/8" chamber. Why would one far exceed the published service load and one be much ado about nothing? I'm not busting anyone's chops here, I'm just trying to understand

[Bruce Day]

The 1 1/8 3 load is 12 ga not 20. I know of no Parker recommendation and think it unwise to shoot that load in a 20 ga.

Parker regularly recommended that load as it’s patterning load in its 2 5/8” chamber length 12s.

[B. Dudley]

Here is something that i have often wondered about parker 20g chamber lengths. As we know, a many of them are 2-1/2” and that is what this thread is about.

Take 12g as an example. Parker bored their chambers at 2-5/8” for intended shell length of 2-3/4”. The 1/8” shorter chamber was intended to provide a better gas seal at the forcing cone and result in better shot penetration. 12g hang tags state specifically “chambers: 2-5/8”... Use: 2-3/4” shells”.

Now, what was the period length for commercially available 20g shells? 2-5/8” or 2-3/4”. The above short chambering in parker 12g guns would suggest that if they followed suit in 20g, then the intended shell for a 2-1/2” chamber would be 2-5/8”. The same 1/8” difference. 1/4” seems like too much difference.

Does anyone have an example of a 20g hang tag showing chamber length and the intended shell length?

[Heff]

I would think if the chambers actually measured 2 1/2", they may have been intended for 2 5/8" shells. The chambers in the 20 ga I was discussing are actually 2 3/8", and I would think were truly intended to be used with 2 1/2" shells following the 1/8" shorter theory. The difference here is not 1/4" but rather 3/8" and why I asked about using a 3" shell with 1 1/8 oz 3 dre load in a 12 ga with 2 5/8" chambers (3/8" shell to chamber length difference)

[Southpaw]

Hey Bruce nice picks and glad to hear someone is tearing them up.

I think in continuation of the discussion where you were enlightening me with the TPS info, we were trying to just to get recoil comparisons to what is actually happen. Btw those charts are awesome. I have another brand sxs 28 gauge that is my brush gun and those choke killing diameter charts you have are helpful.

My point was that just the way sxs guns are made, if you get above 16 gauge the cumulative or maybe one time of too heavy a load can create stock issues on older Parkers and maybe even all older guns using more brittle American walnut. Say if you have a 1 Frame 16 gauge and a 1 frame 12 gauge, inherent with 12 gauge loads your recoil pounds go up and hence you can just have more wear tear issues on the same sized stock. Again almost every field grade 12 gauge Parker I have seen littered across gun shops have some issues with stocks. 16's obviously can if you get loads approaching 12 gauge. I think most 12 gauges are in the 1 1/2 frame but..

I was putting say the same dram equivalent of black powder to grains and coming up with some pretty high numbers in the calculators. The calculators require a grains used of powder. A box of shotgun shells, if you can find them will say dram equivalent. But more and more they don't even say that, they just put a velocity number. I think the calculators are thinking you are using the modern powder grains instead of black powder grains and it produces maybe conflicting results.

BTW Heff, Bruce referenced this chart below from another thread where he was talking about a 16 gauge loads as recommended by Parker. Slide your eyes down and 20 gauge info is there as well.

[Southpaw]

Btw Bruce really like this chart and talking about the different velocities. Man I like those 28 gauge numbers. You get less shot, but what you got, get's there faster than all normal loads.

[Bruce Day]

Todd, you should get and read Parkers The Small Bore Shot Gun.

As for me, I’m off to hunt pheasants.

[B. Dudley]

Todd,
You are just seeing the junk Parkers sitting in gun shops with stock issues and they are sitting there for a reason.
And... the most common frame size for 12g Parkers is by far the 2 frame.