Chamber Length

[charlie cleveland]

it may be that your 20 gauge is a light weight and that will cause it to kick like a 16 ga. i have a 20 lc smith with 2 1/2 inch chambers under 6 lounds..i shoot 2 3/4 inch lite loads through it..off the shelf ammo... i can not tell the diferance between the 2 1/2 inch and the 2 3/4 inch shells both kick like a 16 ga....charlie

[Dean Romig]

The problem with "off the shelf" 20 ga. ammo of any brand is that they are made to operate gas-operated semi-auto shotguns. 2 1/2" low pressure loads are what these old side-by-sides need. If shooting them with off the shelf ammo is uncomfortable for you, just imagine the premature wear and metal fatigue they are producing in our Parkers.

[Bruce Day]

Recoil is:

(wt of shot x muzzle velocity + 4700 x wt of powder charge) squared

divided by

64.348 x wt of the gun in lbs.


So, if you want less actual recoil, increase the wt of the gun, decrease the weight of the powder charge or decrease the shot charge. Chamber length or pressure is not in the formula and has nothing to do with actual recoil.

If you want less felt recoil, get a gun with a straighter stock or add a recoil pad , slip on or fixed.

Pressure in the barrels is a different formula. One can easily look up from p.515 TPS what Parker intended for service loads for the gun. For example, a Winchester 20ga 7/8, 2 1/2dre load results in pressures slightly below the Parker determined service load. Tables are provided in TPS which show the loads that Parker recommended for various weights and gauges of guns. A person can also determine commercial load pressures by backing in reloading data. The belief of short chambers creating high pressures was debunked by Sherman Bell in his DGJ Finding Out For Myself series by using actual testing using strain and pressure gauges and engineering analysis.

[Double Trouble]

Bruce:

How about the weight of the wad ?

; )

[Bruce Day]

OOPS. My error. Thanks for the catch. I used a rifle formula. The wad wt is in there with the shot charge wt. Its basically everything in the hull that goes out the end of the barrel to produce an equal and opposite reaction.

So, if the question is how do I get less recoil, the answer, assuming the gun configuration remains constant, remains to use less shot or less powder or less velocity. The wad wt is pretty much a constant.

[Bruce Day]

Originally Posted by charlie cleveland

.. i can not tell the diferance between the 2 1/2 inch and the 2 3/4 inch shells both kick like a 16 ga....charlie

Exactly. That's because shell length or chamber length is irrelevant to the recoil formula. Its what is in the shells that is significant.

[Double Trouble]

Bruce - I was just being a smart-*ss...

Compared to you guys, I'm fairly new to Parkers, and really new to low-pressure shells like RST.
But one thing I must admit is this : If for no other reason (and since I no longer reload), I would shoot RST shells just because they pattern so well. Then, on top of that, the fact that they don't kick hard & don't beat up my gun makes it hard for me to even look at cheaper shells...

It must be witchcraft !

[Dean Romig]

Originally Posted by John Mazza

It must be witchcraft !

Definitely that!

If you want a really sweet twenty-gauge RST load give Morris a call and ask him for the shells he cooked up for Burt's Gun. Except for the sound I barely knew when these shells went off and the downrange effect was impressive.

[Bruce Day]

Well its not witchcraft or rocket science or brain surgery. The easy answer is to just tell folks to buy RST shells, and I think they are great shells, and Morris and Alex are fine people and great PGCA supporters. However, I like to know the figures, like to know the loading data, like to know what my guns were made for and all those other details that are probably insignificant and even boring for many people. I like to load my own and I like knowing which commercial loads are available for my old guns. All that arcane and detailed BS, I kinda like it.......its probably just me.

[Dean Romig]

Nope, I think it's a wise thing to want to know what we're feeding our pets and pet guns.