doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Velocity and shot payload - Wear and tear

The recent threads about pressure and loads has made me question the suitability of my main hunting handload for use in vintage guns and I�m in need of some considered advice.

I understand the adage about using low pressure to save the barrels and action and light shot payloads to save the wood.
I do not worry about occasionally shooting (50 rounds per year) 1 1/8oz. loads through guns proved for 1 1/8oz and I use loads under 1oz. for target shooting.
I am clear on the oft asked chamber pressure question and keep all of my pressures under 7500PSI.

Previously, I had not fully considered the effect of velocity/payload on the wear and tear on older guns and had really only concerned myself with the size of the shot payload. In light of recent posts and really just pausing for a second to consider the physics, I pose the following question:

How great is the effect of increased velocity on the wear and tear of a vintage gun?
By �great� I mean to ask if the effect is significant or negligible?

If we keep the shot payloads the same and pressures similar but increase the velocity, how much does the increase in velocity affect recoil/abuse to the gun? I�m sure that someone can answer this mathematically!

Consider for a moment the two loads below:

HULL: Federal Gold Medal
PRIMER: Win. 209
WAD: Fed. 12S3
POWDER: Longshot (34.2 Gr.)
SHOT: 1 1/8 oz. 6.5 NP
PRESSURE: 7100 PSI
VELOCITY: 1420 FPS

VS.

HULL: Federal Gold Medal
PRIMER: Win. 209
WAD: CB 1118-12
POWDER: PB (23.5 Gr.)
SHOT: 1 1/8 oz. 6.5 NP
PRESSURE: 7000 PSI
VELOCITY: 1200 FPS


These are used in nitro proved, fluid steel barrels with 70mm chambers.
Thanks!

Using this Recoil Calculator, and hoping someone without my dycalculia will check the math
http://www.omahamarian.org/trap/shotshellenergy.html

IF your gun is 6.5 pounds, the recoil of the 1420 load is 40.1 foot pounds; the 1200 fps 26.8.

For comparison
7/8 oz. at 1280 fps in a 7.5 pound shotgun = 12.7 ft/lbs of free recoil
1 oz. at 1180 fps in a 7.5 pound shotgun = 17.3 ft/lbs of free recoil
1 1/8 oz. at 1200 (3 Dram) in a 7.5 pound shotgun = 23.0 ft/lbs of free recoil

Drew is right.

The gun does not care about the velocity of the payload, only the recoil therefrom and the pressure generated to propel it.

E=1/2 MV2. That squared part is the [censored].

Shotgun,

You just found out that it is not possible to use normal nomenclature for a female dog on this forum w/o being censored.

Ain't that a [censored]!

Anyway, there is nothing to be gained from velocities above 1200 fps when using lead shot for clay target or upland game use unless the shooter just wants more abuse, in which case the gun gets the full brunt too. Want more energy on target or game? Simple, use larger shot.

Study the down range ballistics of lead shot at 40 yards or more in terms of energy, time of flight and remaining velocities & draw your own conclusions.

I think Blue Grouse brings up a very valid concern & Drew confirms it. No need to be unkind to those old guns that have survived this long or been brought back into shootable condition by harming them w/excessive velocities. To what end are these high speed loads the least advantageous? None that I am aware of.

addendum: Many bunker loads [24 grams] are 1350 fps, but it is to get the patterns to open & be more uniform more than it has to do w/terminal ballistics.

[quote=tw]


"Anyway, there is nothing to be gained from velocities above 1200 fps when using lead shot for clay target or upland game use unless the shooter just wants more abuse, in which case the gun gets the full brunt too. Want more energy on target or game? Simple, use larger shot.

Study the down range ballistics of lead shot at 40 yards or more in terms of energy, time of flight and remaining velocities & draw your own conclusions"

Spot on.

I told my brother in law who has a severe case of "magnumitis" the same thing last year at Thanksgiving dinner. He got so upset he jumped up & spilled a full glass of red wine down his white shirt & on the carpet while explaining to me the superior killing power of 1 1/4oz @ 1500 fps for pheasants & that he wasn't going to argue with me about downrange retained velocity.

Heck, until the wine flew all over I thought we were having a friendly discussion.

The best Thanksgiving ever!

Good answers here. Lots of folks focus on reducing payload, then go out and buy some of the very fast 7/8 oz international target loads, which may well generate more recoil than a slower 1 oz load. You have to look at both and do the math.

I have used that longshot recipe, but not in my collector guns. It will give you a sharp punch in the snout, so your gun is feeling it, too. It really has a different recoil signature--sort of like a Sugar Ray Leonard jab...Steve

There you have it!
Drew, thanks for the calculator.
I do suffer from a touch of magnumitis from time to time but I had mostly come to the same conclusion.
I will settle with a 1 oz. load of 6.5 nickel plate shot at 1250 fps and save my 114 year old gun a 53% increase in free recoil.
Really not worth beating up the old girl for one or two decimal places of energy downrange.
In answer to my own question, the increase in velocity is significant!

When most of the early guns were made, they were made for game shooting, or less frequently "live pigeon" shooting. The 'standard' English game set up was a gun with 2 1/2" chambers proofed for 1 1/8 oz of shot. The typical cartridge was the standard Eley Grand Prix, which was 1 1/16 oz, and would have been fairly moderate velocity. Guns would have had barrels between 25" and 30" and weighed between 6 and 7 lbs. 1 oz loads were used to get a little more velocity (Eley Impax)

For heavier use, there was the "live pigeon" gun. This had 2 3/4 chambers and was proofed for 1 1/4 oz shot. These typically weighed between 7 and 8 lbs and usually had 30" barrels. I believe the usual actual load was 1 1/8 oz.

The overall 'build' of the gun, action size, stock strength and safety margin etc was tailored to these limits.

Where heavier loads were required, a 10 bore, 8 bore or even 4 bore was used. It was generally thought that heavy loads where the shot was 'deeper' than the diameter of the cartridge gave poorer patterns.

Of course these ideas are now considered by many very dated, but they came at a time when our Victorian ancestors used to shoot a lot - and were great experimenters. I suspect there is a lot of truth in those old ideas.

The "True" definition of a Square Load for a shotgun is one in which the length of the shot column in the bore is equal to the bore diameter. Approximate loads which give this to the nearest 1/16oz are;
4ga = 3 3/16oz
8ga = 1 11/16oz
10ga = 1�oz
12ga = 1 1/16oz
16ga = 13/16oz
20ga = 5/8oz
28ga = 7/16oz
.410 = 3/16oz

Using the 12ga as standard then the proportionate weight of a shot charge which would give an identical length of column in each gauge, again to the nearest 1/16oz is;
4ga = 2 1/16
8ga = 1 5/16
10ga = 1 1/8
12ga = 1
16ga = 15/16
20ga = 11/16
28ga = 9/16
.410 = 5/16

In loking over these loads it is readily apparent that traditionally over the years the gauges smaller than the 12 have been more often loaded with a column length similar to that of the 12 rather than with a "Square load" = to their own diameter.
The �oz load in the .410 has a column length about = to 1 9/16oz in the 12 while the 3/4oz = a 2 3/8oz load in the 12 for length.