Re-do volumes on Remington+Mossberg shotguns

[tenmillimaster]

Summary

SUMMARY: Bugfixes "Corrects volumes on rem+mossy shotguns"

Purpose of change

I didn't document to my liking the volumes and sources for the shotguns, and additionally, accidentally made one of the hunting shotguns larger than its tactical counterpart.

Describe the solution

Re-audit relevant shotguns.

Describe alternatives you've considered

None.

Testing

None.

Additional context

	Model	Receiver+stock area (mm^2)	Rcvr width (mm)	Rcvr volume (mm^3)	sawn barrel area (mm^2)	sawn barrel length (mm)	total volume (mL)	Sawn barrel volume (mL)	Ref image	image calculations
Mossberg	500 Field	63653.264	35.56	2263510.068	8760.82	323.733	2449.72mL	186.21mL	https://www.mossberg.com/wp-content/uploads/2016/01/50126_500Classic-1.png	https://i.imgur.com/Dh0Oc1S.png
Mossberg	500 Security	66318.466	35.56	2358284.651	1746.528	85.25	2386.39mL	28.10mL	https://www.mossberg.com/wp-content/uploads/2018/11/50429_500-RETRO_Persuader.png	https://i.imgur.com/xPwinRU.png
Mossberg	590 mariner	71650.007	35.56	2547874.249			2547.87mL		https://www.mossberg.com/wp-content/uploads/2016/01/50299-catalog.jpg	https://i.imgur.com/iHBFR5x.png
Mossberg	930 SPX	73782.666	35.56	2623711.603			2623.71mL		https://www.mossberg.com/wp-content/uploads/2016/01/85360_930SPX.png	https://i.imgur.com/6BDECBE.png
Remington	870 Wingmaster	63507.461	35.56	2258325.313	10893.89	406.248	2487.76mL	229.44mL	https://www.remington.com/sites/default/files/styles/product_gallery_1200/public/product/shotgun/galleryimages/870WingmasterMag_BTY.png?itok=88UprSOo	https://i.imgur.com/8NEdUL0.png
Remington	870 Express	65958.499	35.56	2345484.224	1189.384	56.083	2365.30mL	19.81mL	https://www.remington.com/sites/default/files/styles/product_gallery_1200/public/product/shotgun/images/870ExpressSyn2ShotExt_25077_RV.png?itok=ayVVgn9m	https://i.imgur.com/dfulTya.png
Remington	870 MCS	36094.149	35.56	1283507.938			1283.51mL		https://www.remingtondefense.com/assets/images/shotguns/breacher/24975.jpg	https://i.imgur.com/jHplXmL.png
Remington	1100 competition	65432.292	35.56	2326772.304	12775.22	428.636	2625.82mL	299.05mL	https://www.remington.com/sites/default/files/styles/product_gallery_1200/public/product/shotgun/galleryimages/Model%201100%20Competition_82821_0.png?itok=JT9h9U8K	https://i.imgur.com/A0AtNN3.png
KAC	KAC masterkey	30038.372	35.56	1068164.508			1068.16mL		https://www.militaryfactory.com/smallarms/imgs/knights-armament-masterkey-underbarrel-shotgun-united-states.jpg	https://i.imgur.com/HERTjc5.png

Volumes of barrel saw-off equal to:

((imagej area)^2)/4 * pi / Feret length

930 and 1100 receivers assumed to be same width as 500 and 870 counterparts.

870 receiver width from http://www.notpurfect.com/main/87020.htm
500 receiver width measured and provided by a personal contact.

[mlangsdorf]

Revolver shotgun still has a weird barrel volume but that might be out of scope.