• http://www.sjgames.com/errata/gurps/4e/ultra-tech.html
• http://www.sjgames.com/errata/gurps/4e/ultra-tech-2p.html

Ammunitions weights for 10mm guns: 10mm CLP is listed as 0.014lbs which is 98 grains a modern day 10mm round has 155-200gr for the bullet alone. In addition to that there is some weight for the propellant.

A Weight Per Shot of between .025 and .03 allows for a medium {150 grain} or heavy {200 grain} bullet and believable propellant load.

7.5mm seems a bit too light also : 0.006lbs = 42 grains A Weight Per Shot of between 0.01lbs and 0.0125 is more realistic.

check other pistol loadings

On page(s) p.136 The description for the Storm Chaingun mentions that it uses a 100 shot belt but can use the 30 shot magazine of the storm rifle. however, on p. 137, in the table the Storm Rifle uses a 12 shot magazine and the Storm Chaingun (on p.138) uses a 60 shot belt. One or the other is in error.

Chanleys edited weights:

Adjusting magazine weight by increasing or decreasing number of shots:

Name				Weight Old	Old Shots	New Shots	Ammo Weight in magazine

Conventional and ETC Guns

Heavy Pistol, 10mmCLP		2.5/0.7		20+1(3)		37+1(3)		0.7 / (0.014 *1.35) for a standard box magazine
Holdout Pistol, 7.5mmCLP	1/0.2		18+1(3)		25+1(3)		0.2 / (0.006 *1.35) for a standard box magazine
Magnum Pistol, 15mmCLP		3/1		9+1(3)		12+1(3)		1 / (0.060 *1.35) for a standard box magazine
Medium Pistol, 7.5mmCLP		2/0.5		30+1(3)		62+1(3)		0.5 / (0.006 * 1.35)  for a standard box magazine

Machine Pistol, 10mmCLP		3/1		30+1(3)		53+1(3)		1 / (0.014 *1.35) for a standard box magazine
PDW, 5.7mmCL			4.5/1		100+1(5)	64+1(5)		1 / (0.013 *1.2) for a plastic helical
Urban Assault Weapon 
  SMG Barrel, 10mmCLP		8/1		40+1(3)		64+1(3)		1 / (0.014 *1.111) for a light box magazine
  Shotgun Barrel, 18.5mmPC	-/0.75		5+1(3i)		8+1(3i)		0.75 / (0.092 *1) for a tube

Anti-Material Rifle, 15mmCL	30/2		10(3)		9(3)		2 / (0.2 * 1.111) for a  light box magazine
Assault Carbine, 7mmCL		7/1.5		50+1(3)		50+1(3)		1.5 / (0.027 * 1.111) for a light magazine
Gatling Carbine, 5.7mmCL	10/2		200(5)		125(5)		2 - 0.05 / (0.013 * 1.2) for a light helical and a B Cell worth 19,500 shots
Hunting Rifle, 7mmCL		7/0.3		10+1(3)		10+1(3)		0.3 / (0.027 * 1.111) for a light box magazine
Payload Rifle, 25mmCL		38/10		8+1(3)		9+1(3)		10 / (1 * 1.111) for a light box magazine
Storm Carbine, 10mmCL		8/2		50+1(3)		45+1(3)		2 / (0.04 * 1.111) for a light box magazine
Storm Rifle, 10mmCLR		10/1.2		12+1(3)		18+1(3)		1.2 / (0.06 *1.111) for a light box magazine

Civilian Shotgun, 18.5mmPC	6/0.75		5+1(3)		7+1(3)		0.75 / (0.092 *1.111) for a light box magazine
CAW, 18.5mmPC			10/1.5		10+1(3)		15+1(3)		1.5 / (0.092 *1.111) for a light box magazine	
Shotgun Pistol, 18.5mmPC	4/0.7		5+1(3)		7+1(3)		0.7 / (0.092 *1.111) for a light box magazine
Underbarrel Shotgun, 18.5mmPC	1.5/0.75	5+1(3i)		8+1(3i)		0.75 / (0.092 *1) for a Tube

Underbarrel GL, 25mmPC		1.5/0.8		3(3)		3(3)		0.8 / (0.22 * 1.111) for a light box magazine
Underbarrel GL, 40mmPLB		3/2		5(5)		5(5)		2/ (0.4 *1) for preloaded barrel

Light Support Weapon, 7mmCL	15/5		200(5)		185(5)		5 / (0.027 *1) for a belt 
Storm Chaingun, 10mmCLR	        20/6	        60(5)		99(5)		6 - 0.05 / (0.06 *1) for a belt and a B cell worth 9,000 shots/15 minutes.

SplatGun, 15mmPLB		20/10		30(30)		37(30)		10 / (0.27 *1) for a preloaded barrel. or lower weight to 8.1

Mortar Box, 40mmPLB		12/8		16(20)		20(20)		8 / (0.4 * 1) for a preloaded barrel
Mortar Box, 64mmPLB		160/80		30(30)		40(30)		80 / (2 *1) for a preloaded barrel

Tank Cannon, 100mmCL		2,500/40	1(4)		1(4)		40 / (40 * 1) for no magazine.

Assault Cannon, 25mmCL		75/12		34(5)		12(5)		12 / (1 *1) for a belt. Or Increase weight to 34. I suspect gun weight is errata as well, since this appears to be a copy paste of the Heavy Chaingun.
Heavy Chaingun, 15mmCL		75/12		50(5)		58(5)		12 - 0.5 / (0.2 *1) for a belt and C cell worth 10,800 shots/15 minutes
Minigun, 7mmCL			33/10		400(5)		352(5)		10 - 0.5 / (0.027 *1) for a belt and a C cell worth 90,000 shots/15 minutes

Gas-Powered Air Gun Table

Needler, 3mmN			1/0.3		100(3)		54(3)		0.3 / (0.005 * 1.111) for a light box magazine
Paint Pistol, 15mm		1/0.5		20+1(3i)	20+1(3i)	0.5 / 0.025 * 1) for a tube.
Tangler Pistol, 25mmT		2/0.5		4+1(3i)		4+1(3i)		0.5 / (0.12 *1) for a tube.
Wrist Needler, 3mmN		0.1/0.03	25(3)		5(3)		0.03 / (0.005 * 1.111) for a light box magazine. If like the other "mini" weapons, the decimal place got slipped, than weight should be 1/0.3, and shots go to 54(3).
Ice Gun, 3mm ice		1/0.3		20(3)		12(3)		Technically, a cup of water is 0.5, this adjusts shots to 0.3. Also note that ammo weight should b 0.8 to account for the 0.5 lbs of C cell. If you want a cup of water AND the C cell, make ammo weight 1.

Needle Rifle, 3mmN		5/1		100(3)		180(3)		1 / (0.005 * 1.111) for a light box magazine
Paint Carbine, 15mm		4/1		50+1(3i)	40+1(3i)	1 / (0.025 * 1) for a tube.
Tangler, 25mmT			5/1		8+1(3i)		8+1(3i)		1 / (0.12 *1) for a tube.
Partisan Needler, 3mmN		12/1		140(3)		180(3)		1 / (0.005 * 1.111) for a light box magazine. Note, may actually be 140 if the mini fac is in the magazine.


Electromagnetic Gun Table

Electromag Mortar, 64mm		50/10		4(5)		4(5)		10 / (2 * 1.2) for a light helical or light drum. Technically, ammo weight should be 15 lbs, to account for the 5 lbs of D cell.

Gauss Minineedler, 3mm		0.1/0.03	25(3)		7(3)		0.03 / (0.004 * 1.111) for a light box magazine. Note, suspect slipped decimal place for both gun and ammo weight, increasing shots to 56(3), and weight to 1/0.3, accounting for 0.05 lbs of B cell (which alone is heavier than the 0.03 original weight!).
Gauss Pistol, 4mm		2/0.5		40(3)		60(3)		0.5 - 0.1 / (0.006 * 1.111) for a light box magazine and 2 B cells (NOT a C cell!, so the Notes column has Errata too, is should be a [2] not a [3])

Gauss Machine Pistol, 4mm	3/0.5		40(3)		60(3)		0.5 - 0.1 / (0.006 * 1.111) for a light box magazine and 2 B cells. 
Gauss Needler, 3mm		1.5/0.5		100(3)		101(3)		0.5 - 0.05 / (0.004 * 1.111) for a light box magazine and 1 B cell (Notes column errata: should be a [1] not a [2])
Gauss PDW, 4mm			4.6/1		80(3)		75(3)		1 -0.5 / (0.006 * 1.111) for a light box magazine and a C cell

Sniper Railgun, 7mm		20/1.4		30(3)		52(3)		1.4 / (0.024 * 1.111) for a light box magazine. Technically, ammo weight should be 6.4 to include the D cell.
Gauss Needle Rifle, 3mm		6/1		100(3)		112(3)		1 - 0.5 / (0.004 * 1.111) for a light box magazine and a C cell.
Gauss Rifle, 4mm		8.5/1.4		60(3)		135(3)		1.4 - 0.5 / (0.006 * 1.111) for a light box magazine and a C cell.
Portable Railgun, 10mmG		20/1.5		25(3)		11(3)		1.5 - 0.5 / (0.08 * 1.111) for a light box magazine and a C cell. Wouldnt surprise me if this was meant to be powered by a D cell, like the sniper rifle. Weight is then 20/5.5, shots are then 17(3).

Gauss CAW, 18.5mm		10/1.5		30(3)		24(3)		1.5 - 0.5 / (0.037 * 1.111) for a light box magazine and a C cell.
Gauss Shotgun Pistol, 18.5mm	3/0.5		10(3)		12(3)		0.5 / (0.037 * 1.111) for a light box magazine. Technically ammo weight should be 1 lbs to include a C cell.

EMGL, 40mmG			10/3		3(5)		6(5)		3 - 0.5 / (0.33 *1.2) for a plastic helical/drum and a C cell.
Underbarrel EMGL, 25mmG	       2/1 		3(3)		5(3)		1 - 0.5 / (0.09 * 1.111) for a light box magazine and a C cell.

Gauss LSW, 4mm			20/7		300(5)		902(5)		7 - 0.5 / (0.006 *1.2) for a plastic drum and a C Cell. OR set shots to 277(5) for a plastic drum and a D cell. Errata notes column, should be a [4] not a [3] if that is done. Also ROF should be 50, not 20, to match descriptions 3,000 rounds per minute.

Auto EMGL, 40mmG		64/10		20(5)		15(5)		10 - 5 / (0.33 * 1) for a belt feed and a D cell.
Railgun, 40mm			4,000/150p	200(5)		25(5)		150 / (6 * 1) for a belt and external power.
Gauss HMG, 7mm			64/20		200(5)		520(5)		20 - 5 / (0.024* 1.2) for a plastic helical/drum and a D cell. Note: The description of the gun is either in error (there is no 4,000 round cassette) or the weight for the ammo needs to change: 155lbs for 4,000 rounds in a plastic drum and 8 D cells to power it.
Gauss Minigun, 4mm		64/20		1000(5)		2083(5)		20 - 5 / (0.006 *1.2) for a plastic drum and a D cell. Note: Gun and ammo weight are probably copy/paste errors from the HMG, this one should be sent to Dave for double checking. Also ROF should be 166, not 100, to match the descriptive text saying it can fire 10,000 rounds per minute.

Grav Guns

Grav Minineedler		0.1/0.03	100(3)		27(3)		0.03 / (0.001 * 1.111) for a light box magazine, however, like the Gauss Minineedler, I suspect a decimal place was slipped for both gun and ammo weight, making shots 180(3) for a light box magazine and 2 B Cells.

Grav Needler			1.5/0.5		500(3)		405(3)		0.5 - 0.05 / (0.001 * 1.111) for a light box magazine and a B cell. The description pretty much has to be in error, as a C cell alone weighs 0.5lbs.

Grav Needle Rifle		6/1		1000(3)		450(3)		1 - 0.5 / (0.001 * 1.111) for a light box magazine and a C cell.
Sniper Grav Gun			10/1		1000(3)		450(3)		1 - 0.5 / (0.001 * 1.111) for a light box magazine and a C cell. If it really is supposed to be 2 C cells (which weigh 1 lbs by themselves) ammo weight needs to change to 1.5. Shots stay at 450(3).

Heavy Grav Needler		20/4		4000(5)		3,600(5) 	4 / (0.001 * 1.111) for a plastic drum. Ammo weight needs to change to 9 to add in the weight of a D cell. 

Gravitic Railgun		1000/10Fp	2000(5)		33(5)		10 / (0.3 * 1 ) for a belt and external power. Ammo weight for 2000 shots on a belt is 600lbs.

Gyroc Launchers

Gyroc Carbine, 15mm		4/1		10(3)		9(3)		1 / (0.1 * 1.111) for a light box magazine.
Gyroc Launch Pistol, 15mm	2/0.7		6(3)		6(3)		1 / (0.1 * 1.111) for a light box magazine.
Gyroc LSW, 15mm	                12/3		30(5)		25(5)		3 - 0.05 / (0.1 *1.2) for a plastic helical drum and a B cell.
Gyroc Pistol, 15mm		1/0.4		4(3i)		4(3i)		0.4 / 0.1 * 1 for revolver.
Holdout Gyroc, 15mm		0.25/0.1	1(3i)		1(3i)		0.1 / 0.1 * 1 for breach loader.
Underbarrel Gyroc, 15mm		1.5/0.7		6(3)		6(3)

It is listed as 2“ by .1” and 2 lbs. This is way too heavy for its intended purpose and nonsensically dense. Based on the Size Modifier rules, there are three possible resolutions:

• The worm is 2' by 0.1'. The notation meant feet, not inches. (A Nigel Tufnel typo…).
• The worm's dimensions are correct, but the weight should be 0.002 lbs (or neg.), not 2 lbs. This is consistent with the SM table.
• The worm's dimensions are correct, but the weight should be .01 lbs, not 2 lbs. This is consistent with the similarly-sized robobug later in the chapter.

Has an occ of 1+1 but a load of only .1 and too low ST/HP.

check the others.