Why are some sniper rifles so loud?

Factual Questions
21

The M107 sniper rifle weighs 28 lbs unloaded. A 10 rd magazine adds another 10 lbs.

It also has 11,500 ft/lbs of muzzle energy!

22

Okay, here’s some info from my copy of Jane’s Guns Recognition Guide. We’ll stick with sniper rifles in the 7.62 NATO power range as they are the most common.
First the bolt guns:
Accuracy International L96A1 6.5 kb/14.3 lbs
Beretta Sniper 5.55kg/12.21 lbs
Enfield Enforcer 4.42kg/9.72 lbs
FN 30-11 Sniping Rifle 4.85 kg/ 10.67 lbs
GIAT FR-F1 & FR-F2 5.20 kg/ 11.44 lbs
Mauser SP66 6.25 kg/ 13.75 lbs
Mauser 86 4.90 kg/ 10.78 lbs
Parker Hale M82 4.80 kg/ 10.56 lbs
Parker Hale 85 5.7 kg/ 11.88 lbs
Sako TRG 4.7 kg/ 10.34 lbs
Sig SSg-2000 6.6 kg/ 14.52 lbs
Sig SSg-3000 5.4 kg/ 11.88 lbs
Springfield US M1903A4 3.94 kg/ 8.67 lbs
Steyr-Mannlicher SSG-69 3.90 kg/ 8.58 lbs
US M40A1 6.57 kg/ 14.54 lbs
Vapensmia NM149S 5.6 kg/ 12.32 lbs

Now the autoloaders:
Dragunov 4.31 kg/ 9.48 lbs
H&K PSG1 8.1 kg/ 17.82 lbs
H&K MSG90 6.4 kg/ 14.08 lbs
Stoner SR-25 4.88 kg/ 10.73 lbs
Zastava M76 4.20 kg/ 9.2 lbs

I left a few rifles out because specific information wasn’t included for their sniper variants. Out of these 21 sniper rifles, 16 of them come in a pound or more under the (rather arbitrary) 15 pound mark. Of course, if you go with guns of larger of smaller caliber than those in this power range you can get something like the Gepard M3 which uses the 14.5 x 114mm round and weighs 20 kg or the VAL Silent Sniper in 9 x 39 mm Special which weighs only 2.5 kg.

I’m having trouble locating my copy of Small Arms of the World. More when it turns up.

23

Okay, I give up. It was a flippant remark that just expressed some suprise with the weight of the example.

I also lied about being able to kill people with my bike at 1400 meters. It’s more like 50.

24

I thought that flash supressors hide the flash from the firer (thus preventing a little distraction from dazzling), they don’t make the flash invisible to anyone else?

25

I know I’m 6 years and 1 day late to the party, but while we’re talking about how much sniper rifles weigh, I’d like to mention that the Denel NTW-20 uses .79 caliber ammunition and weighs a whopping 68 pounds. (But then I guess I should also mention that it’s South African and is primarily an anti-materiel rifle.)

…Well-played, sir.