SIGforum
FN M249s

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/630601935/m/3520064134

October 08, 2017, 12:11 AM
Copefree
FN M249s
My friend bought one of these. He called me on Thursday with his plan and then sent me a picture of it today that the seller provided (a dealer in Missouri). It’ll be here next week.

It’s coming topped with a really nice ACOG too that he bought with it.

My question — how many rounds can you run through this thing consecutively before it melts? I know the barrel is really easy to change out for exhaustive use but this isn’t a military application, obviously. I’m just curious what a safe fire rate would be. Would a belt with 500 rounds be no problem while firing at a quick pace?


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Mind. Over. Matter.
October 08, 2017, 01:20 AM
Rob Decker
Per the interwebs the sustained rate of fire of an M249 is 100 rounds per minute, and the rapid fire rate is 200 rounds per minute. If you're trying to stay on the safe side I wouldn't exceed that by a wide margin.

I'm not sure if the US Army Technical Manual (TM) is available for open source download, but if so, the no-shit answer to your question should be in there.

The one caveat I'd throw out is IIRC the civilian-spec SAW fires from a closed bolt, whereas the military FA version fires from an open bolt to help dissipate heat. That may affect the rate of fire you can put through the weapon without risking damage to the barrel or other components.


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Death smiles at us all. Be sure you smile back.
October 08, 2017, 03:18 AM
darkest2000
I will bet that, as a semi auto firearm, your finger will be quite sore and tired out before you can get close to "melting" the barrel.

Plus, ammo isn't free you know, take the time to enjoy each shot rather than dumping them all down range at once.
October 08, 2017, 07:37 AM
fritz
quote:
Originally posted by Copefree:
My question — how many rounds can you run through this thing consecutively before it melts?
I’m just curious what a safe fire rate would be. Would a belt with 500 rounds be no problem while firing at a quick pace?

A barrel doesn't have to melt to be damaged. Throat erosion, and its resulting loss of accuracy and muzzle velocity, is what destroys most rifle barrels. Every barrel is different, but your first 500 round dump will likely produce enough throat erosion to noticeably degrade the barrel's accuracy.
October 08, 2017, 07:51 AM
limblessbiff
It's a semi auto and the trigger is like working a Windex bottle, you won't hurt it.
October 09, 2017, 05:45 PM
Creeping_Death
From the M249S Operator's Manual:

THE FIRING OF LONG SUSTAINED STRINGS OF FIRE (SUCH AS 200 ROUNDS IN 2 MINUTES) WILL CREATE A "COOK OFF" HAZARD.

-Page 13, Paragraph 8

Get spare barrels and stick to the 100 round nut sacks!


Evaluating volume of fire vs. shot placement effectiveness.
October 09, 2017, 05:55 PM
Strambo
Yeah, as a semi-auto not a huge deal. Use 100rd belts. Fire off a belt as fast as you can, then let it cool down for a few minutes.

They look cool, but I noticed the civilian retail price is like double what the Army pays for the real ones. Yikes!




“People have to really suffer before they can risk doing what they love.” –Chuck Palahnuik

Be harder to kill: https://preparefit.ck.page
October 10, 2017, 02:28 AM
YooperSigs
8K+ ? Wow. I wish my toy fund was that flush!


End of Earth: 2 Miles
Upper Peninsula: 4 Miles
October 10, 2017, 10:00 AM
jeeperxd
You can get them for a lot less than 8K. I have one and love it.You can also get a DSA RPD for a lot less and mine runs flawless after one trip back for repair.I am not worried about the barrel in either one.