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Merc1500
09-05-2010, 12:03 PM
I've noticed a little interest in determining whether a Magpul front sight would actually melt on a gas block and after how many shots it would take it to actually begin melting. Please post a quick reply on this thread if you too in fact would like to know. If 30 people reply I will stock up on some ammo, mount my brother-in-laws front sight on my ar and post pics on the carnage. If someone has already done this on this forum let me know:)

tomd1584
09-05-2010, 12:08 PM
Directly from the Magpul website:

"NOTE: Cannot be mounted to a railed gas block due to excess heat issues. Front MBUS must be mounted to a railed fore end on the same plane as the receiver rail."


good enough for me, IMO.

=Mike=
09-05-2010, 12:16 PM
Im more interested in what your brother-in-law did.

Merc1500
09-05-2010, 12:21 PM
Well he bought it, used it once sat it on his shelf and hasn't used it since. He is away on vacation now so.......... yea.;)

Merc1500
09-05-2010, 12:34 PM
Directly from the Magpul website:

"NOTE: Cannot be mounted to a railed gas block due to excess heat issues. Front MBUS must be mounted to a railed fore end on the same plane as the receiver rail."


good enough for me, IMO.

Valid point....... but I'm bored today and committed. Anyone else?

thrillhouse700
09-05-2010, 12:49 PM
mount an alum rail section on your bbq and put it on there then have your labor day party tomorrow and see what happens.

sleepercar
09-05-2010, 1:19 PM
mount an alum rail section on your bbq and put it on there then have your labor day party tomorrow and see what happens.

Amen.
Or just go back to the other thread where you already have 20 or so guys telling you not to do it.

zman
09-05-2010, 1:20 PM
Go for it. Visual aids work pretty good :)

jackliu239
09-05-2010, 2:22 PM
I love the smell of burning polymer in the morning. Do it :D

zoglog
09-05-2010, 2:28 PM
my friend says its bs and its just there for caution. ill trust magpul... but itll be nice to see a real test. go for it

Chach
09-05-2010, 2:29 PM
If it's your BIL's and not yours, why not just go ahead and do it? Why do you need 30 people interested? Hell, I'd do it if I had the proper gas block on one of my AR's, carnage is a good thing. :43:

Just be sure to take video and count the rounds, I know I'd watch it.

DREADNOUGHT78
09-05-2010, 2:34 PM
Do it.

xibunkrlilkidsx
09-05-2010, 2:41 PM
Do it.

SubSonicSOPMOD
09-05-2010, 3:19 PM
I'm his brother in law and your all a bunch of ***holes...with that said DO IT!

jonni
09-05-2010, 3:34 PM
do it

DOO EET

Merc1500
09-05-2010, 3:35 PM
Bump. I need more people to convince me. Specially since my local gun range has about 5 uniformed officers at it right now.

Group B
09-05-2010, 3:47 PM
Do it.

Cokebottle
09-05-2010, 3:54 PM
Wouldn't matter whether it melted or not... Gas block is too low for the MBUS and you won't be able to get the pin high enough to zero it.

Kerplow
09-05-2010, 4:00 PM
Wouldn't matter whether it melted or not... Gas block is too low for the MBUS and you won't be able to get the pin high enough to zero it.

who said anything about aiming?;) besides, i think the sight would be high enough with one of these: http://riflegear.com/p-772-jd-machine-upper-height-gas-block-556.aspx

Noobert
09-05-2010, 4:06 PM
Do it.

Merc1500
09-05-2010, 4:09 PM
Ok update. Ar15barrels has generously offered a RAW lower with beta mags for the test. But I have no idea where he's from and he is probably nowhere near but it's the thought that counts. I will head back out to the range with ammo, extra mags, the front sight, camera and ar in hand in about an hour. Waiting for the leos to clear out.:)

Merc1500
09-05-2010, 4:12 PM
The fact that the front sight isn't intended for the gas block as far as actually aiming the thing doesn't concern me. This test is purely to see how much heat this baby can handle.

nemisis1400
09-05-2010, 4:25 PM
Do it!!!

BAGunner
09-05-2010, 4:32 PM
doo eet

Merc1500
09-05-2010, 4:33 PM
Probably should've put this in OT. Would have got more traffic. Think 300 rds will do it?:43:

joelogic
09-05-2010, 4:50 PM
300 sounds right
eNAohtjG14c

Gregchico
09-05-2010, 4:54 PM
I'm curios to see how many rounds it would take to start melting them....

Cokebottle
09-05-2010, 4:58 PM
who said anything about aiming?;) besides, i think the sight would be high enough with one of these: http://riflegear.com/p-772-jd-machine-upper-height-gas-block-556.aspx
He's too cheap to buy a gas-block mount sight.... what makes you think he wants to spend almost as much as a pair of MBUS for a new gas block? :D

vta
09-05-2010, 5:49 PM
i wanna see what happens. do it!

tomd1584
09-05-2010, 6:04 PM
He's too cheap to buy a gas-block mount sight.... what makes you think he wants to spend almost as much as a pair of MBUS for a new gas block? :D

but yet he's willing to waste 300 rounds of ammo to see if it melts :cool2:

Merc1500
09-05-2010, 6:42 PM
Ok that was fun! Didn't do the entire 300 rds. I just did 250. The sight held up perfectly. Magpul knows its sh*t. Previous poster was correct about it being able to shoot while on the gas block. It isn't accurate at all.
Mounted before leaving the house.
http://imgur.com/02Hu1l.jpg
Ready toshoot at the range.
http://imgur.com/gLu5kl.jpg
First 100 rds. No damage whatsoever and just getting warm.
http://imgur.com/VbXKzl.jpg
200 rds. so hot I had to wear gloves. Keep in mind that I had 6 mags and was shooting as fast as possible with two people reloading in between . The ;longest part was taking the pics.
http://imgur.com/fUAM9l.jpg
The 200 rds. worth of boxes.
http://imgur.com/CBpYIl.jpg
After 250. All within about 5 minutes.
http://imgur.com/GzYT1l.jpg

Merc1500
09-05-2010, 6:47 PM
I did not notice any melting at all, the polymer was hot to the touch but hard still and after about 30 seconds it was cool again. I shot a video of the last 50 rds. I have to set up a youtube account and try to figure it out and get something posted. To really melt this mother It;d probably require FA and beta mags. I have neither.

Merc1500
09-05-2010, 6:48 PM
First person to name this range gets a secret prize by the way.

Merc1500
09-05-2010, 6:49 PM
My BIL doesn't count.:p

Merc1500
09-05-2010, 6:52 PM
Resulting carnage on the ground
http://imgur.com/lOhZ7l.jpg
Swept up
http://imgur.com/q6wyAl.jpg
http://imgur.com/npORcl.jpg

Merc1500
09-05-2010, 6:54 PM
Money had no bearings whatsoever on this test. Success did rely on proper equipment however. Which I did not possess. (i.e. FA, and beta mags.)

Cool Hand Luke
09-05-2010, 6:57 PM
Were you able to get the pin up high enough to get any form of accuracy and at least make the shooting fun?

Merc1500
09-05-2010, 6:58 PM
No I was not. I put the pin up as I high as It'd go and still had to shoot about 6 in. higher than it was hitting at 50 yards.

Cokebottle
09-05-2010, 7:10 PM
Not too shabby for a $50 sight!

I might pick up a set of these.... after all, they are just backup sights in case the ACOG gets broken.

Merc1500
09-05-2010, 7:19 PM
Sh*t I guess that was a good review for the Magpul MBUS. Hey Magpul can you reimburse me for that ammo now?:p

Merc1500
09-06-2010, 8:12 AM
Just as I anticipated, I'm running into some bull***t with setting up a youtube account. Might use my sisters.

lehn20
09-06-2010, 8:20 AM
Melt or not, the quality suck and they break off easily from bumping into things or tightening the screw. MBUS are not meant for any serious work in austere conditions. More like airsoft!.
Stay with TROY etc

vta
09-06-2010, 8:39 AM
Melt or not, the quality suck and they break off easily from bumping into things or tightening the screw. MBUS are not meant for any serious work in austere conditions. More like airsoft!.
Stay with TROY etc

maybe you accidently bought the PTS MBUS. mine is mounted real solid. would take a massive bump to knock it off.

Merc1500
09-06-2010, 12:45 PM
Whats the PTS MBUS?

Noobert
09-06-2010, 2:06 PM
It's the airsoft one that Magpul makes

Cokebottle
09-06-2010, 5:24 PM
Whats the PTS MBUS?
It's the airsoft one that Magpul makes
Yup.

Made in China under license. They look identical, I don't believe they say "PTS" on the sight itself, and a lot of these are being sold on eBay as the real thing.

Honestly... when the MBUS is only $100 for the pair, why try to cheap out and save $25 by going to eBay and taking your chances?

Noobert
09-06-2010, 5:29 PM
Actually they are marked
http://www.milsig.ca/store/images/magpul/magpul-pts-mbus-bk.jpg

PolishMike
09-06-2010, 5:40 PM
Its not inaccurate its because you are using a rail height sight on a gas block.

Merc1500
09-06-2010, 5:48 PM
You are correct. I was attempting to use for the role with which it was not intended.

Cokebottle
09-06-2010, 6:11 PM
Actually they are marked
That's good to know.


Nothing a little plastic filler and Alumahyd can't fix :D

CoyoteHunter555
09-06-2010, 6:14 PM
You are correct. I was attempting to use for the role with which it was not intended.

You can get a rail height gas block

slappomatt
09-06-2010, 6:31 PM
I'm pretty sure I have seen a very slim rail spacer somewhere as well. Thanks for doing this test and please ignore all the naysayers. Its only a $40.00 sight big deal. glad to know it will take the heat. for 98% or so of the poeple who own AR's and aren't police or military these are perfect. I owned a set for a while ( sold them on one of my rifles and I'm waiting for the gen 2 for my current build) and I really don't think it would be easy to damage them. you would pretty much have to bash the gun the correct way against a rock or something to break them. and doing that would almost for sure break a 3X the price troy sight as well.

Cokebottle
09-06-2010, 6:43 PM
Agreed... Plastic may be cheap, but it also tends to be more resilient.
Aluminum may bend or break before a good quality reinforced plastic will.

Of course, the moral of the story is if you have flip-up BUIS, leave them in the down position until your primary optics fail.
They are just that... Back-Up Iron Sights, and very few flip-up sights are as durable as fixed sights.

zman
09-06-2010, 8:41 PM
Good job merc! Thanks for indulging us :D

Merc1500
09-13-2010, 11:26 AM
My pleasure. If I hadn't already payed for my MI rear sight I probably would've bought a set of these myself. Might anyway. :43: