Mossberg 500 shotgun, 6 mm version by ACM

[Trasher]

My ACM 6mm is perfect after firing 600-700 BBs. (knock on wood)

[Jin15]

Good to hear Trasher! I'll keep my fingers crossed that mine will run just as well as yours Did you have to lube the o-rings or anything when it arrived or was it fine right out of the box?

 

And Spence, I placed my order last night and Airsoft GI shipped it out today with UPS Ground so Im guessing it will be here sometime between friday and tuesday. I'll letcha know when it arrives!

[Wolfy]

Still so tempted by one of these. But there seem to be a number of lemons out there. Oh well no doubt one will end up in my hands one day.

[Kai_Wolf]

Yeah, I really want one of these too but I cant really tell from the reviews if it is worth it. Skimishability and all. Also, im a bit confused about the FPS results taken. For the 5 bb shot, is it decent? I see some people saying that the FPS is quite low, some saying not so much, so Im not sure what to think. Also, after lubing the O rings (or buying the high pressure ones), is the gun decently reliable with green?

 

My last question was more for the pleasure of just shooting it. When fired, is the ACM 6mm just as loud as the Maru 8mm? Or did they dull this down?

Edited March 30, 2008 by Kai_Wolf

[halofanatic333]

How much gas does the gun use?

[Trasher]

Mine is fine, out-of-box.

It's a great CQB gun for ranges no longer than 20 meters.

From the 5 shot spread about 3 BBs are effective, so a 3 or 4 BB firing mod/version would be better.

[EvilCookie]

Hey Jin, how did your turn out to be?

[chas]

Can anyone post a disassembly guide, please? My tank wont hold the gas anymore, its coming out the barrel as I try to fill it in.

 

Also, a guide on how to make the gun more powerful would be nice.

 

Thanks!

[whosloosin92]

On the buttplate of the stock there are two rubber plugs. Pry those out with a screwdriver and then unscrew the buttplate. After that you need a long screwdriver to unscrew the stock from the receiver. Then unscrew the silver screw located infront of the trigger guard. Pull the trigger assembly out. Pull the pump back and then you can wiggle out the valve assembly.

 

To fix your leaking problem all you need to do is unscrew the valve from the back of the valve assembly and you should be able to find the damaged oring.

 

To make the adjustable hop up all you need to do is drill a hole in the right location on the outer barrel so that you can have access to the screw which puts pressure on the hop up. I'll get some measurements later but I just got back from a long run in the rain. After I eat and get warmed up I'll post again.

[renegadecow]

Short, pistol grip versions just came out in black and stainless (both in 6mm or 8mm).

 

http://www.gunnerairsoft.com/catalog/produ...products_id=956

http://www.gunnerairsoft.com/catalog/produ...products_id=959

 

Makes me want one all over again, hoping that these new ones are less likely to break.

[whosloosin92]

Just ordered a black 6mm. I'm hoping it'll be a good one. My 8mm is perfect so maybe I'm pushing my luck.

[Pariah_WP]

Awesome review and thread. I was going to get one of these for my brother, but after this...I aint sure. Thanks for the info fellahs!

[Jin15]

Just thought I'd take a minute to share my experience with the ACM 6mm M500 after owning one for about a month

 

 

 

 

 

That's my ACM 6mm M500! Customized with a RS Tac-Star heatshield, RS Tac-Star Pistol Grip, shortened outer barrel, and Private Parts steel charging arms (haven't installed the charging arms yet though, as the stock ones are still holding up just fine).

 

Full metal, holds 180 BBs in the internal mag, fires 5 BBs per shot (giving you 36 shots before you need to reload), has about a 90 foot effective range on propane (I'd estimate the FPS at about 270 with 0.2s and propane), gives a great 7 ft tall by 8 ft wide spread at 90 feet, and gets around 45 to 50 shots per fill of gas. All in all I think it's the most awesome airsoft shotgun I've ever owned

 

And to top it all off I got a completely perfect non-lemon one. I've had it for about a month, fired a good 1,000 shots through it, and never had a single problem at all. No leaks, no jams, no funky o-rings, no problems at all. I even tried to break the stock charging arms by slam cocking it one handed Terminator style about 10 times in a row and they just wouldn't break. Much better quality than I expected!

 

It's probably the perfect airsoft shotgun IMHO, the only thing that could make it better would be real Mossberg trades. Other than that I think it's pretty much perfect. Tough as nails, shoots like a demon, and is just...well... awesome!

Edited April 22, 2008 by Jin15

[airsofter0866]

How does it sound to shoot? The sound of my m870 is pretty disapointing

[Jin15]

It's got a good "Snap!" to it. Like somewhere between a "pop" and a "crack!" sound. It's not exactly a realistic bang, but it's a heck of a lot nicer and louder than the pathetic Maruzen M870 pop noise.

[Bodgeups]

It sounds like Rice Krispies after you pour water on them.

 

Fixed for you

[Hick]

I just got the pistol grip version of this in the nickle black finish, and I am very impressed with it so far. First off, the black pistol grip versions are a dark chrome as opposed to the matte black of the full stock one. It has a sling loop attached to the left side of the pistol grip towards the top, and one on the bottom of the magazine tube at the front. It comes with a heatshield and no iron sights of any sort. The finish is sort of a black, brushed, chrome, and it is applied to all of the metal parts including the charging arms, there are a few blemishes on mine, but they are not too bad. The foregrip has a nice rubbery feel to it, but has quite a bit of play to it side to side. The pistol grip is hard plastic and is very comfortable to hold. Apart from the foregrip, the gun is solid as a rock, and has quite a bit of heft to it. The gun is also enormous, it is roughly the same length of a G36 with its stock folded, an MP5A4, or an M733 with its stock in the un-retracted position (up against the rear of the receiver).

 

As others have said, the spread is very good, but there is usually one bb that will fly off a bit randomly and will probably not come close to hitting what you were aiming at, but the rest of the bb's swarm towards what you have the gun pointed at, and they move at a fairly fast velocity as well.

 

Lastly, I got this from Gunner's, and EMS speedpost was $76, bringing the total to $171, however there was a slightly cheaper shipping option, and the site just got updates saying they are offering a new shipping service which should be cheaper than the options they had at the time I ordered this. I ordered it late last thursday night, and it got here this morning, so pretty good time considering I live on the east coast U.S. and Gunner is in HK.

[k.a]

Hick is yours 6 or 8mm??

The description for 6mm shorty on Gunner say "3 bbs per shot", does that means these new guns got single loading tube like the 8mms.

 

[Hick]

Hick is yours 6 or 8mm??

The description for 6mm shorty on Gunner say "3 bbs per shot", does that means these new guns got single loading tube like the 8mms.

 

Mine is the 6mm version and it fires 5 bbs per shot and has three loading tubes like the full stock version, gunner just got that wrong on his site.

 

The differences between the pistol grip model and full stock model are as follows:

 

-Pistol grip instead of stock (duh).

 

-Slightly shortened outer barrel (only a smidge longer than the inner barrel).

 

-No iron sights.

 

-Comes with heatshield.

 

-Different finish.

 

Those are all the differences that I can think of off the top of my head, and just to clarify, the magazine tube is the same length as the full stock's one, so the magazine capacity and internals should be exactly the same as the full stock version.

[Hick]

Here are some pictures of the nickle black pistol grip version of the ACM Mossberg for those interested:

 

 

 

 

A shot next to an M733 for size comparison:

 

 

And the front sling loop, which is basically a key ring:

 

 

Edit: Meant to ask, has anyone put foregrips (specifically the Tacstar one) for the real Mossberg on the ACM, and if so was it an easy fit?

Edited April 30, 2008 by Hick

[Tin]

Just found this thread and wished I had found it weeks ago!

 

I have had a problem with mine not holding enough gas.

 

My initial feelings about this gun were good and the it performed well for half a day. Then it simply refused to hold gas for more than about three or four shots. (Green)

 

I figured out a way of reducing the number of bbs fired with each shot. All that is needed is piece of rubber tube 6mm OD - about 10mm long. Put this into the rotating part of the loading mechanism and Robert is your mothers brother. (I used some rubber tube cut off a metal hook but any 6mm tube will do-the sort you buy from aquarium suppliers for example.)

 

As for the fill problem:

I wasnt sure if it was a fill problem or a release of gas problem so:

 

Tried working on the release valve to make harder to release gas........no joy -Tried the opposite.....no joy. Swapped the fill valve for a different type from a pistol, still no joy but at least I wasn't getting a load of spray back.

 

I went to buy some more green gas and ended up buying Abbey Ultra as my local airsoft shop had run out of green.

YAY!

Now I get just over 60 shots per fill! Each shot = 3bbs so I can empty all three tubes with one fill.

 

Tried green again but still only getting a few shots - go figure.

 

So far I have put about 1000 rounds through it and left it fully gassed with no ill effects.

 

Tempted to go for some cosmetic mods now.

Edited April 30, 2008 by Tin

[Philbucknall]

Will you mod mine please tin?

 

[Tin]

Yup. Bring it to next game. It'll take all of two minutes. (I have some tube left).

[airsofter0866]

Has anyone noticed any difference in performance or quality control between the full stock and pistol grip 6mm version? I want to get one but I cant decide which

[Tin]

A couple of people have asked via pm for details of how to reduce the number of bbs per shot so here goes:

 

Assuming you can remove the stock, trigger mechanism and gas reservoir:

 

You will need to loosen of the grub screw in the base to release the tension on the rotating cylinder.

Remove the four little screws and withdraw the cylinder.

 

 

Cut a short length of rubber tube (6mm diameter) and insert it into the 'barrel end' of the cylinder. (This is a slightly larger diameter than the end that is nearest the stock.)

Push this tube firmly into place.

 

 

 

Test this with the desired number of bbs. Ideally the last bb should stick out everso slightly.

 

 

Put the bits back in the gun and presto.