How to dmr?

[LazzurusMan]

So I've searched online and there are so many different guides on how to dmr a rifle that I'm getting confused. Figured I'd list the parts I'm looking to replace, what I'm aiming for in terms of fps, and ask for suggestions for which brands etc to go for.

So currently my l85 is sitting just under 350fps on .2g with a cut down sp120. I'm aiming for as close to 450 or 1.88j as I can get, with great consistency and good accuracy and range. 

I've already swapped out the stock bucking and nub for a super macron and omega nub.

I was thinking nozzle, cylinder head, piston head and piston. Replace the bushings with bearings, shim the gearbox, correct aoe, cut down the teeth on the piston so it engages properly, replace the stock "high torque" motor with a decent hi torque motor, new metal spring guide, add ptfe tape to stabalise the barrel and then if the fps still needs to go up replace the spring again.

Trigger response is already pretty good on 11.1 lipos with the ares efcs so I don't think I need to replace the stock gears unless they break, or short stroked, unless short stroking will prevent pme (is that even a thing on single shot aegs?)

Have I missed anything? And what brands should I be looking at for parts?

 

[Tackle]

One point, I've previously known some sites to insist on an element of realism when it comes to gun "classification", so for example a support gun using a box mag needs to be just that, a genuine support gun model & not an M4 (etc) with a box mag.

The same could be said for a dmr, so specifically longer guns based upon real world dmr models, sr25 for example, before you start ripping in to your L85 you might want to check that the regular sites you use, or any sites your planning on trying in the future allow non specific dmr's, or even aegs over 350fps. ?

 

[LazzurusMan]

One point, I've previously known some sites to insist on an element of realism when it comes to gun "classification", so for example a support gun using a box mag needs to be just that, a genuine support gun model & not an M4 (etc) with a box mag.

The same could be said for a dmr, so specifically longer guns based upon real world dmr models, sr25 for example, before you start ripping in to your L85 you might want to check that the regular sites you use, or any sites your planning on trying in the future allow non specific dmr's, or even aegs over 350fps. ?

I skirmished at combat thetford yesterday and was talking to the marshals about my upgraded ares mutant and my new l85a3 and whether I could use it as a dmr on site. As long as it's locked to semi auto and not over 1.88j it's a dmr in their eyes. Luckily I can lock it to semi auto with the ares programmer, so I don't need to permanently turn it into a dmr, or do anything like put a screw by the fire selector and ruin the looks of the gun. I also checked if that's allowed and they said as long as I have to do more than just pull the trigger a certain way to reprogram it I'm good.

This way all I need to do to go back to a full auto aeg, in theory, is change the spring to reduce the power and reprogram for full auto.

 

[Rogerborg]

You could do all of that, but you don't need to, just throw in the bigger spring and see how you get on.  1.88J isn't really that much for a gears-n-piston gun.  In particular, I'd stick with bushings over bearings - you're just introducing a new point of failure.  Shimming is always a decent shout, AOE / tooth removal, eh, you might as well, but you're picking up the piston at the point of least resistance so it's not like a heavier spring is going to radically alter what's already happening.

I would focus on air seal, but with the stock components: replace and/or stretch the o-rings and silicone grease them.

Other DMR owners will disagree in order to justify what they've spent on making the bestest DMR evarrrr, and they may even be right, but my rule of thumb is that if you change everything at once, then you'll have no basis for believing that any particular component added the magic.

 

[LazzurusMan]

You could do all of that, but you don't need to, just throw in the bigger spring and see how you get on.  1.88J isn't really that much for a gears-n-piston gun.  In particular, I'd stick with bushings over bearings - you're just introducing a new point of failure.  Shimming is always a decent shout, AOE / tooth removal, eh, you might as well, but you're picking up the piston at the point of least resistance so it's not like a heavier spring is going to radically alter what's already happening.

I would focus on air seal, but with the stock components: replace and/or stretch the o-rings and silicone grease them.

Other DMR owners will disagree in order to justify what they've spent on making the bestest DMR evarrrr, and they may even be right, but my rule of thumb is that if you change everything at once, then you'll have no basis for believing that any particular component added the magic.

Those are very good points. The reason I was going to replace the air seal parts is that I put an uncut sp120 spring in and got to about 400-410 fps, hence I cut down the spring as I hadn't planned in making it a dmr at the time. Reckon a 130 spring would get me there without having to open the box and start changing things? I'd rather avoid it if I can. Already have to spend 50 quid on the damn programmer to lock it to semi only. 

 

[Jez_Armstrong]

Personal opinion 

The Ares L85 isn't the best platform to DMR, I can predict issues, their gearbox cases aren't the strongest 

 

[LazzurusMan]

Personal opinion 

The Ares L85 isn't the best platform to DMR, I can predict issues, their gearbox cases aren't the strongest 

It's the best platform I've got, I don't want to buy another gun yet, and I already have a perfectly usable aeg for full auto fun.

 

[Rogerborg]

The reason I was going to replace the air seal parts is that I put an uncut sp120 spring in and got to about 400-410 fps, hence I cut down the spring as I hadn't planned in making it a dmr at the time. Reckon a 130 spring would get me there without having to open the box and start changing things?

It should do, but airseal is king. I just wouldn't go throwing money at it.  Get some silicone grease, and work on the stock parts.  If you don't have a good seal, then you can stretch the stock o-rings by taking them off the piston / cylinder head, and stretching them over the cylinder. Apply some heat, or leave them there for a while.  Or if your piston o-ring is suspect, BS910 o-rings (19.18mm ID x 2.46mm section) are very slightly bigger than the typical stock ones and can give a good seal.

 

[Fatboy40]

Have you decided on what weight BB's you're going to use ?

The technical side of DMR'ing was straight forward for me, change single part / evaluate change / move onto next part, but getting the right weight was harder as was the hit to my wallet ? (0.40g)

 

[Lozart]

*ahem*

Obligatory post of the thread of all threads 

https://www.reddit.com/r/airsoft/comments/5g58ia/holy_grail_dmr_guide_updated_for_20167

 

[LazzurusMan]

4 hours ago, Lozart said:

*ahem*

Obligatory post of the thread of all threads 

https://www.reddit.com/r/airsoft/comments/5g58ia/holy_grail_dmr_guide_updated_for_20167

Ah, see I try to avoid reddit after it started bombarding me with notifications, messages etc. Cheers for linking that!

One final question before I put together a list of parts and things to do, is it gonna be worth short stroking? I don't see any reason to myself as I'm not gonna use full auto so pme shouldn't be an issue.

 

[Lozart]

Ah, see I try to avoid reddit after it started bombarding me with notifications, messages etc. Cheers for linking that!

One final question before I put together a list of parts and things to do, is it gonna be worth short stroking? I don't see any reason to myself as I'm not gonna use full auto so pme shouldn't be an issue.

Short stroking a DMR? No.

 

[Impulse]

I won't throw my "but why DMR?" into the ring as I think there are more than a few common misconceptions when it comes to DMRs (I have some strong opinions on DMRs), but I think the holy grail covers most points pretty well and you seem pretty set on it. I recently undertook a SR-25 project to run at 1.1J as a "DMR" because my local site rules suck for DMRs, but I also have a spring for a 1.88J variant which is nice and easy to install thanks to a quick change spring system.

My opinion is that quick change spring systems are a necessity for DMRs, either that or a HPA setup (or the patience to take the gearbox apart to change the spring if you go elsewhere), since DMR rules vary across the country. I've seen 1.88J, 1.64J and 1.48J at different sites and events, so if you plan on going to many other sites or events you'll need to consider that.

 

[LazzurusMan]

I won't throw my "but why DMR?" into the ring as I think there are more than a few common misconceptions when it comes to DMRs (I have some strong opinions on DMRs), but I think the holy grail covers most points pretty well and you seem pretty set on it. I recently undertook a SR-25 project to run at 1.1J as a "DMR" because my local site rules suck for DMRs, but I also have a spring for a 1.88J variant which is nice and easy to install thanks to a quick change spring system.

My opinion is that quick change spring systems are a necessity for DMRs, either that or a HPA setup (or the patience to take the gearbox apart to change the spring if you go elsewhere), since DMR rules vary across the country. I've seen 1.88J, 1.64J and 1.48J at different sites and events, so if you plan on going to many other sites or events you'll need to consider that.

Part of the reason I want to do it is it has a quick change spring, so if something happens to my m4 and I need to use the l85 differently or we go to a different sight I can bring it back down to 1.14j.

 

[Rogerborg]

It's a good shout, I run my M4 as a DMR, or with a spring, barrel and barrel extension swap, as a CQB gun pretty much interchangeably.

 

[Leo Greer]

All depends on what you want out of your DMR. Most AEGs with a clean barrel, hop packing, and good quality .25g BBs can hit 50 meters accurately. Not so many can hit 60m, and very few can hit 70. So how far do you want to go?

Y'all over there in Britain seem to call 400 FPS w/ a .2g a DMR and I would say for those power levels you don't need a QC spring guide. For an M150, yeah, you're gonna break your wrist without a QC SG, but an M120 is within wrangling strength.

Before you decide on changing any of your gearbox parts you need to get inside it and see what you're working with. For example, if the stock motor is Neo, it's probably strong enough for what you need. Stock compression parts can also usually be modified to work perfectly well.

For the accurising part of DMR building (what separates you from that idiot with the hot gun over there), it gets a little more complicated. I'm new here to ASFUK (don't try to say that out loud ?), but I spent quite a bit of time over on a couple of the American forums putting together an in-depth accuracy guide going through every portion of modern accuracy tuning:

https://www.airsoftsociety.com/threads/modern-airsoft-accuracy.167208/#post-1878715

Last I checked the "Holy Grail" guide is actually pretty outdated in some areas. Such as the idea of wrapping teflon tape around AEG packings, which originated from bad hop unit fitment combine with the VSR packing mod and not from an actual need. Maybe the updated version fixed this, but I still see people trying to wrap their AEG packings...

 

[Sewdhull]

The key to a dmr is a good hop and airseal so you can send heavy bbs consistently.

You don't get range from fps alone, you'll lose most of that BB speed advantage in 30m.

 

[heroshark]

I think your All over complicating this. All you need is a bipod, massive scope and a huge suppressor. Preferably on something really unsuitable, like a p90. An L85 will do though.

 

[gavinkempsell]

I think your All over complicating this. All you need is a bipod, massive scope and a huge suppressor. Preferably on something really unsuitable, like a p90. An L85 will do though.

Oi...

View attachment 120404

 

[heroshark]

Sorry the suppressor and scope are far too wee for it to identify as a dmr.