Jump to content

Archived

This topic is now archived and is closed to further replies.

TheBauer

The Complete VSR Thread

Recommended Posts

Stick with the original hop unit, anything else is a downgrade in my opinion.

What about the bar 10s hop unit? i have a jg bar 10 as a side project that i bought cheap. should i look around for a tm hopup unit?

Share this post


Link to post
Share on other sites

Hell yes.

 

The BAR-10 unit is a bit sloppy on the QC, and the adjuster wears down and doesn't keep a nice positive click for long (if you were lucky enough to get one that did to start with)

 

 

Some people have had good results with different hop arms in the TM unit, but I've never had a reason to mess with them, mine has been perfect from the off.

Share this post


Link to post
Share on other sites

Hell yes.

 

The BAR-10 unit is a bit sloppy on the QC, and the adjuster wears down and doesn't keep a nice positive click for long (if you were lucky enough to get one that did to start with)

 

 

Some people have had good results with different hop arms in the TM unit, but I've never had a reason to mess with them, mine has been perfect from the off.

 

thought as much, ive being sniping for a while now but had a break recently. Just wanted to re check opinions :)

Share this post


Link to post
Share on other sites

I bought a PDI palsonite HD cylinder & cylinder head the other day because.. well, mainly because I've cut huge holes in my Laylax one to the point it's only usable for short barrels.

 

Was interesting (for me anyway) to note the size difference, with the PDI being thinner but marginally longer. The BS115 is no longer the ideal o-ring for this. Ring A, which gave no compression before, now does, and ring C (22mm OD) is actually the best in terms of fps. There may be something between A and C that works even better, but I guess it highlights the importance of fine tuning it for whichever cylinder/etc you may be running.

 

I'd echo what some others have said before that the PDI cylinder head is far more smoothly constructed, although sadly you have to have a PDI cylinder to use it, of course...

 

After all this messing about I can see why people just stick a longer barrel on to match cylinder/barrel volume. Far easier!

Share this post


Link to post
Share on other sites

I've also been mashing my brains against volume - does this make sense?

 

Due to over-volume of air in the cylinder, shorter barrels mean that the BB starts to leave before optimum pressure has built up behind it. So, you get a lower fps in a shorter barrel than you would using exactly the same setup with a longer barrel.

To counter this, you might choose to stick a bigger spring in there. In theory, this isn't a problem, as a gun that chronos at 500fps chronos at 500fps regardless of barrel length, right? Not quite.

Snipers will generally use heavier ammo. I personally use 0.4g, and as we all know we chrono with .02. This produces energy creep.

When I chronoed a 430 6.08 barrel with a 170 spring with 0.2g I got 552fps.
When I chronoed a 430 6.08 barrel with a 170 spring with 0.4g I got 395fps.
That's 2.83j to 2.90j - This represents a 2.41% energy creep, which if we converted back would give us 560fps. (1.43% speed increase) Okay, 10fps difference, not a big deal. (I guess the imbalance is down to air resistance at point of chrono).

When I chronoed a 303 6.08 barrel with a 170 spring with 0.2g I got 500fps.
When I chronoed a 303 6.08 barrel with a 170 spring with 0.4g I got 381fps.

That's 2.32j to 2.70j - This represents a 16.13% energy creep, which if we converted back would give us 540fps (7.4% speed increase).

The heavier ammo requires more time for the optimum pressure to build, so effectively reduces the problem of over-voluming. This means that the heavier ammo gives a truer indication of the kinetic energy of the gun - the 0.2 reads falsely low. Don't forget as well that the heavier ammo *delivers* more kinetic energy at point of impact (as the slower moving BB loses less velocity to air resistance).  

Normally you'd want to avoid over-voluming as it causes turbulence and reduces accuracy (apparently), but here you can use it to effectively gain on the chrono, since the over-voluming/turbulence won't be present when you use the heavier ammo.

I guess there's still some tuning I could do there. Since the overvoluming is affected like this, it should be possible to reduce the compressible area in the cylinder (by porting) to bring .4s up to 395fps (which the spring can do, remember) whilst still keeping the volume with .2s too high, thus creating an artificially low fps on chrono.

I could always try .43s and see what effect this has on the numbers, or fit a tight bore barrel, or both. Experiments for another day...

 

Of course, chronoing for energy output beats all this, and it's gamesmanship anyway, but the theory behind it is useful.

Share this post


Link to post
Share on other sites

When I looked into this, my train of thought was I don't want too much volume, but nor too little.

 

Therefore to needed to find the correct balance between spring power, cylinder volume, barrel volume and bb weight.

 

The only variable I could be bothered to change was bb weight, so I imagined a graph with bb weight along the bottom and power in joules up the side. This graph would be a normal distribution graph, or bell shaped, with the maximum power output at the top. I found that the perfect bb weight for me was bang inbetween .36 and .4gram, so I use .4s.

 

When I measured the power output difference between .2 grams and .4 grams, it was massive and equated to an "extra" 50fps for me! This makes me think sometimes that sites should measure power on a preferred bb, rather than fps on .2gram bbs.

Share this post


Link to post
Share on other sites

Hatchet That is some great infor regarding the over voluming seeing as i am just about o try a differnt inner barrel very usefull to understand the theory.

 

Another forum has mentioned about using a 560mm barrel to match the cylinder of a VSR the maths is explained there but i wont replicate it. do you find matching would make a real differnce to the muzzle sound of the rifle?

Regarding your look into the piston O rings which is great info have been worried that mine is not doing the best job it could be. Do you only go to Eversley on the ZED days? I have met you there before back in january but i mostly head to the Gunman games that are run there now. I use a Laylax teflon cylinder would you still recomend the same Oring? Do you find PDi differneces with the Cylinder if your using a laylax zero trigger/piston

 

 

Rogue, Although they have differnt limits to us the USA measure the weapons KJ with the prefered ammo so that would be prefereable but i dont think many people would be able to do this and changing all the settings for all the differnt ammo on the game day would take forever.

Share this post


Link to post
Share on other sites

Farding - I think matching makes *a* difference, but not as much as having a suppressor. Obviously the best combination would be a good match and a suppressor. The 303 gives a good crack without it and an acceptable sound with. I think the thing to be careful with barrel matching is that it's very much based on the particular cylinder/etc that you're running, so you can't just base it off someone else's numbers.

 

For example, the PDI cylinder/head has an 88.05 compression zone, wheres the laylax has 93.29 and I'm not sure on the stock. Also you don't necessarily want to get an exact match with whatever ratio they've suggested (I think 2.417 or something is the latest I read) because it will be different with different weights of ammo, etc. The other thing to bear in mind is that 430 is a very useful length because although it's theoretically 2.7:1 or so it's also much easier to get a 430 barrel than it is a 483 or whatever exact length you arrive at. Although stock TM L96 barrels are 500 which is handy, with the 430 you get about a third of the suppressor available, which still makes a marked difference to sound output.

 

 

In this case, it's probably easier to settle for "close enough but useful", because you're not going to get 100% lossless compression and you probably are going to run heavier ammo. If you are going to do it, I'd suggest using a 430 barrel and a PDI cylinder.head (since the head is much better designed), setting up your hop for shooting at best flat trajectory and then chrono for 0.2 and *then* start extending the cylinder port. You might want to do this on an old stock cylinder first though. I've done it on my laylax one and shaved a little too much off. Not horrendous, but probably lost about 20fps just because the compression zone is now so short. Better to err on the side of caution a bit.

 

Incidentally, the tightness of the barrel makes virtually no difference to the calculation, but 20mm or so in length makes a lot more. I think the TM precision barrel that comes with the updated hop is a 6.04, so it's as well to use that really. For the laylax cylinder, yes the BS115 is the closest I've found. I'm using the zero trigger/piston with both setups and I just have to change o-ring between them. I haven't done Eversley in a while, just due to how things have worked out with dates and playing a bit more Combat South/Battle Lakes (BL for the sniping, CS for the AEG), but I plan on going back at some point. Possibly in the winter when it opens up a bit. ;)

 

Currently on the VSR front I'm playing with the R hop, which seems to be going okay but I don't have the distance to check it's actually working. Will report back on that later. And the Top Dead Centre hop adjustment too.

Share this post


Link to post
Share on other sites

Cheers for the info i have just spent a while working out how much i should look to be taking off with the cylinder but have decided that it should be the last thing i try and do as its far more perminate if it goes wrong.

Gonna have to source a few of those O rings then just to make sure they are right for me think thats where i am losing some compression at the moment.

 

I have been wanting the PDI head for a while the reports about it are great but i am unsure if it will match with the laylax teflon cylinder. but the uksniper parts shop have a simmliar style to the PDI that is reported to be the right size for the teflon/standard cylinder.

 

Yea it is a bit of a pain with all the ferns at the moment but it has its moments. might try get myself to battel lakes soon enough. I have been using a R hop for some time now about 6 months with great results and in combo with my TDC it has seen off the right hand curve from my VSR. getting very good range out of it using a standard TM hop rubber for my seal so may find something harder to see any benifits from that. Next jump is an AEG barrel and ER hop with a LRB but thats been on the books for some time. People have reported not just a little more range but what i am after is truely the improvement of consistancy at those ranges.

 

Have to say when fitting the R hop because compresion is so important for consistancy that it can be a bit of a fiddle lots of trail and error. in the end i had it the right size and diameter for the shot but the compression between the patch and the barrel was not what i would have hoped for so i used a very small amount of silicone headgasket sealent that seems to have really helped it be moulded to the hop window on the barrel. 
 

Share this post


Link to post
Share on other sites

I shall bear that in mind. The PDI head won't work with the laylax cylinder, it feels loose just starting to turn it on and I'm pretty sure it'd fly apart at first impact.

Share this post


Link to post
Share on other sites

Get yourself onto airsoft sniper forum .com if you want to get back into it. Unfortunately arnies has become a little bit of a ghost town as of late. ASF is very up to date, and has some crucial new information on it regarding new mods such as the r-hop and TDC as well as the LRB mods.

Share this post


Link to post
Share on other sites

I've just upgraded my vsr with the ASPUK trigger set, 90degree piston, steel spring guide and a 150 spring. It shoots well, getting 490fps with 0.2s, but the bolt pull is no longer very smooth like its catching on something, any thoughts? I'm tempted to lighten the piston also, to eek a bit more power out of it, anyone else tried this?

TDC mod done today, LRBing it on Monday...

Share this post


Link to post
Share on other sites

Personally I wouldn't bother trying to lighten the piston. They're already pretty damn light and you're far more likely to structurally weaken it than you are to make it shoot any better. If you're getting a consistent 490 I'd leave it alone. Especially if you still have hop/barrel mods to perform.

 

Speaking of which, took the R-hopped VSR out the other week. Lots of right hook, but consistently so. Was able to make shots well by the end of the day by putting a 30 degree cant on it, but I've stripped it down and had another look so hopefully that'll be improved next time out. Unfortunate that I don't have access to a nice 100m indoor setting to set it up. Anyone know of one (in the UK)?

Share this post


Link to post
Share on other sites

Personally I wouldn't bother trying to lighten the piston. They're already pretty damn light and you're far more likely to structurally weaken it than you are to make it shoot any better. If you're getting a consistent 490 I'd leave it alone. Especially if you still have hop/barrel mods to perform.

 

Fair point, that's with the standard barrel, I'm tempted to put a tight bore in but this is my third VSR and I've always only seen a decrease in accuracy when fitting one (laylax 6.03 and PDI 6.01)... 

 

Might just R-hop this one and see what happens.

Share this post


Link to post
Share on other sites

Thought I might check here- does anyone in the US have a spare TM VSR-10 hop-up/barrel combo? I'm thinking of building another M1903 conversion that will be relatively low powered  (370 fps w/ .2g) and I was very impressed with TM performance with the last rifle. Unfortunately, I can't find one anymore

 

This time, I might use a 3D printed receiver to make it a little more realistic in appearance:

BAR19032_zpsc7a1fb62.jpg

Share this post


Link to post
Share on other sites

Hey guys. i am very unhappy with my tm vsr 10 gspec... Its all laylax in IT and Its Not as acurrate as my Stock m4 from g&p.

 

The only thing Its Stock is the hopup unit and the Barrel.. 300mm yuk :(

 

Do you have any suggestions?

Share this post


Link to post
Share on other sites

I'd have a serious look at that hop. The standard TM hop unit is good, and you should be able to easily sail a .28 with the standard rubber.

 

Check the rubber us in good order, and get some warm water and soap on it. Give it a good soapy massage to get any greasy residue off it and rinse it and let it dry before reassembly. I've had certain ammo leave on the rubber which didn't help.

Share this post


Link to post
Share on other sites

I did a bit of a mod to fix an issue that I had on my VSR. When I took the action out of the stock to get it in the bag I use for transport (on a motorbike, or I'd leave it in one piece), I noticed I had lost a bolt from the zero trigger, and that I had stripped a thread on the receiver where the trigger bolts on at the front.

 

The weak point, was always gonna be the receiver. Pot metal threads aren't really conducive to longevity, particularly the ones that hold the trigger box on, so what I did was mount nuts in the receiver to take the bolts instead.

 

First up, I drilled from the top side part of the way through. Deep enough to take a steel nut, but not so deep as to have the nut drop through. I chose to measure flat to flat on the nut, and use that size drill bit.

 

20150216_174446_zps92b25afd.jpg

20150216_174424_zps70212293.jpg

 

Then, I used a dremel to shape it to take the nut.

 

20150216_175525_zpsefc91013.jpg

 

Doing it this way, I could have left it there as the hole would have prevented the nut from rotating when I tightened the bolt. Instead, I attached the trigger box to align the whole thing perfectly, and carefully added a bit of epoxy. This filled the space around the nut, but still allows the bolt to come out.

 

20150216_194337_zps1643e1d4.jpg

 

It looks like I slopped it on, but thats just where I wiped away any excess with a cotton bud. I got a bit of sanding down and painting to do when it's cured. anyway, so it's a non issue.

 

Since I already had the dremel and epoxy out, and the scope rail had been removed. I removed the paint from and roughed up the underside of the scope rail and the top of the receiver, added epoxy and bolted them together. 

 

I expect to find another weak point on the design, but for now I'm happy with it. I also took the opportunity to add some threadlock to all the zero trigger bolts, and install a mod I had only just recently read about.

 

When it is cured and I get it sanded, painted, and reassembled I will let you know how that has worked and what it entailed.

Share this post


Link to post
Share on other sites

That is exactly what I do with all my VSR jobs since I stopped being able to get hold of Noobies inserts. I bough a flat end mill bit to do it with so the nut sits dead flat in there. I use a hardener heavy mix of epoxy which goes off thick and rigid and doesn't gloop down into threads. 

Good job:)

Share this post


Link to post
Share on other sites

×

Important Information

By using this site, you agree to our Terms of Use and the use of session cookies.