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THE TM MWS thread

Looking for some advice, or even words of wisdom/caution, regarding inner barrels. 

I'm pretty happy with the stock TM 250mm barrel, but I'm curious to see how, say a Prommy or PDI barrel performs. 

My next build has a 14.5" outer barrel, so I guess I could go up to 370mm. I know the length doesn't really make too much difference to range/accuracy on carbine/rifle barrels, but I think I'm right in saying they can increase FPS slightly? Mine's been close to site limits from stock on .3s, so again, curious to hear from those in the know as I'm not planning on fitting an NPAS.

Bore size is also something I'd like to hear about. The TM barrel is 6.08 I think. Any comments regarding the performance on tighter bores? 

 
C-Diddy said:
Looking for some advice, or even words of wisdom/caution, regarding inner barrels. 

I'm pretty happy with the stock TM 250mm barrel, but I'm curious to see how, say a Prommy or PDI barrel performs. 

My next build has a 14.5" outer barrel, so I guess I could go up to 370mm. I know the length doesn't really make too much difference to range/accuracy on carbine/rifle barrels, but I think I'm right in saying they can increase FPS slightly? Mine's been close to site limits from stock on .3s, so again, curious to hear from those in the know as I'm not planning on fitting an NPAS.

Bore size is also something I'd like to hear about. The TM barrel is 6.08 I think. Any comments regarding the performance on tighter bores? 
Click to expand...
I have run the stock TM barrel and a CrazyJet one. Both were 250mm but the CrazyJet pushed the fps up by 15fps give or take.

Grouping at 10m clamped was slightly tighter with the CrazyJet but there wasn’t much in it. 
 

Accuracy is fine for most ranges you might encounter and torso shots out to 60m with good conditions are possible. Sniping peeking elbows and knees at 20-30m is also fun ?

If you are going to run a 370mm you will defiantly need an NPAS of some kind. 

 
I have fitted a Prometheus 370mm 6.0mm barrel and NPAS to my MWS MK16 build. It is a DMR, normally putting out 1.8J on 0.48s, and the range and accuracy is outstanding. I also have an HAO 416 MWS, which has a 250mm 6.01 PDI barrel, and this rifle is equally impressive in terms of accuracy. I have also had good results from a 410mm Crazy Jet barrel in another of my MWS collection. As many people will say accuracy is down to bore quality, but tight bore barrels in gas rifles always make best possible use of the energy available. If you are going to run at sub 1.14J levels then a 370mm Prometheus barrel in either 6.03mm or 6.00mm form, will take you over the limit. An NPAS does give you the ability to tune the rifle accordingly - for example my HAO in the current 30 degree hot weather, had a 30% power increase which I could adjust through the NPAS.  

 
C-Diddy said:
@Salamanca are you running regular green gas? If so, I'm wondering what 144a would do to those numbers?
Click to expand...
I have tried Nuprol “white” gas (their low powered one, probably close to 144a) and only found a ~20fps drop (305 > 285ish) 

Tempted to get some bottles of the 6kg / 8kg / 12kg gas - can’t remember the brand but having named steps might make it easier to guesstimate!

 
I am running Abbey Sniper gas in the summer which is effectively green gas without silicone (which is why I use it). In the winter and Autumn I run Mapp gas with a Madbull Propane adaptor for filling. Silicone-free Mapp gas provides the same level of power as Guarder black gas, and costs very little from a builder's merchant. I have uprated all springs in the nozzle, and I run 120% or 130% buffer springs with heavier buffer weights. My HAO MWS has a steel CNC Robin Hood bolt carrier with a brass end weight, so plenty of strength and recoil. I feel no need to run 144a in the summer, as all my rifles can easily handle green/sniper gas, and if I need a low muzzle energy level, I turn the NPAS down.    

 
Last edited by a moderator:
Has anyone had worn feed lips on a mag cause bbs to roll out the barrel when they are chambered? Only seems to be one mag doing it!

Manually charging the bolt is fine, but after it shoots and cycles the next BB just rolls out the barrel.

Hop is on (4-5clicks) and hop rubber is pretty new (certainly less than 1500rds) BBs are Warhead. Happens with 110% and 130% buffer springs. Nozzle is in good condition and feeding fine otherwise. This wasn’t an issue with mag #7 and #2 used in the shots-per-gas-fill test I did a couple of days ago.

Only mag #5 ☹️

 
That sounds really odd. Just so I understand, after making ready, a BB is chambered correctly, then, after firing the first round, as the next BB is being chambered by the bolt returning, it just drops out of the barrel, without you pulling the trigger?

 
C-Diddy said:
That sounds really odd. Just so I understand, after making ready, a BB is chambered correctly, then, after firing the first round, as the next BB is being chambered by the bolt returning, it just drops out of the barrel, without you pulling the trigger?
Click to expand...
Yep, exactly that!

I am going to fit new feedlips to #5 and test again. Only thing I think it can be!

 
That just seems really odd as the action of chambering a round, whether manually charging, or from the bolt cycling, is the same ? Hope the new mag lips sorts it

 
Built up a new nozzle tonight to replace the TM one with the broken screw and G&P NPAS that was adjusting its self (and trying to get me banned from the local site Luckily discovered testing at home!)

Set up was the same for all gasses. Minimal Joule creep with 0.28 > 0.32g BBs (lighter ones omitted for clarity)

19DegC, 0.32g BBs from a Guns Modify nozzle / valve / valve spring. G&P adjustable valve stopper - three holes for the cross-nozzle screw to go through at different points so it moves the valve forward or back a set amount. 

MID setting:

Nuprol White 265 - 272fps

ASG Ultrair (beige bottle) 270 - 276fps

So the low power gas is only ~5fps less.

As it was close to the limit I changed it to the LOW setting and repeated.

ASG Ultrair (beige bottle) 230 - 233fps

Nuprol Red 235 - 240fps

Bit too low (equivalent to 295fps on a 0.20g) but fine for CQB.

So “Nuprol super power gas50000!!!!” only added ~6fps.

iT wIlL kiLl Ur GuNz!!! ?

Might try the mid setting with a cut down valve spring, or just wait for the weather to cool down ?

According to Vorsk the V6 gas is equivalent to ASG Ultrair, V8 and V12 both higher pressure. Abbey 144a might be a handy one for warmer days when I don’t want to disassemble the nozzle  in the safezone.

What are others running and do they notice much difference in FPS?

 
@SSPKali I posted this a while back when curiosity about red v green gas got the better of me



I generally run the Zero One gas or ASG Ultrair as standard, but am tempted to get a couple of cans of Vorsk. As an aside, these were results from the standard TM mag. With the Guns Modify P-mags, FPS is higher by 5-15 FPS. 

 
Videos are dead on that post ☹️

Got the Steel and Alu bolts set up with G&P stops and regular plastic valves. ~260fps and ~240fps respectively on 0.32g / ASG gas / 25DegC shed ?

Taking less than half a mm off the back of a plastic valve gives a 20-30fps gain. Rub on some wet&dry on a flat surface….take it slow!

G&P adjustable valve (green one) was showing some wear with the grub screw eating a hole in the brass stop - not all the way through but not ideal!

 
If I never have to remove a trigger box again, it'll be too soon. What an absolutely vicious bastard of a job that was. It has taken more than an hour to get the fucker out, and that was only by resorting to brute force and the bigger hammer!

True to form, despite only wanting to get the trigger box free enough to change the Zet plate, during my fuckery, one of the sear springs made a jump for it. Fortunately I caught it, but that meant that not only have I had to remove the box entirely, but then disassemble it to replace the little sod. 

Unbelievably, everything is now back in one piece, with a beautiful rainbow-hued Bavtac Zet plate installed and working like a charm. 

The externals can wait until the morning. 

 
View attachment 115914

So this ?is the fruit of my labour. I'm going to post a bunch of pics I took during the build and put a parts list together to bore you all with, but today was about getting it onto the range to see what it could do. 

A couple of weeks ago, as an out-of-the-box M4A1 Carbine, it was hitting out to 60m on .28g BBs and Ultrair, with a good degree of accuracy, which, for me means hitting a Figure 11, roughly centre-mass, at that distance. Made me smile, and smile and smile. 

Today, testing this iteration was, well, a huge disappointment. Although the range was like-for-like on .28s and green gas, I just could not get any consistency in shots. One would go straight as a die, resulting in a nice metallic 'clink' off the target. The next would fall short, barely half the distance, then another would fuck off into the stratosphere. 

Adjusting the hop made very little difference to the randomness of the shots. The only internal changes I made were a different Zet plate (which worked brilliantly) an enhanced nozzle return spring and a different hop nub, all by BavTac. I can only assume that, while replacing the hop nub, either the nub or hop rubber is not sitting squarely. Adding weight to this theory is the fact that, with the can on, BBs were shattering before leaving the barrel, or dribbling out like it had a prostate problem. Any other thoughts on root cause before I whip the tools back out?

On the plus side, chucking in .3s and .32s, still with regular green gas, when a shot did go straight, it was heading to the 70m target, so I'm hopeful that when I get this sorted, it'll be chucking white plastic death out to decent distances. Oh, and IMHO it looks gorgeous. Yes, it's another URG-I, but it's still a handsome beast.

Gas testing will have to wait. I now have 8 variants to try in the name of science...and bored curiosity. 

 
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