some questions about m4 accuracy

[Insaniac]

Okay, I have a CA m15a4

Upgrades include: systema tightbore barrel, m120 spring, systema hopup

I've used my gun outdoors and I've adjusted the hopup, but I still find that my BBs are somewhat erratic in terms of left and right curving. Now I can't say 100% that its due to wind because I have not tested my range indoors, but I have fired it on relatively calm days. Also I do not know my guns effective range, I know it won't be a bullseye everytime at like 100+ feet.

However I post this because I feel that with the hopup and tightbore I am not getting better accuracy than any of my other stock AEGs.

Also while I'm asking, would using .28s or some heavier BB be a good choice to increase accuracy?

[Fox]

The first question I ask to you is;

At what range do your BB's start curving to the left or right?

Wind plays a huge factor in BB's flight paths. I've played on windy days before where I've seen my gun shoot pretty much sideways, because of wind.

The long and short is yes, heavier BB's are always a good place to start to improve accuracy. With that set up you should be able to hit the 80-100 foot range for human sized target accuracy. You will always have curve though with right to left.

Now, .28's might not be a bad choice, but you also have to balance cost and supply. This is why I would recommend .25's. Not that .28's are terribly hard to find, but you never know when you might need BB's. .25's you can pretty much find anywhere, in decent quality. Any decent airsoft store will stock them, and you can have them.

I would try .25's if you're not already shooting them.

And, at 100 feet never expect an airsoft gun to bullseye unless it's a very high tuned sniper rifle. Your goal should be the ability to hit a human sized target at a range of 75 to 125 feet. The farther, the range, the harder it will be to hit, naturally.

[Insaniac]

thanks Fox, you help me out a lot. I am not sure of the range at which they start curving, I'll test it out though. I will probably try my friends .28 bbs and see how they work just to get a feel.

[Fox]

Not a problem. Test out what range you start curving, if you have access to .28's try them out see how it works, but as I said for the sake of it all - try using .25's too. They're much cheaper, easier to get too.

I know i use .20's right now and due to recent events and outings I will be stepping up to .25's for all play now once I buy some.

[Wraith]

I have pretty much that exact setup in my CA M4. The only difference is I have not yet replaced the hopup unit. I use .25s for my ammo, usually Airsoft Elites when possible. I can consistantly hit a human sized target out to about 125' on a calm day. Pinpoint accuracy is good out to about 75'. But any wind at all and that range starts dropping.

I would definately say to use a heavier BB. .28s will work, though you may not need them depending on what kind of accuracy you are going for (.25s work great.). I noticed when I pushed my muzzle velocity up to around 400 that the .20s start getting a little erratic in their flight. The heavier weights of bbs will negate this effect. However, wind is still going to play a major factor and there isn't too much you can do about that. The heavier bbs will reduce the effects, but never completely eliminate it. The brand of bb could also play a role in your accuracy. Some bbs have an air bubble in them which will throw the flight off slightly.

You should notice an increased range over your stock AEGs. Not a whole lot extra, but an increased range none the less.

[namloot]

My son has a G&P M4 Marine with a Prometheus 6.03 barrel, a Systema hop up unit with a Systema bucking and a Big Out H nub. It has a Madbull M120 spring, shooting 435fps w/ .20g BB. Using Marui .25g BBs, he can hit a man sized target 9 hits out of 10 shots at 225 feet (about an 18" grouping).

I'd try Marui, Excel or KSC .25g BBs. An H nub might help a bit also.

[Fox]

I have to say I'm speculative of the 225 ft claim. I can see 125, maybe even 150 with the H hop up and that FPS.

But 225 feet is approaching high end sniper rifle range..

[Sidd]

Also one thing I has seen with Airsoft gun accuracy that is often over looked. Check to make sure your hop up bucking is installed properly. I know from personal experience even the bucking just a little off I have seen it have some drastic effects on BB curve.

Second make you are are holding you guy upright, this is also something I am guilty of. Often times I have caught myself holding either a rifle or a pistol tilted to the left. This also effects how the BB arcs in flight

[Insaniac]

whats a big out h nub?

I probably want to change out my bucking to systema I unfortunately forgot to do that when I upgraded the gun, I don't want to pay 20$ bench to change the bucking however.

[McBango]

Originally Posted by Insaniac

whats a big out h nub?

I probably want to change out my bucking to systema I unfortunately forgot to do that when I upgraded the gun, I don't want to pay 20$ bench to change the bucking however.

http://www.airsoftatlanta.com/images..._h-hop_jpg.jpg <-- That is the nub. I heard they work great and I plan on purchasing a few for myself.

You ought to run some tests before you go buying a bunch of different parts. For each test, there must be only one variable at a time (excluding wind and humidity, but make sure its consistant while running the tests).

Also remember that Systema "tight bore" barrels are only 6.04mm in diameter. Other brands manufacture even tighter barrels, which in turn can produce better results.

[Texx]

Another thing you might check is the nozzle on your mechbox. I have seen damaged nozzles cause consistency problems. If you have one of the + nozzles, sometimes the grooves crack or are damaged and cause the flow of air to push the BB with a different spin than desired. This can cause the BB to spin at an angle.

[namloot]

Originally Posted by Fox

I have to say I'm speculative of the 225 ft claim. I can see 125, maybe even 150 with the H hop up and that FPS.

My son and I have 4 upgraded AEGs that can hit a man sized target 9 hits out of 10 shots at 225 feet.
TM M14 (most accurate)
TM AUG
G&P M4
TM AK47 (least accurate)

Originally Posted by Fox

But 225 feet is approaching high end sniper rifle range..

My son has a KJ M700P, it's completely stock. Tuned to shoot 525fps using Maruzen Grand Master .29g BBs, (on a calm day) he can consistently hit a man sized target at 300 feet.

Try different BBs, you would be amazed at how different brands shoot. My son and I tried every brand .25g BB we could find. TM was the most accurate, then Excel then KSC. Some brands had more then double the grouping size at range (175'+). That would mean my son's M4 getting an 18" grouping at 225 feet with TM .25s, using poor quality BBs would give a 36"-48" grouping. Some of the BBs we tested did shoot that poorly.

As a note, G&G .25g and .28g bio BBs are quite good for bios. If you field requires bio BBs, try them.

[Insaniac]

Thanks for all the replies. I think first things first is I need to test my M4 accuracy at known ranges in a windless consistent environment (easier said than done however )

Actually I guess I should get my fuse fixed first.

regarding BBs, anyone know where I could get high-grade bio .25s in bulk?

[Fox]

I believe Airsoft Smith or Airsoft Arms can both get them.

[Wraith]

Originally Posted by Texx

Another thing you might check is the nozzle on your mechbox. I have seen damaged nozzles cause consistency problems. If you have one of the + nozzles, sometimes the grooves crack or are damaged and cause the flow of air to push the BB with a different spin than desired. This can cause the BB to spin at an angle.

Sorry, don't mean to hijack this thread, but Texx could this cause a drop in muzzle velocity as well? I have dropped 100fps on my M4 and can't explain it. Spring appears good still. O ring hasn't been checked yet, and I figure I'll go ahead and replace it when I have it opened up again. But the airnozzle is something I hadn't even thought of.

[McBango]

I know I'm not Fox, but I highly doubt air nozzle damage would drop it down 100 fps (that is if its not completely destroyed). Either your O ring is damaged and you arent getting normal compression, or you forgot to decompress your spring for a long time. Also take in consideration that temperature can effect velocity; if you chrono'd in winter conditions, it will not be the same as if you were to chrono at warmer temperatures.

[Grease Man]

Originally Posted by McBango

I know I'm not Fox, but I highly doubt air nozzle damage would drop it down 100 fps. Either your O ring is damaged and you arent getting normal compression, or you forgot to decompress your spring for a long time.

Air nozzle damage can easily cause that much of a drop, I've seen it numerous times. However, I would check your o-ring first to make sure you have good compression in the cylinder. I would also check out your hop up and bucking.

[Texx]

On my CA33, I kept having BBs veer off to the right. When working on the mechbox, I noticed the + nozzle the previous owner had installed had chipped. My thoughts on the idea behind the + is that it is vectoring the airflow and trying to create additional compression.

Problem I've seen with the + shaped nozzles is that eventually the metal inner nozzle slamming into the back of the + part has somewhat of a cookie cutter effect and eventually the plastic chips out.

With a chip in the + that would allow more air to flow through that side than the other. Pushing the BB more from that side could place more of a spin on that side.

After replacing it with a O nozzle, the shots flew straight. I began noticing this on other AEGs I worked on as well and began checking that when people complained about it.

Sorry, don't mean to hijack this thread, but Texx could this cause a drop in muzzle velocity as well? I have dropped 100fps on my M4 and can't explain it. Spring appears good still. O ring hasn't been checked yet, and I figure I'll go ahead and replace it when I have it opened up again. But the air nozzle is something I hadn't even thought of.

100fps, I would check the o-ring on the piston but also around the cylinder head. Loss of compression - maybe a leak.

[McBango]

Grease Man and Texx could be correct... Wraith, you should reply back once you diagnose the issue.

As for the original topic of this thread... I hope what we discussed helps you (Insaniac).

[Insaniac]

yes indeed, I have learned a lot in this thread. Once my fuse is fixed I shall test my gun, post results see what to do from there.