LMG + tight bore = win?
 

Been playing support role for a year now and love it so much I took the plunge into a g&p m249 and want to do some planning/shopping for upgrades. Was thinking of getting it r hopped so was looking at either a promy 6.03 or those modify 6.06 barrels. Reason for the 6.06 is my echo1 pkm comes from factory with a 6.06 and it shoots like a dream for a stock LMG. Any suggestions on which is better from you're experience is greatly apreciated

lmg = wide bore

DMR = tight bore

Or you can buy a new barrel for the LMG every few months.

Better to spend the money on compression work and just use the stock barrel. A bit of spread at range is a good thing in an LMG where you're using it for suppression.

Good compression work means that your spread cone of fire is more consistent so that you know at what range your gun meets the accuracy of other guns being used with and against you, and where your spread drops so that you can lay fire on targets without thinking about it.

A fancypants barrel won't help if you don't have the consistency and precise air volume to back it with anyway, so start with some compression service and anything which might help the longevity of the gun through volume of fire, then go from there.

I was aiming more for range improvement vs an accuracy with the r hop. But I will do some more work on getting the compression better and more consistent.

I guess when having an rhop done it makes sense to have it done to an aftermarket barrel, but your stock GP is probably more than up to the job unless you can see or measure any defects.

Barrel bore is really inconsiquential. in all circumstances barrel quality is the most important trait of a barrel. end of story. tightbores offer a slighly higher fps for the same volume of air but increase the risk of fouling and loosing accuracy, because of this an average bore barrel is ideal for all applications (6.03-6.06ish). However with the exception of LMGs: because your shooting so many bbs even a average bore barrel is bound to foul so you may as an LMG user find that sacraficing air effeciency for a widerbore and less fouling is beneficial, but you should definantly never buy a 6.01 barrel for any general use application, esspeically as an LMG user

I swap all mine out to 6.03, change out the piston to the cnc version and bullgear hopup units for the A&K type M249. Never had much love for the G&P personally based on the feeder for the mags but either way I love a tighter setup for saws.

The feeder is half the reason I wanted a g&p. My classic army mk46 has been one of my most reliable running guns I own but only issue I have is that damn tube goes from the mag to the gun. Sometimes jams up in there requiring a flick or two to get going.

A good r-hop is win, no matter how you slice it. Barrel bore is semi-important, but tight is not all it's cracked up to be. 6.03-6.04mm is where you want to live with any platform. So a 6.03mm, stainless steel promy is best and safest. It doesn't matter if it's a sniper rifle or assault, etc. For your G&P M249, get you cycling super smooth and your RPS solid. Probably around 35 RPS or so. Run a high quality BB (obviously), and either go light, like 0.20g for crazy ricochets and mayhem, or heavy like 0.30g for laser brush-cutting. You'll find the balance that works for you. Might want to look into a mosfet.

Rather then start a new post I will piggy back on this one.

In need of a new inner for my G&P Stoner. Previous owner put in a 6.01 Madbull and it has tiny gouges inside that are affecting range.

Would throwing in something like the Madbull Stainless Steel barrels be more then enough or spend the extra $30+ and get a prommy?
Barrel will be r-hopped of course.

get a prommy or pdi
the quality of the barrels far surpass what the "budget" barrels can do.
Madbull is good but prommy is better. especially if you are going to Rhop it

PDI 6.05 or 6.08

At 6.08 can the air cause more deflection inside the barrel? Or does bore size really have any effect on accuracy?

My current understanding is that the BB rolls along the top of the barrel due to the backspin placed by the hop up, in which case it doesn't really matter what size bore so long as it is consistent and smooth.

Wouldn't an upside down V shape "rail" provide better accuracy than a round barrel as there is less contact?

Bore size alone does not affect accuracy or range (technically), although too-tight could be an issue. The tighter it is the more effect you'll get from dust and grease in your barrel on the BB. Tightness will have an effect on velocity, tighter being higher vs lower on the same power source. What I mean is, if you don't change the spring size, say an M130 spring, will have varying velocities due to bore width. In fact wider bore barrels, like 6.08 plus can show significant velocity drop and may require a larger spring or power source to get the BB down range nicely. A heavier spring is tougher on your gun from drawing more battery to cycle, giving you less shots, to outing more tension on your internals overall and making your motor work harder.

All that being said, stack up three guns with the exact same hop, BBs and velocity, but with different note-width on their barrels and technically your shots should be the same or similar. They probably won't be, but in theory. So for all of the previously said reasons my opinion is strongly that 6.03-6.04 is the best range of barrel, no tighter and no wider. You don't have to worry about fouling and cleaning as much, or even often to be honest, and you don't need to enhance your spring or gas flow to comensate for power loss. Your focuses should be: barrel quality, BB weight and quality, and most of all hop-up.

As an aside; back when standard guns came with 6.08 barrels, PTWs came with 6.04 and most sniper projects ended up with 6.03 barrels. These are still popular setups today if that tells you anything.

yeah, going to stick with a prommy. I guess it was a silly question to ask :P