Insert based VS backed barrel Kits and systems.

[beefstew]

Ok, i was starting an arguement today. Am i stupid for assuming that a backed barrel system will shoot smoother and get better efficiancy than a insert based kit? it seems to me like the threads and back being one peice of metal would make the inner id of the barrel very consistant, and wouldnt have much of a "lip" like a freak does. I was comparing a empire kit that is backed, to a freak system, and then to a scepter kit. I know that empire had some problems with there barrels, but i bought the SS backs for the set and it seems to be much smoother and of a general better quality. In any case, this is what i noticed.

On an Angel:

Empire kit. The empire kit comes with 5 backs, and each fit the breech perfectly, leaving no lip to speak of, and shoot great. if you look down the barrel from the tip with the smallest back, you will notice the edge of the back is of an equal distance to the tip edge all the way around.

Freak: let me say this before anything else. This freak back is almost new, the insert oring has not been crushed at all. Now when i put in the .685 cert i can see down the tip that it is uneven, and through way of the roto-breech see that the insert diffinatley leaves a small lip (does not match perfectly with back) so the ball would hit the back, and then hit the insert. I also noticed that the inserts were a bit flimsey and could probably break quite easily.

scepter: seems to be that the inserts are of a higher quality and coating, the insert lines up with the back almost seemlessly, but there is still an uneven ring when looking into the breech from the tip.

What are your opinions on the differences between insert and backed barrel kits?
Thanks
Phil

[Load SM5]

I was always of the opinion that the solid backed barrels were better after I sold my Freak and picked up an Edge kit. But I think that was largely due to the Freak. The insert felt flimsy and never lined up just right. But I did recently pick up a Sceptre kit and it works great. It's really high quality and the inserts lock perfectly into place each time. The lip in mine looks to be symetrical all the way around.

[ReTro Boy]

I've always thought that fixed bore backs...or a couple of fixed bore barrels...are better than an insert based barrel system. Much better consistency and much more accurate measurements. I switched to the Evil Pipe a couple of months ago and I'll NEVER go back to a freak.

The Scepter, on the other hand, fixes many problems the freak had. They have locking inserts and longer inserts...both significant advances. I've never tried one, but from what I've read and heard from users, it is at least better than the Freak...but I still love my Pipe.

[Evil Bob]

There are alot of theories on performance of inserts vs solid backs, some wild speculation, some solid fact, the bulk of it comes down to how the parts were manufacturered (the care and attention to detail) and the choice of medium the manufactuere used in constructing the parts. With today's tempering processes, it's possible to get a very thin piece of aluminum to become very hard, meaning that there are good insert systems out there that are solid performers, it all depends upon how far the manufacturer wants to go to get your $$'s.


Basic paintball physics:

Other then manufacturing methods used, we need to keep in mind basic physics that take place during the firing process. Tom did alot of research on barrel length and the effect of expanding gasses with a high speed camera and determined that the optimal barrel length is 8", that's the point at which the ball is basicly up to speed and traveling under it's own inertia and the expanding gas behind it has diminished to the point where it is no longer exerting sufficient pressure on the ball surface to affect it's velocity. An 8" barrel is also very efficient, it takes the smallest volume of air to propell a paintball up to 300 fps. Any length shorter or longer requires more air volume to achieve the desired exit velocity.

That being said, then we need to take into account the effective barrel length when we go shopping as well as how the parts were manufacturered if we want the best performance/bang for our buck. Ideally, the closer to 8" you are, the better your accuracy/efficiency will be. I've seen some inserts systems (OTP particularly, 3 1/2 inches) that are very short, these shorter barrels result in the propelling air still pushing on the ball as it exits the effective barrel length, this can cause drift, wobble, and spin as the ball continues to accellerate in the larger bore area of the barrel, this will affect your accuracy.

So when you go shopping for a barrel kit, the closer to 8" of effective barrel you are (inserts and backs length, do not count the larger bore ported area that shouldn't come in contact with the ball), the better off you will be.

Manufacture:

With inserts, the tolerances can be extremely tight, leaving little material left for strength or durability. An old axium states "the more complicated the mechanism, the more parts it has, the greater the potential for failure". This holds true to some extent with the insert systems, you have multiple pieces that should just slide right together perfectly, which isn't always the case.

With the solid backs, the manufacturer process is alot simpler and the manufacturer has alot more material to work with, the only real concern here is getting the bore size right and the front and back to mate properly.

If you want maxium strength, go with the solid backs. Like I said at the start of this post, modern heat treatments can result in very thin inserts being very strong. That boils down to the manufacturing process; is the manufacturer going to spend the extra money and cut into their overall profit potential to get the best part possible or are they going to maximize their profits and cut corners?

When you scour through the forums looking for a barrel system, look for posts regarding both problems and praise people are have for the the system you are interested in. Look specificly for:

Do the parts fit properly?
Are the tolerances close or perfect?
Are there alignment issues?
Do parts appear to be rather fragile?
Have users broken said parts trying to install the product?

Some of the failures we have heard about in the field with Smart Parts are mostly quality control issues. Whomever packaged the Full Freak kit at the factory didn't properly QC the product before shipment or they would have noticed that one of the inserts doesn't seat right. Is a company willing just to chunk a kit together and ship it to fullfill orders or do they take the proper time to assure that the kit will work as advirtised?

Some, like the Freak Pop-n-Fresh agressive porting breaking/shearing and the twisting SS backs are design problems.

Ideally, you want to get the most for your money, so spend the time, do some solid research, and dig out everything you can about the product you want to purchase, that way it's not you that is posting the horror stories later on down the road, hopefully you will be posting nothing but praise for your purchase.

I personally, prefer the solid back solutions over inserts, more meat to hold onto when you screw the back into the marker body, less likely to get damaged or break, with that in mind, I bought a Pipe. However, the Pipe also has some agressive angled porting on the tip, so you need to be very careful that you don't crank on the tip too hard or it will break, always use the much sturdier back to tighten it down. If I were ever to return to using inserts, I would definitely buy a Scepter, best insert system I've had the pleasure to use.

-Evil Bob

[beefstew]

i like my empire kit and am probably going to sell the freak and the scepter.
Thanks
phil