X-Valve/Boomstick Inconsistency???

[abartjc]

I am having major problems with my Minimag. Here are the specs:
X-Valve with Level 10
14" Dye Boomstick
PMI 88/3000 Tank, preset at 850PSI

Everything else is stock. I am shooting PMI Premiums and also some Zap Spanks. Every place that I have read has recommended the Premiums for the Boomstick. What is weird is that when I take the barrel off, I can drop a premium right through the barrel.

My problem is:
When shooting over a chronograph, my FPS fluctuates like crazy! I shoot from 285 to 354 to 233 to everywhere in between. I have lubed EVERYTHING that can be lubed and that is not the problem. I did however change back to the stock barrel and shot a consistent +/- 8 FPS.

Should I send the barrel back? Should I try a different type of paint? What are the chances that the box of PMI that I had weren't up to spec? Should I try to add a regulator? Anyone? Thanks,

abartjc

[andrewnelles]

odd, maybe bad paint to barrel match?

[craltal]

While the balls shouldn't just fall through the barrel, the vast difference in velocities belies a deeper problem. A bad paint/ barrel match can't account for a 121 fps difference. That screams an air system problem to me. make sure everything is properly installed/ lubed, but not over-lubed.

[abartjc]

So, obviously it is a problem with my paint/barrel match. Everywhere I have read, people are recommending using the PMI premiums, that is what I am using now and the ball falls right through the barrel. What else should I try to use?

abartjc

[craltal]

correct, you don't have a good paint to barrel match. BUT there is no way that a 121 fps difference is caused by that alone. You are having air problems as well.

[abartjc]

If I am having air problems, then why do I get a +/- 8 FPS with my stock barrel using the same paint? Please provide information to back your assumption.

abartjc

[deathstalker]

Originally posted by craltal
BUT there is no way that a 121 fps difference is caused by that alone.
I used to see 80 fps differences when using some 4 year old Big Ball. It's stuff that I've kept around for "torture tests" and it works great for that purpose. :) I would first try paint that has a better fit. It's going to be cheaper and easier to diagnose/fix your problem than working with your air source.

[Dayspring]

If you're not using the RT chrono procedure, your chrono readings will be all over the scale.

[abartjc]

If I don't have an inline regulator, how do I set my PSI to 700? I have a preset 850PSI tank.

abartjc

[Dayspring]

You don't.

850 will work just fine.

[Plazmic]

I'm about to Chrono my new X-valve. Where do I find the RT Chrono procedure? Is it that fire, hold the trigger down, then fire again thing?

[Dayspring]

Yep.

[Enemy]

check to make sure that the lvl 10 bolt is not striking the boomstick.. that is why agd is going to threaded barrels.. i had that happen with my lvl 10 when it was sitting too low it did give me some crazy inconsistancys with the barrels.. the two ways i would check this is one try fitting the bolt in the barrel if it rubs there is a problem.. next would be to put the barrel on and drie fire the gun if you hear a ting noise then there is your problem..

[athomas]

There have been many instances of the Boomsticks not fitting mags very well at all. Maybe that is part of the problem. The biggest part of the problem is probably the paint to barrel match. If the paint is not consistent, it exagerates this problem. I would bet that some of the paint drops right through while others actuall fit or are even tight. This could cause the big velcocity swing you are experiencing.

[Plazmic]

Actually, Premiums are very consistent. So, while it may not be a perfect match, it will be the same difference in size from one ball to the next.

[abartjc]

Thanks for all the help,
I have come to the conclusion that indeed it is the paint to barrel match. The premiums that I was shooting were a lot smaller than ones that I bought at a local store. I guess the batch Blue/Yellow with Yellow fill premiums that I bought online were just one of those cases where they came out smaller. I bought a case of premium purple/gold with gold fill at a local paintball park and they fit perfectly (no rolling out the barrel) and the velocity was pretty consistent. Would it be that hard for everyone to use the same size paintball and barrel?!?

abartjc

[Plazmic]

I can't believe you have Premiums that are the wrong size! I wonder if those were Premiums at all.

[abartjc]

Try measuring your premiums with a ruler. I measured one of mine to be about 1.6mm. They are indeed premiums, as least I would hope so, because it says premium on the box.

abartjc

[lloyd_kinky]

Would it be that hard for everyone to use the same size paintball and barrel?!?
Yes, it would be very hard, and expensive.

We all shoot .68 caliber paintballs, but the production of a "gelatin type" projective(paintballs) can only be so accurate. Also, different manutacturers have slightly varying balls sizes. I'd say the window for actually paint size could be from .675 to around .695. I may be wrong, I'm just putting some numbers out. The standard Boomstick has a bore of .688 I believe. So, average paint is often great in a boomstick, but when you reach eith extreme is size, you'll see problems. Thats why we are shifting to barrel systems. You have several options so if ya need to buy a different brand of paint, for example, you have a barrel to match it. . Also, a given bag of paint from the same batch could be, say, .679 on a cool dry day. On and warm humid day, that same paint might measure .690, let's say(probably an exageration). You barrel, made of metal won't expirience even close to that same amount of diameter change in normal temperature changes.

~Parker

Also, you can't measure paintballs accuratly with a ruler, you need a set of calipers, or better yet, and bore gauge, I think WDP makes one.

[Plazmic]

Very good discussion, Lloyd. I hadn't even considered temp changes.

I use a J&J Ceramic, which is somewhat sensitive to large bore paint, so I've never had a problem with a ball being too small in that barrel. Premiums have measured on my ball sizer have always been the same to within .005. I've never had a batch of Premiums be so far off that they didn't fit the same sizer setting without adjustment. That's through 4 cases in the last 4 months.

I also have used Big Balls a lot. There is a little bit more variance on those, but only very slightly. Maybe I am just storing them well or something.

[trains are bad]

I'm happy if my paint falls through my barrel. Less breaks that way.

To be honest I do not see a big improvement when I get paint that fits my barrel. I just have a few barrels and use one that's closest. JMO

[Plazmic]

Actually, I'm right with you, there. I have two barrels that I use: the J&J Ceramic and an All American. If the paint is tight on the J&J, I use the AA. If I try to squeeze larger paint through the J&J it breaks like crazy. If it's a little small (rare on the J&J) it is still very accurate. Together the two barrels cost me about half of what a Freak system costs and I couldn't be happier. Up to this point, I haven't broken a single big ball or Premium since I put in the level 10 and got the J&J. That's 4 months with not a single ball break! My shot groupings are very tight, so I can hardly justify moving to any other barrel system than the two one piece barrels I have now.

[ghideon]

Originally posted by Plazmic
Actually, I'm right with you, there. I have two barrels that I use: the J&J Ceramic and an All American. If the paint is tight on the J&J, I use the AA. If I try to squeeze larger paint through the J&J it breaks like crazy. If it's a little small (rare on the J&J) it is still very accurate. Together the two barrels cost me about half of what a Freak system costs and I couldn't be happier. Up to this point, I haven't broken a single big ball or Premium since I put in the level 10 and got the J&J. That's 4 months with not a single ball break! My shot groupings are very tight, so I can hardly justify moving to any other barrel system than the two one piece barrels I have now.

Exactly, no need to get a new fangled barrel system when you can pick up used barrels for $25-35 a pop. Got an E-Mag barrel, a Lapco AS, Lapco Bigshot and a J&J Ceramic that way to compliment my older style All American.