PCP air pistol velocity

[Tony C.]

I was checking the velocity of my recently acquired Moeini CM 162 E1 and surprised to see that there's a difference of almost 80f/s when the cylinder is fully charged and when the cylinder pressure is under 100bar just before the cutoff mechanism kicks in preventing the pistol from loading. When pressure is at 200bar, the first 10 shots or got as fast as 545f/s, then it gradually level off at about 510f/s, the last 30 or so shot will got down to almost 470 f/s using 530mg pellets. I wonder if other PCP air pistol is doing the same, my Anchutz 2002 air rifle also slow down as the pressure drop, but it has a much bigger cylinder so its not that big a problem. Would a 300bar cylinder maintain a consistant velocity longer? I though the cutoff mechanism on the CM 162 ensure a constant velocity until pressure drops below a certain level, that dosn't seems to be the case. guess I have to make sure to shoot no more than 100 or so shots and change cylinder, is that what other folks are doing?

[Bill177]

Hmmmm, is PCP really an improvement over Co2?

[RobStubbs]

To me those velocities sound wrong - I'm sure they should be consistent no matter how much air is in the cylinder. I would check with Morini or their service agents that the guns or seals aren't faulty.

Rob.

[Randy Bimrose]

I would check with our host, they do repair work on Morini and can easily determine and repair the problem.

[Chris]

Regardless of what the velocities do the important thing to remember is what is your group doing. No matter what the velocity change is from shot to shot as long as the group is tight I would not worry about it.

I would be supprised if you would get a very tight group with a large vatiation in velocity, but it could happen. I have not tested my Styer through an entire cylinder but it might be interesting to do.

Bill177, Lets keep it positive. Please.

[Randy Bimrose]

In disagreement with the last poster, wide swings in velocity by a gun of that quality is not normal. It would be prudent and wise to get in touch with Pilkingtons and get the gun checked over just for peace of mind. Also if something is developing it may be cheaper now than later. Having fixed a number of guns where the cost of repair would have been less had the customer come in earlier...............your choice.

[Richard H]

You also have to look at the testing.

[Tony C.]

I thanks everyone who express intrest in my posting, I had went back and repeat the test again twice, so far, I'm unable to duplicate the abnormal velocity I recorded before. The pistol shot consistantly around 500f/s, velocity dip slightly when pressure drop below 100bar just before the cutoff mechanism kicks in around 490f/s. The pistol is new, I wonder if the internal parts need a few hundred shots to settle down, for now every things seem fine, but I never seems able to shoot 200 shots as Morini claim, 180 or so is all I get, is that true for other CM 162 shooters?

[Mark Briggs]

I never seems able to shoot 200 shots as Morini claim, 180 or so is all I get, is that true for other CM 162 shooters?

Recently a friend of mine had an interesting conversation with Francesco of Morini Competition Arm. In that conversation Francesco stated that the CM162 tends to shoot better at lower velocities, and that most are adjusted to fairly low velocities when leaving the factory. He also indicated that many shooters increase the velocity as a result of a belief that "faster is better". In the case of the CM162 the manufacturer does not believe that faster is better. As a result, the claim of 200 shots is most likely based on the factory speed setting.

Just as a small case in point, my CM162Short doesn't shoot worth a darn at higher velocities. In fact, at 500 fps the group size is about three times the size of the groups at around 460fps. Consequently my pistol is now set to shoot at about 465fps using H&N Finale Match Glatt (rifle) pellets, and I get over 150 shots per cylinder. Keep in mind these are the short cylinders! If you're getting 180 shots with a muzzle velocity near 500 fps then you're probably very close to the mark in terms of shots versus velocity.

[Eddie Tsoi]

Quite agree with Mark that Morinis shoot better in relative lower velocity than others.

According to the manual, the factory set velocity is app. 150m/sec, which is 495ft/sec. Later on for some reasons (my own problem) the velocity had varied. I can still shoot in the 9 and 10's but it is not the point on the target that I suppose it should be. Fianlly I determined to have a fix on the AP in one free Sunday afternoon with the aid of a rest. after removing the grip from the frame and attached the electronic device on again with some strong tape, it is easy to adjust the velocity with the minimal effect on the position of the AP. After about 60 - 70 shots, I finally set the velocity to app. 140 - 143m/sec (460 - 470ft/sec). The result was impressive, I can punch a hole of app. 5mm with 10 shots, which is even better than the grouping when the AP was out from the factory with only 5 test shots.

It is well worth trying to do a grouping test if you are really demanding and concentrate on one type of pellet. I use Finale Match High speed 4.50 instead of the factory recommended 4.49mm and I ususally bought a lot of 50 tins which can last for almost one year.

Lastly, as for the results, my overall groupings improves and now I can shot several shoots with the impact holes overlapping each other in each 10 shoot series.

As for Mark's number of shoots per fill, if you are using AR pellet which is heavier, you are using more air preasure to get to a same velocity as compare to AP (high speed) pellet. So 150 shoots is respectable.

As tiime goes by, you cannot avoid to have old O rings and seals which make the AP to shoot less shoots or your velocity drops, but somehow if you can get a stable velocuity for 120 shoot or so, it is good enough for a full competition. There is no worry at all.


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