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Artilheiro wrote:I wish someone could tell me how should I adjust my Marauder Benjamin .22 cal for the greatest number of shots possible with pellets JSB 15.9gr of 5:52 at a speed of 870ft/sec. I want to load the cylinder with 2900psi.

Artilheiro- Let me preface by saying mine is a .177 but will try to help any way possible. Likewise, I don't claim to be an expert, but it's only what I've seen with mine and what I've read here and there. First off, is there any particular reason you have chosen 870 fps and a fill pressure of 2900 psi? Likewise, I'm assuming your doing some hunting with this and would like the highest fpe you can obtain? Unfortuately, getting the most fpe can come at a cost, meaning accuracy. And there is no point in having 40 fpe (for example) if you can't hit anything. Right? What you first need to decide is at what range you would like to shoot to, ie out to 50, 60 yds. The best way to decide on a particular fps setting is to see how accurate it is at your longest distance. Hopefully you have a chrony because otherwise this is all for naught. With your tank at 3000, try shooting down to 2000, this will likely be a good 100 shots or so and doing so over the chrony at the same time will save time and pellets. With your current settings, hopefully you'll have a significant range in fps. If you didn't get up to 900 fps try opening the metering screw and increase the hammer spring tension and stroke length (good only at the higher fill pressures). The idea here is to compare the fps with accuracy, not obtain the longest string yet. The JSB 15.9 might not group well at 900 but does at 850 at your 50 yard target. I'll stop here for now and continue after hearing back from you. Thanks. Steve

Ok. So your going to be using the Mrod for field target competition out to 60 yds. If you haven't already done so, be sure you take a look at these two websites, for additional information on the Marauder, especially the "A" team site. http://www.crosman.com/blogs/croswords/?cat=47 and http://ateam.100free.com/Crosman.htm. Ray and Hans Apelles (the "A"team) are professional field target competitors not to mention were personally responsible for the design and development of the Marauder.

So again, do you have a chrony? Without this, trying to tune your rifle to the best velocity will be impossible. So as stated earlier you'll need to do some preliminary testing to determine which pellet your rifle likes best. I have had great success with the Crosman Prem. Heavy 10.5 (.177) so your rifle may respond the same with the CPH 14.3. You may want to also purchase the pellet sample pack from http://straightshooters.com/straightsho ... mpler.html, this will allow you to try many different pellets to see which responds best. So again, before you can tune your rifle to obtain the best shot strings you'll need to see which velocity gives you the best grouping. Ok? So you'll to do this first before we can proceed.

ps. I've also read that field target competitors usually use a .177 and generally tune the velocity to the 575 fps range. So you may want to experiment in that range as well by turning the metering screw way in.

Artilheiro wrote:Steve, I have cronografo Crony model Alpha. The category is not Field Target is Metallic Silhouette (5 chicken silhouettes distant 18 yards, 5 pig silhouettes distant 23 yards, 5 turkey silhouettes distant of 28 yards and 5 ram silhouettes distant 33 yards). In some competitions, we also 5 chickens silhouettes greater than those placed at 18 yards that are 50 yards away. These siluetas are made of steel plate of 1 / 8 inch. The competitions is disputed in two categories, open sight and Optical sight. There is no distinction as ammunition. Therefore, in the same competitions can be weapons .177 and .22.

ARTILHEIRO RJ/RJ

Ok. That's great. So with the Alpha chrony, perform the tests as indicated earlier and see at which velocity you get the best groupings. Good luck.