The Xisico Sentry Fan Club :)

[M_thompson42nd]

Hello all. I recently purchased a sentry  .25 cal (705)-9T.  I'm new to PCP guns and figured this would be a good starting point to lean from.  I can tell from the short time I've spent with the rifle that it needs some fine tuning to get the best results. My rifle is one of the newer versions, and there doesn't seem to be much technical information available for it on the web. I talked to mike at flying dragon and he says there isn't much either.
Does anyone have any ideas or information on where I should start to get this thing performing to its full potential?
For example. These are just a few of my consearns......
Smooth out the cocking lever travel.
I feel air hitting men in the face when firing and feel it coming out near the trigger group.
The barrel and shroud seem not to fit fully into the receiver block. Slight gap between shroud base and receiver face. I tried pushing it up against the receiver fully after loosening the barrell retainer screw, but then you can't insert the magazines due to a lack of clearance from breech end of barrell pushing out too far.  Just to name a few  .
Thanks for any help anyone can give.

[Wayne52]

I do recommend taking these guns apart, like Mike said there's very little info about them but the way that I've been doing it is just take them apart and see how they work, I think there's exploded view pdf's in this thread somewhere that'll be very helpful to see what's in them.  I've been getting up and over 50fpe with my 25 cal bolt action 705-2.  These guns are a heck of a lot of fun and built pretty darned good except for China assembly, sometimes they don't do such a great job but when they're right they really are a nice solid shooter.  I blew the head right off from a chipper this morning, it's in the hunting gate where the picture is.

[Hoosier Daddy]

Glad you found your way here Matt.
 A couple pages back from your post you will find the data you were looking for.
 Sorry to hear of your issues. My 702-3 is one of my favorites!

[Zeddymon]

Hello all. I recently purchased a sentry  .25 cal (705)-9T.  I'm new to PCP guns and figured this would be a good starting point to lean from.  I can tell from the short time I've spent with the rifle that it needs some fine tuning to get the best results. My rifle is one of the newer versions, and there doesn't seem to be much technical information available for it on the web. I talked to mike at flying dragon and he says there isn't much either.
Does anyone have any ideas or information on where I should start to get this thing performing to its full potential?
For example. These are just a few of my consearns......
Smooth out the cocking lever travel.
I feel air hitting men in the face when firing and feel it coming out near the trigger group.
The barrel and shroud seem not to fit fully into the receiver block. Slight gap between shroud base and receiver face. I tried pushing it up against the receiver fully after loosening the barrell retainer screw, but then you can't insert the magazines due to a lack of clearance from breech end of barrell pushing out too far.  Just to name a few  .
Thanks for any help anyone can give.

air hitting you in the face is the barrel orings
the block gap is common i understand, to make perfect as a last resort you might have to do some whittling where the plastic meets the wood so you can slide it back that little bit, first try pushing the action forward, the plactic forearm is in 2 pieces it will slide over the shroud tube, leave the barrel tight, you will have to loosen stock screws
maybe the postioning is affecting your sidelever travel because the trigger group would then be back a hair

[M_thompson42nd]

Thank you for the point in the right direction Wayne and Zeddymon. Every little bit helps.
And thanks for the warm welcome hoosier.
I'm sure once i get all the kinks worked out it will be my go to AR.

[Nvreloader]

Matt here is a diagram for the side lever listed in these posts,
https://drive.google.com/file/d/1yGddIP0iopy0VzXZPSYdhXk3dCFdO5r4/view

My 25 cal was very gritty in the bolt area also, took apart and found OEM alum shavings in the lube they used.
What ever you do try NOT to take the psi gage off, there is a small rubber type "O" ring inside,
that butts up to the bottom of the gage stem, part# 21, it will leak unless everything is perfect.

Removing the fill port adapter, part #23 from the main pressure tube is no problem,
I found very little lube on the interal "O" ring. I made a rod that fit very closely into the fill port hole,
grabbed the main pressure tube with a good pair of nonslip rubber gloves, and unscrewed the fill port adapter.

Yours should have the burst disc part# 105, hidden under the plastic forearms, you have to remove the burst disc,
then remove the inside adapter part# 102, the burst dics seats into, I can't remember the thread diameter for the hole etc.

If you tear it down, check part #39 to see if it has and "O" ring on each end, and make sure the trigger group is as far forward,
(muzzle end) before tightening everything down, if you don't do this you will not be able to fire it,
and or have cocking problems etc.

HTH's

Tia,
Don

[Hoosier Daddy]

FYI Matt...
Zeddymon is "connected" somehow but I have never been able to nail him down to admitting just HOW. 

He has sent me parts you can not find anywhere.
 So when he speaks, I listen.

[Zeddymon]

FYI Matt...
Zeddymon is "connected" somehow but I have never been able to nail him down to admitting just HOW. 

He has sent me parts you can not find anywhere.
 So when he speaks, I listen.

i am an independent sales rep for Xisico, though still have not seen a penny,  just trying to get the best out of Xisico for every one, i felt it was a strong and sturdy platform that could be as popular as the QB
As an independent i enjoy only the privilage of doing what i feel is best, team building, which is not what i'm told to do by any means

Matt thanks for being part of GTA, lots of great people here who inspired me to go from airgunner to sacraficial lamb so to speak

[Hoosier Daddy]

What a great job you do Zdenek
Thank you for your support and spreading the word!

[M_thompson42nd]

Great info everyone. Thank you so much!

[Wayne52]

Zed I've never had a QB myself however I know now just how strongly and well built the Sentry's really are.  I honestly think that the type that Scott has would be really nice for modifying because of having the separate tube's rather than having the one long tube.  It would be much easier to incorporate a drop block like the Hawkes have.  The way that the valve is mounted in the Sentry is about the most solid setup I've ever seen for a PCP valve because there's simply no way that valve will ever move at all once secured.  I honestly don't think that Sentry's are a copy of any other gun either, they appear to be an original design I'd say

[Nvreloader]

Wayne

+2

With that 1/4" steel rod holding the valve in place, plus the 4 screws,
IMHO I don't think there is another more secure valve in any other AG that I am familiar with.............

Plus you can change the valve top and with a larger thread diameter and bore down to the TP,
more than the .523" dia hole ending at 1.033" deep it has now,
you could easily enlarge the inside valve hole to around .812" x 1.00" deep with 7/8" threading for the valve top.

Has anyone figured out the volume/cc's of the plenum, mine measures 19-1/8" long.............
to the top of the valve.

Can someone, Please give me the cc's of the plenum tube................

Thank you,
Don

[M_thompson42nd]

Reply to info request on page 18 post #346
Sorry it's a little late, new to the forum

Purchased 4/16/2020
Model 705-9t .25 cal.
Long barrell and air res.
Serial #112000269
Side lever
Gauge on end of tube
Burst disk @@@. In place where old gauge location.
Manual saftey
Zero mods.

[Nvreloader]

Matt
Thanks for the update, I think you like her...................

Don

[Nvreloader]

Well, I give up for the time being, this leaking Sentry is put back together, and filled with 1000 psi,
and I'll put it in the dark safe until the parts get here,
may be this will change her stubborn mind..............

I'll tear down the leaking 25 tomorrow, and see what's the problem, and do a spec sheet on her,
and post the results for comparison to the 22 Sentry etc.

Don

[M_thompson42nd]

Don.
I do. And I'm sure I will even more when I get her back from Mike. I just shipped it out today for a some Melic TLC. I know I should have gotten the tune when I bought it. But it was at my limit budget wise stock.
Hopefully you can figure out all your issues. I wish I was more knowledgeable and could help.

[Wayne52]

One of the big advantage's I have since I'm retired and single now is time on my hands for tinkering and I do get carried away with it.  One thing I really would like to have is a lathe for tinkering with too, especially since I've gone head over heels with these danged air guns . . . . they can be a lot of fun however at times they can be a pain in the a s s.

[UnderPressure]

Here is some more info to go with Post # 477,

The bbl is not choked, that I could find..........

I attempted to get the twist rate of the bbl, and as close as I can get is 1 x 18" ? twist
I tested it several times.

Tia,
Don

Were you able to measure the barrel groove diameter?

[UnderPressure]

With this gun having a radial transfer port (in the barrel) feeding three transfer ports (also in the barrel) I'm thinking round ball projectiles must have been a consideration when it was designed?

Otherwise wouldn't it be easy to get full bore sized barrel porting while still allowing even the shortest pellet or slug to be used? (re: a person could enlarge each of the three barrel ports substantially with no chance of it being too big for even the smallest pellet or slug)

EDIT: After watching the JSAR Hawk Video I see that Hajimoto is recommending a maximum drill size of 3/16" (.188") for the breech transfer port--->

[Wayne52]

Russ the guns shoot slugs that I cast really good IMO !!!