Has anyone ran slugs in the .25 cal. 250z yet? If you have what size did you have luck with? Thanks.
Barra Slugs in the 250z
- Thread starter OneAcreFarmer
- Start date
Good morning everyone… thought I’d share a little early morning action using @JFranco fantastic slugs. If you haven’t tried them yet you need to. Best slugs I’ve shot out of my Barra.
This is the same rabbit. I’m zero’d to 75y so you’ll notice the huge hold under on the first shot which the rabbit manages to totally matrix his way out of…. Second shot is 85 yards and if you have the sound up you can clearly hear the slug hitting him…
This is the same rabbit. I’m zero’d to 75y so you’ll notice the huge hold under on the first shot which the rabbit manages to totally matrix his way out of…. Second shot is 85 yards and if you have the sound up you can clearly hear the slug hitting him…
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@Cantona256 How did you open up the transfer port on your 250z? From what I could see the only way to access it is thru a threaded hole in the bottom of the block and it’s already as large as possible. Unless i would rethread the hole for a larger bolt.
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Yeah the little air channel defo needs to be opened up too which I haven’t done. I did the transfer port on the valve assembly and the exhaust port in the intake sleeve… since they a matched it would stand to reason that the Venturi effect causes the air to accelerate through there and the pressure drops subsequently.. not sure what happens when it hits the the 4.4mm exhaust port. All I know it’s that the gun feels a lot better this way and I’m getting 65fpe while still getting about 25 a fill(as long as it’s warm outside haha)
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It’s definitely not a full port and polish but it’s been really effective for creating a “medium tune.” Should have the plenum mod installed in the next month or so which will make my current numbers super easy to achieve?
If you want a plenum I have the guy’s email.
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So I did some asking around and the answer to the question is to drill the block out to just a hair below the size of the threads so you don’t have to rethread. I probably won’t do that yet as I’m already really loving how it shoots and I wanna see how the plenum does. Plus he’s working on some poppet Valves and dual ports for more power increases as well.
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I just got the 250z in .25 and was curious what everyone else's experience is with the hammer spring. I've increased the reg from 2000 to 2400 and I'm having a hard time getting the FPS to settle. I seem to get highest speeds at 0-1.5 turns in, but the ES still jumps around 5-10fps and it'll lose speed after each shot until I adjust the spring again. This is consistent with pellets and slugs 25-34gr. Seems like it needs to be adjusted below 0. Above 3 turns and it sounds like hammer bounce and velocity drops off significantly.
Not enough reg pressure? Hammer spring issue? Regulator issue? Operator issue? I'm still new to the game and my only other experience with PCP is an Avenge-X .22.
I also plan on getting the power kit and opening the thimble to 4.4mm.
Not enough reg pressure? Hammer spring issue? Regulator issue? Operator issue? I'm still new to the game and my only other experience with PCP is an Avenge-X .22.
I also plan on getting the power kit and opening the thimble to 4.4mm.
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1) welcome to the club broski.
2) the hammer spring does very little below 2500/2600 psi. It’s pretty weak. I would back the HS all the way back. Check the velocity and use the hammer spring to make tiny adjustments. Pick the slug that shoots the best then shoot groups of 5 from 25y… don’t rezero just shoot groups… give the HS like 1/8-1/4 of a turn until the groups look super crispy.
3) you can save yourself some trouble and order some Airshootist Reg butter. My 250z had creep issues till to took the reg apart, gave it a light polish and relubbed with the reg butter. Better yet do the whole gun with it.
4) if you’re trying to shoot slugs real fast get the hammer spring kit. If not you won’t need it… the weight on the kit adds a ton so even with it in you’ll likely barely use the HS… Personally I have the slug weight in but the stock spring. I have it turned in about 1/16th from flush… I have the reg at 2800 psi and getting about 980fps from my 32gr franco slugs. So about 68-69fpe with 20-25 a fill.
5) If you do the thimble valve( exhaust port) then do the transfer port too. It’s on top of the valve. If you have mismatched diameters you’ll get a pressure drop near the slug. You will get slightly more power but you’ll need to put the reg up higher. If they are matched you won’t get the same issue. Once I matched my ports I was able to drop from 3k to 2.8psi and still got slightly more power than before.
There has also been a lot of tuning talk over on the H.A.M. Forums. Feel free to join up there too.
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Awesome, thanks for the info! Is there any kind of guide or instructions for this procedure?
I'll be sure to check out HAM too.
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Nope… keep in mind doing so will void your warranty… but if you choose to proceed it’s quite easy. There’s a good video on YouTube from 802_Airhead that will show you how to take it apart. There’s some pics on HAM the thread “working on it” and I have some pics and stuff to help.
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I just received a chronograph today. Now the tuning starts in earnest. Hopefully I will have some time this weekend to mess around.
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ohhhhhh $hit let’s gooooooo! Can’t wait to hear the results… got Bladefin over on H.A.M. Shooting his AEA’s 30gr slugs at 960fps now. Hes just working on getting it fine tuned on the group size. But yeah I can’t wait for you to get yours tuned up. 4 months later and I’m still genuinely surprised by this gun. In a good way…
These pictures show the difference between the 30gr at 65fpe vs 32gr at 69fpe… I’ve got the 32gr Franco’s doing 980fps now.
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