I've been experimenting with 177 slugs off and on with my RTI compact. Not getting to serious about it. I done some barrel work and had JSB KO 10.3 or 13gr shooting pretty good but not as well as it shoot pellets. I thought that was good enough and took it pesting. It done a good job but I thought maybe I could get it to shoot slugs better. I removed the barrel and went to polishing it a bit more. Concentrating on a tight spot I found just up from the breech and a bit on the choke. Meanwhile I had ordered some 13gr zan slugs I wanted to try (already had 13gr JSB KO slugs) the zan slugs came in and I had time today to shoot/tune my rifle to see if zan slugs shot good.. today was a bit windy. I went for it anyway. Zan slugs shoot great! Even the JSB KO groups improved. They both seem to prefer the reg set at 120 bar (don't remember HS setting) giving me 920fps. I had it shooting a bit more hot (980fps) but it just sounded better at present tune (920fps) I now have a great 177 slug shooter... this is my 80 yard group from earlier this afternoon. Starlings beware!! 
- The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back click HERE.
RTI 177 slugger
- Thread starter Jasonmc
- Start date
Excellent work on your barrel and tune to get that superb group @ 80! Starlings are in big trouble!
Upvote 0
Thanks guys.. I'm so wound up over finally having a compact 177 slug shooter! After today's test/tune and practice session I'm ready to head out on the farm and pop a few starlings this up coming week.
Upvote 0
Just a quesiton, the transferport restrictor how much mm u have it to reach that velocity 3mm or 4mm? thank you !
Upvote 0
A lot of guys don't use a transfer port restrictor.
I use a 3mm restrictor on my prophet 1, I've played with a few sizes but 3mm works for me. Pellets and slugs up to 13 grain.
Upvote 0
But with a 3mm you can get enought speed ? with what reg pressure ? because I was wondering if 4mm port was too big and you lose pressure when slug love high pressure
Upvote 0
Yes, plenty of power and speed.
13 grain slugs and 10.3 grain pellets. Same reg pressure 118. 16 grain slugs, same tune.
Without knowing what you are trying to achieve, power, slugs, pellets, weights etc. Plus any local power limits you may or may not have its all subjective.
It all just experimenting, to find what works for you personally.
Good luck.
Upvote 0
Because I hear lot of peopple saying that slug love 150 bar regulator but on rti a lot use 120/125 so I was confused
Upvote 0
For shooting slugs in .177 my regulator never goes above 120.
My 118 regulator pressure is tested on my reg tester.
Most of the figures you quote are for .22 and above.
What RTi do you have and what barrel?
Have you worked on the barrel, polishing?
Upvote 0
I have rti priest 177 with 51cm LW barrel but with the 3mm port and 125 bar reg and hammer spring maxed I can't reach more then 900fps with the 13 grain I would need to increse reg pressure how you can reach 940 with 118 bar on reg ?
Upvote 0
Ok, on the priest. I believe you need to increase your hammer weight.
Easy job.
Look up a guy called supremaratio, or similar.
He is Italian and very helpful.
Upvote 0
I'm pretty sure the reg pressure is around 140 bar on my Stoeger Bullshark and it's shooting KO 10.03s around 1000 fps and the 13.43s 920. Both of them them are regularly grouping under 1.5" at 100.
Upvote 0
I honestly don't know... I originally bought it as a 25cal with the 400mm long barrel (RTI compact). Sooo... Possibly a 4mm. I also swap on a 510mm 22cal barrel.. ( I prefer a 22 for small game and pesting) but the 177 shooting slugs has proven to be very capable. My barrel is the LW that had a tight choke.. I used bore paste and bore polish to open up the choke some..and take care of a right spot near the breach.. ( it took a while to do as I was taking my time) I tend to use my adjustable regs to find what bar I need for a give pellet/slug to shoot well. With 13gr zan slugs my rifle preferred it at 120-125 bar.. once I know this I ordered a fix reg for it. ( I have 3 RTI rifles and use fixed regs on them all. I have a lot less creep with a fixed reg) in my early experiments with slugs I read and watched videos of people cranking up the pressure to 150+ for slug shooting.. i couldn't get mine to shoot well with it cranked up so high .. I possibly could have if I had added some weight to the hammer to make it work but it worked out very well with a factory hammer weight and spring with a 125 bar reg setting.
Upvote 0
Thats not bad for 80 Yards.
In my Maverick ( 700 mm ) i find the Zan ( 13 gr ) fly best around 960 FPS, this is 86,,,,,, Meters AKA silly Euro units.
Using a REG pressure of 90 BAR.
In my Maverick ( 700 mm ) i find the Zan ( 13 gr ) fly best around 960 FPS, this is 86,,,,,, Meters AKA silly Euro units.
Using a REG pressure of 90 BAR.
Upvote 0