For you airgunners

Welcome to the Leverguns.Com Forum. This is a high-class place so act respectable. We discuss most anything here ... politely.

Moderators: AmBraCol, Hobie

Forum rules
Welcome to the Leverguns.Com General Discussions Forum. This is a high-class place so act respectable. We discuss most anything here other than politics... politely.

Please post political post in the new Politics forum.
User avatar
AmBraCol
Webservant
Posts: 3651
Joined: Fri Mar 30, 2007 8:12 am
Location: The Center of God's Grace
Contact:

Re: For you airgunners

Post by AmBraCol »

Interesting info, Tutt. Yep, a lot of air rifles have fairly short rifled sections, it's amazing what you can do with a spring, a swept volume of air and a fairly short barrel. I'm curious as to why they went with that short of a barrel, but suspect it's due to the amount of air available for propulsion. What size is the transfer port on that thing? In a PCP you can get more use out of a longer barrel if you have a good sized plenum to draw from. Springers and rammers are limited to their swept volume of which there's no practical way to increase. You can reduce the swept volume with short stroke kits and such, but not increase without going to a whole new compression tube, etc. I'm intrigued by the Carnivore series of springers, but have only seen one come up for sale here and didn't have the funds to allocate.
Paul - in Pereira


"He is the best friend of American liberty who is most sincere and active in promoting true and undefiled religion." -- John Witherspoon

http://www.paulmoreland.com
http://www.pistolpackingpreachers.us
http://www.precisionandina.com
User avatar
CowboyTutt
Advanced Levergunner
Posts: 3712
Joined: Tue Sep 11, 2007 8:27 pm
Location: Mission Viejo, CA

Re: For you airgunners

Post by CowboyTutt »

Paul, I got lucky and may have found that information online. Good comparison chart in the link.

https://www.gatewaytoairguns.org/GTA/in ... ic=26322.0

Swept volume is 87 or 84.8 cm3 in the missing chart in the thread. I just calculated it, its 84.82 cc's or 5.174 cubic inches. I put a few rounds down it today before it just got too hot in the early afternoon. Its hard to cock, I can start it one handed while standing but it takes me 2 hands to finish it (50 lb pull weight, maybe more when new). With practice it will get easier. Also, because of the very slow velocities, your follow through has to be very steady.

-Tutt.
"It ain't dead! As long as there's ONE COWBOY taking care of ONE COW, it ain't dead!!!" (the Cowboy Way)
-Monte Walsh (Selleck version)

"These battered wings still kick up dust." -Peter Gabriel
User avatar
CowboyTutt
Advanced Levergunner
Posts: 3712
Joined: Tue Sep 11, 2007 8:27 pm
Location: Mission Viejo, CA

Re: For you airgunners

Post by CowboyTutt »

Got this direct from Hatsan, they are good about responding to emails.
Andy,

The twist rate for airguns will almost always be different than that of most powder-burners. Air rifles often provide much less muzzle energy than firearms. The pellets are often travelling slower and are lighter weight than bullets, so the twist rates must change to keep them stable.

We do not normally recommend using slugs in the mod135. While it may be one of the most powerful production break-barrel guns available, it still does not quite have the power to work well with heavy slugs.
I did see a guy on YouTube who intentionally dieseled some pellets in my similar 30 caliber 135 with vaseline. It was doing like 700 fps from 525 fps!!!! An almost 200 fps improvement.

https://www.youtube.com/watch?v=9o-vbwNjplw

This has me wondering if you could load the air spring with helium could you increase the velocity and still not be any harder to cock? You would have to be sure the seals are suitable for helium as the molecules are much smaller and could escape and recharging is a pain in a air springer usually. Helium does not increase the pressure, and rifles are pressurized to the same level, but it seems to me the smaller molecules move faster because they have less mass.

-Tutt

P.S. Just learned that at least 2 companies are doing the same using nitrogen, which is much cheaper but not as powerful as using helium.
"It ain't dead! As long as there's ONE COWBOY taking care of ONE COW, it ain't dead!!!" (the Cowboy Way)
-Monte Walsh (Selleck version)

"These battered wings still kick up dust." -Peter Gabriel
Post Reply