any NON PCP .177 that can produce close to 30fpe?

[oldpro]

 Anyone know of any non pcp air rifles that can produce close to 30 fpe in .177?

[Doug Wall]

A Hatsan 135 might be close.

[HYspd]

hatsan torpedo 155 with pile drivers?


i do beleive you are gonna need a very heavy for caliber projectile to stay sub sonic at more than 22fpe if i have my data straight...

[Eddie_E]

I seem to remember the late Kenny Kormandy getting over 28 FPE from a Hatsan 125 Sniper.(coil spring version).

[Leaded]

I’m getting 27-28FPE with a Hatsan Torpedo 150 Sniper Vortex Using JSB Heavy 10.34s (I increased ram pressure to about 150 bar) Ram is stamped with a max of 160bar but I haven’t gone above 150 so I assume it’ll probably hit about 30FPE at 160. The Torpedo 155 Is a very similar gun but longer barrel, uses the same ram so I assume it’ll do similar power.

[Back_Roads]

 I have a Hatsan 135 Vortex in .177 that will do very close to that and may exceed with the right ammo IIR.

[Leaded]

Regarding the Hatsan Torpedo I mentioned a few posts up, it has top power but also accuracy, see post below for a 70yd group I shot earlier in the summer and you can see how it does in the 30yd rested target matches (competes well with the German springers as well as PCPs!). I also qualified for the NUAH club with the gun.

70yd group
https://www.gatewaytoairguns.org/GTA/index.php?topic=174983.0

30yd target matches gate (I think I shot in every match but one this year)
https://www.gatewaytoairguns.org/GTA/index.php?board=18.0

Power and accuracy, but one note is that it is a heavy gun, best for shooting from a rest.

[Roadworthy]

You could look into the Diana 350 with the coil spring.  I think the gas spring version has a wee bit more power.

[Rob M]

i missed the 177 part.. the Cap tuned webleys would likely do 30 fpe with a slug , and thats about it.. Maybe a theoben dual magnum.. Im sure a modded pumper ( similar to  the millenium pumper ) could also do it ... A smalleer piston pumper would be ideal to achieve the pressure needed, as a larger bore pumper like the 392 becomes impossible past about 2200 psi.. I think Bob pumped a 1377 mechanism to 2900

[subscriber]

Diana 350 is about 20 FPE in .177.  About 22 FPE in .22.  At least that is what mine run at, unmodified.

The snag is that the .177 bore volume is small and can't take advantage of the "huge" swept volume and massive spring used in "super magnum" springers.  To get more of that power out, a .22 or .25 are required.  Think British made Webley Patriot family of airguns.

Is this for slug shooting, Travis?

[oldpro]

Diana 350 is about 20 FPE in .177.  About 22 FPE in .22.  At least that is what mine run at, unmodified.

The snag is that the .177 bore volume is small and can't take advantage of the "huge" swept volume and massive spring used in "super magnum" springers.  To get more of that power out, a .22 or .25 are required.  Think British made Webley Patriot family of airguns.

Is this for slug shooting, Travis?

Yes as a slug shooter to pack around using Nicks new slugs

[subscriber]

Yes as a slug shooter to pack around using Nicks new slugs

30 FPE at 950 FPS suggests a 15 grain .177 slug.  At 1000 FPS, it suggest a 13.64 grain slug.

How much loss to friction from the extra bearing length would be interesting.  May have to lengthen the "chamber throat" or use some sort of loading probe to shoot them from a springer.  That is, unless the slug has near land diameter section, with a driving band at the back (or very close to the back), similar in diameter to a typical pellet skirt:  0.002 to 0.004" over groove diameter.  The latter could load with finger pressure, yet seal like a waisted pellet.

A heavier slug would not need as much "holding" by the skirt flare in the chamber to build peak pressure, as a light pellet.  So, the driving band could be just 0.002" over groove diameter, due to the inertia of the slug helping to hold it before "takeoff".  The question is still, which airgun manufacturer's groove diameter?  Ditto for the land diameter.  If the slugs were cast, there could be a narrow front and rear driving band that would accommodate a range of bore and groove diameters, without being too tight or too sloppy...

I like pellets that load at an estimated 2 lb into my break barrel springers.  Anything over 5 lb is too much.  Over 10 lb and fingers hurt in a hurry.  Especially with small caliber pellets.

[subscriber]

These NSA slugs look swagged, with no driving bands; so finding springers with compatible bore diameters would be a must... Reaming a shallow loading cone chamber might be required for best results.  Applying too much loading force will distort the slugs, or hurt the customer's fingers.  Slugs that "drop in", without a special chamber, would tend to "drop through"...

30 FPE with 12.5 grainers would suggest a MV of 1040 FPS.  Even if that was only 1000 FPS due to friction (or blow-by), 27.5 FPE would still be pretty impressive in .177.  Especially for a springer.

[subscriber]

The question is what might a springer chamber look like that would allow easy slug loading, while still being compatible with diabolo pellets.  I explored that question usig Lothar Walther land and groove diameters for conventional rifling:  https://www.lothar-walther.de/barrel-blank/airgun/standard-profile-with-choke/1453/airgun-blank-choked-4-5mm-air-od-10-mm-l-605-mm?c=273

I assumed a breech cone of 45 degrees.  The engineer in me thinks 30 degrees per side would make for better pellet skirt alignment, but it does not "look right" compared to Weihrauch and Diana break barrels out there.  Even if the original breech cone angle is 40 degrees per side, it does not really affect the analysis below.

I measure a small sample of .177 pellets for the distance between the unfired skirt OD to head OD.  These seem to be right around 4.5 mm.  So, I decided that in order to fully support even wadcutters, the full land diameter portion of the barrel bore should remain 4 to 4.25 mm from where the pellet skirt sits against the breech cone (not the barrel face).

If slug diameters are less than groove diameter, then the new chamber cone would not need to end at the groove diameter.  It could be a little smaller.  In any event, the resulting slug chamber cone ends up with a taper of just over 1 degree.  That should enable easy loading with the fingers, and spectacular alignment of slug to bore.

Obviously the "best" dimensions for the slug cone would depend on the exact slug diameter and the exact land and groove diameters involed.

Now, I have seen low powered air guns with a chamber that has more than the single breech cone to make loading pellets easier.  The P17 chamber feels like this.  How relieving the lands as I am suggesting would affect the accuracy of diabolo pellets in a 30 FPE springer remains unknown.  I can see the pellet reaching significant velocity over that first 4.25 mm of travel, such that the pellet skirt might experience some skidding in the shallow lead-in section of the lands.  On the other hand, providing the lands don't strip completely, the worst case is a little more blowby between pellet skirt and the unloaded side of each land.  This does not have to affect pellet stability in the bore as the pellet would still be fully constrained.

If the effective breech cone minimum diameter is larger, pellets would be released earlier in the shot cycle.  This may not matter with heavy diabolo pellets, but might might shooting lighter pellets even more prone to slamming the piston into the end of the compression cylinder. 

If the idea is to only shoot slugs, then pellet considerations are moot.

[HYspd]

i only put a mild countersink on a .22 break barrel to ease loading and lost 50 fps...

this brings up a statement by the Cardrews about the intial resistance of projectile movement was a strong factor in developing chamber pressure...

[subscriber]

i only put a mild countersink on a .22 break barrel to ease loading and lost 50 fps...

What angle and diameter did you make it?  What was it before?

Apart from easier pellet release, a larger ID, more gradual slant, or more rounded breech cone also increases the total volume of the breech.  While this small change might seem trivial, increasing the effective transfer port volume has a significant effect on the "compression ratio"; thus on the peak pressure, and therefore the efficiency of  a springer powerplant.

[Blowpipe Sam]

Before I would engage in all that machine work I think I might look for a heavy pellet that could produce similar results.

[subscriber]

Before I would engage in all that machine work I think I might look for a heavy pellet that could produce similar results.

Based on the quote by the original poster below, the slugs he wants to shoot already exist.  Now the question is if  a springer exists that would work with them.  You might ask, why not a PCP?  I am sure he has his reasons.

Yes as a slug shooter to pack around using Nicks new slugs

So, perhaps either the airgun chamber or slug design may need to be modified for this to work.  Whether it will be worth the trouble is for the OP to figure out.

[HYspd]

i only put a mild countersink on a .22 break barrel to ease loading and lost 50 fps...

What angle and diameter did you make it?  What was it before?

Apart from easier pellet release, a larger ID, more gradual slant, or more rounded breech cone also increases the total volume of the breech.  While this small change might seem trivial, increasing the effective transfer port volume has a significant effect on the "compression ratio"; thus on the peak pressure, and therefore the efficiency of  a springer powerplant.

45^ and maybe .010 in from land face to OD.....like i said a mild countersink, factory is a sharp 90^ to bore....just enough to ease the thumb abuse when loading Crosman pellets...and well i it did so that, but it also slowed down from 770 to 720fps too...trade offs,,always trade offs

[Ex.Magnum]

Anyone know of any non pcp air rifles that can produce close to 30 fpe in .177?

I have an oldskool UK Patriot in .22 now downtuned with Theoben gasram, but on its original spring doing some 42-43joule (31fpe) so I m guessing a .177 Patriot with original spring could be somewhere along 36-37joule or 27fpe. Oldskool Patriots however are becoming quite scarce (if you want a good one anyway).

This much said,
A low cost alternative for your needs – and all in all not too bad looking either- is the Artemis GR1600W . According to factory specs : 29,5 fpe

https://www.fusil-calais.com/en/2447-artemis-gr1600w-air-rifle-177-bore-40-joule.html




Factory page :
http://www.artemis-airgun.com/#details/series/showproduct.php?lang=en&id=54