96fpe with 55grains is nothing to sneeze at. i know peoples been hitting the upper mark of 100fpe. and 100fpe with 43 grains is actually excellent! i bought marauder parts with RAI tubes and drop block and Cothran balanced valve. i got about 20 shots give or take at lesser fpe with 500cc carbon. thats actually low on shot counts...with no SSG. I am willing to share anything and everything and expects nothing back. i have also invested in a new lathe but its only under 2k. its worth it to this hobby of mine. i sometimes turn stuff through the night! i see 90cc is very usable for .224. i would go with minimum "24 barrel and your custom big valve! who cares about shot counts, get the power down range first then figure the efficiency later.
My original .224 cal Hayabusa had a 29" barrel and a 3000 psi fill pressure, unregulated.... It was full bore porting, but has a 0.088" probe, so the smallest porting (the chamber) is the equivalent of 0.206".... The ammo was RWS swaged .22LR equivalent from Holland, at 41.3 gr. because of the slightly larger diameter.... I achieved 106 FPE when maxed out (0.61 FPE/CI), and when backed down to 95 FPE I got a 20 shot string within 4% ES, or 14 shots within a 2% ES, at 1.15 FPE/CI....Last year I fitted a simplified balanced valve, which allowed me to also fit an SSG.... I also increased the bullet weight to 47.6 gr., using the .224 Bowman.... It now maxes out at 113 FPE at 3000 psi, and backed off to 1000 fps (106 FPE) the efficiency is 1.16 FPE/CI.... It will shoot the original 41.3 gr. bullets at the same 106 FPE, and get over 1.10 FPE/CI doing it.... This shows the efficiency gains possible with an SSG.... I have not tried it with a 55 gr. bullet, but have no doubt it will do 110 FPE (950 fps) while maintaining an efficiency of over 1.10 FPE/CI.... Tethered at 200 bar (2900 psi), it should do that all day long.... Bob
Gino, I'm having very good results with the RedMan liners from Brownell's. Oddly, the 1-20 is still proving the more accurate. The 1-16 that should have the edge simply is not in the same universe as the 1-20 sadly. The 1-2- will give me 1/2 to 3/4" at 80 yards with the 31.4 gr decked Arsenal noble and the 39 gr. NOE spire point is half that. Odd!Both barrels are fully polished and crowned and CF tub wrapped and installed in the Mini Raptor. The 1-20 cf bbl actually out shoots the tensioned TJ.s barrel. No doubt the issue is the TJ's is a .214 pellet barrel. GRRRR!!!I am still temped to try Shorty's barrel porting. LOLI tried posting last night, but it would not let me do so. I would like to post a few pic's of targets with the Decked slugs at 31.4 gr's.
Howabout this barrel https://www.lothar-walther.de/barrel-blank/rifle/standard/1321/barrel-blank-5-6x52r-od-12-mm-l-690-mm-cr-moly-steel?c=34 with these bullets https://noebulletmolds.com/site/archives/152156 If you can get 110 fpe out of your gun that should be quite similar to .257 and 225420 bullets in performance and we all know that combo to be a performer.
It is a wee bit off subject, but I bet some fun could be had with that .220 Russian barrel
Seems I have been missing too long from this thread!I ported the barrel to be slightly over bore in order to cancel out the loss of the area taken up by the probe.It is oblong and done on the mill. For the set screw to have something to bite, I used a no seam steel tube only slightly larger in dia. to the liner, then wrapped the barrel in two cf tubes. I have a not yet available FX. Superior "Heavy" Slug Liner in .22 that should be here this week. My only concern is that the smaller bore of the FX liner will show a smaller area of the slug base for the air to push against. I do not expect it to produce the same level of power the .223 Redman's liner from Brownell's does. That and I don't currently have any sizers that small. GRRRRR!!!The Brownells liner as installed is only 19 1/2 inch in length. I will set the FX up at either 22" or 24". Hope this of sets the loss of fps from the smaller dia bore. Knife/Mike
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