New (to me) Toy Day
- Thread starter Sqwirl57
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Obturation-
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling.Wikipedia
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling.Wikipedia
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True. But you want a projectile that deforms consistently AND in a manner that engages your particular rifling agreeably, no? A pellet of one shape and size isn’t going to deform the same as one of a different shape and size.
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It’s exactly what seems to be happening with the batch of AA Falcons I have. The skirts flare/balloon more due to their softness and thin-ness.
That said, I have seen light “Green” pellets also produce good results despite having thicker skirts and being harder. At first I was confused, until I realized they are fatter and make up for lack of flaring by having a tighter fit from the get go.
-Marty
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Surely and I'm only looking for results ultimately. It is fun to think about the minute details and I was just sharing that word, obturation. Hollow Base Wad Cutters are popular in 38 Special target pistols. Or at least they are amongst old timers, older than me even. I love experimenting but was always afraid of the HBWC as the skirt was known to blow off when loaded past the sweet spot velocity / pressure.
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And a great word it is, much appreciated. I knew it happened but didn’t have a word for it. I love the minute details, that’s why I posted what I posted. My guess would be it has something to do with why even guns of the same make and caliber can prefer different pellets. And across brands with different twist rates and depths of rifling etc. probably even more pronounced. I’m new to airguns so I’m absorbing all I can and investigating the rest. My wife is just shaking her head. She’s seen me tear into bicycles, and RC cars, and slot cars. Looks like airguns are next!
Marty, I wonder how the shape of my more recent JSB RS 13.43 compares to yours? Use them in Kim’s HW50S and my 2240’s, excellent in both.
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Ok so I couldn't help myself and ended up ordering a full power spring from ARH and a 25mm piston seal from Vortek. The gun is shooting great as is but if I can get 16fpe out of it while still driving them tacks, I will be a happy, happy man.
Also managed to find a factory set of iron sights for the gun. I dont necessarily need them but I kind of want the factory look to be complete while I can still get the parts.
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I have the ARH spring in one of my LGUs too. It’s a good spring but there is no guarantee that the original spring guide will fit tightly. I’m not sure if ARH makes custom guides for it, but if it hasn’t been shipped yet you may want to check with him if he will make one or you can make it yourself if you have a lathe…
-Marty
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Hopefully it'll fit the factory guide but worse case scenario I do have a lathe so no biggie
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You mentioned that you have the Rowan trigger in your LGU; does this trigger work with the original safety or does the safety become disabled once installed? Thanks!
-Marty
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My safety still works. I'm not having any of the oddball safety issues that seem to plague these guns with the factory LGV trigger either. I did just place an order through Rowan for another trigger for the LGV though. I tried to tolerate it but failed.
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New ARH spring is installed. VERY HAPPY NOW! We'll see how it groups tomorrow. New piston seal arrives on Thursday so I'm curious to see if I get a small bump there. I'm happy either way though. I have a few other ARH springs in guns and they all seemed to settle in a bit so I'll recheck velocity in a tin or two.
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690 fps is respectable for a 15.9 grain .22 pellet. Will be waiting to hear what the upgrades do.
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Alright so lucky day today. My Vortek piston seal showed up a day early so I tossed it in and did a full clean and relube. The gun shoots wonderfully for nearly 17fpe. Re-ran the gauntlet on my pellets here and it still seems to still eat everything from CPHPs to Baracuda 18s, but seems especially fond of the smaller head sizes. The Norma 15.9gr still seem to reign supreme through this gun though. Here's a 20 shot group at 30m with them and the current chrono numbers.
Accuracy wise, this gun didn't seem to lose even a single step going from 13fpe to 17fpe. It's almost like it was made for it haha. I had very similar results when I gave my .22 97K the full power treatment too.
Accuracy wise, this gun didn't seem to lose even a single step going from 13fpe to 17fpe. It's almost like it was made for it haha. I had very similar results when I gave my .22 97K the full power treatment too.
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That is damn good. Nice shooting. I need a calm day for 50 yards groups and I’ll post mine from the LGU.View attachment 330906
Got my LGV .22 in this afternoon (thanks @Flintsack !). Spent about an hour testing pellets and settled on the Norma 15.89gr. The bore seems to be a bit smaller than what I'm used to with the HWs because the JSBs and FTTs are a bit to snug and kind of click into the breech. The smaller Normas glide in much more smoothly and as a result seem to be shooting a bit better.
I'm absolutely amazed at how smooth shooting this gun and the LGU both are. Really is ashame they aren't around any more.
10x Norma 15.89gr, 30m, Front and rear bags
View attachment 330907
One got away from me a bit but I'm still very happy with this. I'm a little underwhelmed with the power level but thats easily fixable. Its currently hovering around 13ftlbs but I'm thinking I would like to see it in the 15-17ftlb range. Thoughts?
Edit: First 50yd group (5x). It may be in my best interest just to leave this gun alone for now
View attachment 330915
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