Initial impressions and short range results:
I received my new barrel from Jim late last week, and installed it over the weekend. Visually, the barrel simply exudes quality – it looks great all the way round, with excellent machining, a great crown and inleade, and even a nice look to the main length of the barrel. I pushed a few patches through it to make sure it was clean and then pushed a few JSB 18.1 grain pellets through it to see how they looked before I installed it. I can confirm what Jim has said in the past - this bore is tighter than the LW barrels. The pellets push through smoothly, but with considerably more effort both to get them started and through the choke than needed on the LW barrels. The end result is that the pellet head shows more “engagement” with the barrel even across the grooves than my LW barrels do across the lands – and the engagement on the lands is very pronounced, as one would expect. Here is an attempt to show the difference in the rifling marks:
I had asked Jim to set mine up to work with a .25 caliber rear shroud mount, so it is machined to fit the .22 cal breech but has a hard shoulder interface to the breech (Note: doing this requires providing Jim the exact dimension to machine the barrel down to for the breech interface). The barrel fit the breech without any noticeable play, but is clearly looser in the breech than the LW Poly was – I have to apply considerable pressure to seat that barrel in my breech. So I installed it normally for my initial tests, with a plan to apply some Loctite later if everything is promising – which I did after about the first 100 shotss. I am using GardenSniper's solid aluminum front shroud mount, and of course this gun is regulated.
I can say that the results on paper shooting indoors at 21 yards (my limit) are very promising. I have put several hundred pellets through it at individual bulls (25 yard benchrest, scaled down to 20 yards), while shooting over my chrony. I have been trying to find the best sweet spot for accuracy with JSB 18.1s out of the tin. I have found very good results at around 825 fps, and also up around 875 fps, but around 850 was not as good – there may be something going on harmonically there that I will need to investigate. I have not tried many other speeds nor other pellets (other than a few JSB 15.9s to see the speed delta and to see how they looked over ten shots while I had the JSBs down to a lower power level - they did about the same as the 18.1s)
When I say “very good” I mean that if I do my part and keep the barrel clean, all but a very few number of shots out of hundreds will fall about 0.25” ctc from each other at this distance – but that does not tell the full story. In a typical 10 shot row on my 100 bull target sheets, there are strings of 3 or 4 shots that are all just about dead on top each other (under 0.05” ctc), but I have not been able to hold that for a full five shots yet, let alone ten. My best 5 shot groups would be about 0.1” ctc and the best 10 shot groups are a little under 0.2” ctc, but the many are right around 0.2" ctc too. This is about on par with my LW Poly barrel, although I am hopeful that I can find a bit more accuracy with some more work. Also, I have not seen what it can do at 50 yards, which is the real test - this barrel may hold things tighter at a distance, which is what Jim really strove to do with this barrel design. Also, while the total spread seems to be similar to my Poly, the distribution of the shots around the center seems to be tighter than the Poly - which is a good thing! So I do have much more testing to do, including testing other pellets. Also of note, out of about 400 shots at individual bulls, there were probably only about 3 or 4 “flyers” that ended up about 0.3-0.4” from the POA, and I would attribute these ones to the pellets themselves, although I saw no obvious issue with them from a quick inspection while loading into the magazine. So out of every 10 shots, about 80% are scoring a ten, and 20% are scoring a nine - and those 4 "flyers" scored no worse than an eight. In summary, I think the barrel has a lot of good potential in terms of accuracy.
A few other observations:
First, I am noticing a definite degradation in accuracy after about 35 shots or so, and this is easily corrected after one pass of my boresnake that has ballistol on it. I noticed similar behavior with the LW Poly when new, and over time the need for a cleaning pass stretched out to more than 100 shots. I don’t know if that pattern will hold with this barrel due to the more aggressive engagement of the rifling and choke, but I am hopeful.
Second, there is a definite reduction in power with this barrel. This is something that Jim has said to expect with the Hammer Forged barrel, as he has said that the increased bore contact will cost as much as 30 fps from a standard rifled barrel, and maybe more from a Poly barrel. So the efficiency is well down from what I had before with my Poly barrel. I was getting 40 shots at 32 FPE with JSB 18.1s from a 3000 psi fill with the Poly barrel (note: this gun is regulated with a heavily modified flow path, if you have not read about it before), but with this one I am getting only about 33 shots at 31 FPE as it is currently set. Unfortunately this negates the principle reason I decided to try one – to have accuracy as good as or better than the LW Poly but with a quieter shot report (from more air space in the shroud – the 0.63” LW barrel gives off a noticeably louder bark than the smaller diameter barrels due to all the air space it consumes in the shroud). Since I am using more air to get close to the same energy level as the Poly, it seems to net out at about the same sound level – but that is just by ear and not measured. Of course the power penalty would probably have been less obvious if the comparator were not a Poly barrel, and I can still get plenty of energy and accuracy out of the gun with it. That said, the Poly only shoots really well at high power levels, so if this barrel can shoot as well or better at lower power levels it really could work out for the better.
Lastly, all of this is out of just the first tin of pellets I have been working with. Things could get quite a bit better (or worse) from a different tin, so time will tell. Also, the pattern of the shots does seem to indicate that sorting might be really beneficial - I don't really want to go there, but when I see 6 or more shots out of ten hitting inside 0.1" it sure begs the question of what is throwing the other few pellets wider.
I plan to see what this barrel will do with the JSB 15.9 grain pellets, and that could be a real nice set up for speed and shot count if I get the accuracy where I want it. I will keep testing and will post the results, most likely after I get some good 50 yard shooting in with this barrel. So far, I am quite pleased with it.
by AlanMcD » Wed Oct 08, 2014 1:28 am 
