New Pellets in Holland

[SeanMP]

LOL...yes I remember Len getting very upset about that and threatening to call Dennis personally to have you thrown in airgun jail...or something.

I spent last evening perusing examples of the various .223 offerings before I got back to you and it looks visually like they all have at least a 28" barrel. My feeling is it's easier to trim than to stretch a barrel so for the extra $10 might as well say 30". We need to hit a very narrow band of velocity to optimize the twist and the more things we can get in our favor the easier that's going to be.
I've never used TJ's liners but a lot of blanks have a minimum amount you need to trim off. Is this the case with these liners?

I would need at least 28" to be able to snuggle a 250cc tube in underneath it and have it look right visually. And it still wouldn't be a crazy big rifle. It lands right in the middle range of the Remington 700

I was also thinking that if there ever was a an ideal time for an airstripper this would be it.

[rsterne]

I talked to Mike, and he can do 30" no problem in the .224" x 14" twist x 1/2" OD, and IIRC, they are about 1/4"-1/2" over, typically.... They are hammer forged CrMoly, so if they have a section that needs trimming off, I would guess he does that first.... Since we're paying by the inch, I'm sure it will all be usuable.... I'll get a MO on Tuesday when we are in town and have them shipped directly to you....

Geez, add an airstripper and you'll be pushing 4 feet (or more).... "give me 40 acres and I'll turn this rig around".... This is getting exciting, I spent a restless night with "visions of airgun parts dancing in my head"....

Any more songs you wanna hear?.... NOT !!!

Bob

[rsterne]

I've been researching the Ballistics Coefficients for .22LR 40 gr. bullets today.... Depending on manufacturer and velocity, I've found values from a low of about 0.092 to a high of 0.158 for the subsonic, and from a low of 0.104 to a high of 0.141 for the supersonic rounds.... The we have the Sierra chart, which looks more mathematically calculated than measured, which says subsonic 40 gr. has a BC of 0.169, and supersonic is 0.145.... If I throw out the few high and low ones, the range is a lot narrower, subsonic runs about 0.125 to 0.150, and supersonic from 0.120 to 0.140.... When you consider how similar in shape the .22LR bullet is from brand to brand, I'm surprised the variation is that wide.... However, what does this mean for a rifle shooting 1000 fps, sighted in at 42.5 yards (for a 1/2" kill zone) in terms of the drop and wind drift (10 mph crosswind) at 100 yards?....

BC of 0.090 - drop at 100 yards = 9.43" - drift at 100 yards = 3.85"
BC 0.100 - drop 9.27" - drift 3.45"
BC 0.110 - drop 9.15 - drift 3.12"
BC 0.120 - drop 9.04" - drift 2.86"
BC 0.130 - drop 8.96" - drift 2.63"
BC 0.140 - drop 8.88 - drift 2.44"
BC 0.150 - drop 8.82" - drift 2.27"
BC 0.160 - drop 8.76" - drift 2.12"

Compare this with a .25 cal 15.4 gr. JSB King at the same velocity (what the Condor guys shoot)....

BC 0.034 - drop 12.31" - drift 11.04"

Comparing the most probable BC for the subsonic .22LR bullet of 0.140 to the .25 cal JSB King, the drop is 3.43" less (significant, but not crucial), but the wind drift is a staggering 8.6" less (ie only about 1/5th as much).... THAT shows why this is the preferred round for 100 yd outdoor benchrest....

Bob

[SeanMP]

It's stunning to see the differences in drift at 100yds. I would be fairly certain the difference would be large shooting through the boil on a hot summer day as well.

I'm looking forward to squeezing the trigger on this thing more and more everyday.

[rsterne]

Yeah, it's kind of an order of magnitude improvement over pellets.... I wonder what the BC of the 41.5 gr bullets will be.... even more curious about the 64.5 gr, but without a fast twist barrel to shoot them from who knows....

Did you notice that a Condor 500 cc (30.5 CI) tank is only about 1/2" longer than the 22CI (360cc) tank I'm using on the Hayabusa?.... and about 1/2" larger in diameter.... I wonder if it's practical to do a dual tanker, a 22 CI for the forestock and a 30.5 CI tank for the buttstock.... A total of 52.5 CI (860 cc) would be sweet if the ergonomics could be made to work.... at least 15 shots?....

Bob

[SeanMP]

I guessed that you were trying to see if you could fit the larger condor tank into your design. That would be pretty sweet if you could get the porting to work.

Now if you were working with a modular block design you could run a port through the less busy breech area and down into the plenum

[rsterne]

Yeah, I won't be trying to fit that into my Hayabusa.... this would be an entirely new design, stealing your double block style.... The MRod stock on the Hayabusa is heavy, and I was thinking an all metal double tanker would be pretty cool.... It would be very useful for Big Bores and my .410 Air Shotgun project as well.... The ergonomics are the problem, to get the rear tank to function properly as the stock/cheekpiece.... Not having a Condor, I'm pretty much in the dark on that part of the equation.... It might be a mockup kinda deal.... One problem I haven't solved is how to do an RVA with the rear tank in the way.... any ideas on that?.... Removing the tank to do hammer spring adjustments is NOT acceptable....

Bob

[SeanMP]

Your right the geometry would require some thinking. You would need to get the tank block far enough back to allow for a grip

[rsterne]

My concept for a dual tanker is more like this....



I would either use two identical 22 CI (360cc) tanks, or possibly a 490cc (30CI) Airforce Tank for the rear one.... The 22 CI are 11.4" long x 2" OD and the 30 CI are 11.8" long x 2.5" OD (roughly).... The lower block would house the valve, hammer, and spring.... the upper one is the breech.... I could use a PRod trigger assembly, although there may be a better choice.... Too bad Blue Fork Design isn't doing his grip frames any more....

With the 22CI tank butted up against the back of a PRod trigger group, and with no buttplate, the length of pull is 15".... That's a touch long, but I could live with it.... I think the height of the top of the tank would be close to the right height for my cheek to line up with the scope (depending on breech height).... The 2" tank, being slimmer, might be better in that regard.... Relative to the breech, the rear tank is quite a bit lower than the Condor, eliminating the high scope rail.... so that's a good feature....

Just all blue-sky thinking at this stage.... The RVA would still be the problem, plus a seat for the hammer spring.... and the hammer might have to have the sear catch in the middle or near the rear to latch onto the sear.... The valve would draw from the front tank, the passage through the block between the tanks could be just 1/8" and still work just fine....

Bob

[SeanMP]

I like it!

The only reason I suggested using the lower block for the rear tank mounting is that would give you access to the RVA. In fact I plan on putting a knurled/threaded cap here with the RVA incorporated. As you explained the rear handled bolt once the lug is rotated up out of the way you would be able to unscrew the cap and withdraw the spring and the hammer. That would save a lot of time during tuning.

Then you could recover that 1" drop in centerline with one of those fancy adjustable combs that slide over that condor tank