josjor - 8/24/2006 8:48 AM
Hey all. Well, looks like the Crosman/Mendoza RM577 is headed for the scrap heap as there seems to be either a broken spring, bad seal, or both and CDT says parts are not offered. So.........considering the RWS Diana 34. I'd love the 52, but the checkbook wins out this time.
I've just been plinking but would like to hunt some with the gun. My own accuracy not involved, what do most of you feel is the effective range for different game using this power of rifle in .177?
thanks
Josjor:
You can't take your own accuracy out of the equation, because that is the limiting factor with respect to range-to-target when hunting with .177, or any other caliber of airgun for that matter.
However, if you are shooting dome-head pellets of 7.9-8.0 grains in weight with ballistic coeffecients of .024 or higher out of a gun capable of putting out 14-15 ft/lbs of power at the muzzle, you'll still have over 9 ft/lbs of energy at 50 yards. That is plenty to ruin a jackrabbit's day. I shoot chukar partridges in season with a .177 R-9 running at 15 ft/lb and it'll give complete, through and through penetration out to 50 yards. These birds are about the same size, weight, and build of a "rock dove" or common "pooper pigeon."
I wouldn't even consider a 34/36 in .22, as the velocity is so low compared to .177.
The key to effective hunting with .177, aside from shot placement, is paying attention to pellet selection and using pellets that carry the most velocity and energy downrange. In other words, you want the pellets with the highest ballistic coeffecient.
The all-time champ on that score is the Crosman Copperhead Pointed 7.9 grain with a BC of .028 in most mid-magnum rifles. Crosman Premiers in 7.9 and 10.5 will also typically yield a BC over .025 in most guns. Kodiaks are typically .026-.027 or so. JSB Exacts will usually be over .022 BC.
These will be the flattest flying, hardest-hitting pellets because they carry velocity well. By contrast, a pellet like an H&N Wadcutter might have a BC around .009 or so. Because of this, it'll shed velocity quickly and at 50 yards will hit with about 3 or 4 ft/lbs when fired from a 12 to 15 ft/lb gun.
BC is a little-understood and often dismissed aspect of exterior ballistics in the airgun community, but I think it is vital in airgun hunting.
Given the choice between .22 and .177 in a mid-magnum springer for hunting use, I'll take .177 firing high BC domed pellets, every time, as long as that choice is legal.
Consider that a gun shooting .177 Copperhead Pointed at 855-860 ft/s will have a maximum point blank range that is right about 50 yards, assuming a 1" kill zone. That same gun in .22 firing 14.3 grain pellets will normally be shooting them in the 625-675 ft/s velocity range, and will yeild a maximum point blank range of less than 40 yards, even if you can find pellets with the same .028 BC to shoot out of it.
So, from a given mid-magnum spring-piston powerplant, .177 doesn't just shoot A LITTLE flatter than .22, it shoots A LOT flatter with pellets of high BC.
Also, because velocity gets squared in energy calculation while projectile wieght doesn't, it is entirely possible for a .177 version of a particular rifle to deliver more ft/lb at 50 yards than its larger caliber counterpart will.
While I prefer .20 for general use, the fact of the matter is that I can kill all the rabbits, quail, squirrels, and chukar the law allows with a mid-magnum springer in .177 out to 50 yards, too. If .20 wasn't an option, .177 would be my main caliber.
-JP
http://www.uplandhunter.net