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I was reading where gas checks increase accuracy by giving a regular, flat bullet base, but that is for powder burners. I have a .45 air rifle, pushing a 300 gr bullet about 800 fps. I wonder if a gas-checked bullet would work in an Airgun? Would the gas check be hard on the barrel? Any thoughts?
I don't see how an aluminum or copper GC could hurt a steel barrel.
Thanks!
General rule of thumb I always went by with my powder burners was over 1400 fps use a gas check.
Now there may be advantages to using one in a large bore airgun. But is it worth the cost?
And only you can answer that question.
Interestingly, gas-check style bullets, without the gas check fitted, tend to be very accurate in airguns.... often more so than the same design in a flat base.... It could be the slight difference in CG location, or that the last driving band is molded in, and therefore concentric and perpendicular to the axis of the bullet.... A flat base bullet can have base irregularities from either incomplete fill out, or from asymmetric cutting of the base by the sprue plate, or both.... Having the last part of the bullet to release from the crown do so evenly all the way around is critical to accuracy....
Bob
I both reload for powder guns and shoot air guns and have for most of my life. I have not dove into the big bore air guns yet. I plan on that for one of my near future purchases. First off most air gun barrel rifling is set up to shoot a pellet unless you purchase a special barrel for slugs. Some of the big bore air rifles past 30 cal come with a slug barrel. I have not seen one of these barrels to observe the rifling for a slug barrel. There are also several different types of air rifle barrels. Land and grove (similar to a regular rifle just not as pronounced), Land and grove with choked end (This is one of the more popular style barrels), smooth with barrel twist end (Found in the FX airguns), and then smooth barrels mostly found in the older and in cheaper air rifles that shoot pellets and bbs.
Big bore air rifles are a relative new venture for air rifles and both the barrel style and types of ammo are changing to meet this. I would be interested in your findings in regards possible velocity changes and accuracy.
That IS interesting, rsterne! I’m going to have to check it out.
Time, I’m shooting an Airforce Texan SS in .457. It pushes a 300 gr bullet at around 800 fps and has a Lothar Walther rifle barrel. I’m casting my own bullets and trying to figure out the best performance. You are right that this is new stuff, but is sure fun!
Some early .22 air guns used a round ball with a greased felt wad glued to the bottom to provide a gas seal and keep the bore clean and lubed.
The lubed felt wads used for C&B revolvers should work okay for some of the larger bore PCP air guns in .30, .35 and .45 .
Has anyone simply sized down a jacketed bullet to accommodate the bore of one of the big-bore air guns and tried shooting that? In my mind's eye I can see possibly sizing down a 200 grain 45 caliber jacketed hollow point just to see what kind of results one would get.
I'm sure it would work but just how well it will work is yet to be seen. I think that the big bore air gun genre is slowly inching it's way toward that end anyway.
HollowPoint
I've never tried it, but those who have find they lose a lot of velocity, because by the time they size it small enough to not jam in the bore, they get too much blowby.... The jacket material is just too hard, and presents too much friction, for the low pressures we have to drive a bullet, compared to a PB....
My homegrown Hayabusa .457 launches a 340 gr. bullet from a 45/70 at 850 fps on 3600 psi.... That is 550 FPE.... 8-)
Bob
The back end is the Steering End! Doesn't matter what launches it.
If you can get the gas check seated perfectly everytime then it will shoot good. However a plain based boolit with a perfect base will probably shoot better.
The whole point of a gas check is to seal the bore so there is no Blow By which causes leading.
However a Plain Based Boolit that is the right size will also seal the bore,,,, so there is no leading,,,, so the Gas Check becomes superfluous.
Also Air Gun Chamber Pressures are not even in the same Ball Park as Powder Burners, so I can see no reason for an alternate seal.
Also if the Germans didn't think of this,,, it probably doesn't need to be done.
Randy.
Makes sense Randy! I think I will see if I can find a good gas-checked mould, but not put the gas check on it like Bob suggests.
Maybe look for a Boolit that has two driving bands like a regular Diabolo Pellet has. The resistance of a bullet with more surface area contacting the bore will slow the bullet down. In Fact,,, I would think that a .45 caliber Diabolo Pellet would be the hot tip?
We actually shoot .73 caliber Diabolo Style Shotgun Slugs and some get pretty spectacular accuracy when shot in Rifled Barrels.
Needless to say a .73 caliber pellet that weighs 525 gr will knock down just about anything it hits. Serves to reason that a .45 caliber version would have a similar effect. Also since the pellet only contacts the bore on the front and rear driving bands the Velocity should be higher due to less resistance.
I imagine some mould maker could make this.
Randy
Would think that the "gas check's" main purpose is to prevent the melting of the base of the bullet depending on powder used and Target velocities. Could also look into some of the lead bullet coatings like HiTek to see if it would make an difference in accuracy.