Some times the choke isn’t the problem a slight bur or defect at the crown has caused problems for me.
That being said I’ve found the 22 JSB knock out slugs do well in several of my 22 cal guns ( FX impact and crown) the .217 diameter.unchoked barrel The .216 did poorly but shot respectable well in my daystate red Wolf which I believe has a choked barrel. I don’t think many of the air rifle barrels are machined as carefully as the stuff that’s available for powder burners. I may be wrong but my guess is if you combined a true match barrel with equally exacting ammo ( slugs or pellets) you would have no need for a choke and much more consistent grouping. I’d think too that if air rifle actions were modeled after powder burners with screwed in heavier barrels accuracy would be improved. Air rifles are just made differently and probably because we don’t need actions which have to contain the high pressures that are required for even rim fire guns. I think we give up somethings doing things as they are done. BUT I’m no engineer or fire arms expert. I do have a bore scope and I haven’t looked at an air rifle barrel yet that has impressed me all that much.
You've hit the Nail pretty much on the head here. Yes, a LOT of short cuts are taken with ag barrels in general. Wit highly inflated prices for the work done.
I have both choked bbl's and un chokes bbls that shoot slugs. However, remember, I design and test slugs as a passion. As does my good friend Tofazfou. We have both found the same things. While some choked barrels shoot slugs well, it is not the norm. What is of vital importance is the the slug be sized to the grove dia. In a non choked bbl. the slug has to be no more than .0003 over, and often does well with -.0001 under.
IN a choked barrel, the same is true. However, regardless of the grove dia. of the bbl, only the grove dia. of the choke matters. Period.
I rec'd an FX Superior Heavy bbll in .22 that was of course choked. It was before they were released to the public. It was the worst shooting bbl. I've ever shot a slug thru. Uppon close inspection, I fond that in the choking of the barrel, the worker had spun the barrel while applying the pressure of the press to choke it. it ended up being a complete smooth bore for the last 2 inches. Not even the b ginning of a twist of any kind what so ever.
I contacted FX, as AI was supposed to test the bbl. several times, (Which I paid in full for) and they have yet to bother returning my calls or emails.
I removed the choke polished the bore, re-crowned and and dit is tack driver of the highest order. It is mounted in a Raptor.
As many AG's as i have tested, only one choked bbl. is a true pinpoint shooter. It is Made by CZ, which make their barrels to PB quality spec'. It is fully lapped and polished from the factory. It will hold 1 to 3/4 at 100 yards in good conditions with ease.
The biggest issue is that most shooters have no knowledge of what i takes to shoot slugs ir cast and size same. We PB shooters have learned this for well over a century.
Air gunners and slug makers have in many cases spun their wheels in trying to find success, where the knowledge of what works and doesn't work is well known. Worse yet, the bit wig U-Tube stars such a Dubber completely dismiss all knowledge on the subject. I tried to help him, but was of course ignored. Same with FX. I could have saved them a lot of time, and customer the headache and expense of having to purchase and try so many iterations of the same theme with slightly tweaks over and over again. but I guess it is what it is. they sure have made a lot of money on using the air gunners as test pigs, so I gues s it was/is in their best interest financially. As long as people keep reaching of re3h golden ring and falling for it. The pursuit of accuracy is surely one of our most cherished goals. And it is being used to great effect in making a dollar by many of the companies.
Want a sure fire accurate bbl. for shooting slugs, purchase a pb barrel liner designed with the twist rate for the fps and length of slugs you intend to use. Like I said, they've been doing this for well over a century, with a very high degree of precision. Forget that it is an airgun, as that mentality only fits pellets. It is a slug shooter, Air or Powder.
Knife
Fx bbl. before choke removal. o
after choke removal, and before correct sizing .
Now after sizing to correct grove size. Adn shot with my off hand due to an injury.
And finally after a full polish,
This is the same slug from an inexpensive PB barrel liner form a leading gunsmithing supply only now a .223 rather tan the .218 FX, so more power as well.
Oop's wrong pic.
PB liner, under 40 bucks. Hello!
They are available in just about any cal. with a verity of twist rates. For instance, in .22, if you want to shoot a light slug, order a firearm .22 short barrel. If heavier, a .22 Long Rifle bbl. It has already been well documented and is industry standards. From regular factory quality to the best custom barrels made. All available to your. And yes, they shoot pellets just fine!
Brownell's Gunsmithing Supply for starters, TJ's for heaver liners, to some of the finest custom match and bench rest barrels known to man. All at your finger tips. And all proper heated, top grade steels that can be cleaned with a brush without damage. No soft Air gun low quality steel whatsoever.
Knife
