Slugs and choked barrels

[Dairyboy]

So I'm looking to shoot slugs out of a choked barrel. The barrel in question is a 20" TJ 1:26 .300. The barrel itself is .300/.294 and the choke is .297/.2935. Now I see alot of people say shooting slugs you want basically same size or .001 under. So that means I would need to size down slugs to .297 or .296. NOE only goes to .298. Also would .296 be too small for the bore? I could always if need be chop the choke off and get the barrel rethreaded. I'd only lose maybe 1-1.5" of barrel. Curious on thoughts. Slugs will be NSA 47gr and 50gr which Nick says shoots really good out of the 1:26 TJs

[triggertreat]

Those NSA types have a lot of surface area.  I would remove the choke based on my choked GM barrel experience.  I have sized down to 0.249 with it and it still shoots terrible even with slugs that only have one drive band.

[GSu]

I haven't the area too shoot much past 60 yards but the NSA 47 grain shoot great out of my .30 flex 20" barrel.  No paper shooting but minute of hanging empty CO2 cartridge.  They make nice holes in those empty green propane bottles.
Cast some of the 30-50A Accurate recently.  10 yard quick test show promise but I haven't been aable to get out to shoot further to test.

[Dairyboy]

Yeah Keith you make a good point there. I have the barrel out and gun torn apart and I'm wondering if I should just send it out now.

That's good to hear Glen! Seeing this is making me hesitate on getting the choke removed. I have 55yds in my backyard and then can test oh 200yds+ if wanted on the farm. I really want an SS valve for this gun to be pushing the slugs with ease of cocking. Or could go cothran with a reg but would like to keep it unregulated. Hmm what to do

[shorty]

Try under sizing and then knurling. It helped me with the 25 cal hunters in my 25 Mrod but still not perfect. I would say it's night and day though. I rolled the projectile on a piece of wood with a knurling tool but I think a file will do the same thing.

[bear air]

That sounds interesting. Do you basically file the slug down to allow for the choke? I wouldn't mind trying some out of my MMHF barrels in 22 and 25 but they have very tight chokes which I don't want to remove. Dillon I would try to find an alternative solution before removing the choke. And if you don't have to have it done theres your money for the upgraded valve. BAM! LOL. Good luck Dillon.

[KnifeMaker]

That sounds interesting. Do you basically file the slug down to allow for the choke? I wouldn't mind trying some out of my MMHF barrels in 22 and 25 but they have very tight chokes which I don't want to remove. Dillon I would try to find an alternative solution before removing the choke. And if you don't have to have it done theres your money for the upgraded valve. BAM! LOL. Good luck Dillon.

No sir, but if you use light pressure, and roll the bullets between two files,it will impart a cross hatched surface to them. Really helps with a choked barrel.


Knife


 

[KnifeMaker]

Both of the last two barrels I removed the choke on, It only took a little over 1/2" on one, and not quite 3/4" on the other.


Both were instantly more accurate with slugs. Both were much more accurate with NOE pellets as well. They did loose a tiny bit with JSB's however. 


The 34 gr JSB's in .25 were no longer touching on the steel plate at 76 yards, but they were all still Squirrel Head-Dead. LOL


Mike

[Dairyboy]

So I got my order of slugs from NSA in today and man I'm showing very real promise with them. I didn't even clean the barrel first and had multiple 5 shot groups with 4 touching at 55yds. With both the 47gr and 50gr. What to do what to do....I'm thinking I'm gonna order the sizers first and go that route before I get the choke removed. Wouldn't hurt I guess. Worst case I'll send it out if they don't work good.

[Bullfrog]

I’ve always had great results with swaged bullets with choked barrels. I’d try a bunch of different bullets first before chopping your barrel down. I would say that all of my choked barrel guns shoots at least some bullets well. Even some cast bullets. Just like with any other barrel and projectile, you just experiment with different bullets and sizes until you find what works.

I believe you can have the best of both worlds between a pellet and slug shooter. No reason to sacrifice one for the other.

[Kinetic45^]

My personal experience is mostly in unchoked rifles but I have had some experience with a few choked big bore .30 and .35s and it seems that the bigger the bore the less adverse the choke is on shooting slugs. The corollary is that as bore goes smaller it's more sensitive... and hence so many people can't get slugs to shoot that well in the .177 and .22 pellet guns (of course there are exceptions, someone always comes up with one).  I believe its based on how much swaging happens to disrupt the bullet, on a pellet there are tiny rings of bore contact so not much effects it, but on the slug there is a lot of material that has to be moved and compressed, more so on a smooth sided bullet than one with grooves or knurling.  But when you get to the bigger bore, the percent that is effected is a much smaller percent of the entire bullet than what happens with a .22 slug for example...

I think that's also why the Bob's Boat Tails do a bit better in my choked .25 rifles, the two bands pass through the choke basically like a pellet does.

It really comes down to what you plan to shoot the most, ie: your rifles purpose; target, hunting, etc. as to keep or remove the choke. One thing I've learned, in airguns there is no "universal all around", there will be compromises and you just have to go the fork that is most useful (to you).  Havn't really seen what you really want to do with this one yet in this build.
And I'd want to know the FPE level of the rifle primarily in deciding on choked or unchoked so what's the platform you are putting the barrel on?
Without that I'd say:  choked=lighter to medium projectiles;  un-choked= medium to heavier ones.

Final thought: it's like the old saying "measure twice, cut once".  If you leave it choked and don't like it you can always cut it off. (and that comes from someone who prefers unchoked)

[KnifeMaker]

I added:I added, the 34 Gr. .25 JSB MK II's were no longer touching at 76 yards, but were stils "Squirrel Head dead. LOL


The Noe .25 Magnum pellets  that were 1 1/2 to 2' were now shooting the same as the JSB's' Not all touching, but very-very tight. the bullets were the same, where as before, they were larger in groupe size to the NOE pellets before the choke removal, and with many fliers. The fliers are gone, and the pellets and bullets both shoot squirrel head worthy at the same 76 yards now. 


Knife 

[Dairyboy]

Good to hear Travis! After yesterdays results I decided to order some sizers and see how it does before I mess with the barrel. Seems a much better route if I don't need to cut the choke off.

Carl, I guess I didn't make it clear did I lol. It's on my Flex which I unregulated. Was pushing 85fpe avg before with the 44.75gr JSB from 2700-2150psi over 21 shots. Not sure where it's at exactly now but I cranked the hammer spring all the way in for testing. Will need to chrony to see power wise but looking for around 95-100fpe. Pesting is all that will be done with it. Well maybe some long range plinking on rare occasion but mainly 80yds+ pesting. Got pellet pushers that got everything closer taken care of. Mainly looking for a good shooter long range and in wind hence moving to slugs.

Mike, good to know about your results. Honestly wouldn't mind if pellets weren't as "accurate" but knowing the barrel was designed for the 44.75gr JSBs and have had a few of the barrels unchoked, they do a good job shooting them unchoked. But main goal is keeping it strictly a slug shooter

[Mod90]

Some good points raised here.
If it were me, I'd start by trying slugs that are the same size as or just barely larger than the choke.

[Wayne52]

The only guns that I've shot my cast 30 grain BBT's in were unchoked.  I need to cast up more myself because I just received a new hollowpoint mold  
Seems like I've read somewhere that choked barrels on airguns are there because with a choked barrel you can supposedly shoot more of a variety of pellets with them however they're not inherently good for shooting slugs with a choke.