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Ghost Slug barrels are now available

Lee unsworth

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Slug barrels for the alpha/delta and brk ghost are now available in 177-22-25 - more 177-22 are in production and delivery due 1-2 weeks there was some .25 barrels ready to ship . .30 barrels are in the testing stage and will be due imminent, you can fill out the online form above to request the 28inch slug barrel with or without shroud and also with or without chrono

IMG_7503.webp
 
It would be helpful for the slug barrels to know what twist rate there is so you will know what slugs it will be possible to use.
I don't thing there is any formular that works like that in an airgun, but nice if it did, life would be so much easier! As you ask, the current .25 slug barrel for ghost is 1:17.7 (standard twist) and in .177 its 1:30. This is worked out by trial and error of hundreds of different styles and types of slugs over the last 2 years by at least 10 different testers. Groove depth and choke are very different on the slug barrels to the pellet barrels, and its this that makes the biggest difference. 20241017_155416.jpg
 
I don't thing there is any formular that works like that in an airgun, but nice if it did, life would be so much easier! As you ask, the current .25 slug barrel for ghost is 1:17.7 (standard twist) and in .177 its 1:30. This is worked out by trial and error of hundreds of different styles and types of slugs over the last 2 years by at least 10 different testers. Groove depth and choke are very different on the slug barrels to the pellet barrels, and its this that makes the biggest difference. View attachment 9408
Any specs on the .22 slug barrel by chance!?🙏🙏 Also the link to order a barrel doesn't seem to work? I have been following @Soren Drost and paying great attention to his .177 testing. But it is the amazing BC and punch of the .22 that I crave😍
 
Having my Corbin press in 218 I would love to make custom slugs for the rifle and get as much out of it as possible. I know this HP model I have is possible of high power, now just need a barrel
 
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I don't thing there is any formular that works like that in an airgun, but nice if it did, life would be so much easier! As you ask, the current .25 slug barrel for ghost is 1:17.7 (standard twist) and in .177 its 1:30. This is worked out by trial and error of hundreds of different styles and types of slugs over the last 2 years by at least 10 different testers. Groove depth and choke are very different on the slug barrels to the pellet barrels, and its this that makes the biggest difference.
Twist rates are going to be mainly decided by two factors in a slug barrel, twist required for stability and twist giving optimum group size. The twist rate for stability will be governed largely by slug length so there will be a maximum slug length, and by inclination slug mass, which can be stabilized for a given twist rate. If the maximum slug length which can be loaded into the rifle is known, then a twist rate can easily be found which will stabilize it using the standard equation for stability factor. Because length and mass tend to go with each other, the same could be done if there is a maximum mass which can be fired.

Optimizing twist rate for group size is a little more complicated, but again, if certain slugs are chosen as best for the internal ballistics of the gun, then the optimum twist rate can be determined using a six degree of freedom model. There are equations for calculating error sizes, but they may not be best because of the assumptions simplifying them, hence the use of the sixdof model. Using these methods you should soon find a narrow band of stability factors which tend to give the best results and from the stability equation you can again get a band of twist rates to model and test.

The fact is that contrary to what "experts" apparently agree, external ballistics science does work on slugs and pellets just as it does on bullets, shells and everything else ever fired from any type of gun at any speed.

While the above will not necessarily give you the absolute best solution, it will eliminate a lot of non-starters and will enable you to drastically reduce the number of designs and tests needed, saving time and money.

For shooters, knowing what the twist rate is in the barrel will give them some idea what length or mass of slug can be stabilized, or they can use one of the freely available stability calculators to give them an idea.
 
Pellets are not slugs, We need a pellet barrel or a slug barrel , I have pellet guns and I shoot pellets , When I get a slug gun or a slug barrel I will shoot slugs ,
Its that simple people.
Mike
 
Far from an expert but my understanding is Slugs need a different twist rate and of course no choke, I think you just got lucky,
This one that I'm referencing had the standard LW twist rate....and a choke.

On that whole choke/no choke concept.....completely different barrel and gun situation than the good slug barrel I mentioned above.....but I bought an unchoked LW blank about 4 years ago and paid a machinist buddy to make it fit a pretty high end gun. That barrel shoots better with pellets than slugs (to the tune of netting me a 3rd place finish at the American Field Target event at EBR in 2022). Two years prior to that, the same machinist buddy cut me a couple Korean barrels (new/old stock) for yet another high end gun. Both of the Korean barrels were also unchoked. Those barrels also preferred pellets over slugs.

Unfortunately, much of the commonly accepted "facts" about slugs in our industry simply don't hold water.

Lots and lots and lots of barrels (and money) later, I'm of the firm opinion that a barrel either likes a particular slug, or it does not. Much the same way a particular barrel prefers a particular pellet. The bummer, and the hard reality check, is that barrels that prefer a particular slug are much fewer and farther between than a barrel that does well with it's preferred pellet.

From my personal barrel experimenting, the majority of quality airgun barrels (one coming from a respected barrel maker) will put at least one variety of pellet into 3/4-1" groups at 50-55 yards.

But for slugs (and again, the caveat of a quality barrel maker), the ratio of good/bad is more like 1:20-25. Ie I have personally experimented with slugs in 40-50 barrels, and only found slug success in two barrels. A handful of the others were mediocre at best (1.5-2" groups at 50 yards) and the accuracy results from slugs from the other 80% of those 40-50 barrels have been abysmal.

I'm cautiously optimistic about BRK's newly marketed "slug barrels." I truly hope they have found success in the mystery of why slugs are so picky about the barrels they're being fired from. BRK certainly has deeper pockets to throw at the problem than I do.
 
This one that I'm referencing had the standard LW twist rate....and a choke.

On that whole choke/no choke concept.....completely different barrel and gun situation than the good slug barrel I mentioned above.....but I bought an unchoked LW blank about 4 years ago and paid a machinist buddy to make it fit a pretty high end gun. That barrel shoots better with pellets than slugs (to the tune of netting me a 3rd place finish at the American Field Target event at EBR in 2022). Two years prior to that, the same machinist buddy cut me a couple Korean barrels (new/old stock) for yet another high end gun. Both of the Korean barrels were also unchoked. Those barrels also preferred pellets over slugs.

Unfortunately, much of the commonly accepted "facts" about slugs in our industry simply don't hold water.

Lots and lots and lots of barrels (and money) later, I'm of the firm opinion that a barrel either likes a particular slug, or it does not. Much the same way a particular barrel prefers a particular pellet. The bummer, and the hard reality check, is that barrels that prefer a particular slug are much fewer and farther between than a barrel that does well with it's preferred pellet.

From my personal barrel experimenting, the majority of quality airgun barrels (one coming from a respected barrel maker) will put at least one variety of pellet into 3/4-1" groups at 50-55 yards.

But for slugs (and again, the caveat of a quality barrel maker), the ratio of good/bad is more like 1:20-25. Ie I have personally experimented with slugs in 40-50 barrels, and only found slug success in two barrels. A handful of the others were mediocre at best (1.5-2" groups at 50 yards) and the accuracy results from slugs from the other 80% of those 40-50 barrels have been abysmal.

I'm cautiously optimistic about BRK's newly marketed "slug barrels." I truly hope they have found success in the mystery of why slugs are so picky about the barrels they're being fired from. BRK certainly has deeper pockets to throw at the problem than I do.
It seems odd though i think pellet gun barrel mfg’ just aren’t trying. I mean how long have powder burners been pushing lead slugs down a barrel? And then you look at the tiapan i just bought not too long ago it will make a 1 hole group @50 and shoot 1”-1&1/4” groups at 100 right out of the box without much fiddling
 

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