I had a TJ barrel 1:22 twist made for my avenger and it works great for slugs up to 46 grain or so. I tried NSA's 55.5 grain slugs but they keep getting stuck in the barrel. They are very hard to load and it appears they are engaging the rifling way too much fun to their extra length causing them to get stuck before firing. Coincidentally I'm going to have another TJ barrel made with a 1:16 twist and would like to be able to shoot virtually any slug length I want. Does anyone go back and forth shooting somewhat light slugs (34 grain) to heavy 50+ grains slugs with same freebore length? Is there a point where too much free bore will dramatically hurt performance of the shorter slug? Just want to be better informed so I can have a better game plan this time for the larger slugs.
Freebore length
- Thread starter revenger
- Start date
I think you answered your own question in the first 3 sentences.
I just cut a TJ 1: 22 barrel leadin deeper for heavy slugs, and it won't shoot lighter slugs even close to accurate.
Just my experience.
I just cut a TJ 1: 22 barrel leadin deeper for heavy slugs, and it won't shoot lighter slugs even close to accurate.
Just my experience.
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That's what I was afraid of. The only thing is I don't actually know where the gun will peak at for slug size. I think at full power the gun will want 50+ grain slugs I'm thinking. Right now it can send 46 grain slugs around 1020 fps or so pretty easily, hence the need for a faster twist barrel.
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I built my TJ around one slug. When you truly get it right, you quickly realize nothing else works. If you want to try something else, it’s back to the lathe.
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Are they the same size as the other 46 gr slugs OD wise tj barrels are usually pretty tight just asking
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Some slugs or bullets don't like a lot of freebore or jump before the rifling others do it would be a trial and error to see what does well and what doesn't
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think this is a few barrels that do not work unless your lucky . would it not be less $$$ to adjust the slug instead of the barrels ?
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Yes they are the same diameter slugs. Just the 55.5 grain is .492 in length and the 46 grain is .439 in length. Odd because I have some boat tails that are longer than the 55.5 grains but they don't get stuck. May just be the way the slug is designed
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Flat base on the 55 gr that get stuck ? If it is the more bearing surface on the flat base causing problem?
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Well it is flat base but I haven't had any issues with my other flat base slugs. I think I may just be seating the slug too much into the rifling causing it to get wedged.
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Are they all shorter though if the 55 gr is longer with a flat base there will be more in contact with the rifling just a thought
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Vetmx nailed it for you. I've cut the barrel to a slug, and I've made slugs 1-2 tenths of a gr. at a time (increasing O.A.L.) to match an existing barrel.
But, if you want to test that 55gr. just make a new bolt that seats the slug .053" shorter than your current one. Assuming the slugs have the same ojive and base. And the back of the slug is past the HPA port.
But, if you want to test that 55gr. just make a new bolt that seats the slug .053" shorter than your current one. Assuming the slugs have the same ojive and base. And the back of the slug is past the HPA port.
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@revenger as an experiment, you could make handheld tool that you hold into the breech that seats the slug deeper to test how engaging the rifling more changes speed and accuracy. This should give you an idea of how they work simply going down the bore
I am going through a bit of change here as well having to go from a no-longer available super accurate rebated boat slug that essentially chambered deeper into the rifling, as compared to the current flat based slug that has more bearing surface, chambering the same depth from the probe. They are slower and for some reason not as accurate, though the same diameter and nose.
I am going through a bit of change here as well having to go from a no-longer available super accurate rebated boat slug that essentially chambered deeper into the rifling, as compared to the current flat based slug that has more bearing surface, chambering the same depth from the probe. They are slower and for some reason not as accurate, though the same diameter and nose.
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