Need advice on B.Bore arrow conversion
Ive been working on a arrow conversion for Riverside’s big bore valve and I hit a couple of snags. First the breech I made bored through past the tap for the cocking knob. I have a lowprofile brass insert thats worked well in the past, but I need to seal the bottom somehow without loseing any more depth.
2nd nobody makes arrows with a 1/2”Od so I’ll have to reduce down with tubing to fit for 2512 arrows. Now in the intrest of controling blow back would it be best to start at the opening with the right ID before the air expands to its fullest? like in the 1st barrel pic or a gradual reduction like in the 2nd barrel pic? and if the gradual funneling would be best, then how far apart between reductions? I have my opinions on these things, But I could be wrong and I’d like to get this right the first time 😕 So any ideas especially on the blowback control would be greatly appreciated.
Thanks,
Tag
pic of b bore breech compared to a stock one
close up
breech and brass insert
even arrangement of tubing?
gradual reduction?
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Viewing 14 replies - 1 through 14 (of 14 total)
I remember that feeling, when I started reloading with black powder in my Dillon 550.
Fist couple times it was safety glasses, Kevlar wrapped throat and ballistic vest.
After a couple times I just went for it.
Roachcreek
Yeah…
have to hunt up the roll of kevlar cloth and loosely wrap the frame I figure then start with no bolt fitted and work from there
who knows, may end up with some new shrapnel in my body if I get stupid as I was in my youth 😉
Two rednecks at a Minnesota gun show,” Did you see that blind man at the table with no fingers?”
“Yes the one with the arrow necklace.”
Good luck Jim
Roachcreek
Okay I get what you are saying
Just recieved the modified kit from TD, will be building up a battered ole’ Condor frame to do the beta testing
Probably start with a stock AF hammer spring and partial fills and work up from there this next week on vacation
I think it can all be balanced out at much higher power than the current conversion
wish me luck 😉
seeing how you have toyed, heck built one of the more powerful big bores did you have any issues with a tank dump?
thing is there is a great deal of room for the charge to rapidly expand and further the charge isn’t pushing a slug down a rifled bore
Guess I will have to find out as this is totally uncharted territory for all of us 😉
When a big valve is feeding a restricted bore/outlet it will keep the breech slide pressured holding the valve open. That will dump the tank.
Yes I struggle making power AND not having a tank dump. 🙂 But remember on a .45 the barrel is 0.625″ o.d. and the i.d. is .457″ so the effective area is greatly reduced.
Closing forces must be greater than the hold open force(s)
A Blod valve is a good design for big port and flow wth good closing
force(s)
Walter….
I tried a blod bigbore valve on my .25 using a short grdual reduction from th od down to breech od. It did not go well! The result was each time I fired, the breech was fired back and recocked the rifle with such force it damaged the breech and the FRAME 😯 👿 I had Sean adjust things so the mating between th and breech was VERY tight, a really good tight seal. Even then it still wanted to blow apart…
Voltar: Why would the tank tend to dump any more than running a heavy .45 slug in a big bore conversion?
seeing how you have toyed, heck built one of the more powerful big bores did you have any issues with a tank dump?
thing is there is a great deal of room for the charge to rapidly expand and further the charge isn’t pushing a slug down a rifled bore
Guess I will have to find out as this is totally uncharted territory for all of us 😉
Why did you eat some bad cheese? 😀
I predict a tank dump.
What about a small back pressure hole?
i’ve been scratching my head with this one for a while and i think that a gradual reduction in dia would be the way to go but also start out a little closer to the final diameter so its not as drastic of a reduction (i hope this makes sence given how tired i am rite now)….i would think that the air flow going through a gradual reduction would in fact increse the velocity of the air flow (but the back pressure as well) which might allow for higher fps with less volume of air needed to get the arrow there….or this could all just be the ramblings of a tired monkey… 🙄
Thanks Sub, you must have been scratching your head and writing at the same time I was 🙂
Well I need to get this thing cranking, so If no one chimes in soon Im going with the funnel at a rate of decent yet to be determined. In other words Im going to guess. Not very scientific, but sometimes you just need to go for it 😛
tag-
i’ve been scratching my head with this one for a while and i think that a gradual reduction in dia would be the way to go but also start out a little closer to the final diameter so its not as drastic of a reduction (i hope this makes sence given how tired i am rite now)….i would think that the air flow going through a gradual reduction would in fact increse the velocity of the air flow (but the back pressure as well) which might allow for higher fps with less volume of air needed to get the arrow there….or this could all just be the ramblings of a tired monkey… 🙄
Viewing 14 replies - 1 through 14 (of 14 total)
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Fist couple times it was safety glasses, Kevlar wrapped throat and ballistic vest.
After a couple times I just went for it.
Roachcreek
“its only a flesh wound”
” but you’ve got no arms”