Drillin' holes in a barrel
- Thread starter Wilbur
- Start date
John Kielly
Shari's fan club
Considering that .22 rapid fire pistols used to have (still have?) ventilation holes closed with grub screws all along the top of the barrel.......
L
lead head
Guest
Holes
Wilber,
I've seen 22 pistols with what is called ports drilled in the top of the barrel to keep the muzzle from rising when fired. Also a lot of the USPSA open class pistols have the same holes drilled in them for the same reason. They open class pistols also use a compensator to do the same thing but this is screwed onto a threaded barrel.
Now what you got up your sleeve? Ha Ha
Larry
Wilber,
I've seen 22 pistols with what is called ports drilled in the top of the barrel to keep the muzzle from rising when fired. Also a lot of the USPSA open class pistols have the same holes drilled in them for the same reason. They open class pistols also use a compensator to do the same thing but this is screwed onto a threaded barrel.
Now what you got up your sleeve? Ha Ha
Larry
D
Douglas
Guest
If you check an old 52D's barrel where it's D&T'd, prolly give you a pretty good idea. I got a 40X stripped barrelled receiver one time from CMP that had five holes toward the muzzle, the two factory holes and three others. Whoever did it was a real bubba, the holes did not line up straight and one was almost through, not quite. But it did leave a dimple on the inside. Good thing I didn't want the barrel. Thanks, Douglas
Bill Wynne
Active member
Wilbur,
I can't answer that question but I wonder why would you be doing that?
Is it to mount something or is it to lighten the barrel?
Concho Bill
I can't answer that question but I wonder why would you be doing that?
Is it to mount something or is it to lighten the barrel?
Concho Bill
F
Fatback
Guest
Wilbur
You might talk to someone at the Radford Arsenal. A fellow at the state lab told me he sold an action from there that had holes in it where gauges were screwed in to test the pressure. I would have to assume that these holes were pretty close to the front of the chamber.
You might talk to someone at the Radford Arsenal. A fellow at the state lab told me he sold an action from there that had holes in it where gauges were screwed in to test the pressure. I would have to assume that these holes were pretty close to the front of the chamber.
J
jGEE
Guest
I always consider the size of the hole. I don't know rimfire pressure just guessing 20,000 PSI. Figure a #29 drill bit for an 8x32 tap is pretty small compaired to a square inch.
I'm not good with match but divide the area of the drill bit into 1 sq inch -divide that number into 20,000 and you will get the pressure pushing on the bottom of your drilled hole. Probably not going to be over several hundred psi -which doesn't take much thickness to contain. my view joe
I'm not good with match but divide the area of the drill bit into 1 sq inch -divide that number into 20,000 and you will get the pressure pushing on the bottom of your drilled hole. Probably not going to be over several hundred psi -which doesn't take much thickness to contain. my view joe
J
J. Pendergraft
Guest
It could depend on what drill bit you are using. The very center of the drill does alot of pushing vs. cutting so if you get too close to the bore there will likely be a dimple pushed into the bore surface. IMO I'd want the drill point to stay about .025" from the bore. Depending on the diameter of the holes you might begin with a smaller than finished diameter drill.
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D R Greysun
Guest
I always consider the size of the hole. I don't know rimfire pressure just guessing 20,000 PSI. Figure a #29 drill bit for an 8x32 tap is pretty small compaired to a square inch.
I'm not good with match but divide the area of the drill bit into 1 sq inch -divide that number into 20,000 and you will get the pressure pushing on the bottom of your drilled hole. Probably not going to be over several hundred psi -which doesn't take much thickness to contain. my view joe
D R
B
billyg
Guest
Hey Wilbur.
Thinking about a Tamerlane concept.
It works. If long enough and has proper weight distribution. It can be used parallel or angled to flight line 0 to 90 degrees I think.
Veeerie Interrestinng.
Thinking about a Tamerlane concept.
It works. If long enough and has proper weight distribution. It can be used parallel or angled to flight line 0 to 90 degrees I think.
Veeerie Interrestinng.
J
jGEE
Guest
D R
Mr Greysun i think my math is correct -but it has been 45 years since i was in the 8th grade -maybe i have made a mistake. My original guess does seem to be close. Mr. Greysen i would appreciate it if you would point out my mistake, i don't want to mislead anyone here at BC. thanks joe
J
jGEE
Guest
Yes 20,000 is an assumption on my part for subsonic rounds -sorry.
When your talking PSI , it is easy to forget that's total pressure over 1 sq inch. I guess in real terms a #29 bit is only 1/69th of the sq inch and would only hold 1/69th the total pressure. I think this is correct. joe
M
MKnarr
Guest
The diameter of a #29 drill is .1365 so R=..068
Therefore A= (.068)sqd x 3.1412 = .0145 Sq In.
The Maximum pressure for a 22LR according to SAAMI is 24000 lb/sq inch and of course that is going to be at the breech.
Therefore Pounds =lb/sq in *sq in or 24000PSI*.0145 sq in= 348 pounds pressure on that .0148 sq inch where the hole is. That's not on the bottom of the hole but the inside of the barrel in the area under the hole.
Therefore A= (.068)sqd x 3.1412 = .0145 Sq In.
The Maximum pressure for a 22LR according to SAAMI is 24000 lb/sq inch and of course that is going to be at the breech.
Therefore Pounds =lb/sq in *sq in or 24000PSI*.0145 sq in= 348 pounds pressure on that .0148 sq inch where the hole is. That's not on the bottom of the hole but the inside of the barrel in the area under the hole.
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pacecil
Guest
To Wilbur
I'm embarrassed at the replies you are getting. Guys multiplying psi times sq in and getting psi. And then some multipling and dividing by numbers the pull out of the air and getting some imaginary number they pull from who knows where.
J Pendergraft gave you a pretty good answer but the rest of these idiots are laughable. If I was you I'd delete this whole thread as pretty much a joke!
I'm embarrassed at the replies you are getting. Guys multiplying psi times sq in and getting psi. And then some multipling and dividing by numbers the pull out of the air and getting some imaginary number they pull from who knows where.
J Pendergraft gave you a pretty good answer but the rest of these idiots are laughable. If I was you I'd delete this whole thread as pretty much a joke!
P
pacecil
Guest
To Wilbur
I'm embarrassed at the replies you are getting. Guys multiplying psi times sq in and getting psi. And then some multipling and dividing by numbers the pull out of the air and getting some imaginary number they pull from who knows where.
J Pendergraft gave you a pretty good answer but the rest of these idiots are laughable. If I was you I'd delete this whole thread as pretty much a joke!
I'm embarrassed at the replies you are getting. Guys multiplying psi times sq in and getting psi. And then some multipling and dividing by numbers the pull out of the air and getting some imaginary number they pull from who knows where.
J Pendergraft gave you a pretty good answer but the rest of these idiots are laughable. If I was you I'd delete this whole thread as pretty much a joke!
What a refreshingly modest post. What was "laughable" about MKnarr's post, you conceited, pompous, fool?
J
jGEE
Guest
A critic
Mr. pacecil i respect your comment -your thoughts are welcome here. A little more help would be appreciate. Nobody has "multiplying psi times sq in and getting psi". When i see your post i always read them, usually there is a bit of wisom in there.
I "thought" you may know what you were talking about. I think MKnarr and myself are correct on this on. If not if you would like to be helpful, please point out a soultion.
Without a soultion in my view you become a Critic.
A CRITIC IS THE ONE THAT COME DOWN AFTER THE BATTLE AND SHOOTS THE DEAD.
my 2 cents, joe
Mr. pacecil i respect your comment -your thoughts are welcome here. A little more help would be appreciate. Nobody has "multiplying psi times sq in and getting psi". When i see your post i always read them, usually there is a bit of wisom in there.
I "thought" you may know what you were talking about. I think MKnarr and myself are correct on this on. If not if you would like to be helpful, please point out a soultion.
Without a soultion in my view you become a Critic.
A CRITIC IS THE ONE THAT COME DOWN AFTER THE BATTLE AND SHOOTS THE DEAD.
my 2 cents, joe
M
MKnarr
Guest
Mr Pacecil, I thank you for your astute observation. I did indeed multiply instead of divide, however the answer is still correct because when I did it on paper I did it correctly. Please don't be embarrassed by someone else's mistake. It is for them to be embarrassed, not you. Fortunately you are not the only engineer on this forum, and having seen your past mistakes, I would think you would be more embarrassed then me. If Wilbur so chooses to delete this thread because I typed an error, It won't bother me in the least because your post will go with it.
Jim Brossman - Senior Engineer and consultant.
When I make a mistake I will own up to it and use my real name. Will you?
Edit: It turns out the only mistake I made was believing pacecil knew what he was talking about. My original formula was correct.
Lb=Lb/sq in*sq In.
Jim Brossman - Senior Engineer and consultant.
When I make a mistake I will own up to it and use my real name. Will you?
Edit: It turns out the only mistake I made was believing pacecil knew what he was talking about. My original formula was correct.
Lb=Lb/sq in*sq In.
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