The Accurate Reloading Forums
barrel thread/safe reciever dia.

This topic can be found at:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/631102963

17 November 2005, 12:22
Woodjack
barrel thread/safe reciever dia.
What would be the safe limit for a reciever diameter if it was to accept 1.0" thread?
what is the depth of thread for that 1.o" thread?
17 November 2005, 16:16
jeffeosso
quote:
Originally posted by Woodjack:
What would be the safe limit for a reciever diameter if it was to accept 1.0" thread?
what is the depth of thread for that 1.0" thread?


this aint a lecture, just facts

after one decides if it's square, whitworth, or V singlepoint threads, and which angle (60 is the most common in the english speaking world) threads are defined by ID/OD, major,cord (or pitch) and minor diameters and then the depth (height) based off thread count)

since a receiver is an ID in this question, you just look at the OD end of the thread...

a 1" threaded barrel shank coming into a threaded ID will have what as it's largest (therefore the receivers max "depth") if just shy of 1"...

here's why..
a 1"x12 barrel will have a major of about .9975 (assuming class 2 fit) and a minor around .95 (not doing math this early, dang it)

so the depth (max cut in the rec) will be about 1.0" and the opening will be about .9525

I won't even presume to tell you what a safe wall thickness is.

jeffe


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
17 November 2005, 20:54
Grandpasez
My Ruger 77 is great example of a one inch
thread in an action that is strong enough
to hold big overloads. Thread length is .7
inches, reciever ring is 1.32 inches at smallest
diameter.These would be good minimums to
go by.. Ed


MZEE WA SIKU
17 November 2005, 21:04
OMJ
The thread depth is usually pitch/2. The "tap drill" or hole before threading is usually the theoretical major dia. minus the pitch. Example: 1-16 (inch), subtract 1/16" from 1" = .937. Metric threads are much easier, example: 6 X 1 uses a 5mm tap drill.

For the answer to your question of minimum receiver wall, I'd suggest that you ask that question on a board where more engineers and metallurgists hang out. Most receivers are larger in dia. than needed to accomidate the bolt raceways, provide a shoulder for the barrel to press against, etc. Opinion, not fact based.
17 November 2005, 22:13
hawkins
The barrel stub holds the chamber pressure. the reciever holds the bolt and barrel together, and transfers the recoil to the stock. The receiver nust be "stiff enough " to hold the barrel in alignment witrh the receiver.
Good Luck!
17 November 2005, 23:25
tiggertate
If all that ain't confusing enough, what really matters is the hoop strength of the threaded shank and that will vary not only with major/minor thread diameter but also cartridge diameter at the shank plus brass strength.

So your 1" barrel thread will contain different pressures with different diameter cartridges and/or cases, meaning you could have a variety of reciever ring dimensions and still be safe for for different rounds. That's obviously a nanufacturing nightmare so everyone has a fixed size to cover all bases.


"Experience" is the only class you take where the exam comes before the lesson.