Differences and similarities between centerfire MD's and rimfire MD's

Differences and similarities between centerfire MD's and rimfire MD's



CYA friends:


First of all, Happy 4th of July.


______________________________


Now.


The muzzle device for RFBR has pretty much been standardized for the past 20 plus years, or so.


Probably 95%, or more, of RFBR guns are equipped with the HH/MD, and for good reason; it is correctly configured to stop the muzzle of RFBR sized barrels.




The above can not be said for our CFBR friends.


Which is a shame, since stopping the muzzle of a CFBR barrel shouldn't be any more complicated than for a RFBR barrel.




Therefore, is it possible for our CFBR friends to have a standardized MD available to them, just as we do in RFBR?


__________________________



What are the differences and similarities between centerfire MD's and rimfire MD's:



Similarities:


The main similarity between the two, is they're both designed to stop the muzzle of a gun barrel, when fired.


This means both centerfire and rimfire MD's must place the correct amount of weight, at the correct location past the exit of the crown, to be able to stop the muzzle.


Unfortunately, a lot of our CFBR friends, and even an occasional RFBR shooter, feel a MD, in their case "tuner", is used to tune a load to the barrel, or vice versa, during competition.

____________________________


Differences:


Centerfire MD's have to deal with recoil, which defines how they're attached to the muzzle.

(Hence the subject of another thread currently here at CYA)



Also, since centerfire barrels are usually much stiffer than rimfire barrels, the weight requirement of the MD past the exit of the crown is slightly different.



Barrel stiffness determines the location of the exact center of the parallel node of a naked barrel.



The stiffer the barrel, the closer the exact center of the parallel node is to the exit of the crown.


Therefore, most CFBR barrels do not need as much weight ahead of the exit of the crown, as do RFBR barrels.

_____________________



CYA friends, my gut tells me there's an excellent opportunity for a MD maker, like Harrell's for instance, to provide a proper MD for CFBR shooters that will allow them to stop their muzzles just as we do in RFBR.



So here's what I believe could make some MD maker own the market for CFBR MD's, just like Harrell's does today in RFBR.



They must provide a MD that does not require the muzzle of the barrel to be threaded.


While at the same time providing a CFBR MD that places the correct weight at the correct location past the exit of the crown, to stop the muzzle.



Your friend, Bill Calfee

Thanks Wally

Bill Calfee said:

Differences and similarities between centerfire MD's and rimfire MD's



CYA friends:


First of all, Happy 4th of July.


______________________________


Now.


The muzzle device for RFBR has pretty much been standardized for the past 20 plus years, or so.


Probably 95%, or more, of RFBR guns are equipped with the HH/MD, and for good reason; it is correctly configured to stop the muzzle of RFBR sized barrels.




The above can not be said for our CFBR friends.


Which is a shame, since stopping the muzzle of a CFBR barrel shouldn't be any more complicated than for a RFBR barrel.




Therefore, is it possible for our CFBR friends to have a standardized MD available to them, just as we do in RFBR?


__________________________



What are the differences and similarities between centerfire MD's and rimfire MD's:



Similarities:


The main similarity between the two, is they're both designed to stop the muzzle of a gun barrel, when fired.


This means both centerfire and rimfire MD's must place the correct amount of weight, at the correct location past the exit of the crown, to be able to stop the muzzle.


Unfortunately, a lot of our CFBR friends, and even an occasional RFBR shooter, feel a MD, in their case "tuner", is used to tune a load to the barrel, or vice versa, during competition.

____________________________


Differences:


Centerfire MD's have to deal with recoil, which defines how they're attached to the muzzle.

(Hence the subject of another thread currently here at CYA)



Also, since centerfire barrels are usually much stiffer than rimfire barrels, the weight requirement of the MD past the exit of the crown is slightly different.



Barrel stiffness determines the location of the exact center of the parallel node of a naked barrel.



The stiffer the barrel, the closer the exact center of the parallel node is to the exit of the crown.


Therefore, most CFBR barrels do not need as much weight ahead of the exit of the crown, as do RFBR barrels.

_____________________



CYA friends, my gut tells me there's an excellent opportunity for a MD maker, like Harrell's for instance, to provide a proper MD for CFBR shooters that will allow them to stop their muzzles just as we do in RFBR.



So here's what I believe could make some MD maker own the market for CFBR MD's, just like Harrell's does today in RFBR.



They must provide a MD that does not require the muzzle of the barrel to be threaded.


While at the same time providing a CFBR MD that places the correct weight at the correct location past the exit of the crown, to stop the muzzle.



Your friend, Bill Calfee

Click to expand...

__________________________


Thanks Wally for correcting the 503 fault........bc

Bill Calfee said:

Differences and similarities between centerfire MD's and rimfire MD's



CYA friends:


First of all, Happy 4th of July.


______________________________


Now.


The muzzle device for RFBR has pretty much been standardized for the past 20 plus years, or so.


Probably 95%, or more, of RFBR guns are equipped with the HH/MD, and for good reason; it is correctly configured to stop the muzzle of RFBR sized barrels.




The above can not be said for our CFBR friends.


Which is a shame, since stopping the muzzle of a CFBR barrel shouldn't be any more complicated than for a RFBR barrel.




Therefore, is it possible for our CFBR friends to have a standardized MD available to them, just as we do in RFBR?


__________________________



What are the differences and similarities between centerfire MD's and rimfire MD's:



Similarities:


The main similarity between the two, is they're both designed to stop the muzzle of a gun barrel, when fired.


This means both centerfire and rimfire MD's must place the correct amount of weight, at the correct location past the exit of the crown, to be able to stop the muzzle.


Unfortunately, a lot of our CFBR friends, and even an occasional RFBR shooter, feel a MD, in their case "tuner", is used to tune a load to the barrel, or vice versa, during competition.

____________________________


Differences:


Centerfire MD's have to deal with recoil, which defines how they're attached to the muzzle.

(Hence the subject of another thread currently here at CYA)



Also, since centerfire barrels are usually much stiffer than rimfire barrels, the weight requirement of the MD past the exit of the crown is slightly different.



Barrel stiffness determines the location of the exact center of the parallel node of a naked barrel.



The stiffer the barrel, the closer the exact center of the parallel node is to the exit of the crown.


Therefore, most CFBR barrels do not need as much weight ahead of the exit of the crown, as do RFBR barrels.

_____________________



CYA friends, my gut tells me there's an excellent opportunity for a MD maker, like Harrell's for instance, to provide a proper MD for CFBR shooters that will allow them to stop their muzzles just as we do in RFBR.



So here's what I believe could make some MD maker own the market for CFBR MD's, just like Harrell's does today in RFBR.



They must provide a MD that does not require the muzzle of the barrel to be threaded.


While at the same time providing a CFBR MD that places the correct weight at the correct location past the exit of the crown, to stop the muzzle.



Your friend, Bill Calfee

Click to expand...

Howdy Bill,

Would a standard Harrell's MD work on a .223?

Now, don't laugh..........too much...........

As it happens, I have what is supposed to be a pretty decent match grade AR in .223 that I have barely shot. Got it used, seems to have been a low round count. I have not had the chance to really find out how good it is. The guy who built it has a great track record of having his guns win at Camp Perry.

The barrel is 26 inches long, and, if I recall, .85 in diameter.

With a centerfire .223, I would think the MD would not have to have anything machined, as long as it fits the barrel. I might have to shim it with something to make it fit, as I'd have to pull a MD off of another rifle with a slightly larger diameter.

I don't know what effect the gas block and gas tube would have on the barrel vibrations. The rifle seemed pretty accurate if I recall correctly, last time I shot it was well before the back surgery.

Can you see any issues with shooting a .223 through a standard Harrell's MD?

Take care,

Greg

Friend 404tbang

404tbang said:

Howdy Bill,

Would a standard Harrell's MD work on a .223?

Now, don't laugh..........too much...........

As it happens, I have what is supposed to be a pretty decent match grade AR in .223 that I have barely shot. Got it used, seems to have been a low round count. I have not had the chance to really find out how good it is. The guy who built it has a great track record of having his guns win at Camp Perry.

The barrel is 26 inches long, and, if I recall, .85 in diameter.

With a centerfire .223, I would think the MD would not have to have anything machined, as long as it fits the barrel. I might have to shim it with something to make it fit, as I'd have to pull a MD off of another rifle with a slightly larger diameter.

I don't know what effect the gas block and gas tube would have on the barrel vibrations. The rifle seemed pretty accurate if I recall correctly, last time I shot it was well before the back surgery.

Can you see any issues with shooting a .223 through a standard Harrell's MD?

Take care,

Greg

Click to expand...

_______________


Friend 404tbang:



No.



Being as you'd be dealing with recoil, even the mild recoil of the .223, you'd still need some more positive way to attach the HH'MD than clamping it.



Greg, if the fit between the barrel and MD were absolutely gauge class, you might be able to tighten it and keep it on the muzzle, under recoil.


But......................


I suspect you'd have to tighten it so much, to keep it in place, that you'd pinch the bore.......



If I were going to try to clamp a HH/MD to a .223, here's what I'd do:


First, I'd make sure the HH/MD was bored to a gauge fit to the barrel.......this is mandatory.


Then I'd use alcohol and clean the inside of the HH/MD and the outside of the muzzle of the barrel.


Next I'd take powered rosin and apply it to the inside of the MD and outside of the muzzle of the barrel.


And I'd work the rosin into both of these surfaces with finger pressure...


You can tell when you have a rosin treated surface prepped, because you can press you finger against the surface and drag it, and your finger will meet resistance.


Then blow off any excess rosin and clamp it to the barrel with no more than 25-30 IP of torque.


Before I started shooting, I'd put a piece of masking tape on the barrel, up against the MD.


Then I'd start shooting while watching to see if the MD was moving....


Your friend, BC

Bill Calfee said:

_______________


Friend 404tbang:



No.



Being as you'd be dealing with recoil, even the mild recoil of the .223, you'd still need some more positive way to attach the HH'MD than clamping it.



Greg, if the fit between the barrel and MD were absolutely gauge class, you might be able to tighten it and keep it on the muzzle, under recoil.


But......................


I suspect you'd have to tighten it so much, to keep it in place, that you'd pinch the bore.......



If I were going to try to clamp a HH/MD to a .223, here's what I'd do:


First, I'd make sure the HH/MD was bored to a gauge fit to the barrel.......this is mandatory.


Then I'd use alcohol and clean the inside of the HH/MD and the outside of the muzzle of the barrel.


Next I'd take powered rosin and apply it to the inside of the MD and outside of the muzzle of the barrel.


And I'd work the rosin into both of these surfaces with finger pressure...


You can tell when you have a rosin treated surface prepped, because you can press you finger against the surface and drag it, and your finger will meet resistance.


Then blow off any excess rosin and clamp it to the barrel with no more than 25-30 IP of torque.


Before I started shooting, I'd put a piece of masking tape on the barrel, up against the MD.


Then I'd start shooting while watching to see if the MD was moving....


Your friend, BC

Click to expand...

Howdy Bill,
Thanks for the explanation and instructions! Aggravatingly enough, the MD I thought I could use is bored too big. Not even close to a guage fit. I may still try this, but with an MD bought just for this rifle. That'll have to wait for awhile until I get back to work.

Sure do appreciate you taking the time to explain this to me. I appreciate all the posts you make, gives me a chance to learn!

Take care,

Greg

Friend 404tbang

404tbang said:

Howdy Bill,
Thanks for the explanation and instructions! Aggravatingly enough, the MD I thought I could use is bored too big. Not even close to a guage fit. I may still try this, but with an MD bought just for this rifle. That'll have to wait for awhile until I get back to work.

Sure do appreciate you taking the time to explain this to me. I appreciate all the posts you make, gives me a chance to learn!

Take care,

Greg

Click to expand...

_____________________



Friend 404tbang:


You're welcome.



Jeff Patterson gave me some steel shim stock for Christmas a couple years ago.


Ranges in size from .001" to .012"........and very uniform in thickness......


If the OD of your barrel and the ID of your MD are straight, no taper, the MD could probably be shimmed.


___________________


Greg, if you've got a gauge fit between the ID of the MD and OD of the barrel, it's amazing the resistance to moving under recoil powered rosin provides.


An interesting story:


I have a friend who's an airplane pilot.


I was talking to him one day about how a radial engine works.


And I learned that the crankshaft in a radial engine is two piece, because the master rod is one piece and has to slide over the crankshaft journal.


In other words the master rod doesn't have a rod cap like an automobile engine.


Now here's the mind blowing part:


Once the master rod is slid onto the crankshaft, the other half of the crankshaft is slid onto the same shaft as the master rod, then simply clamped to it with a big clamp bolt....


There's no key way........that half of the crank is held on simply by clamping force.


He said some radial engine re-builders use powered rosin on the shaft that the 2nd half of the crank shaft clamps to.


When they put the two halves of the crank together they have a fixture that aligns the halves perfectly, then the clamp bolt is tightened.



If what he told me is true, I don't think I want to fly in a plane with a radial engine......rosin or not.


It's hard to believe there's no key way to hold the crank halves together, but he said there's not, just clamping force.



Most interesting stuff...



Your friend, BC