Well if any of you enjoyed watching Richard Franklins videos on precision gunsmith, as I did, you may have been wondering about the "quiet crown" which he illustrates.
The idea is not to reduce the sound but direct it more forward and in particular direct the shockwave/concusive force in a more forward direction.
Having developed a flinch years ago from way too much 300 and 338WM, I figured anything that would stop that 'smack' from hitting me in the face was worth a try. So I started on this project.
Firstly I was able to pick up a short (20in) heavy barreled Howa/Hogue model, in 223. This rifle is destined for rechambering eventually, so in the meantime I planned to abuse the hell out of the barrel, which incidentally was .850 at the muzzle.
Out of the box the rifle if pretty nice, though the stock was longer than I wanted, and regrettably Hogues cant easily be shortened, and I wasn't willing to buy another stock, so I fabbed up a shorter buttpad. Other than that, I like the stock, but they are not meant for much in the way of precision, they are only pillar bedded, not the more expensive aluminum chassis version.
The trigger is quite nice out of the box, no real pull (maybe 2mm) or over travel, the weight is a little high (I have no scale, but it is said to be 5lbs).
Anyway after getting it to fit, and making sure it worked I tore it down and had Striker 'greenify' the rifle.
I decided to keep this a budget build, and went with Leupy PRW steel bases, then modified them with an extra cut,
Regrettably the rear Rem 700 bases do not align as one would like on these rifles, with them projecting forward into the feed/ejection port area:
The only other issue was the quality of the milling inside the trigger guard, it was a little rough, hidden under the black epoxy coating, but visible under the thinner gunkote
Anyway the last step I had taken before refinishing was to do the counterboring for the quiet crown. Unfortunately I didnt have access to a small carbide boring bar that Franklin uses, and had to use a regular steel boring bar. To start off with a 1/2inch drill was used to remove the bulk of the material, and then the boring bar was used to cut the counterbore deeper, and after a couple of resharpenings, used to face off the crown to a sharp 90 like Franklin illustrates.
In all the process was well over an hour.
The depth was about 1.5inchs, the theory going that this is removable, and on a 20in even if I cut it off now, the barrel will still be over 18inchs.
the casing is a 308, and that gives an idea of size, Franklin seems to make his even bigger, but I wanted to keep the barrel walls thick-ish incase they were too thin and were thus easily damaged.
Well yesterday was range day, and man was it bad. The Howas 1:12 twist may have been part of the reason it generated palm sized groups at 100yds with the heavier match loads, but either way the results were universal, from either a bag or bipod. Frankly I suspect the stock and optics more, a bedding and better scope might solve the precieved problem.
That said I was interested in the muzzle, how and how well it worked.
After plowing about 80rds down range in rapid succession a check of the muzzle showed alot of residue buildup:
As for the promised shock decrease, I felt it did happen, at 8ft away there was no perceptable shockwave, at 6ft you could just feel it in your nose. When actually behind the trigger, you noticed none. This is all perception though, with out some serious monitering equipment there to check it. I would think it would cut the shock as well as a Noveske brake/flash suppressor, but without two side by side guns with the same barrel lengths its only a guess. Compared to the M4 there the shockwave was marginal, the M4s clearly evident at 10ft.
All in all, looks cool, but I would say the jury is still out on this one, that said, if your crown is screwed, rather than start clipping inchs off, its always an option. I personally figure it needs to be wider than mine, but it certainly doesnt seem detrimental on Franklins guns.
The idea is not to reduce the sound but direct it more forward and in particular direct the shockwave/concusive force in a more forward direction.
Having developed a flinch years ago from way too much 300 and 338WM, I figured anything that would stop that 'smack' from hitting me in the face was worth a try. So I started on this project.
Firstly I was able to pick up a short (20in) heavy barreled Howa/Hogue model, in 223. This rifle is destined for rechambering eventually, so in the meantime I planned to abuse the hell out of the barrel, which incidentally was .850 at the muzzle.
Out of the box the rifle if pretty nice, though the stock was longer than I wanted, and regrettably Hogues cant easily be shortened, and I wasn't willing to buy another stock, so I fabbed up a shorter buttpad. Other than that, I like the stock, but they are not meant for much in the way of precision, they are only pillar bedded, not the more expensive aluminum chassis version.
The trigger is quite nice out of the box, no real pull (maybe 2mm) or over travel, the weight is a little high (I have no scale, but it is said to be 5lbs).
Anyway after getting it to fit, and making sure it worked I tore it down and had Striker 'greenify' the rifle.
I decided to keep this a budget build, and went with Leupy PRW steel bases, then modified them with an extra cut,
Regrettably the rear Rem 700 bases do not align as one would like on these rifles, with them projecting forward into the feed/ejection port area:
The only other issue was the quality of the milling inside the trigger guard, it was a little rough, hidden under the black epoxy coating, but visible under the thinner gunkote
Anyway the last step I had taken before refinishing was to do the counterboring for the quiet crown. Unfortunately I didnt have access to a small carbide boring bar that Franklin uses, and had to use a regular steel boring bar. To start off with a 1/2inch drill was used to remove the bulk of the material, and then the boring bar was used to cut the counterbore deeper, and after a couple of resharpenings, used to face off the crown to a sharp 90 like Franklin illustrates.
In all the process was well over an hour.
The depth was about 1.5inchs, the theory going that this is removable, and on a 20in even if I cut it off now, the barrel will still be over 18inchs.
the casing is a 308, and that gives an idea of size, Franklin seems to make his even bigger, but I wanted to keep the barrel walls thick-ish incase they were too thin and were thus easily damaged.
Well yesterday was range day, and man was it bad. The Howas 1:12 twist may have been part of the reason it generated palm sized groups at 100yds with the heavier match loads, but either way the results were universal, from either a bag or bipod. Frankly I suspect the stock and optics more, a bedding and better scope might solve the precieved problem.
That said I was interested in the muzzle, how and how well it worked.
After plowing about 80rds down range in rapid succession a check of the muzzle showed alot of residue buildup:
As for the promised shock decrease, I felt it did happen, at 8ft away there was no perceptable shockwave, at 6ft you could just feel it in your nose. When actually behind the trigger, you noticed none. This is all perception though, with out some serious monitering equipment there to check it. I would think it would cut the shock as well as a Noveske brake/flash suppressor, but without two side by side guns with the same barrel lengths its only a guess. Compared to the M4 there the shockwave was marginal, the M4s clearly evident at 10ft.
All in all, looks cool, but I would say the jury is still out on this one, that said, if your crown is screwed, rather than start clipping inchs off, its always an option. I personally figure it needs to be wider than mine, but it certainly doesnt seem detrimental on Franklins guns.
... either way the screw on version would able to show the difference in shot to shot accuracy. however something that screws onto the barrel of a gun and makes it quieter may raise the eyebrows of LE. even though you aren't containing it. I love it. I have flinching prob's. I'll try it. Hmmmmm... bull barrel with muzzle brake inside bloop tube?? interesting??? 30" barrel with 10" muzzle braked Bloop would be prolly pretty quiet. 
