Help: Need to fill this gap (pics)

Strbrd22

Strbrd22

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Aug 1, 2024
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Western NY
#1
Swapping out the muzzle device on my Badger 2013 since I’m not running it suppressed anymore. Went w an Area 419 hellfire. When I go to install it, I have a gap between the barrel (Rock Creek, Sendero contour) and the muzzle device. I ordered a Silencerco spacer but it doesn’t fit. Are there any fixes on the market? A shim or similar or am I going to have to get something custom cut? Thanks!
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#3
redneckbmxer24 said:
Those threads look way longer than they should be. I would address that instead of trying to stack shims. What’s the length of the threads measured from the shoulder to the muzzle?
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I will measure when I get home. I’m sure they are. This rifle was built by USMC PWS and the armorer perfectly threaded the barrel blank to the Silencerco brake and timed it. Might just have to go back to that brake…
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#5
Well that’s pretty dumb to not thread it to standard specs. Being PWS really no recourse there. I would just pull the barrel and send it somewhere and have it shortened. If you’re looking to move to a brake for recoil reduction over the can the Silencerco brake isn’t going to be anywhere near as effective as the 419.
 
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#7
redneckbmxer24 said:
Well that’s pretty dumb to not thread it to standard specs. Being PWS really no recourse there. I would just pull the barrel and send it somewhere and have it shortened. If you’re looking to move to a brake for recoil reduction over the can the Silencerco brake isn’t going to be anywhere near as effective as the 419.
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Yeah the armorer that built my rifle also drove an ambulance to work with a christmas reindeer decoration strapped to the hood sooooo haha. But im not super worried about recoil reduction - its a 6.5 so its not bad, just could be better. Classic case of thinking I could just swap a part to make things better and here I am.... smh
 
#9
The difference is that the 419 adaptor isn’t threaded entirely though, if you look at the end as you screw it on you will see them bottom out. It’s got about .620” of threads so that it has a bit of wiggle room over the .600 thread spec. Your muzzle is way over that by the looks of it. The silencer co just has the threads run the entire way through so it can’t bottom out. A bit less refined method but also doesn’t encounter the issue with this out of spec aspect.
 
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#12
spife7980 said:
The difference is that the 419 adaptor isn’t threaded entirely though, if you look at the end as you screw it on you will see them bottom out. It’s got about .620” of threads so that it has a bit of wiggle room over the .600 thread spec. Your muzzle is way over that by the looks of it. The silencer co just has the threads run the entire way through so it can’t bottom out. A bit less refined method but also doesn’t encounter the issue with this out of spec aspect.
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correct. so my rifle was threaded to fit the silencerco specifically and it was timed so that it bottoms out and is flush at the same time. I wasnt aware of barrel thread specs but that seems to be my issue. Now, any ideas save for having my barrel cut to make it work or would a shim mess up the harmonics / create more problems than solutions?
 
#14
Rob01 said:
Those are the inner threads correct? What about the outer piece that screws back to snug it up?
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Correct. The outer piece is completely separate and there is no issue of that impeding my ability to install the brake - its all on that inner piece where the gap shows up / the device interfaces with the barrel because I run out of threads.
 
#15
You’ve got 4 options.

1. Put the Silencerco back on and run it.

2. Try to find another brake that will accommodate the depth.

3. Send it out to have threaded to spec.

4. Stack shims until you can seat the adaptor.

As previously stated, I would correct the out of spec threads so it’s not a problem now or in the future if you want to use something else.
 
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#17
You can have a gunsmith shorten the length of the threads and re-crown, but then you've got to send it/drop it off.

Or, you could measure the overall length of the threads, and I could make you a shim/spacer real quick and send it to you, no charge. It'll be 416 stainless in the white at that cost...
 
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#18
All joking aside who cares

It’s a 6.5, shoot it out and when you get a new one get it squared away.

Spending 100$ to fill a gap that doesn’t add performance on a cartridge that is not lasting 3k rounds, is a waste of money if you look at it from that direction.

Now we all know looks are what counts but..just shoot it and have fun
 
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#19
my Dasher barrel has the same thing. my gunsmith did it on purpose to allow the muzzle to sit flush with the first port of an ACE break. My thunderbeast break will not sit flush just like your issue. but my new Fat Bastard does just fine and muzzle sits flush with first port in it as well...
 
#20
Threads should be .600 from muzzle to shoulder I believe. Measure it with the caliper and take Rubicon Precision up on their offer.
Other option is send it to a smith and have them blast what appears to be about 0.100" off the length and re-crown.
 
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#23
Some of the ASR mounts have a wall with relatively small through hole before reaching the first opening on the brakes or the opening into the flash hinder version. That wall is considerably deeper than 0.625" from the shoulder of the device.

They are now opening up that through hole but the earlier versions with smaller holes basically created a chamber between the muzzle and that wall that could only vent forward through the bore hole if mated to a shorter muzzle tenon.

This creates a chamber that could could catch and build up carbon crud at the crown. Since it is impossible to monitor the muzzle and false chamber without a borescope, I didn't want my customers to have a potential issue. My typical customers are running suppressed and keeping the ASR muzzle devices in place for the duration.

On those barrels I purposefully threaded a longer muzzle tenon to place the muzzle close to that smaller wall and through hole and eliminate the false chamber.

I am pretty sure I'm not the only one that did this before SiCo opened up that first hole.

There have been other brakes (mostly self timing with lock collars) that have callouts for tenon lengths longer than 0.625", so your muzzle is not necessarily "out of spec".

Your builder wasn't necessarily sloppy or incompetent. He was likely paying attention to what components he was working with.

Edited for spelling cause I type like shit from my phone.
 
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#25
For everyone’s future reference:
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On barrels slightly exceeding A419 spec for Hellfire max thread length I’ve just stacked precision shims to move the shoulder forward.
 
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#26
Cody S said:
where did your comment go about how no major barrel manufacturer laps a choke into their bore? I cannot find it.
I  really want to discuss this further with you and Mr. Cross.
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I don’t believe I ever said any such thing as “no major barrel maker….etc”.

My relevant post is as follows (not sure why you couldn’t find it). @Terry Cross would be a far better person to discuss this with than I. His knowledge and experience are far deeper and wider than mine.

And perhaps @Frank Green may weigh in on if chokes get built into precision rifle barrels. Cheers.

Post in thread 'Help: Need to fill this gap (pics)'
https://www.snipershide.com/shooting/threads/help-need-to-fill-this-gap-pics.7232406/post-11788486
 
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#29
Cody S said:
my guy cuts off the breech and contours it after length is set.
I pay extra for things like the hand lapped choke in the bore, I'd like to keep it.
clearly I'm not too far off because my guns have shot tiny groups at distance and I've won several (local) shooting competitions and have some cool trophies.
but I don't know it all, I don't even own a lathe, I just know a few guys who do.
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The bore doesn't suddenly choke down at the end of a blank.

Don't think of it in terms of the choke in a shotgun barrel.

Are you paying someone extra for what you describe?
 
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#30
Cody S said:
my guy cuts off the breech and contours it after length is set.
I pay extra for things like the hand lapped choke in the bore, I'd like to keep it.
clearly I'm not too far off because my guns have shot tiny groups at distance and I've won several (local) shooting competitions and have some cool trophies.
but I don't know it all, I don't even own a lathe, I just know a few guys who do.
Click to expand...
Describe what a hand lapped choke is, how it’s achieved, and the purpose.
 
#32
Terry Cross said:
The bore doesn't suddenly choke down at the end of a blank.

Don't think of it in terms of the choke in a shotgun barrel.

Are you paying someone extra for what you describe?
Click to expand...
no, just standard work he does on bench rest guns.
I won't say his name because this guy is smart, I am not as smart. if something is wrong, it was lost in translation as we were shooting or cutting up.
my *novice* understanding is the bore chokes down a couple tenthousandths of an inch during the last little bit of travel.
I could have misunderstood, I could just be misremembering. but I'm about to call some barrel manufacturers lol.
 
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#33
Cody S said:
no, just standard work he does on bench rest guns. again, I don't even slug a bore or own a lathe.
also I tend to leave all my blanks at full length so it's never an issue for me personally.
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So you're paying extra for leaving the blank almost full length?

Does your builder cut any of the muzzle end of the blank at all before crowning?

You said he cuts the breech end to get your final length? How much breech end does he cut away?
 
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#34
Cody S said:
no, just standard work he does on bench rest guns.
I won't say his name because this guy is smart, I am not as smart. if something is wrong, it was lost in translation as we were shooting or cutting up.
my *novice* understanding is the bore chokes down a couple tenthousandths of an inch during the last little bit of travel.
I could have misunderstood, I could just be misremembering. but I'm about to call some barrel manufacturers lol.
Click to expand...
Could you be thinking of a rim fire barrel that's been tapper lapped?
 
#36
Strbrd22 said:
Correct. The outer piece is completely separate and there is no issue of that impeding my ability to install the brake - its all on that inner piece where the gap shows up / the device interfaces with the barrel because I run out of threads.
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Possible solution for you.
Try a Precision Armament self timing brake. They time differently than a hellfire. Minimum thread depth with collar all the way in is .750” with timing collar out a little it can easily accommodate .800-.825” of threads.
These are excellent brakes.
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#37
Terry Cross said:
The bore doesn't suddenly choke down at the end of a blank.

Don't think of it in terms of the choke in a shotgun barrel.

Are you paying someone extra for what you describe?
Click to expand...
I won't speak for all barrel makers here....

I'll say we always strive for a uniformity of the bore over the length of the barrel. I'll say yes we are lapping some choke into the bores of the barrels.

That being said and I've gotten into it pretty good with the BR guys. I ask this... why the hell are you buying a 29" blank and your cutting it to 21" to 22" installed? If there is choke lapped into the barrel I'll guarantee your cutting it off.

Get the barrels blank length closer to the finish length your going to end up at.... so if your going to finish the barrel at 24" get a 25" blank ( at least from us ) because if there is choked lapped into the bore of the barrel it's just in the last few inches and it might only be say .0001" to .0002" of choke.

Terry is correct.... and I'll say usually the end of the blank doesn't all of a sudden have .0005" of choke in it. Like he said... it's not like shotgun barrel. It's gradual over the last few/several inches. Again we still strive for a 0 uniformity of the length. So you could have choke... and you might not.

And here is a good one for you all.... lets say you grab this barrel made by so and so button maker for example.... you think you measured the bore and you found the choke/tight spot so that's where you decide to cut and crown the muzzle. Your odds are high that cutting and crowning the muzzle especially if you thread the muzzle also... the machining operation will relieve the stress in the material and the bore will open up on you. It happens more than you know. So what do you do then?

In the pic of a button rifled barrel... look how much that steel moved on the face of the one blank after the button went thru it. Button rifling doesn't remove the material... it displaces the material.

The attached video shows the same thing but he's measuring the barrels with a pin gage. The last two are ours. I know who's the other barrels are in the video and I'm not saying who but all button barrels. His argument in the video is to pick the largest thread size you can get away with to help prevent this happening.

This isn't a thing that happens with cut rifled barrels. In fact I just recently cut a 1/2-28 muzzle thread on a 9mm barrel and the muzzle o.d. was only .720" before threading. So a 1/2" muzzle thread on a .355" groove size barrel only leaves about a .182" wall thickness per side. My bore didn't go sour at all (open up).



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#38
you can also tighten a muzzle brake on the bore of the barrel to tight and actually distort the bore as well. Take it off and the bore typically goes back.

That thin castle nut on the muzzle for M14 rifles... yes you can tighten that thin wall castle nut tight enough to distort the bore of the barrel and that's right before the muzzle crown.... do that and the accuracy is right out the window. Same with the figure 8 nut at the gas cylinder.... set that up to tighten up too much... and you can actually bow the barrel up towards 12 o'clock and you can run out of down elevation on your sights and can't get it zeroed at a 100 yards.
 
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#39
Frank Green said:
I won't speak for all barrel makers here....

I'll say we always strive for a uniformity of the bore over the length of the barrel. I'll say yes we are lapping some choke into the bores of the barrels.

That being said and I've gotten into it pretty good with the BR guys. I ask this... why the hell are you buying a 29" blank and your cutting it to 21" to 22" installed? If there is choke lapped into the barrel I'll guarantee your cutting it off.

Get the barrels blank length closer to the finish length your going to end up at.... so if your going to finish the barrel at 24" get a 25" blank ( at least from us ) because if there is choked lapped into the bore of the barrel it's just in the last few inches and it might only be say .0001" to .0002" of choke.

Terry is correct.... and I'll say usually the end of the blank doesn't all of a sudden have .0005" of choke in it. Like he said... it's not like shotgun barrel. It's gradual over the last few/several inches. Again we still strive for a 0 uniformity of the length. So you could have choke... and you might not.

And here is a good one for you all.... lets say you grab this barrel made by so and so button maker for example.... you think you measured the bore and you found the choke/tight spot so that's where you decide to cut and crown the muzzle. Your odds are high that cutting and crowning the muzzle especially if you thread the muzzle also... the machining operation will relieve the stress in the material and the bore will open up on you. It happens more than you know. So what do you do then?

In the pic of a button rifled barrel... look how much that steel moved on the face of the one blank after the button went thru it. Button rifling doesn't remove the material... it displaces the material.

The attached video shows the same thing but he's measuring the barrels with a pin gage. The last two are ours. I know who's the other barrels are in the video and I'm not saying who but all button barrels. His argument in the video is to pick the largest thread size you can get away with to help prevent this happening.

This isn't a thing that happens with cut rifled barrels. In fact I just recently cut a 1/2-28 muzzle thread on a 9mm barrel and the muzzle o.d. was only .720" before threading. So a 1/2" muzzle thread on a .355" groove size barrel only leaves about a .182" wall thickness per side. My bore didn't go sour at all (open up).



View attachment 8514080
Click to expand...

Thanks, Frank. But I rode the short bus to school so I tend to need it spelled out slowly.

What I understood you to say is that if you lap choke into a bore it’s not intentional and is just coincidental to the hand lapping process and in any case is .002” max. That your goal at Bartlien is zero deviation of bore size across the length of the blank.

And you didn’t actually say this but it’s sort of implied by the info you provide; if a button barrel manf tells you they lap some choke at the muzzle end this is perhaps to compensate for expected expansion from stress relief during muzzle threading.

Correct?

And, If I’ve utterly misunderstood, don’t spare my feeling, lay it on me. lol.
 
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#40
We try to lap choke into the bore… but it’s being done by hand. So no guarantees.

The button guys… if they are or can lap choke into the bore I don’t think it is to offset the bore opening up/going sour. Still to some extent you don’t know if it’s going to happen or not.

Watch the video… I’ve seen it myself where the bores changed .0004” to .0005” opening up at the muzzle end.
 
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