Curious on things you have found. Thanks.
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Curious on things you have found. Thanks.
For what it's worth, at least with the Switchlug, they are pretty open about their POI shift.
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We tested point-of-impact repeatability by shooting 5 shot or larger groups at 100 yards, and removing and re-torqueing the barrel between every single shot. POI repeatability has proven to consistently return within +/- .5MOA, and in many cases significantly less. As a matter of course we recommend always confirming your zero after a barrel change, but you can be confident in the ability of a rifle with a properly installed Switchlug system to hold its zero and return to it.
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For the system to function with maximum repeatability, the lug and action should be properly bedded into the stock. This immobilizes the lug during barrel changes when the clamp is loosened for barrel removal or installation. If ordering a new stock for use with this product, order with an oversize recoil lug pocket as the SwitchLug is .350″ thick. Chassis systems that do not obstruct the area around the recoil lug can also be used. Again, for maximum repeatability we recommend bedding the lug pocket and front action ring area with Devcon epoxy. If you choose not to bed your chassis the SwitchLug will work, but you will likely experience a shift in POI on your first 2-3 shots after a barrel installation as the action and lug settle.
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I haven't had a chance to thoroughly look at the instagram/facebook discussion because legitimately anything is more important, but maybe a reason for some of the difference is because the actions were not bedded in the chasses/stocks?
Also, +/- 0.5 MOA is +/- 0.15 mils which is on the same order of magnitude as the changes that others have observed.
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We tested point-of-impact repeatability by shooting 5 shot or larger groups at 100 yards, and removing and re-torqueing the barrel between every single shot. POI repeatability has proven to consistently return within +/- .5MOA, and in many cases significantly less. As a matter of course we recommend always confirming your zero after a barrel change, but you can be confident in the ability of a rifle with a properly installed Switchlug system to hold its zero and return to it.
...
For the system to function with maximum repeatability, the lug and action should be properly bedded into the stock. This immobilizes the lug during barrel changes when the clamp is loosened for barrel removal or installation. If ordering a new stock for use with this product, order with an oversize recoil lug pocket as the SwitchLug is .350″ thick. Chassis systems that do not obstruct the area around the recoil lug can also be used. Again, for maximum repeatability we recommend bedding the lug pocket and front action ring area with Devcon epoxy. If you choose not to bed your chassis the SwitchLug will work, but you will likely experience a shift in POI on your first 2-3 shots after a barrel installation as the action and lug settle.
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I haven't had a chance to thoroughly look at the instagram/facebook discussion because legitimately anything is more important, but maybe a reason for some of the difference is because the actions were not bedded in the chasses/stocks?
Also, +/- 0.5 MOA is +/- 0.15 mils which is on the same order of magnitude as the changes that others have observed.
I view switchlug more like a shoulder setup, like AIs. The key difference is whether there is shoulder cutout on the barrel side.
Already discussed in the thread. I think it works to certain level and purposes, not my personal choice for match/competition.
I have two Nucleus actions with barrel nut Barlocs. Current plan is to take them and a deadblow hammer to the range this weekend. I'll satisfy my own curiousity if nothing else.
Current planned protocol is shoot a group, smack barrel, shoot a group, smack barrel harder, shoot a group, etc.
For both, I am gonna start them cold in the AM and heat the barloc up with a little torch just to check temp difference as well at the end of a series.
If I don't get any POI movement, I will make index marks, pull the barrels, re-install them, and give it another go to see if installation makes a difference.
I don't care about return to zero on a barrel change, yes, I think the Barloc is gonna give the most variability of the systems out there. Most of the discussion was here was general stuff and philosophy of use. I get all that.
If anyone has any specific information, experience, comments about the POI shift on an installed Barloc, well, I'd like to have it before my test. It is interesting to read the comment about the two barrels and three results of different barrel headspacing systems. Not sure how much causation is in the correlation, but something to explore.
As for personal experience, once in more than 500 rounds have I experienced anything I would consider a POI shift. But, I was also switching from virgin brass to my second firing, so I chalked it up to that. It is my match gun, gets drug around everywhere I shoot, goes in soft cases, sometimes with a second rifle, has a suppressor on it most of the time, and doesn't get babied. I followed ARC's procedure to the "t" in installation, and torqued using a Borka.
Current planned protocol is shoot a group, smack barrel, shoot a group, smack barrel harder, shoot a group, etc.
For both, I am gonna start them cold in the AM and heat the barloc up with a little torch just to check temp difference as well at the end of a series.
If I don't get any POI movement, I will make index marks, pull the barrels, re-install them, and give it another go to see if installation makes a difference.
I don't care about return to zero on a barrel change, yes, I think the Barloc is gonna give the most variability of the systems out there. Most of the discussion was here was general stuff and philosophy of use. I get all that.
If anyone has any specific information, experience, comments about the POI shift on an installed Barloc, well, I'd like to have it before my test. It is interesting to read the comment about the two barrels and three results of different barrel headspacing systems. Not sure how much causation is in the correlation, but something to explore.
As for personal experience, once in more than 500 rounds have I experienced anything I would consider a POI shift. But, I was also switching from virgin brass to my second firing, so I chalked it up to that. It is my match gun, gets drug around everywhere I shoot, goes in soft cases, sometimes with a second rifle, has a suppressor on it most of the time, and doesn't get babied. I followed ARC's procedure to the "t" in installation, and torqued using a Borka.
Was it more of an issue on the shouldered barloc? or the barrel nut barloc?
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I dunno much of all about that. I am gonna test the barrel nut version though...
Barloc gets pulled but you can still buy the mags?
Makes no sense.
Makes no sense.
Every magazine manufacturer has a group of people for whom they work great, work okay, and don't work at all without modification to the lips, follower, etc...
Hundreds if not thousands of combinations of receiver, DBM, stock, inlet geometry, cartridges, spacing, binding, etc... so it's no wonder they're a weak point. I've personally had nothing but smooth success with them. But that's a whole 'nother topic.
Hundreds if not thousands of combinations of receiver, DBM, stock, inlet geometry, cartridges, spacing, binding, etc... so it's no wonder they're a weak point. I've personally had nothing but smooth success with them. But that's a whole 'nother topic.
I’ve done the same except for the proof. Read the liner was thin and they could be damaged. Have you done any proof barrels this way with positive results?
Thought the Barloc was going to be the fix to the above problem.
I haven’t tried it with a Proof, and wouldn’t recommend it. Just too much risk on a pricy barrel. If I ever get ahold of a shot out one I’ll do some abuse testing and report back.
That’s in reference to my preferred installation method, specifically using my vise to clamp a barrel while it’s still installed in a chassis or stock.
Ross Vise
Ross Vise
The Barloc is more of an inverted V band clamp design, the beveled faces are used as a force multiplier, not really much in common with a set screw. Sadly it lacks the mating faces.
Shot a PRS match today with normal banging around and rough handling, zero POI shift. Even had a first round hit at 800 after someone not watching their step knocked my rifle over by kicking the barrel. I say the barloc is GTG. While not as good as a shoulder barrel, is easier to install barrels and set headspace then standard barrel nut.
Tested my barloc today. TL-3 action, 6 Creed, shouldered barloc. Shot 3, banged on the barrel with a piece of wood about 5 -10 times, shot 3. Did it 3 times. No noticeable shift. I’ll keep testing, but I’m feeling pretty good about it.
Saw this thread a couple days ago and typical as my luck would have it I banged the hell out of my 24” proof carbon the next day. Double checked zero and walked first round impacts out to 985 then wind beat me at 1180 but Got right back on the horse at 1280. I’m far from professional but both my Shoulded Barloc’s have proven greater than anticipated thus far..
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LRI is doing them too.
I’ve had Josh at PVA, John at Area419 and GAP barloc shoulder multiple barrels. Talked to Marc at Spartan Precison and he said send it as well, No problem. So there are many fine options to have a barloc barrel spun up. Just have to make the phone call or shoot the email over?
I guess I will have some testing to do. I couldn't get a hold of PVA in time to change my barloc cut option. Looks like my barrel ships out this week. I do not plan to take that barrel on and off to swap barrels but I hope there are not POI shifts from banging the barrel around. Does anyone have any more test results to share?
How is it that this thread has gone this far without someone stating that it is far more likely that theturrets of the scope are far more succeptable to an impact to the barrel than a barloc.if used properly the barloc is an extremely secure way of tensioning a barrel. Ted did a good job when he designed it. Scopes are far more of a weak point in a system than barloc.
Because the topic of the thread is wanting to know why ARC suspended sales of the Barloc. It’s not about scope Turrets getting banged. We are wanting to know why and some have done some testing or are in the process of doing some to see if there is an issue. Personally ive not experienced any. I’m sure we all would agree with you that scope turrets getting hit will shift point of impact. Has anyone heard direct from ARC what the issues are, if any?
I first heard of this issue last week from ARC, it was the guy that answers the phone and takes orders. I don’t remember his name. He told me that some people suspected a poi shift after banging their barrel against something. I expressed my opinion to him and he somewhat agreed with me but they were cautious until they had done more testing. I’m not implying people are hitting scope turrets and seeing poi shift but hitting barrel and sending a shock through their scopes that causes a poi shift. It’s just a more likely scenario than movement occurring in the tenon threads under the kind of tension Barloc puts them under.
Let's hope that the fix is handled better than the magazine follower debacle...
LRI does this. PVA isn’t the only gunsmith in the world ffs....
I once did a rubber mallet test on some rifles. AR, AR10 in 6.5, and two bolt guns (tikka and AI AX 338). I would have called each hit a medium smashy smash.
Lessons Learned:
1. QD scope mounts didn't hold up as well as flat out clamp style scope mounts.
b. Make damn sure you seat the cross slot or other recoil lug on a scope mount against the picatinny slot.
III. Many scopes would move under reverse recoil impulse.
Four: SPUHR makes an excellent product...even better when you use rosin in the rings and make sure you get any lube off the scopes.
V. A fairly light rubber mallet tap will break the scope turret right off a gen 1 vortex PST. Same with the early LOW made bushnell optics.
6. You could get a strong POI shift out of a suppressor when you tapped on it.
5. If an AR platform gun has any slop in the extension to upper mating, you can move it with a solid enough hammer blow. Especially true with tapping on the barrel nut mounting interface with rails that mount on the barrel nut itself.
If I had to guess on the Barloc situation, I would say that yes it can move. Imagine the following insane engineering experiment:
-Place a 2 ft threaded piece of allthread into a solid tube 12" long. The tube is threaded inside and fits the allthread tightly. Clamp the tube for the rear 4" in V blocks. Snug the allthread up to the tube with a nut. Deflect the allthread and measure its return to position zero.
-Replicate this exact situation. Instead use a 4" long tube that is clamped in the v blocks. Make up the rest of the 8" with flat washers. Deflect the all thread and measure.
The Barloc is engineered well in that it uses conical seating surfaces which will help it try to center itself again after deflection, and it will resist deflection initially more than a flat joint. However, it has 3 sliding surfaces versus just 1 for a shouldered barrel. If I were trying to cut down on POI shift in this assembly I might actually use graphite lube on each conical interface to help it re-self-center. It would be interesting to see what the groups do as well. Might help, might hurt.
Conical clamping and thread clamping (just another form of conical clamping) are well accepted methods for creating a high tension joint like this.
Lessons Learned:
1. QD scope mounts didn't hold up as well as flat out clamp style scope mounts.
b. Make damn sure you seat the cross slot or other recoil lug on a scope mount against the picatinny slot.
III. Many scopes would move under reverse recoil impulse.
Four: SPUHR makes an excellent product...even better when you use rosin in the rings and make sure you get any lube off the scopes.
V. A fairly light rubber mallet tap will break the scope turret right off a gen 1 vortex PST. Same with the early LOW made bushnell optics.
6. You could get a strong POI shift out of a suppressor when you tapped on it.
5. If an AR platform gun has any slop in the extension to upper mating, you can move it with a solid enough hammer blow. Especially true with tapping on the barrel nut mounting interface with rails that mount on the barrel nut itself.
If I had to guess on the Barloc situation, I would say that yes it can move. Imagine the following insane engineering experiment:
-Place a 2 ft threaded piece of allthread into a solid tube 12" long. The tube is threaded inside and fits the allthread tightly. Clamp the tube for the rear 4" in V blocks. Snug the allthread up to the tube with a nut. Deflect the allthread and measure its return to position zero.
-Replicate this exact situation. Instead use a 4" long tube that is clamped in the v blocks. Make up the rest of the 8" with flat washers. Deflect the all thread and measure.
The Barloc is engineered well in that it uses conical seating surfaces which will help it try to center itself again after deflection, and it will resist deflection initially more than a flat joint. However, it has 3 sliding surfaces versus just 1 for a shouldered barrel. If I were trying to cut down on POI shift in this assembly I might actually use graphite lube on each conical interface to help it re-self-center. It would be interesting to see what the groups do as well. Might help, might hurt.
Conical clamping and thread clamping (just another form of conical clamping) are well accepted methods for creating a high tension joint like this.
That sounds extremely unlikely considering the kind of recoil most of our scope are made to stand.
I wasn't suggesting they were. Lighten up Francis
I had a similar thought process to add some type of lubricant to the conical surfaces to facilitate self centering after impact. Much the same way I use a small amount of grease on the mating surfaces of my scope rings to the picatinny rail.
I don’t know that this will fix anything. It’s pure speculation without knowing what is causing the issues. Design vs material or both. Or none at all. If I were home I would test it but it’s gonna be 5-6 months before that will happen.
I like a switch barrel in many ways - its good for the "fear the man with just one rifle" type mentality. It lets me train and shoot the same rifle and optic the way I want depending on the day and the situation.
It also lets me shoot proof steel barrels in my guns for the high volume training stuff, and the carbon ones for when I have to go walk places.
It also lets me shoot proof steel barrels in my guns for the high volume training stuff, and the carbon ones for when I have to go walk places.
Any updates on this?
You know you can do that with non "switch barrel" rifles, right?
I swap between shouldered barrels (6.5 cm and 6BRA) all the time. Zero shift changes 0.10 mils at most. Don't have to worry about my zero changing with any little bumps.
I think most don't realize how easy it is to swap out shouldered barrels. You don't need a "switch barrel" system to change your barrel out.
So, I didn't do a whole lot of testing, cause one really solid whack moved mine. Who knows if it is Barloc, rifle chassis not bedded, or what. This happened.
#1 is my first shot into the dot.
whacked barrel really hard
#2 is my second shot at a new dot (down low)
#3 and 4 were follow up and were back on the new dot.
I guess the moral of the story is really smashing your barrel can change POI. But, for me one shot put it right back. I never had any issues at matches, and didn't recognize any issues from tossing the rifle in the back seat of the truck in a soft case.
Pretty substantial move.
Interesting as it tried to migrate back.
Now the question is what would a similar shouldered barrel do.
And that's what I want to know. We need a baseline to measure against.
The optimal test will likely have the following:
Torque everything and go from there. That said, lol. I'm not thinking anyone but ARC might be able to do a setup like that. Then again, they could probably make a dedicated test action. Something square sided and bolted to a table, with no machinist vise involved.
- Same action.
- Action clamped in something like a machinists vise. clamp upside down with bolt handle sticking out the rear of the vise. Not in a chassis or stock. Vice bolted to a concrete table that is 100% solid.
- Barloc and shouldered barrels. Same manufacturer and same contour.
- A 3 pound weight hung from two linear motion rails suspended at different heights. Bolt to the test table.
- Dial indicator on the back of the action to make sure it doesn't move.
Torque everything and go from there. That said, lol. I'm not thinking anyone but ARC might be able to do a setup like that. Then again, they could probably make a dedicated test action. Something square sided and bolted to a table, with no machinist vise involved.
I am surprised ARC has been silent on this. I think a few hours in their shop would determine if normal banging around would change anything.
When I installed mine before this issue came up, I torqued and loosened the Barloc several times to stretch, form or whatever you might call it, the threads. I do the same when installing AR barrels.
I wonder if the POI shift can be eliminated by retorquing after shooting a few rounds to get everything settled in.
When I installed mine before this issue came up, I torqued and loosened the Barloc several times to stretch, form or whatever you might call it, the threads. I do the same when installing AR barrels.
I wonder if the POI shift can be eliminated by retorquing after shooting a few rounds to get everything settled in.
When doing that with ARs, it's generally to help spread anti-seize compound equally. At least that's been why I've done it.
I would hope the barloc wouldn't be actually deforming the threads, even temporarily. That would be a much bigger issue and also harder since everything is steel here as opposed to aluminum for an AR receiver.
Maybe - but probably not. It’s an axial cone and they will move. And then attempt to recenter themselves.
It’s worse the closer to the center the main cone contact patch is.
One thing that may cause this behavior to abate is by machining steps in the cones.
Or using a different surface finish. Or going the other way and lubing the interface.
It’s worse the closer to the center the main cone contact patch is.
One thing that may cause this behavior to abate is by machining steps in the cones.
Or using a different surface finish. Or going the other way and lubing the interface.
I’ve yet to do a bang test on any of my 4 barrels or my buddies Barloc setup but there is no doubt they can shoot if semi taken care of. This group was shot with a savage Pre-Fit and Barloc barrel nut from a new shooter on his second time out shooting at my range with factory ammo. I wonder if there there is any POI variation between a Barloc shouldered barrel and savage Pre-Fit style with Barloc nut and everything else being equal?
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Mine was well lubed on all surfaces with Break Free upon installation. I haven't tried banging it and don't plan to make any changes on that rifle unless there is a factory fix from ARC.
