I am putting a new barrel on my ar, does anyone have a action block and headspacing gauge you'd be willing to loan out?
Gunsmithing looking to barrow some ar 15 stuff.
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Re: looking to barrow some ar 15 stuff.
the headspace should be set with your bolt and the barrel extension. you won't be able to change that when installing the barrel on the AR.
the headspace should be set with your bolt and the barrel extension. you won't be able to change that when installing the barrel on the AR.
Re: looking to barrow some ar 15 stuff.
I figured that would be the case. Can't hurt to check though, right? Anybody know any tricks on holding the upper without an action block? I might just have to pony up and buy one.
I figured that would be the case. Can't hurt to check though, right? Anybody know any tricks on holding the upper without an action block? I might just have to pony up and buy one.
Re: looking to barrow some ar 15 stuff.
Oriented like how the receiver is in this picture. This is how I did my AR-10's which I couldn't find an action block for.(at the time)
Obviously you don't want to crush the 2 receiver lugs so make the bottom piece of wood shorter to fit between the 2 lugs. I'd make sure to keep the receiver square and centered between the 2 vice jaws. Don't want any off axis force. Make it snug, not insanely tight. Don't want to crush the upper. If you have a delrin bore guide, shove it in there, it will keep it from getting crushed.
Oriented like how the receiver is in this picture. This is how I did my AR-10's which I couldn't find an action block for.(at the time)
Obviously you don't want to crush the 2 receiver lugs so make the bottom piece of wood shorter to fit between the 2 lugs. I'd make sure to keep the receiver square and centered between the 2 vice jaws. Don't want any off axis force. Make it snug, not insanely tight. Don't want to crush the upper. If you have a delrin bore guide, shove it in there, it will keep it from getting crushed.
Re: looking to barrow some ar 15 stuff.
That looks like a sweet set-up. I guess I could just bang one out on the cnc.
That looks like a sweet set-up. I guess I could just bang one out on the cnc.
Re: looking to barrow some ar 15 stuff.
An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit.
An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit.
Re: looking to barrow some ar 15 stuff.
That's great, I never thought about clamping the barrel, that seems reasonable to me. It should all torque the same, and would be clocking the receiver to barrel instead, right?
That's great, I never thought about clamping the barrel, that seems reasonable to me. It should all torque the same, and would be clocking the receiver to barrel instead, right?
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
It's late and I may be stupid but exactly how do you tighten a spinning barrel nut to an unsecured receiver while the barrel is clamped in a vice?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
It's late and I may be stupid but exactly how do you tighten a spinning barrel nut to an unsecured receiver while the barrel is clamped in a vice?
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smokshwn</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
It's late and I may be stupid but exactly how do you tighten a spinning barrel nut to an unsecured receiver while the barrel is clamped in a vice? </div></div>
The pin on the barrel extension engages the notch on the front on the the receiver, nothing can spin other than the barrel nut. Thread the barrel nut onto the receiver, clamp the barrel up as close as you can and still have clearance for the wrench, torque & clock the nut.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smokshwn</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
It's late and I may be stupid but exactly how do you tighten a spinning barrel nut to an unsecured receiver while the barrel is clamped in a vice? </div></div>
The pin on the barrel extension engages the notch on the front on the the receiver, nothing can spin other than the barrel nut. Thread the barrel nut onto the receiver, clamp the barrel up as close as you can and still have clearance for the wrench, torque & clock the nut.
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job.
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Salmonaxe</div><div class="ubbcode-body">Oriented like how the receiver is in this picture. This is how I did my AR-10's which I couldn't find an action block for.(at the time)
Obviously you don't want to crush the 2 receiver lugs so make the bottom piece of wood shorter to fit between the 2 lugs. I'd make sure to keep the receiver square and centered between the 2 vice jaws. Don't want any off axis force. Make it snug, not insanely tight. Don't want to crush the upper. If you have a delrin bore guide, shove it in there, it will keep it from getting crushed.
</div></div>
i used wood and a vise to do my MA-10 this way and it really didnt require too much clamping pressure to hold iit steady and allow me to get the nut to 45 ft lbs. didnt need to spend $$ on a one time tool. you could use big C clamps to clamp it to a table too with wood on top
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Salmonaxe</div><div class="ubbcode-body">Oriented like how the receiver is in this picture. This is how I did my AR-10's which I couldn't find an action block for.(at the time)
Obviously you don't want to crush the 2 receiver lugs so make the bottom piece of wood shorter to fit between the 2 lugs. I'd make sure to keep the receiver square and centered between the 2 vice jaws. Don't want any off axis force. Make it snug, not insanely tight. Don't want to crush the upper. If you have a delrin bore guide, shove it in there, it will keep it from getting crushed.
i used wood and a vise to do my MA-10 this way and it really didnt require too much clamping pressure to hold iit steady and allow me to get the nut to 45 ft lbs. didnt need to spend $$ on a one time tool. you could use big C clamps to clamp it to a table too with wood on top
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job. </div></div>
I can see how you're working it, but I don't like the idea of the steel pin against aluminum upper taking the torque when I have to get that extra half of a gas tube notch.
FWIW a receiver block seems like a one use tool but in reality my has paid for itself several times over.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job. </div></div>
I can see how you're working it, but I don't like the idea of the steel pin against aluminum upper taking the torque when I have to get that extra half of a gas tube notch.
FWIW a receiver block seems like a one use tool but in reality my has paid for itself several times over.
Re: looking to barrow some ar 15 stuff.
i think you could pull them pins if your worried about deformation. i put wood on top and between the pins, castings or whatever and clamped mine as they didnt have those blocks for a 308 ar yet and i was too lazy to get any delrin off ebay. in my case i was building just this one rifle. i swear, lol. i scoured the net for a $15 crowfoot socket for my barrel nut just to not have to buy a $30 one, lol. plus you know everything for the 308 is a little higher. dang man they dont tell you that when you start
i think you could pull them pins if your worried about deformation. i put wood on top and between the pins, castings or whatever and clamped mine as they didnt have those blocks for a 308 ar yet and i was too lazy to get any delrin off ebay. in my case i was building just this one rifle. i swear, lol. i scoured the net for a $15 crowfoot socket for my barrel nut just to not have to buy a $30 one, lol. plus you know everything for the 308 is a little higher. dang man they dont tell you that when you start
Re: looking to barrow some ar 15 stuff.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job. </div></div>
I'm going to disagree on principle. The forces involved are the same. You will either apply torsional force to the receiver or to the barrel. For the pin to come into the equation, you would have to hold the barrel nut stationary while rotating either the barrel or the receiver.
The barrel nut acts upon the ring of the barrel extension applying friction as the nut is tightened. When you hold the receiver, the friction wants to rotate the barrel extension and the pin in the receiver. When you hold the barrel, it's the friction between the threads that will want to rotate the receiver against the barrel extension pin. We could argue physics but in the end it's the same. The question is which is better at absorbing the twisting force, the receiver or the barrel?
Granted, the Delrin blocks shown are a sound method of holding the receiver. If you had to rely simply on the take down pin bosses to hold the receiver and bear the twisting force, then it's my opinion that holding the barrel instead of the receiver would be more mechanically sound.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body">An alternative is to clamp the barrel instead, that way you're not putting stress on the receiver.
ETA, I generally use a Field gage to verify headspace on new assemblies. Mind you, you need to remove the ejector and extractor from the bolt. Brownells sells the field gage, good thing to have in your AR kit. </div></div>
By doing it this way you are relying on a small pin and its not the proper way to get the desired torque. There is the possibility that that small pin can bend or dick up your upper where they mate and when you finish building if you have a front sight it would be turned over a bit creating another problem. I would think anyone with a CNC or even a mill would have no issue making up the proper tools for the job. </div></div>
I'm going to disagree on principle. The forces involved are the same. You will either apply torsional force to the receiver or to the barrel. For the pin to come into the equation, you would have to hold the barrel nut stationary while rotating either the barrel or the receiver.
The barrel nut acts upon the ring of the barrel extension applying friction as the nut is tightened. When you hold the receiver, the friction wants to rotate the barrel extension and the pin in the receiver. When you hold the barrel, it's the friction between the threads that will want to rotate the receiver against the barrel extension pin. We could argue physics but in the end it's the same. The question is which is better at absorbing the twisting force, the receiver or the barrel?
Granted, the Delrin blocks shown are a sound method of holding the receiver. If you had to rely simply on the take down pin bosses to hold the receiver and bear the twisting force, then it's my opinion that holding the barrel instead of the receiver would be more mechanically sound.
