Modern Sporter - Build Discussions

Brianma65 said:
I’ve only built two AR 10 and three AR 15 and I’ve used the .223 no go gauge once.

Now I just make a dummy rnd and chamber it, if the bolt closes, its a go .

If the bolt don’t close, then your SOL:)
Click to expand...

The point of using go/no go gauges is moreso to check for excessive headspace with the no-go gauge, not the ability to chamber a round. That being said if you are using quality parts chances are that by design you won’t have issues. However for my own peace of mind I always check headspace in all my builds and recommend anyone putting together their own to do the same. Also, if you are buying gauges you are better off with getting a no-go and a field gauge vs a go gauge.
 
smokenhope said:
The point of using go/no go gauges is moreso to check for excessive headspace with the no-go gauge, not the ability to chamber a round. That being said if you are using quality parts chances are that by design you won’t have issues. However for my own peace of mind I always check headspace in all my builds and recommend anyone putting together their own to do the same. Also, if you are buying gauges you are better off with getting a no-go and a field gauge vs a go gauge.
Click to expand...

Wouldn’t you also be able to check that with a dummy rnd. What would be considered excessive head space?

I understand how it works on a bolt, as I’ve installed a couple of barrels on a savage 10 TR, using the gauges.

But to have excessive headspace on an ar15, wouldn’t you have to have some very out of spec parts?
 
Last edited:
The dummy round would basically be acting as a go guage. And max headspace is different for .223 and 5.56. I believe 5.56 is 1.4736. That’s also bigger than most .223 Remington field gauges.
Failing on a no-go guage also doesn’t make it unsafe but if the bolt closes on a field guage I probably wouldn’t be shooting it. Sometimes all it takes is a bolt swap, tolerance stacking can add up sometimes, but yes if using higher-end parts chances are that this wouldn’t be an issue.
However for the time it takes and the cost/ borrowing of the gauges I definitely think it’s a good idea to be sure.
 
smokenhope said:
The dummy round would basically be acting as a go guage. And max headspace is different for .223 and 5.56. I believe 5.56 is 1.4736. That’s also bigger than most .223 Remington field gauges.
Failing on a no-go guage also doesn’t make it unsafe but if the bolt closes on a field guage I probably wouldn’t be shooting it. Sometimes all it takes is a bolt swap, tolerance stacking can add up sometimes, but yes if using higher-end parts chances are that this wouldn’t be an issue.
However for the time it takes and the cost/ borrowing of the gauges I definitely think it’s a good idea to be sure.
Click to expand...
Thanks
 
robab said:
What’s thoughts on go/no go guages. I don’t have a set. Is it vital? I don’t want to roll the dice on $2000 worth of parts. Any thoughts. ??
Click to expand...

I picked up .223 go and no go and a 5.56 no go for pretty cheap. Worth having. Like you said not worth the roll of the dice. More than a loss of some parts of the rifle you could lose parts of yourself.
 
Again, to my point about breaking this thread up.....but I suppose you can search.
I am on the light weight track, got a Brownells light weight BCG inbound, MRA pencil, the hand guard....yea thats a problem light and strong = $$$ so still trying to figure that out.
Stock, not so much of a problem, lots of choices, just a matter of compromise in terms of LOP and cheek weld. I run a PRS on my AT15 and love the fit, weight, well thats another story, but I only carry it for 30 some odd seconds in a 3G stage. Some folks here have some pretty optimistic ideas about weight, I would be interested in realistic build ideas. I think 7.5lbs is a fair target. Thoughts?


jonbpc said:
Hi guys , So im new to this platform/rifle. While we wait for delivery i thought i would start buying some parts here and there. Not looking for high end stuff, nor cheap junk. There seems to be so many brands and price differences. Hard to grasp it. Some good suggestions to point me in the right direction would be great. I havent purchased a thing yet. thanks
Click to expand...
 
docscoutjr said:
Again, to my point about breaking this thread up.....but I suppose you can search.
I am on the light weight track, got a Brownells light weight BCG inbound, MRA pencil, the hand guard....yea thats a problem light and strong = $$$ so still trying to figure that out.
Stock, not so much of a problem, lots of choices, just a matter of compromise in terms of LOP and cheek weld. I run a PRS on my AT15 and love the fit, weight, well thats another story, but I only carry it for 30 some odd seconds in a 3G stage. Some folks here have some pretty optimistic ideas about weight, I would be interested in realistic build ideas. I think 7.5lbs is a fair target. Thoughts?
Click to expand...

If you really want to get crazy, I bet you can get it to 5 lbs w/o optics.
 
Moore to my point about breaking this up into more focused threads, e.g. weight, fit, CDN only etc... I would love to see the math + actual available product to Canadians + NR legal on a 5lb build.
griffin86 said:
If you really want to get crazy, I bet you can get it to 5 lbs w/o optics.
Click to expand...
 
I’m in the mid 6lb range with mine sporting an ASC-L stock, full mass carrier, etc.
The 17” battle arms rail is very light and rigid. But V7 makes a 16.5” magnesium alloy piece that is insanely light


docscoutjr said:
Moore to my point about breaking this up into more focused threads, e.g. weight, fit, CDN only etc... I would love to see the math + actual available product to Canadians + NR legal on a 5lb build.
Click to expand...
 
docscoutjr said:
Moore to my point about breaking this up into more focused threads, e.g. weight, fit, CDN only etc... I would love to see the math + actual available product to Canadians + NR legal on a 5lb build.
Click to expand...


Maple ridge pencil barrel w/ thread protector 26 oz
titanium gas block and gas tube 1 oz
Brigand Arms hand guard 5 oz
Titanium BCG 8 oz
Brigand arms grip 2 oz
BAD Sabertube 5 oz
buffer and spring 5 oz
LPK 5 oz
Slick side receiver set 20 oz

You're at 4 lb 13oz
 
Last edited:
griffin86 said:
Maple ridge pencil barrel w/ thread protector 26 oz
titanium gas block and gas tube 1 oz
Brigand Arms hand guard 5 oz
Titanium BCG 8 oz
Brigand arms grip 2 oz
BAD Sabertube 5 oz
buffer and spring 5 oz
LPK 5 oz
Slick side receiver set 18 oz

You're at 4 lb 11oz
Click to expand...

I see even after you have edited it, your weights are wrong. 270g + 286g = 556g which is 19.6oz.
 
docscoutjr said:
Again, to my point about breaking this thread up.....but I suppose you can search.
I am on the light weight track, got a Brownells light weight BCG inbound, MRA pencil, the hand guard....yea thats a problem light and strong = $$$ so still trying to figure that out.
Stock, not so much of a problem, lots of choices, just a matter of compromise in terms of LOP and cheek weld. I run a PRS on my AT15 and love the fit, weight, well thats another story, but I only carry it for 30 some odd seconds in a 3G stage. Some folks here have some pretty optimistic ideas about weight, I would be interested in realistic build ideas. I think 7.5lbs is a fair target. Thoughts?
Click to expand...

Bcm makes a very nice 17” handguard, the KMR which is a keymod used to be made with a magnesium alloy and only weighs like 9oz.
 
You must log in or register to reply here.
Back
Top Bottom