NRL build - barrel and scope questions

The chassis and barrel profile are easy ways to cut weight. Light weight suppressor will help too. my guess is that you could probably get away with a #5, #6 hunter profile or light palma without worry about your barrel walking . You could potentially get away with a #4 but that would be cutting it close
 
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I'm not winning any matches, and I shoot matches with a .30-06, granted, but I've never gone above 10x in an NRL match. I cannot imagine any scenario where I would even think about going to 30x+.

Even if I were shooting a lady gun in 6.5 I'd never want to go past 15x
The recoil on that big super manly WW1 30 cal probably dictates how much zoom a guy can get away with without losing sight picture. I think for most lady shooters like myself, 14-18X zoom is the sweet spot.
 
What's not feasible? If a carbon barrel and a steel barrel weigh the same, why is the balance any different other than the obvious possible differences on how that weight is carried across the length of the barrel?
As I mentioned, you have to go way down in contour with a steel barrel, which affects heat dissipation.

Weight distribution is a thing, too, as you said, but it's likely pretty minor.
 
As I mentioned, you have to go way down in contour with a steel barrel, which affects heat dissipation.

Weight distribution is a thing, too, as you said, but it's likely pretty minor.
I'm also specifically speaking about using an ACC for NRL-Hunter. My partner in shooting the Teams division used an ACC with Stiller action, #3 Benchmark, and LRHS 3-12x scope, and balance was certainly sub-optimal. He was a few ounces under 16 lbs. I wanted to use a 26" M24 steel barrel on my setup, but it wasn't even close to making weight.
 
As I mentioned, you have to go way down in contour with a steel barrel, which affects heat dissipation.

Weight distribution is a thing, too, as you said, but it's likely pretty minor.

Well its not like a carbon of similar weight is going to be any better at dissipating heat.

I'm also specifically speaking about using an ACC for NRL-Hunter. My partner in shooting the Teams division used an ACC with Stiller action, #3 Benchmark, and LRHS 3-12x scope, and balance was certainly sub-optimal. He was a few ounces under 16 lbs. I wanted to use a 26" M24 steel barrel on my setup, but it wasn't even close to making weight.

How did it get so heavy, Triple pull? The g2 ass end could get some weight out of there. There's a 12# rifle in this thread with triple pull, ZCo, and fluted rem varmint tube. Surely the XLR element isn't 4# lighter than an ACC.
 
Also, not sure if you've already got the chassis but gen 1 base was a fair bit lighter than gen 2 but gen 2 ass end is notably lighter. So if weight is critical, gen 1 base, gen 2 stock seems to be the way.
 
The recoil on that big super manly WW1 30 cal probably dictates how much zoom a guy can get away with without losing sight picture. I think for most lady shooters like myself, 14-18X zoom is the sweet spot.

Yeah that's exactly what I said. 10x for what I shoot, 15x for 6.5
 
Well its not like a carbon of similar weight is going to be any better at dissipating heat.
It's got a much larger surface area, so I'd bet that it is. A CF barrel of similar contour would be much worse, for sure.
How did it get so heavy, Triple pull? The g2 ass end could get some weight out of there. There's a 12# rifle in this thread with triple pull, ZCo, and fluted rem varmint tube. Surely the XLR element isn't 4# lighter than an ACC.
Sorry, I misremembered. I also had almost a pound of internal weights in the ACC to help with balance, since I had the weight budget. Yes, if I took out those weights I could get away with another pound in barrel weight, bumping the barrel weight budget to about 5 lbs.

Tenacity with rail and pins: 31.875 oz
ACC Gen 1 w/o weights or attachments: 84.75 oz
2 internal ACC weights: 15.25 oz
TT Special: 1.75 oz
IBI CF Hunter 22" in 6.5 CM: 46 oz
Maven RS1.2 with AAD caps and Burris XTR Sig rings: 34.5 oz
Heathen G2 4-port and tuner: 7.25 oz
Ckye pod single pull: 21.75 oz
Burris scope level: 1.375 oz

Total: 15 lbs 3 oz
 
It's got a much larger surface area, so I'd bet that it is. A CF barrel of similar contour would be much worse, for sure.
Larger surface area of a worse conductor if i'm not mistaken. The tests ive seen of temp increase/decrease rate of carbon vs steel of a similar weight weren't conclusive or significantly different IIRC. I just dont buy that carbon is a better alternative based on performance at any normal sporter contour weight and above.
Sorry, I misremembered. I also had almost a pound of internal weights in the ACC to help with balance, since I had the weight budget. Yes, if I took out those weights I could get away with another pound in barrel weight, bumping the barrel weight budget to about 5 lbs.

Tenacity with rail and pins: 31.875 oz
ACC Gen 1 w/o weights or attachments: 84.75 oz
2 internal ACC weights: 15.25 oz
TT Special: 1.75 oz
IBI CF Hunter 22" in 6.5 CM: 46 oz
Maven RS1.2 with AAD caps and Burris XTR Sig rings: 34.5 oz
Heathen G2 4-port and tuner: 7.25 oz
Ckye pod single pull: 21.75 oz
Burris scope level: 1.375 oz

Total: 15 lbs 3 oz

Makes sense. The longer fore end on gen 1 ACCs should help allow weight added to be further forward as well so help a hair more than g2.
 
Larger surface area of a worse conductor if i'm not mistaken. The tests ive seen of temp increase/decrease rate of carbon vs steel of a similar weight weren't conclusive or significantly different IIRC. I just dont buy that carbon is a better alternative based on performance at any normal sporter contour weight and above.
You're correct, but it's difficult to test since what actually matters is the temp of the surface steel in the bore. The rest of the barrel steel/CF simply acts to conduct and disperse heat away from the bore. Given that steel and CF barrels have very different contours at like weight, it's difficult to determine how the two compare at dispersing heat from the internal bore surface area. It's certainly possible to test this, but I've not seen any tests that do it this way. Most that I've seen compare the temperature at the external surface.
 
You're correct, but it's difficult to test since what actually matters is the temp of the surface steel in the bore. The rest of the barrel steel/CF simply acts to conduct and disperse heat away from the bore. Given that steel and CF barrels have very different contours at like weight, it's difficult to determine how the two compare at dispersing heat from the internal bore surface area. It's certainly possible to test this, but I've not seen any tests that do it this way. Most that I've seen compare the temperature at the external surface.
Alterra arms had one on youtube not too long ago. I think they tested bore temps but its been a while since I watched.
 
Alterra arms had one on youtube not too long ago. I think they tested bore temps but its been a while since I watched.
They tested bore temp and graphed heat dissipation. Shouldn't surprise anyone since the carbon is mostly epoxy and epoxy is an insulator, but the carbon barrels heated up faster, and held heat way longer than steel.
 
They tested bore temp and graphed heat dissipation. Shouldn't surprise anyone since the carbon is mostly epoxy and epoxy is an insulator, but the carbon barrels heated up faster, and held heat way longer than steel.
Not really. Here's the test: https://www.allterraarms.com/carbon-vs-steel-rifle-barrel-test/

As a disclaimer, I'm not a CF barrel proponent. Having said that, I would challenge some of the conclusions they draw, as well as the methodology of the test. First, nowhere do they say how they controlled the initial heat transfer to the bore in terms of ammo consistency, time between shots fired, time between the last shot and getting the probe into the bore, etc. Second, in the 1-shot test they call a 4 deg F difference insignificant, while in the subsequent tests they draw conclusions based on differences of ~5 deg F. Lastly, there is a clear trend in all their plots that CF barrels did, indeed, dissipate heat faster. Over longer shot strings, the CF barrels initially rose to higher internal temps, but then their internal temp decreased faster than that of the steel barrels.
 
Not really. Here's the test: https://www.allterraarms.com/carbon-vs-steel-rifle-barrel-test/

As a disclaimer, I'm not a CF barrel proponent. Having said that, I would challenge some of the conclusions they draw, as well as the methodology of the test. First, nowhere do they say how they controlled the initial heat transfer to the bore in terms of ammo consistency, time between shots fired, time between the last shot and getting the probe into the bore, etc. Second, in the 1-shot test they call a 4 deg F difference insignificant, while in the subsequent tests they draw conclusions based on differences of ~5 deg F. Lastly, there is a clear trend in all their plots that CF barrels did, indeed, dissipate heat faster. Over longer shot strings, the CF barrels initially rose to higher internal temps, but then their internal temp decreased faster than that of the steel barrels.
Rate of decrease is a weird sticking point. If it’s hotter at 1 minute and still hotter at 10 minutes it doesn’t really matter if the carbon cooled down by a higher percentage over that time period.
 
Rate of decrease is a weird sticking point. If it’s hotter at 1 minute and still hotter at 10 minutes it doesn’t really matter if the carbon cooled down by a higher percentage over that time period.
I agree with you that the absolute temperature is what actually matters. I'm pointing out that the CF barrels actually did dissipate heat faster.

I would argue that if 4-5 deg F is insignificant in the first test, then I'm not sure it's meaningful in the subsequent tests.
 
Alterra arms had one on youtube not too long ago. I think they tested bore temps but its been a while since I watched.
I'll also point out that in this test they used deeply fluted steel barrels of similar contour to the CF barrels. My original point was that a steel barrel of similar weight to a CF barrel would have a smaller contour.

Using fluting on the steel barrels, as they did in this test, introduces a new variable that is not controlled (one style of barrel uses fluting, while the other does not). What if you were to flute the CF barrels for an apples-to-apples comparison? Again, I'm not advocating for one barrel material over another, but as a physicist myself, scientific rigor is important to me when considering testing results, conclusions, and data.
 
I'll also point out that in this test they used deeply fluted steel barrels of similar contour to the CF barrels. My original point was that a steel barrel of similar weight to a CF barrel would have a smaller contour.

Using fluting on the steel barrels, as they did in this test, introduces a new variable that is not controlled (one style of barrel uses fluting, while the other does not). What if you were to flute the CF barrels for an apples-to-apples comparison? Again, I'm not advocating for one barrel material over another, but as a physicist myself, scientific rigor is important to me when considering testing results, conclusions, and data.

I think the idea being many people use a larger barrel with flutes to get to the same/similar weight as the CF. Would be cool to see all three side by side.


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