I posted a thread but it seems to have disappeared.
It was long winded lol but I'll keep this one shorter.
This new barrel will close the bolt on a no go gauge. Barely but it closes so I'm not that worried about it.
The issue I have is the short throat. I loaded some 140 gr sierra mks at 2.810" as the data states. They won't come close to chambering in the rifle. I had to seat them all the way to 2.755" before they would clear the lands. I've emailed them a few times but haven't come to any conclusions yet with them. They just keep asking the same questions about what bullet I'm using even though I told them like 3 times. So I plan to call tomorrow. Just wanted opinions from others before I call. Should I be concerned? I plan to shoot 1k yds with the rifle and I also have about 5.5k in the rifle/scope combo. I just feel the throat is really too short.
...IIRC, this was for an AR10 build..
....a simple answer would be to get a set of tools like the Hornady Lock-N-Load® O.A.L. Gauge, a modified case in the caliber(s) you have, calipers, Lock-N-Load® Bullet Comparator, and Bullet Comparator Inserts. With these tools you can measure EACH brand/type of bullet you might use in YOUR chamber to determine where exactly that bullets ogive profile contacts the lands AND the resultant COAL. These tool will also allow you to determine the COAL and CBTO measurement of each bullet to your chamber AND if that COAL measurement will fit in your magazines. For some VLD type bullets (secant ogives) the measured COAL might exceed the magazines allowable max length.
...granted the SIERRA online load data indicates a COAL of 2.810", conversely Hodgdon's online load data indicates a COAL of 2.780", Alliant 2.8" for the same bullet...the measurements from other loading manuals/sites will also vary due to their individual testing equipment and protocols.
... EACH brand/type of bullets ogive profile (secant/tangent/hybrid) has an immediate impact on the seating depth in direct relation to your specific barrel's chamber, hence the need to measure. Tangent ogives make contact with the lands sooner (bullets seat deeper), secant ogives make contact later (bullets seat longer, BUT may exceed magazine allowance). Hybrid ogives will be anywhere in between. Sierra SMK's are tangent ogives, although the newer offerings appear to be transitioning to "hybrids". (That's why PROOF CS kept asking you what bullet you were using, more than likely they have recommendations for multiple bullets they have tested.)
...in your previous post you indicated putting a piece of tape on the rear of the NOGO gauge prevented the bolt from closing on it, you may need to verify if the bolt itself is in spec, i.e. face depth too deep, lug length too short. How you tested also comes into play, i.e., did you remove the ejector & extractor from bolt before testing, did you remove bolt from BCG or did you allow the BCG to close under buffer spring pressure on the gauge? Typically it's best to test headspace BEFORE barrel installation and only with the bolt (ejector & extractor removed), using finger strength to rotate the bolt.
....your loaded COAL of 2.755" is within the SAAMI spec for 6.5 Creedmoor, which has a min of 2.700" to max of 2.825" for
Cartridge
Over
All
Length. You may be overthinking this or misinterpreting/misapplying data you have collected.
...if the expectations of your purchase weren't met, seek return/refund/replacement..
