Case length question.

[Roughwater]

I realize this is a very old post but still very pertinent today. I can't speak for every rifle but for my BCA 16" Grendel barrel the Alexander Arms data would be the most appropriate. If you want to check your own barrel's Chamber depth get you a Sinclair Chamber depth gauge. I checked my 16" BCA barrel and the chamber depth using the gauge was 1.543". So technically I could trim my cases to 1.528 and still be at a very safe .015 from the chamber. Best way for you to know is to check for yourself. The gauge is very inexpensive. All it requires you do do is resize and trim down an old Grendel case to a length of about 1.4". Start the gauge in the case neck and slam the bolt down a few times on the case. Then measure the length of the case to the top of the Gauge.

16 in barrel case depth1.jpg

[Velocity]

I bought a Sinclair chamber length gauge a couple days ago and the dang gauge would have fell in the case if it wasn't for large rim.

The gauge diameter measures .262 and the once fire case I.D. is .2665

LRRPF52
Can you tell me how a new Starline case that measures 1.5075 and I loaded it and shot it, now the case measures 1.502?
New barrel, this was the 3rd shot through it.

[imaguy3]

I bought a Sinclair chamber length gauge a couple days ago and the dang gauge would have fell in the case if it wasn't for large rim.

The gauge diameter measures .262 and the once fire case I.D. is .2665

LRRPF52
Can you tell me how a new Starline case that measures 1.5075 and I loaded it and shot it, now the case measures 1.502?
New barrel, this was the 3rd shot through it.

Yea they also have this in bright red on their website... "Should not be used in handguns, semi automatic rifles, lever actions rifles and pump action rifles."

Regarding your case length measurement, I'm gonna go with user error on the measurement side of things. I use the hornady bullet comparator and anvil base set when I'm checking case length as it provides a flat base to ensure the case isn't tilted. Then I use the flat spot next to the bullet opening against the case mouth.

https://www.amazon.com/Hornady-AB1-Lock-N-Load-Anvil-Base/dp/B005CMMIM4/ref=pd_lpo_3?pd_rd_i=B005CMMIM4&psc=1

https://www.hornady.com/reloading/precision-measuring/precision-tools-and-gauges/lock-n-load-bullet-comparator#!/

Even using that to check finished ammo, if the case isn't perfectly flat and the bullet aligned you can still get untrue measurements.

[Happy2Shoot]

I bought a Sinclair chamber length gauge a couple days ago and the dang gauge would have fell in the case if it wasn't for large rim.

The gauge diameter measures .262 and the once fire case I.D. is .2665

LRRPF52
Can you tell me how a new Starline case that measures 1.5075 and I loaded it and shot it, now the case measures 1.502?
New barrel, this was the 3rd shot through it.

sinclair-chamber-length-gauge-insert-case_0b6fb8a4-1341-498b-a533-2dd0649dfd35_600x600.jpg

Case overall length can get shorter because a die is thinner than your fat chamber. When you fire your brass, it goes from thin and tall to short and fat. Resize it and see if it gets longer again.

[jasper2408]

I bought a Sinclair chamber length gauge a couple days ago and the dang gauge would have fell in the case if it wasn't for large rim.

The gauge diameter measures .262 and the once fire case I.D. is .2665

I looked at my instructions that came with my Sinclair chamber length gauge and it states to full length resize the case before using the gauge.

The instructions on the Sinclair webpage does state to use a fired case without resizing it first. You could use it that way if you used a neck only sizing die or Lee collet die.

[Velocity]

I have the Hornady bullet comparator and anvil base set, but wasn't able to find the modified case anywhere, then came across the Sinclair Chamber Length Gage for $5.99.

Talked to Scott at Brownells today and he confirmed the Sinclair Chamber Length Gage is for BOLT RIFLES only.