So I used the hornady oal gauge and I am getting a consistent reading of 2.255 with my comparator, or 2.935 for Coal. Does this seem correct? Seems long. I understand rifle, chamber, barrel is different so we can eliminate that. But just wanting to know if others who reload have gotten a similar number? The hornady eldm is 2.81. So my bullet hangs out almost 1/8 past sammi
2.935 oal for 6.5cm sound correct???
- Thread starter Dog
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2.255 sounds in the ball park for a CBTO (cartridge base to ogive) measurement (where the ogive touches the lands). Longest COAL i've measured was in the 2.85-ish area. What bullet are you using? Bullets can have difering lengths in front of their ogives.
I am using Berger 140 hybrid. With 2.255 with comparator. Then measuring the cartridge from tip to primer is 2.935.
I might be wrong, and someone correct me if so, but I 'think' SAAMI specs for chamber length is 2.825. That's from bolt face , breech end of chamber to the end of 'free bore' and where the rifling begins. A bullet's meplat (tip) can extend further than 2.825" and even at that its ogive may not necessarily yet be at/touching the lands.
If you are using a Hornady ELDM 140, (I do ), your ogive measurement is pretty close to what I get at 2.255, but your COAL (2.935) is way over what I've ever come up with. Again, if using the 140 gn, I'd say you are incorrectly measuring the COAL.
BTW, if I load my 140 ELDM to COAL of 2.81 (with a CBOT of the 2.255 area) I am roughly .040" off the lands. That's assuming I am measuring correctly
I'm loading for Ruger's RPR and its chamber.
Hopefully someone will jump in here who can give you an unequivocal answer. lg
If you are using a Hornady ELDM 140, (I do ), your ogive measurement is pretty close to what I get at 2.255, but your COAL (2.935) is way over what I've ever come up with. Again, if using the 140 gn, I'd say you are incorrectly measuring the COAL.
BTW, if I load my 140 ELDM to COAL of 2.81 (with a CBOT of the 2.255 area) I am roughly .040" off the lands. That's assuming I am measuring correctly
I'm loading for Ruger's RPR and its chamber.Hopefully someone will jump in here who can give you an unequivocal answer. lg
Ps. The 2.935 number is touching the lands. Also are you running the lri barrel chambered for the eldm? That could play a rollI might be wrong, and someone correct me if so, but I 'think' SAAMI specs for chamber length is 2.825. That's from bolt face , breech end of chamber to the end of 'free bore' and where the rifling begins. A bullet's meplat (tip) can extend further than 2.825" and even at that its ogive may not necessarily yet be at/touching the lands.
If you are using a Hornady ELDM 140, (I do ), your ogive measurement is pretty close to what I get at 2.255, but your COAL (2.935) is way over what I've ever come up with. Again, if using the 140 gn, I'd say you are incorrectly measuring the COAL.
BTW, if I load my 140 ELDM to COAL of 2.81 (with a CBOT of the 2.255 area) I am roughly .040" off the lands. That's assuming I am measuring correctly
Hopefully someone will jump in here who can give you an unequivocal answer. lg
Also, The 140 eldm’s measure 1.373, the Berger 140 hybrid measure 1.393I might be wrong, and someone correct me if so, but I 'think' SAAMI specs for chamber length is 2.825. That's from bolt face , breech end of chamber to the end of 'free bore' and where the rifling begins. A bullet's meplat (tip) can extend further than 2.825" and even at that its ogive may not necessarily yet be at/touching the lands.
If you are using a Hornady ELDM 140, (I do ), your ogive measurement is pretty close to what I get at 2.255, but your COAL (2.935) is way over what I've ever come up with. Again, if using the 140 gn, I'd say you are incorrectly measuring the COAL.
BTW, if I load my 140 ELDM to COAL of 2.81 (with a CBOT of the 2.255 area) I am roughly .040" off the lands. That's assuming I am measuring correctly
Hopefully someone will jump in here who can give you an unequivocal answer. lg
Our posts are 'passing in the night' I think the Berger Hybrid has a hybrid ogive and is indeed longer in front of the ogive than is the Hornady 140 ELD-M bullet. The Berger is a long sleek looking 'little devil'. Someone put on-line a table that lists most all of the bullets and their lengths. Do a search for that, if possible. I don't have the link. However in a text file of my own I show the Berger 140 Hybrid at a length of 1.402" and the Hornaday 140 ELD-M length of 1.374". FWIW
I think the Berger Hybrid has a hybrid ogive and is indeed longer in front of the ogive than is the Hornady 140 ELD-M bullet. The Berger is a long sleek looking 'little devil'. Someone put on-line a table that lists most all of the bullets and their lengths. Do a search for that, if possible. I don't have the link. However in a text file of my own I show the Berger 140 Hybrid at a length of 1.402" and the Hornaday 140 ELD-M length of 1.374". FWIWFYI, the longest COAL I can load for is 2.86 due to the constraints of my magazine, unless I want to single feed. The longest COALs I do load to are 2.81 and 2.80 because that is the max COAL my AR-10's mags will hold. So, I end up trying to find my best or most accurate loads through which bullets the rifles 'like' and powders and charge weights. Bergers are not one of my bullets. (only because they are expensive)
If I've caught up with the comments, you are using Berger, and it touches the lands at the 2.25ish area and with a COAL in the 2.9s. If so, I'd search around and see what the users of the Berger bullet you use, see how far off the lands they are loading to, an average, and start there. That will of course shorten your COAL.
That''s a wow in my book. I'm doing okay with mine. I've got a couple loads where all the bullets in the group are touching at 100. Mine shoots good. I've only owned my RPR since this early spring and started reloading with my army buddy in AZ last January. He owns an RPR in 308, so when I got back home I bought one in 6.5CM (same as my RRA Ar-10 is chambered in). I'm happy. Not a competitor or competition shooter. Retired and all this is one grand hobby. Enjoy it a lot.
There are some great people participating in the few forums I joined. Learning a lot. Nice chatting with you Dog, and I am sure those Bergers are gonna fly like lazers!
Thanks for all your help. If you haven’t, Check out accurateshooter forum. That’s the other one I’m apart of. It’s all benchrest shooters, but they are basically mad scientists when it comes to reloading. You will learn A-LOT.
And you for yours, I picked up on a couple things. And am already on accurateshooters. Comment there under 'LGKLAS'. Totally agree with you on that forum! And the last rifle forum I am on is 6.5 Creedmoor, under 'lg65cmsd'. Good members there too. And specific to our caliber.
As far as 6.5CM goes and on Youtube, two channels I subscribe to are: Bolt Action Reloading and Johnny's Reloading Bench. Neither are 'mad scientists' but both have lots of videos on loads for our caliber. I'm working with 4 bullets and 3 powders and have gotten a lot of 'start points' watching their vids and that's saved me some money, time and barrel life. As these forums have.
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