Fairly new to reloading and I am measuring the cartridge base to the ogive/lands junction with the hornady OAL gauge and mitutoyo calipers. I'm getting a spread of readings from 2.2185" to 2.2495" with the 140 GR Hornady ELD-M. Rifle is a Defiance action and BT barrel. Any of these numbers look ok? Also how far off the lands are you loading the 140gr ELDs?
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6.5 CM CBTO
- Thread starter Gjb89
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Both numbers look ok, just not from the same rifle. .030” is a big spread when measuring to the lands. I would expect to see a .005” diff in measurements, maybe even .010”, but not .030”. To be clear, I’m not judging, just giving an opinion.
Finding the length to the lands can be tricky. I’ve never used the Hornady tool, but I can see how it could be really accurate.
I usually break my bolt down to nothing but the bolt body and extractor, take a once fired case and write “dummy” on it in sharpie, and never use it for anything else. I’ll seat a bullet long in the dummy case, then put the case on the bolt face under the extractor groove, and run the whole mess into the chamber slowly, and close the bolt. Open the bolt and slowly/carefully pull the dummy round out. Look at the ogive for any marks from the lands. If there’s no marks I assume that I didn’t jam it into the lands, only made contact with the lands. Take measurement, and repeat 4, 5, 10 times. Record the measurements, and go with the average, assuming all measurements are within .010” of each other.
In my creed with a 130 Berger hybrid I have a COAL of ~2.900” to the lands, with a CBTO of ~2.296”.
All that being said, I load to mag length. With the 130, I’ve been seating to 2.820” COAL, a good .080” short of the lands. I may play with it some to see if I can get a little more out of the rounds with seating depth changes, but haven’t so far.
I’m sure someone on here with experience with Hornady tool will chime in with some advice.
Finding the length to the lands can be tricky. I’ve never used the Hornady tool, but I can see how it could be really accurate.
I usually break my bolt down to nothing but the bolt body and extractor, take a once fired case and write “dummy” on it in sharpie, and never use it for anything else. I’ll seat a bullet long in the dummy case, then put the case on the bolt face under the extractor groove, and run the whole mess into the chamber slowly, and close the bolt. Open the bolt and slowly/carefully pull the dummy round out. Look at the ogive for any marks from the lands. If there’s no marks I assume that I didn’t jam it into the lands, only made contact with the lands. Take measurement, and repeat 4, 5, 10 times. Record the measurements, and go with the average, assuming all measurements are within .010” of each other.
In my creed with a 130 Berger hybrid I have a COAL of ~2.900” to the lands, with a CBTO of ~2.296”.
All that being said, I load to mag length. With the 130, I’ve been seating to 2.820” COAL, a good .080” short of the lands. I may play with it some to see if I can get a little more out of the rounds with seating depth changes, but haven’t so far.
I’m sure someone on here with experience with Hornady tool will chime in with some advice.
I’m not the best person to tell you if it’s acceptable or not as I don’t know much but I just did the same thing with a new barrel last night 140eld with the hornady tool and I have been told if your not careful you can push the bullet into the lands .005+ with too much pressure but when I did it last night I got a spread of.0025 total over ten rounds then I confirmed my measurement with a dummy round as explained above but I do know some bullets push/stick in the lands easier than others
You shouldn't be getting that big of a spread in Overall length when using the exact same bullet and case each time. I would keep taking measurements until you get a spread of a couple thou between measurements. You can always load a dummy round long and test fit it. If the bolt doesn't close, seat a couple thou deeper and try again.
I don't even know what my Cartridge overall length is, but they fit in an AICS mag. I just know that I load my Berger 130 Hybrids to 2.234" from base to ogive. That's about a 0.010" jump in my rifle.
I don't even know what my Cartridge overall length is, but they fit in an AICS mag. I just know that I load my Berger 130 Hybrids to 2.234" from base to ogive. That's about a 0.010" jump in my rifle.
Howa HCR 6.5CM 140 ELD-M CBTO just touching with the Hornady 5-26 insert in mine is 2.271”
A good load at this stage is at 2.2555.
This is using the semi stripped bolt method. Semi stripped as in the ejector is still in the bolt as it’s a bugger to get out so I grind a relief in the case so the ejector isn’t interfering with the case. You also need a dummy round with little to no runout as that will affect your result.
A good load at this stage is at 2.2555.
This is using the semi stripped bolt method. Semi stripped as in the ejector is still in the bolt as it’s a bugger to get out so I grind a relief in the case so the ejector isn’t interfering with the case. You also need a dummy round with little to no runout as that will affect your result.
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I would say you got it idk what the chances are but that’s the same measurement as me also I’m loading them .020 off the lands after looking around this site everyone seemed to be loading them .015-.030 so I started with .02 and even after a seating depth test it was my best result
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