I just build a 6.5x55 rifle from a savage 110 action. I am getting info together to start loading test loads and was figuring out the distance to the lands. What I measured surprised me. Seven times I measured 3.075 to 3.077. The max OAL listed is 3.150. I checked and the go gage fits and the no-go gage does not. Should this be a concern?
surprising data
- Thread starter wkillette
- Start date
Wkillet,
The first drawing below is bullet and case and cartridge terminology, just to be sure we are all on the same page. Note that the start of the ogive mentioned before is called the shoulder of the bullet. Actual contact with the rifling begins at or just in front of that shoulder, depending on exact bullet diameter.
The second drawing shows the relationships between the cartridge and the chamber dimensions. What your gauge measured is shown just under the chambered cartridge as "Hornady gauge measures this". It is from breech end of the case head to the throat (start of the rifling). This drawing shows the difference between that and the longer COL next to the bottom of the drawing, giving a .308 dimension as an example.
The third drawing below shows how two bullets with very different COL's can have the same jump to the lands of the rifling, proving you need to check each bullet for its own COL, if that is what you will use to gauge bullet seating depth.
The first drawing below is bullet and case and cartridge terminology, just to be sure we are all on the same page. Note that the start of the ogive mentioned before is called the shoulder of the bullet. Actual contact with the rifling begins at or just in front of that shoulder, depending on exact bullet diameter.
The second drawing shows the relationships between the cartridge and the chamber dimensions. What your gauge measured is shown just under the chambered cartridge as "Hornady gauge measures this". It is from breech end of the case head to the throat (start of the rifling). This drawing shows the difference between that and the longer COL next to the bottom of the drawing, giving a .308 dimension as an example.
The third drawing below shows how two bullets with very different COL's can have the same jump to the lands of the rifling, proving you need to check each bullet for its own COL, if that is what you will use to gauge bullet seating depth.
Did you buy a BNIB barrel that isn't finished?
"...the go gauge fits and the no-go gauge does not..." Fits what? The only gauge of either type should be headspace gauges. There is no fit or not fit though. Just the bolt closes on the Go and not close on the No-Go.
"...The max OAL listed is 3.150..." No it isn't. OAL for a 142 is 3.050".
"...the go gauge fits and the no-go gauge does not..." Fits what? The only gauge of either type should be headspace gauges. There is no fit or not fit though. Just the bolt closes on the Go and not close on the No-Go.
"...The max OAL listed is 3.150..." No it isn't. OAL for a 142 is 3.050".
Thanks Unclenick, I am printing your post and placing it in my research notes folder. That explained a lot. The previous posts by others helped as well.
Thank you
go guage fits - bolt closes=fits
no-go guage does not - bolts does not close = does not fit.
Since I didn't get the results I expected, I verified I had the headspace correct after replacing the barrel.
As for the max OAL for any 6.5x55 round the OAL is 3.150. I learned the ogive bases from Unclenick's post.
Thank you
go guage fits - bolt closes=fits
no-go guage does not - bolts does not close = does not fit.
Since I didn't get the results I expected, I verified I had the headspace correct after replacing the barrel.
As for the max OAL for any 6.5x55 round the OAL is 3.150. I learned the ogive bases from Unclenick's post.
Glad to help.
You can always check the SAAMI drawing when in doubt about standard COL. It shows 2.75-3.150 inches will fit and feed in magazines intended for SAAMI standard compliant ammunition.
Sierra tested the 142 grain bullet with 3.100" COL, according to their databook.
Of course, if you load a round to a recommended COL and find the Hornady gauge reads the head-to-ogive data point to have much less than the 3.076" that you got when touching the lands, you then have the option to load longer. It just may not fit a magazine, which means single loading. If you get under about 0.030" from the lands, the pressure starts going up, and reaches something in the neighborhood of 20% higher when you actually touch the lands with the bullet.
You can always check the SAAMI drawing when in doubt about standard COL. It shows 2.75-3.150 inches will fit and feed in magazines intended for SAAMI standard compliant ammunition.
Sierra tested the 142 grain bullet with 3.100" COL, according to their databook.
Of course, if you load a round to a recommended COL and find the Hornady gauge reads the head-to-ogive data point to have much less than the 3.076" that you got when touching the lands, you then have the option to load longer. It just may not fit a magazine, which means single loading. If you get under about 0.030" from the lands, the pressure starts going up, and reaches something in the neighborhood of 20% higher when you actually touch the lands with the bullet.