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Hi
I am relatively new to reloading. I decided to change the bullets I use in my .270 from partitions to Hornady SP. The Hornday bullets are a lot cheaper to shoot at the range. Both bullets are 130 grain. Is it unusual to have to bullets the same grain to have a difference in OAL. I checked both in the chamber of my rife using a modified
shell casing. Thanks for the help
Absolutely not unusual, and to be expected. Two bullets off the same production line can vary in length too, enough to produce slightly different points of impact. That's why you measure and sort if you're looking for extreme accuracy.
And two different bullets may want to be seated differently with regard to distance off, or into the lands. You just have to experiment.
Just a warning though; you're about to step into the rabbit hole of hand loading. Welcome to the addiction!
Bullet legnth/seating depth, is based from the ogive of the bullet to the rifeling in the barrel, and not from the tip of the bullet.
After a load has been established for a particular bullet, it would be common for some reloaders to create a dummy round
for that particular bullet for future use for die setting etc. Different bullets even of the same weight, could cause slightly different o a legnths.
Factory rifle chambers are built to comply with certain industry standards known as Sammi specs.
Factory loaded ammo regardless of type is loaded to safely comply with those standards.
The degree of time and effort put forth to assure (good) loads, will vary according to both the particular individual, and the type of shooting activity they pursue.
I use the Ogive tools and even at that, I may have 4 of the same identical bullet clear the lands and then have one stick (I start close the lands and work back on load test)
At some point I arrive at a safe setting that does not have bullets sticking in the lands.
As long as it is not over pressure its not a problem but if they call a cease fire you have to get the bugger out.
Different mfg had wildly different ogive shapes even for the same bullet type.
Reloading manuals use COAL as that is easier and not eveyr0one is not into the extra steps and micrometer needed for Ogive setting.
Those tips vary even more than the Ogive does.
I'm using a hornady ogive comparotor. Put modified casing with bullet in my rifle to see where it touched the lands. The 2 bullets have different lengths to the ogive so I am assuming the will not be the same distance off the lands of my gun. Or am I missing something???
We have learned receintly that "when things are different, they are different". The two bullets You are talking about are different. Deal with them individually. Good Luck :-)
Bigstone65Quote:
Originally Posted by Bigstone65
After I got out of the military in 1973 and bought my Rockchucker press all I had was a plastic Lyman vernier caliper and kept things "simple".
I had a .270 and used Hornady bullets and I "cheated", I just seated the bullets to the middle of the cannelure, and called it good enough.
If you seat the bullet deeper into the case or seat the bullet long it raises the chamber pressure.
The seating depth in the manuals is at the lower midpoint of the pressure curve.
That being said when fireforming new cases if needed I reduce the load by two grains and jam the bullets into the rifling. This holds the case against the bolt face and prevents the case from stretching in the base web area.
If I was you I would seat to the cannelure and find the best load then if you wish you can "carefully" play with the seating depth.
I can tell you this, for over ten years after starting to reload my deer hunting ammo was seated to the cannelure or manual OAL and deer never knew the difference.
Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/relo...-rifle-reloads
Bigstone65 one of the general safety rules of handloading is when there is a change in your load IE, bullet, primer, powder, brass, always go back to the starting load and work your way back up, watching for any signs of high pressure.