6DTI question

seasley

seasley

New member
Having difficulty getting accurate measurement to the lands with my hornady gauge

The bullet is barley in case, and is way off from dimensions on oal from what I have looked up

Any help would be appreciated
 
The Hornady tool was very difficult for me to get consistent readings. I prefer the Sinclair tool and AR15 insert.
 
Try the cleaning rod method. With the bolt in the upper, insert a cleaning rod with a flat tip from the muzzle, and mark the rod at the muzzle when the cleaning rod hits the bolt, and retract it 3 or 4 inches. Now remove the bolt, insert the bullet and lightly push it up to the rifling with a short rod. Now carefully push the cleaning rod back towards the chamber till it touches the bullet, and measure from the muzzle to the mark you made on the cleaning rod. You can use tape to mark the cleaning rod.
 
On the hornady gauge, the bullet isn’t in gauge at all when I set it to the lands after I pull it out, so I don’t know what to do
 
It's not unusual to have bullets barely in the case when checking DTL. Bullet shape has a huge influence. Those long pointy ones are hugely different than the short fat ones. I've seen same weight bullets in the American 30 in 110 grain that would vary as much as .100 in DTL. Same wight. Different shape.

One you get the bullet against the lands and crank the little knob down on the sliding rod just pull it out and ind drop the bullet you just used back in the case and measure. Be sure to use the SAME bullet.

I use to use the Hornady set up and make my own cases for perfect fit to my specific chamber but found it to be difficult to be consistent. Ritch turned me on to the Sinclair tool and all was good in my reloading room. I will set down and measure a whole slough of bullets for a new barrel that I in intend to use and keep track of them in a binder on each barrel. I have over 30 binders on the shelf each with their own data.


I also measure all my bullets for various things like base to ogive, ogive to tip and shank length. With a bit of math I am able to see a difference in same weight bullets and see some indications on why I might see pressures earlier or stabilization problems in some twist rates. I admit I am a data freak and have exemplar bullets for each caliber I load. My boxes contain easily 100 plus that I use to measure my DTL. All bullet measurements are spreadsheeted for quick reference with five measurements along with part number and BC.

Greg
 
What is the twist on the barrel....... if it is throated to shoot 95 or 100 gr bullets...... the 58 vmax may not be in the case when you touch the lands...... try it with a longer bullet with a similar shape as the 58 vmax. Then see how that compares to the 58 gr. HTH Just a thought.
 
1-12 twist

I received my Sinclair OAL Gauge, and from the lands is 2.279 measured 3 times

I have loaded rounds to 2.260 with 30 grains of h322, and it’s holding a nice little group

Im debating on adjusting the OAL or to change powder charge to see if it gets better
 
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I use powder charge weight to find a .4-.5 gr range where the vertical dispersion is the smallest. Then I test seating depth. This is for hunting rifles,where I never shoot loads that can touch the lands. I usually start 0.010+ off because "commercial" bullets often vary .003-.005 in a box. AR's require more "slop" and oal mag length is always part of load development. I just prepped my 20p brass from last 4-5 months, all for an AR. Brass was all moved 0.003-0.0035 from fired. I never move a bolt gun brass that far.
 
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