Hornady Overall Length Gauge

Reloading
1

Jim,

Are you planning to do an in depth video on using the hornady Overall Length Gauge? I hear you refer often to seating the bullet 30 thou off the lands but it would be nice to see how you calculate that.

I’ve tried with a few different rifles and I don’t feel like I can accurately measure my overall length with this tool. I consistently get slightly different measurements so I don’t feel comfortable seating a bullet 30 thou back from my inconsistent OAL.

Any help would be much appreciated!

2

I have no idea where my seating depth video is, lol. I was surprised to see this question because I know I made a video about this for the course, but I don’t see it there, so I’m going to re-record a video tomorrow and add it in.

3

Jim, you rock! Please don’t hesitate to make it a longer video if needs be. I’d rather have a slower, longer video if it takes that to get the information out there then something super concise. I appreciate your help!

4

@backfire I dont see this vid on the channel in You tube did you ever re do It?

I’m really interested to know a few points how snug do you let the bullet get in the riffling . I’ve seen those say snug It in. I’ve heard others say It should just kiss the riffling like he one clicks a mouse. Im getting very different readings depending and I’m not so confident I know what I’m doing with this. I can read with calipers with good repeatability any help from you are any other would be great

Anybody else really jump in thanks!

5

I made a post similar to yours a few months back concerning the OAL gauge. I followed several other videos and guides and was also getting inconsistent results. The 6.5 prc is was attempting to measure almost had two different spots where it felt like the bullet was contacting the lands. When I measured the first place I felt resistance it was VERY clear that it was way too short compared to the OAL of box ammo. When I pushed just slightly past the first bump I could get to a secondary area where it was difficult to tell if I was forcing the bullet into the riffling or contacting the lands. My results were varying way too much to call it conclusive.

I ended up doing a loctite style measurment and looking for a node in the data. I loaded my E-LDX 20-thou off the assumed spot and extracted a few rounds to check for any hangups. I have not had time to get to the range to test these loads yet.

I know there are others having this same problem after a brief internet search.

6

thanks for the input I watched peiter at impact media do both and get within a half thou i’m off by hundreths from loctite to oal sort of concerned dont want to load anything until I feel like that measurment is good

Any thoughts?

7

I use the hornady gauge and really jam it in there. I don’t think you can truly enter the rifling using the little plastic rod. I make sure to keep the rifle in the same orientation which is easy enough to do with a bipod or gun vise. I use the little brass set screw to make sure the gauge is always in the same orientation. I then use a cleaning rod to gently push the projectile out. I do this 3-5x and then take the average. Doing it this way the numbers are always close. I always back it off 10-20 thou or more off of this number. Seems to work.

8

Thanks so I cut a modded once fired case from my barrel and I believe the hole is not perfectly perpendicular . going to a machinest tomorrow to cut the tap on a lathe so It wil be perfect. I made 2 locktite carts and they are within 1/2 a thou of eachother going to confirm with the oal once I get the new modded case.

Im pretty nuts. I’m trying to get ultra precision its a challenge so at each step I’m trying to cut out error manage consistency and drive myself nuts. we shall see the huge spread is bothering me and I think its going to boil down to the modded case. Im using Lapua brass and the shoulders are ultra tight in headspace measurements SD 0.00063 which is great looking to keep rolling with elite numbers through out the process should yield the results im looking for in group size. Its really just a game at this point but a fun one none the less.

Thanks for any and all help in this

9

It’ll change over time too.

10

yeah it erodes have to spot check. just have to get confident with the measurments