Hornady Interlock RN 180gr length

Slinky Pickle · October 12, 2020, 05:50 PM

Every database that I can find (QL, GRT and various online ones) indicates an overall length of 1.168" for the Hornady Interlock RN 180gr bullets. I have a couple of boxes of them that I've used on my .303 Savage loads. I've measured them personally and they appear to be 1.063" in length. Has any one else stumbled across this issue? I just don't understand why so many databases show the same, incorrect value.

**44 AMP** · October 12, 2020, 06:20 PM

Seems to me the answer would be GIGO.

Garbage In, Garbage Out...

Slinky Pickle · October 12, 2020, 06:23 PM

What's really weird is that the number is slightly different in some of the databases. Not even close to the actual length but different enough that you would think it came from another source or measurement.

**44 AMP** · October 13, 2020, 01:04 PM

here's something else to further boggle the mind...

I just looked at one of my Hornady books, which shows 7 different 180gr bullets (one a RN). and while it doesn't give the length of the bullets, it does give the COL of loaded rounds.

Three different COL's. Now, if we assume that the rounds are loaded with approximately the same amount of bullet inside the case, you've got 3 different lengths sticking out.

Maybe a computer program will allow for that, but it needs correct data to give accurate results, and some generic number doesn't necessarily work.

T. O'Heir · October 13, 2020, 01:41 PM

You weigh 'em? They old? What are you measuring with?
Hornady 180 grain weights will vary according to the shape of the bullet. A 'spire point' can go to 1.236".
Closest weight to 1.063" is a 150 grain spire point at 1.064".
No idea how old this is.
https://www.jbmballistics.com/ballis....shtml#Hornady

**Unclenick** · October 14, 2020, 01:40 PM

Slinky Pickel,

Most bullets are run on multiple machines with multiple tooling sets, so they don't match exactly. That's normal. The worst offenders are hollow points on match bullets which often come out slightly slanted and I've measured 15 thousandths of length variation in one box of Sierra MatchKings before, most of it due to the tips, but a little (about 0.003") was due to difference in base to ogive where it meets the throat. The bullets still shot just fine, as what happens to the nose near the centerline has very little effect on exterior ballistics, at least, not until you get to beyond 800 yards. Anyway, tooling varies the exact dimensions.

October 12, 2020, 05:50 PM	#1
Slinky Pickle Junior Member Join Date: March 28, 2018 Posts: 9	Hornady Interlock RN 180gr length Every database that I can find (QL, GRT and various online ones) indicates an overall length of 1.168" for the Hornady Interlock RN 180gr bullets. I have a couple of boxes of them that I've used on my .303 Savage loads. I've measured them personally and they appear to be 1.063" in length. Has any one else stumbled across this issue? I just don't understand why so many databases show the same, incorrect value.

October 12, 2020, 06:20 PM	#2
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,833	Seems to me the answer would be GIGO. Garbage In, Garbage Out... __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

October 13, 2020, 01:04 PM	#4
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,833	here's something else to further boggle the mind... I just looked at one of my Hornady books, which shows 7 different 180gr bullets (one a RN). and while it doesn't give the length of the bullets, it does give the COL of loaded rounds. Three different COL's. Now, if we assume that the rounds are loaded with approximately the same amount of bullet inside the case, you've got 3 different lengths sticking out. Maybe a computer program will allow for that, but it needs correct data to give accurate results, and some generic number doesn't necessarily work. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

October 13, 2020, 01:41 PM	#5
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	You weigh 'em? They old? What are you measuring with? Hornady 180 grain weights will vary according to the shape of the bullet. A 'spire point' can go to 1.236". Closest weight to 1.063" is a 150 grain spire point at 1.064". No idea how old this is. https://www.jbmballistics.com/ballis....shtml#Hornady __________________ Spelling and grammar count!

October 14, 2020, 01:40 PM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Slinky Pickel, Most bullets are run on multiple machines with multiple tooling sets, so they don't match exactly. That's normal. The worst offenders are hollow points on match bullets which often come out slightly slanted and I've measured 15 thousandths of length variation in one box of Sierra MatchKings before, most of it due to the tips, but a little (about 0.003") was due to difference in base to ogive where it meets the throat. The bullets still shot just fine, as what happens to the nose near the centerline has very little effect on exterior ballistics, at least, not until you get to beyond 800 yards. Anyway, tooling varies the exact dimensions. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 12, 2020, 06:23 PM	#3
Slinky Pickle Junior Member Join Date: March 28, 2018 Posts: 9	What's really weird is that the number is slightly different in some of the databases. Not even close to the actual length but different enough that you would think it came from another source or measurement.