Hornaday Bullet length gage?

[Nvreloader]

When using the above tool and measuring total overall bullet seating depth,
I can NOT get the same results for overall length.

I have a couple of same caliber inserts and there is a big difference in the readings when changing between them,
and using approximately the same pressure/feel during the readings etc.

Would I get better results, if I turned an accurate steel insert, instead of using the OEM Alum inserts?

What size of REAMED hole diameter would be the best, for 22 and 7mm calibers?

Does the hole size really MAKE a difference providing the hole is the right size for the bullet?

I would believe a very slight breaking of the sharp Steel edge, on the BULLET SIDE should be done,
or a slight bevel/tapered edge??

What say you?

I know that this tool is not a High Performance type of tool, but I am just starting into the LR area.

Tia,
Don

 

[chkunz]

When using the above tool and measuring total overall bullet seating depth,
I can NOT get the same results for overall length.

I have a couple of same caliber inserts and there is a big difference in the readings when changing between them,
and using approximately the same pressure/feel during the readings etc.

Would I get better results, if I turned an accurate steel insert, instead of using the OEM Alum inserts?

What size of REAMED hole diameter would be the best, for 22 and 7mm calibers?

Does the hole size really MAKE a difference providing the hole is the right size for the bullet?

I would believe a very slight breaking of the sharp Steel edge, on the BULLET SIDE should be done,
or a slight bevel/tapered edge??

What say you?

I know that this tool is not a High Performance type of tool, but I am just starting into the LR area.

Tia,
Don

Are you trying to get the cartridge overall length with the bullet making contact with the lands?

 

[DIBBS]

Your comparator measures to the ogive, not cartridge overall length. There are slight variations in bullet length, bullets are made in different dies, and your COL cartridge overall length will vary slightly. That being said...

From the hornady website:

Measuring cartridge lengths across bullet tips is not a reliable or repeatable method for measuring your loaded rounds. It's common for variations of up to .025" to exist from one round to the next. Our Bullet Comparator solves that problem by measuring rounds from a reliable surface on the bullet, the ogive, to provide consistent, precise measurements of your rounds. The Bullet Comparator is also used to check uniformity of bullets from base to ogive.

It's a useful tool, but depending on the amount of shooting you do, you may need to chase the lands as the throat slowly erodes to keep your jump or jam to the lands the same.

 

['Freak]

I see folk badmouth Sinclair’s equivalent bullet comparator inserts all the time which is machined with a taper and then a short straight section to more accurately emulate an actual chamber throat, but because of this the things can’t be used on shorter projectiles or most anything loaded short enough to run from a magazine. Davidson Seating Depth Checkers have the taper but not the straight section so theirs don’t swallow up as much of the projectile’s length as do Sinclair’s. Hornady’s stuff is the shallowest of the bunch machined only with a caliber specific orifice. To get an accurate measurement using the Hornady inserts, the projectile gotta be aligned perfectly perpendicular to the orifice inside the insert.

 

[Nvreloader]

T Rex,

You are correct,
I am attempting to find the lands, to establish the jam/jump length needed etc.
If I understand these meanings correctly, slightly confused on the exact meanings/terms??

Jam = bullet ogjive just touching the lands??
Jump= bullet jumps into the lands from whatever distance??

Tia,
Don

 

[fguffey]

Would I get better results, if I turned an accurate steel insert, instead of using the OEM Alum inserts?

Yes, it has to do with the datum. Measured from seems simple enough but there are efforts made to make the datum bullet friendly, I want to imprint the rifling on the bullet, I want to imprint the datum on the bullet. I understand a radius on the datum drops 'the measure from' below the surface of the tool.

If the datum is a straight drilled hole through the surface closing the tool allows the user to zero the tool. But, if the user is going to use the tool as a comparator and zeroing is not necessary continue to compare and zero with a standard. The head space gage is a standard, for those that understand 'datum' can make head space gages.

F. Guffey

 

[fguffey]

I am attempting to find the lands

Find the lands? I drill the primer pocket/flash hole out on a case with good bullet hold, I want all the bullet hold I can get. I would use tension but have no way to measure neck tensions.

After drilling the primer pocket/flash hole I seat 'the bullet' and chamber. After chambering I use a cleaning rod to push the bullet out of the case and into the lands. Once the bullet imprints on the lands I remove.

After removing the case with the bullet I use it as a transfer, I transfer the measurements from the chamber to the seating die. I adjust the seating die to the transfer, When the seating plug contacts the bullet the die is adjusted to 'zero' off the lands. If I choose to seat the bullet .020" off the lands I lower the seating plug .020".

I do not find it necessary to start over everyday, with good bullet hold I can save and use the transfer again.

Reloaders with the Hornady bullet length gage can use the transfer to determine the distance from the bolt face to the lands. IF! they understand the length of the case off sets the length of the chamber.

F. Guffey

 

[chkunz]

T Rex,

You are correct,
I am attempting to find the lands, to establish the jam/jump length needed etc.
If I understand these meanings correctly, slightly confused on the exact meanings/terms??

Jam = bullet ogjive just touching the lands??
Jump= bullet jumps into the lands from whatever distance??

Tia,
Don

OK here is the dirty little secret. You will hear folks talk about this as if they can make this measurement within 0.001 but it is not possible with the tools we have to make the measurement, like you are using. Add on top of that the variability introduced with each persons technique and you have a lot of variability in the measurement. If you do the best job you can making this measurement and take ten measurements using the same bullet you will be amazed at the variability in the data. Then if you measure the variability in the bullets and add that in then things get worse. So many folks make unrealistic claims that most people think they are doing something wrong. I make the measurement and I use it but I understand the limits of the measurements and use the measurement accordingly.

 

[Nvreloader]

Gstaylorg,

I am really confused now,

You said,
With the Hornady OAL gauge,
pushing the bullet in until it just hits the lands and noticeably stops would be called "touching".
Farther into the lands would be a "jam",
although you likely need to go into the lands .020"-.025" to reach a "hard jam".

Anything not touching or farther into the lands would be a "jump" or "off".

Did you mean that FROM the lands would be jump/off the lands??

My normal method of using this Stony Point tool, is to make sure the case shoulder is firmly against the clean chamber shoulder,
then hold the tool there and using moderate thumb pressure to push the bullet untill it stops all forward movement, into the lands,
lock the settings down and measure to the ojive of the bullet to the overall length of the bottom of the case.


Tia,
Don

 

[Lapua40X]

Nvreloader ... the most important point you can take away from this discussion is that with the tools you're using you can't expect unquestionable accuracy in the resulting data. Best you can hope for is something only slightly better than a WAG and that data is useful only as a starting point from which you will make incremental adjustments until you achieve your accuracy goal. The term "jam", along with many other terms shared in these forums, will be used to mean one thing in the vernacular of one reloader. Because the degree of jam can vary dramatically depending on the rifle, the person collecting the data, etc., it has no truly common definition. IMO, you can drive yourself insane (and give your wife grounds for divorce) trying to create a flawless reloading result. That is especially true when you consider that as soon as you get it all worked out and put a few hundred rounds down the tube the throat dimensions have changed and the data you placed so much confidence in last month is worthless this month.

 

[waldo1979]

I just replaced my Hornady OAL gauge with the Sinclair gauge and found it produces more accurate and repeatable results. In order to use the OAL gauge effective you also need the headspace gauge and bullet comparator gauge. The reference shell for .223 for example has 0.007" less headspace (head to datum) than my fireformed cases. In the end you'll want an ogive to head measurement.

Even if I had a fireformed reference brass and If I removed the resistance on the plastic slider, it takes 3 -4 hands to effectively use the Hornady gauge (one to hold in the gauge, one to work the slider, one to use the set screw and one to work the dowel). I think the sandwich method works best, using a dowel to push the bullet out of the jam to tell how much resistance exists when pushing the bullet into the jam.

I can get a reading on the Sinclair gauge in 3-5 tries wherein I have pages full of inconsistent readings from my Hornady gauge. One thing about the Sinclair gauge is I haven't quiet figured out how all the measurements add up, but they do. After using the gauge I seat a bullet to max and inspect for jam marks after gentily closing the bolt/receiver.

 

[suberjc]

I started off years ago with the Sinclair nut thingey. It is a completely relative measuring device but once you learn to use it you won't use anything else. I normally will only get .5 - 1.5 variance in length from base to ogive using it and I have occasionally pulled bullets and almost always the difference is in the bullet.

 

['Freak]

Try the Sinclair Bullet Seating Depth Tool #749-004-650 w/standard guide. Once I got the thing figgered out, I found when using the Sinclair tool it’s easier to get repeatable so more accurate results than when using the “Hornady Lock-N-Load OAL Gauge”.

 

[Nvreloader]

Thank you for the info,

I was confused about the terms etc.
I was using touching AS jam length etc,
I didn't realize that going deeper was also jam, depending on how deep you went into the lands etc.

I am using the Original Stoney Point tool along with Horn inserts etc, plus some custom made inserts for my other wildcats cases.

I will turn up some accurate Steel inserts and see what the REPEATABLE results will be.

Tia,
Don

 

[fguffey]

I am using the Original Stoney Point tool along with Horn inserts etc, plus some custom made inserts for my other wildcats cases.

I will turn up some accurate Steel inserts and see what the REPEATABLE results will be.

Accurate steel inserts, a hole drilled perpendicular is as accurate as it gets, that leaves the diameter of the hole, after that someone wants to place a radius at the top, after the radius forget calling it accurate.

Original Stoney Point tool

I have one, complete with the cases threaded for the tool, I do not use it but I have one. I want all the bullet hold I can get, I want the case length from the shoulder to the case head to match the length of my chamber from the shoulder to the bolt face. If I use their threaded head cases I have to add the difference in length between the case and chamber sometimes referred to as case head clearance.

Then there is the 'how many times am I required to check/test/measure'? Once, after pushing the bullet to the lands I adjust the seating die to the test case. I secure the die to the press and seating stem to the die and measure, after measuring I zero.

At, to, beyond or off: I am the fan of the running start, I want my bullet to have 'the jump'. I also want to know the distance from the lands to the bolt face. It is not necessary to start over every day. I save the test case with good bullet hold, the tip of the bullet can change by design but the diameter of the rifling and bullet contact will change very little. I want to know where the rifling is located.

Not often but I have pushed bullets out of the case before contact was made at the rifling.

F. Guffey