Hornady Lock'N'Load Overall Length Gage

[soulezoo]

Factory Rem 700s often come with gargantuan leades. I haven't measured mine in a while, but like RedRalleyZ, I have way more leade than I could ever want.

I won't likely ever shoot a bullet that's depth sensitive because of the volume we shoot. I'm too impatient to be checking and adjusting jump every several hundred rounds.

Not always. My Rem 700 in .25-06 has little room. In fact, with sierra 120 gr game kings, I can barely load to max oal. My Rem 700 vssf in .220 swift is similar. My Rem 700 classic in .300 wby has more relief, but not as much as my Mark V.

[markm]

Yep. I said "often" assuming it's not always the case. When I re-barrel my .308, I'll probably have to drop my load a full grain.

[T2C]

Hornady makes great reloading equipment, but I never purchased a Hornady Lock'N'Load Overall Length Gage. Different bullets have different profiles, so I use the bullet I am about to load to get the maximum C.O.L. reading. I use a straight piece of wood dowel rod, two paper clamps and a caliper.

I size the neck of the case down just enough to get tension on the bullet being inserted into the empty brass. The first reading is with the bolt closed on an empty chamber. You slide the wood dowel in until it touches the bolt face and attach a paper clamp to the dowel with the clamp touching the muzzle. Slide the dowel out several inches, then insert the empty brass with the bullet you are going to load in the chamber. Slowly close the bolt until the bullet touches the lands, then press the bolt into full battery. Insert the dowel until it touches the bullet tip and attach the second paper clamp to the dowel with the clamp touching the muzzle.

The distance between the edges of the two clamps that touched the muzzle is the maximum C.O.L. for that particular bullet. The easiest way to get the reading is to measure the distance from outside to outside of the clamps and subtract the width of one of the clamps. Remove the empty brass and bullet from the chamber. If the bullet moves, reestablish the C.O.L using the measurement you just obtained. Then use a bullet comparator and caliper to measure the distance from the base of the brass to the bullet ogive. (That is the measurement I use when adjusting the seating depth on the reloading die.) Keep the measurements in a log book for your rifle.

I usually subtract 0.010" from the maximum C.O.L. as a starting point. If you are developing a load with the bullet touching the lands, start with the minimum recommended charge weight for the powder you are using and increase the charge weight until you hit the accuracy node or see signs of excess pressure. If you see signs of excess pressure reduce the charge weight until the signs of excess pressure are gone.

Check the maximum C.O.L. every 1,000 rounds so you can adjust the loaded cartridge length to compensate for throat erosion. Keep the data in a rifle log for future reference.

I have been using this technique for years with a great deal of success. If you are reloading .223 or smaller diameter cartridges, you probably won't be able to find a small enough piece of wood dowel and may have to purchase a piece of drill rod.

[Thump_rrr]

I would add a Hornady bullet comparator to the list if you don't have one.
This way you are measuring to the ogive of the bullet where the lands would contact and not the tip of the bullet.

[Lefty223]

What different lengths of jump to the lands do you guys test at when developing precisions loads? (e.g. .10, .050, .025?) Do you do test loads in varying lengths before or after dialing in with a powder selection and charge?

In my precision arms, semi-automAR or bolt guns, I run my load through Dan Newberry's "Optimal
Charge Weight" (OCW) method first. Note, this is different than shooting Craig Audet's 'ladder' system and I, along many, believe it to be far superior.

Per Dan's OCW, I run the bullets 0.020" off the lands. Once the optimal load is determined, I'll adjust bullet hump to see what that bullet likes, then the only other possible tweaks would be primer selection or possibly neck tension.

[Lefty223]

I would add a Hornady bullet comparator to the list if you don't have one.
This way you are measuring to the ogive of the bullet where the lands would contact and not the tip of the bullet.

Hear, hear ... this is a much more precise way! I find ogive variation to be 0.0 + 0.001" 0.002 range) on most lots of Sierra SMKs where comparable match bullets from competitor (cheaper) brands will have a much larger variation, like +/- 0.002" (0.005" range).

Checks on VLDs, which I only experimented with, was mixed (due to ultra long ogive over its length?), either having little to no variation or a skewed variation ... with 3-4 measured in a row at X measurement and then the next 1 a good 3-5 thousandths away ... wot the?

That said, I don't that 'overall length to the ogive consistency' by itself is the prime indicator of a bullet's potential performance, but I do believe that the uniformity of the SMK jacket thickness (truly concentric bullet) is what gives it the edge - for me - in my precision reloading.

[T2C]

Thump rrr is on the mark with his comment. Bullets lengths vary a great deal and can cause you to scratch your head when trying to set up the seating die for C.O.L. A bullet comparator to check length to the ogive is a must in my opinion. I use this one sold by MidwayUSA. https://www.midwayusa.com/product/74...28-30-calibers

[gunnerblue]

I've had a lot of success with mine. For certain, get the comparator set to measure ogive/rifling contact. The Berger reloading manual has an excellent article comparing Cartridge Overall Length to Cartridge Base to Ogive length. I would suggest reading it if you haven't already done so.

[Thump_rrr]

The best comparator set in my opinion is the one sold by Sinclair International (Brownells)
The inserts are Stainless Steel instead of aluminum.
It's not cheap but better.
http://www.sinclairintl.com/reloadin...prod34014.aspx

[Lefty223]

sinclair comparator ... inserts are Stainless Steel instead of aluminum. It's not cheap but better.

Better? 2-3X the price better? Sadly ... no.

As a former machinist and now engineer I can attest that the Stoney Point/Hornady comparators are perfectly suited for their intended use. To me, anything else is a waste of money- as these work, are precise to the 0.000", and with good technique and offer a TREMENDOUS value for the money. But then again I like winning PCC matches, whilst using my vintage Oly 9mm setup, against guys spending 2-3X the price, haha!