OAL variance with Hornady tool.

[Axis II]

Its been awhile since ive loaded 223rem and I decided to check chamber with the Hornady OAL tool, modified case and 55gr v max. According to my notes from a year or more ago I had an OAL of 1.843 with the bullet comparator I was in the lands. Today I measure and 1.843 was my first try and then it started going down from there. 1.838, 1.833, 1.834. I ran a brush in the chamber to see if it was dirty and blocking it but kept getting the same low numbers. Before I had this took I ran 2.230 for an OAL from base of case to bullet tip and never had an issue. I even tried being a little forceful and got 1.843 again but the average is 1.833-1.838.

Any idea why this is so low now? I'm trying to tweak a good load by using different primers and adjusting OAL a little bit but this has me stumped!

 

[Blue68f100]

Are you using the same box/lot of bullets? I always check every time I get a new lot of bullets. I’ve seen this may times. Its possible your fist lot had a slightly smaller dia.

 

[KYregular]

Is this the tool you are using? I am assuming this is a bolt gun, I have had the same issue with my 30-06. Have you cleaned the gun before measuring? This can make a difference if theres is even the slightest build up in the chamber.

 

[Axis II]

Is this the tool you are using? I am assuming this is a bolt gun, I have had the same issue with my 30-06. Have you cleaned the gun before measuring? This can make a difference if theres is even the slightest build up in the chamber.

yep, that would be the tool paired with the bullet comparator that goes on the calipers. The rifle was cleaned a few months ago when I put it away for the winter. Bolt gun-savage axis 223rem.

 

[Axis II]

Are you using the same box/lot of bullets? I always check every time I get a new lot of bullets. I’ve seen this may times. Its possible your fist lot had a slightly smaller dia.

I buy them in bulk so I'm not 100% sure if its the same lot. If I remember correctly I had a 250rd pack and a 100rd pack and I may have used the bullets from one or the other the first time.

 

[KYregular]

yep, that would be the tool paired with the bullet comparator that goes on the calipers. The rifle was cleaned a few months ago when I put it away for the winter. Bolt gun-savage axis 223rem.

In that case you have to make sure that you do your best to use even pressure when pushing the bullet into the lands every time. No matter how careful you are it will vary a few thousandths, you just have to average it out. If the the bullet sticks one time and not the next, i guarantee you you will have different measurements. Take your time, you will get it.

 

[Axis II]

In that case you have to make sure that you do your best to use even pressure when pushing the bullet into the lands every time. No matter how careful you are it will vary a few thousandths, you just have to average it out. If the the bullet sticks one time and not the next, i guarantee you you will have different measurements. Take your time, you will get it.

according to my notes from the first time it was very repeatable and it is now I get 1.834 about 7 out of 10 times but I don't get how its shorter than before. I could see 1.840-1.843 but to drop down 10k that's a lot IMO. Just had me a little worried. would a normal 22cal brush and solven clean out the lands or do I need something a little larger to clean it good say a 30 cal brush?

 

[KYregular]

This seems work well for me, you might try it. You could try a 30 cal brush as well, or a combo of both. Good luck

 

[berettaprofessor]

Could the variance be in your caliper that you’re using after you reach the lands? I’ve never had the Hornady tool vary much but an electronic caliper could go bad...

 

[Axis II]

Could the variance be in your caliper that you’re using after you reach the lands? I’ve never had the Hornady tool vary much but an electronic caliper could go bad...

they are harbor freight ones. I am going to pick up a chamber brush, clean the rifle again and then try it and if its off buy a good set of calipers.

 

[Walkalong]

https://www.amazon.com/dp/B01MDU0SBC?psc=1

These have been working well for me. Matches up with my more expensive dial calipers, but being digital it makes it easy to read quickly.

The Harbor Freight ones are not like they used to be.

 

[Axis II]

https://www.amazon.com/dp/B01MDU0SBC?psc=1

These have been working well for me. Matches up with my more expensive dial calipers, but being digital it makes it easy to read quickly.

The Harbor Freight ones are not like they used to be.

Thanks! I will check into those if these turn out to be junk. Several years ago my buddy checked them against his grandfather $500 machinist calipers and they were on my about 1-2k. I would imagine after 2-3yrs they might be losing the touch.

 

[Walkalong]

Try a fresh battery.

 

[Bartojc]

Try a fresh battery.

Whenever I have gotten weird numbers from my calipers this has been my issue. Now I always have a spare on hand.

Same for electric scales.

-Jeff

 

[Axis II]

Try a fresh battery.

I put the new one in back during the summer when the old one went out. I will grab another one and throw it in just incase.

 

[Poper]

ohihunter,
It's very possible that the bullet you are using to get your depth to lands measurement today has a slightly different configuration than the one you used previously. Believe it or not, bullets are not identical even when coming from the same lot! This is because there are probably multiple machines running simultaneously making the same bullet and the variation that comes out of a single machine.

My sorting procedure for competition bullets is thus:
1) I use the comparator to sort the bullets by length from bullet base to ogive. (I want exactly identical bullets here.)
2) I sort the largest group of these by diameter. (I want exactly identical bullets here, too.)
3) I sort the largest group of #2 by weight (+/- 0.1gr.)

With a little luck, I find bulk bullets generally give me a 17% to 20% yeild of "perfect" bullets. With a premium bullet like Sierra, it will vary greatly from lot to lot, but a 25% yield is generally what I anticipate. Berger seems to be the most consistent and it is not unusual to get a yield greater than 75%. Those Bergers that do not make the "perfect" category are generally not far from the mark. All bullets mfrs will have culls when sorted like this.

One of the reasons I do my sorting in this manner is that for competition shooting, I must rule out every variable possible.

BTW, I use the RCBS Precision Mic tool to measure my distance to the lands. The included "dummy" bullet is hard steel and tends to give more closely repeatable measurements. Then I know the precise distance from the base of the case to the engagement of the lands.

I hope this helps.

 

[berettaprofessor]

You guys are making me feel good about my decision to buy a dial caliper when I started reloading rather than an electronic.

 

[Poper]

You guys are making me feel good about my decision to buy a dial caliper when I started reloading rather than an electronic.

Yup.
I have both and use the dial almost exclusively. Actually, it's been so long since I used the electronic one the battery has probably gone dead.

 

[quest4perfection]

yep, that would be the tool paired with the bullet comparator that goes on the calipers. The rifle was cleaned a few months ago when I put it away for the winter. Bolt gun-savage axis 223rem.

I kept getting varying readings so I made sure to clean well first, then rotate an empty sized case into the chamber and twist it to make sure it was touching bare metal, then run LNL/comparator. Shooting overbores like 22br results in stubborn carbon deposits that need addressed frequently both there and a few inches into the bore.

 

[Axis II]

I kept getting varying readings so I made sure to clean well first, then rotate an empty sized case into the chamber and twist it to make sure it was touching bare metal, then run LNL/comparator. Shooting overbores like 22br results in stubborn carbon deposits that need addressed frequently both there and a few inches into the bore.

How do you clean the carbon out? I am thinking about getting an AR15 chamber brush and giving it a good scrubbing and then run the bronze brush through there a little.

 

[quest4perfection]

How do you clean the carbon out? I am thinking about getting an AR15 chamber brush and giving it a good scrubbing and then run the bronze brush through there a little.

An AR brush seems a necessary tool in the box-getting into nooks is an issue.
I started using Kroil and Boretech Carbon Remover (suggested/used by my smith and fellow shooter). Clean well using a brush, then soak overnight with one or the other, clean again. http://handloads.com/articles/default.asp?id=9 is a recipe I will try soon. "Ed's Red: kerosene, acetone, Dexron II, etc...caustic but supposedly effective.

I have been thinking about this carbon thing a lot because I shoot some overbores that are very prone to carbon, from the throat forward about 5 inches. Seems like if a person put some carbon remover in there immediately after firing last round the heat may help remove carbon upon arriving home. Dunno. Experience with gas grills has taught me to wire brush immediately before it sets hard on the metal-same principal I suppose.

BTW-Kroil has a reputation for "creeping." It seems to get under the carbon to some degree. On a stubbornly rusted bolt/nut I sprayed it liberally, let set overnight and turned the nut off. Many at my range use it. The Bore-Tech Carbon Remover is relatively odorless.