Reloading with OAL Guage

[WyldeShot]

First time doing this.

I am using an OAL gauge with a comparator, measuring the ogive on an AR .223 Wylde 1:8 18" barrel using Sierra Match King 69 gr bullets. OAL kist measured 1.952". I will be using Varget powder and Hodgdon website says COL of 2.235. I understand that difference is because I am measuring the ogive not the tip.

Question I have, do you typically seat the bullet to the actual length, in this case 1.952" or do you take off a certain length? I have heard that you are suppose to subtract anywhere from a could of thousandths to a couple of hundredths to allow for a jump. Are there any risks to seating to 1.952"?

Thanks from a new reloader!

 

[ChristianPatriot]

I've read that you're supposed to start load development jammed and work towards jump. If you find the max load with the bullet jammed into or touching the lands than theoretically going to jump will decrease pressure. There's some debate but that seems to be the general consensus.

 

[WyldeShot]

Min is 24 gr and max is 26 gr. I figure I will start at 25 gr unless someone says that's not safe.

 

[ChristianPatriot]

26 is probably book max. 45 grains of Varget was book max for my 175gr .308. I got to 46 grains with zero pressure signs. Now of course I would never ever advocate going over book max without being very very careful. 25 will be plenty safe.

 

[ChristianPatriot]

As always: trust but verify.

 

[WyldeShot]

26 is probably book max. 45 grains of Varget was book max for my 175gr .308. I got to 46 grains with zero pressure signs. Now of course I would never ever advocate going over book max without being very very careful. 25 will be plenty safe.

Thanks! I'm fairly new to reloading and very new to load development so I error on the side of caution.

 

[ChristianPatriot]

Thanks! I'm fairly new to reloading and very new to load development so I error on the side of caution.

Always a good idea. You're "supposed" to start with book max and go back 10% and then work up in 1% increments. Once you get close to book max, inspect every case for pressure signs.

 

[WyldeShot]

Always a good idea. You're "supposed" to start with book max and go back 10% and then work up in 1% increments. Once you get close to book max, inspect every case for pressure signs.

Interesting. Unless my math is terrible 10% off max would be under the min. Anyways, I always look for pressure signs in new loads.
Thanks!!

 

[ChristianPatriot]

Interesting. Unless my math is terrible 10% off max would be under the min. Anyways, I always look for pressure signs in new loads.
Thanks!!

I don't have much experience hand loading for the AR platform. Maybe it has something to do with getting the bolt to cycle.

 

[Leo]

First time doing this.

I am using an OAL gauge with a comparator, measuring the ogive on an AR .223 Wylde 1:8 18" barrel using Sierra Match King 69 gr bullets. OAL kist measured 1.952". I will be using Varget powder and Hodgdon website says COL of 2.235. I understand that difference is because I am measuring the ogive not the tip.

Question I have, do you typically seat the bullet to the actual length, in this case 1.952" or do you take off a certain length? I have heard that you are suppose to subtract anywhere from a could of thousandths to a couple of hundredths to allow for a jump. Are there any risks to seating to 1.952"?

Thanks from a new reloader!

1) you do realize that anything loaded longer than 2.260" (base to tip) will not feed through the action.

2) generally when loading single shot ammo and chasing the lands, you do not load with the ogive on the lands when chambered. .010" to .015" free bore off the lands would be minimal. Starting on the lands will change the way the pressure curve builds. I would strongly recommend that you do not start with bullet interference. Don't do it. Successful precision bench resters competitors who use the "soft seat" method have already experimented and adjusted the powder charge.

3) I believe that the base to tip measurement is quite a but longer than 2.260" when the 69 grain bullet is 1.952 (base to ogive) Match bullets such as MatchKings, Hornady, or Nozler bullets are really pretty tolerant of jump. If you load 20 for an ogive to land jump of at least .015" and load 20 that have a lot more jump when loaded to 2.260" (base to tip) and do a serious accuracy comparison on a target, you will likely see almost no difference, if you can see any difference at all.

 

[WyldeShot]

1) you do realize that anything loaded longer than 2.260" (base to tip) will not feed through the action.

2) generally when loading single shot ammo and chasing the lands, you do not load with the ogive on the lands when chambered. .010" to .015" free bore off the lands would be minimal. Starting on the lands will change the way the pressure curve builds. I would strongly recommend that you do not start with bullet interference. Don't do it. Successful precision bench resters competitors who use the "soft seat" method have already experimented and adjusted the powder charge.

3) I believe that the base to tip measurement is quite a but longer than 2.260" when the 69 grain bullet is 1.952 (base to ogive) Match bullets such as MatchKings, Hornady, or Nozler bullets are really pretty tolerant of jump. If you load 20 for an ogive to land jump of at least .015" and load 20 that have a lot more jump when loaded to 2.260" (base to tip) and do a serious accuracy comparison on a target, you will likely see almost no difference, if you can see any difference at all.

Thank you so much for the info. I was not aware of this. So if I understand you correctly I should start at a min 1.952-.010=1.942 ogive. If it's longer than 2.260 then I should start at 2.260?

 

[Leo]

Thank you so much for the info. I was not aware of this. So if I understand you correctly I should start at a min 1.952-.010=1.942 ogive. If it's longer than 2.260 then I should start at 2.260?

Correct, If you want it to feed through the action. 2.260" is the longest you OAL (base to tip) that you should use. Ocassionally a slight variance in manufacturing may leave a bullet tip slightly irregular and the OAL out of you seater die may vary and the bullet tip scrape the inside of the magazine. I load about 2.252, and have no trouble.

If you are loading extra long ammo that can only be used as a single loaded round, your ogive measurement (1.952") minus .010" would be MAX.

I have been an experimenter with anything I have been involved with for as long as anyone can remember. I will not tell you that you should not try chasing the barrel throat around to see if you can gain any accuracy. Plus you also realize the throat erodes as you shoot your rifle, so that measurement will always be moving.
I spent an entire season remeasuring the freebore and adjusting my loads.

My personal experiment was to design my own chamber and have both a reamer and finish reamer custom made that was way shorter than SAAMI spec. . In my chamber, a 77 grain MatchKing could touch the lands while loaded to 2.235" oal, easily feeding through a normal AR magazine. I developed my own load data for that measurement. As the throat wore, I adjusted the loading OAL to keep my freebore jump consistant. Even as it changed, the rounds would still feed through the rifle. The down side was that normal ammo loaded in the rifle could be hazardous. After all the work and expense, I came to the conclusion that it really did not gain me much, if anything, while greatly complicating my life. When that barrel was shot out that fall, I went back to a more conventional chambering.