Quick help! Min OAL

[JonProphet]

So, my handy dandy Lee book says that a 168 grain projectile's minimum OAL for IMR4064 is 2.800. I have several rounds that measure in at 2.760 to 2.790. Do I have to remove the round and reseat the bullet?

-JD-

 

[sloughfoot]

No. Especially with the reduced charge you are starting out with. It will be fine. 41.5 of 4064 is nowhere neaar maximum.

 

[ckcollins2003]

The 2.790 would probably be alright, but the 2.760 is extremely short and may cause pressure issues. The deeper you seat the bullet, the more pressure is pushed into the chamber.

When loading for my uncle I used an OAL of 2.797 and a light powder charge just so I knew they would work fine in his rifle without pressure issues.

Your seating shouldn't be that far off from round to round either. You should check to make sure your seating die is locked down tight and not moving. I usually double check my OAL after every 10 rounds or so just to make sure they are all the same. Start long and work your way down to whatever length is for your rifle, or 2.800 if you want factory standard length. 2.800 is mostly used in magazine fed rifles.

ETA: I assume your talking about the .308 cartridge as well. It wasn't exactly specified in your post. And if you're loading for accuracy out of a bolt action rifle or just a plinking AR-10 round would be a bit different.

 

[JonProphet]

I'm measuring just at 41.5 grains. I put everything aside that measured under 2.770 or less.

Thanks guys.

-JD-

*Edit* My OAL is now 2.820.

 

[U.S. Patriot]

My question is, how are you having so much variance in OAL?

 

[42769vette]

fire away

 

[jackadew]

What cartridge are you loading? The three reloading manuals i just looked at all give MAXIMUM OAL not mininum OAL. I'm guessing you are loading 7mm-08, 284 Winchester or .308. My manuals give MAXIMUM OAL of 2.800 for both the 7mm-08 and 284 Winchester...and a MAXIMUM OAL for the .308 of 2.810

 

[JonProphet]

Lee's manual only gives minimum.

I'm loading .308. 168 Grain.

Reason why I'm getting so much variance is because this is a new setup and I'm still fine tuning it. I'm now getting 2.805 and that is every cartridge out now.

I was having issues with the dies... stupid mistakes.... and again, just fine tuning this turret.

-JD-

 

[42769vette]

Lee's manual only gives minimum.

I'm loading .308. 168 Grain.

Reason why I'm getting so much variance is because this is a new setup and I'm still fine tuning it. I'm now getting 2.805 and that is every cartridge out now.

I was having issues with the dies... stupid mistakes.... and again, just fine tuning this turret.

-JD-

this is not really what your talking about, but it sounds like your fairly new so here is a tip.

when measuring for variance make sure to measure from the ogive. your seating die seats a bullet from the ogive, you can have some oal variance but your measurement from the ogive be spot consistant

 

[JonProphet]

Vette I have no idea what you are talking about. But the book I'm using...says MINIMUM OAL. I'm keeping it at 2.810 and I checked at this point, the rounds load without anything different in the bolt.

*Edit* Taken directly from Lee's Modern Reloading, 2nd Edition: "The Over All Length (OAL) must e at least as long as indicated in the load data for all maximum pressures loads. Bullets may be seated deeper for reduced loads".

-JD-

 

[ckcollins2003]

Vette I have no idea what you are talking about. But the book I'm using...says MINIMUM OAL. I'm keeping it at 2.810 and I checked at this point, the rounds load without anything different in the bolt.

*Edit* Taken directly from Lee's Modern Reloading, 2nd Edition: "The Over All Length (OAL) must e at least as long as indicated in the load data for all maximum pressures loads. Bullets may be seated deeper for reduced loads".

-JD-

The ogive is where the bullet rounds out to a point. Basically it's what does not touch the rifling.

Be safe, it sounds like you're doing alright. At least you're starting with the minimum charge and working your way up. My tip would be to back your seating die out and turn the top all the way out. Seat your first bullet, and turn the top of it down until you reach the point that you want your bullets seated at (2.800 for example). From there on out all of your bullets will be roughly the same length as long as you don't move the die.

Remember to start long, as you can always seat the bullet deeper. If you go too short, you gotta pull it and seat it again. Just go slow at first, it'll work itself together and you'll be all kinds of relieved and happy.

 

[JonProphet]

Yeah, that's what I did CK. I'm pretty set on the bullet depth. We'll see tomorrow.

-JD-

 

[42769vette]

my comment was not a safty concern at all more of a precision concern. basically when you are loading for precision the oal is less important than the lenght to the ogive. that is how you determine the bullets jump to the lands

 

[JonProphet]

ya, I know what you are talking about. It is mentioned int he book. At this point, I'm not ready to do that. We'll see how these rounds perform before i start doing "custom" loads.

Thanks.

 

[Broom_jm]

JD,

When it comes to rifle loads, each manual will give you a recommended seating depth for a specific bullet. It has little or nothing to do with the powder. The recommended depth is usually a product of magazine length and most guns have a long enough throat to seat further out than this.

I would get the data from the bullet manufacturer's manual or website. For example, if you're shooting a 168gr A-Max, get Hornady's data, but if it's a 168gr SMK, use Sierra's data. It is sorta weird that the Lee manual is showing a MINIMUM OAL...most every manual I have shows maximum, but even that is just a guideline for rifle cartridges.

Sounds like you're still working your way up on the learning curve. Hang in there, follow recipes EXACTLY, and read up a bit on how to determine the best seating depth for YOUR rifle. If you'd like some tips on this, send me a PM and I'll get you started on the right track.

Jason

 

[JonProphet]

So, where is the data for a 168 Grain A-max from hornaday? I looked, not finding it.

 

[walker]

Hornady 7th edition, 168gr A-Max #30502 B.C.:0.475 C.O.L. is 2.800 for both the 308 Winchester and the 308 Winchester Service Rifle. There was no data for IMR4064 in the 308 Winchester, but there was for the 308 Winchester Service Rifle.... 36.1gr-2100fps.... 37.4gr-2200fps.... 38.8gr-2300fps... 40.2gr-2400fps... 41.6gr-2500fps. Rifle:M1A, Barrel:22" 1 in 10 twist, Case:Hornady/Frontier, Primer:Winchester WLR. I hope this can help you.

 

[Broom_jm]

Hornady 7th edition, 168gr A-Max #30502 B.C.:0.475 C.O.L. is 2.800 for both the 308 Winchester and the 308 Winchester Service Rifle. There was no data for IMR4064 in the 308 Winchester, but there was for the 308 Winchester Service Rifle.... 36.1gr-2100fps.... 37.4gr-2200fps.... 38.8gr-2300fps... 40.2gr-2400fps... 41.6gr-2500fps. Rifle:M1A, Barrel:22" 1 in 10 twist, Case:Hornady/Frontier, Primer:Winchester WLR. I hope this can help you.

Thanks for the specific info, Walker! Rep'd!

JD,

Note that this length (2.800") is their recommendation for this bullet. That may be the longest possible length your gun's magazine can hold, and if you plan to load/fire from the magazine, this is crucial. Best accuracy is usually obtained by seating slightly longer, based on the chamber of your gun and what it likes. This is not "custom" reloading, per se, but a little more advanced than following the load recipe, verbatim.

I have 8 different guns/barrels that are single shot, break-open types. There is no magazine length to be concerned with, as they have none. For these guns, cartridge OAL is determined entirely by the chamber of the gun and what shoots most accurately. If you look at a bolt-action rifle in this light (for example, if you were going to hand-feed each round into the chamber) then OAL is sometimes quite a bit longer than the SAAMI specification most reloading manuals publish. Make sense?

 

[JonProphet]

Of course, thanks!