Discussion in 'Handloading and Reloading' started by JackSprat, Jan 9, 2016.
Well, if they ARE 139 gr flat base Interlocks, the COL listed in the Hornady manual is 2.775".
If you are working up this load from below the max charge for the powder you have chosen, you don't need to worry about pressure increases from seating a few thousandths deeper if you really want the top of the case to line up with the cannelure.
You didn't say if you are planning on crimping, but that isn't necessary as proper neck tension is all that is needed. So if you are not crimping, there is nothing wrong with leaving the cannelure above the top of the brass if you'd rather not seat the bullets deeper.
IOW, ignore the cannelure.
I bought a quantity of the 139gr .284" Boat tail blems several years ago. Love them!
I seat to 2.825" as this puts them touching the grooves on my Rem. Mod-7. This is where I see best accuracy. Fits magazine as well.
Favorite powder is Reloader17. I see 3,000 fps from 20" barrel. Published max load.
Rifle isn't a tack driver, but punches far above its weight.
Best accuracy has been with IMR4350; however H4350 and RL17 aren't far behind.
IMR4064 nor H380 gave nearly the speed nor accuracy for me.
Just seat them where they shoot most accurately, and will fit the magazine. This is one of the perks of reloading, that being, we have the ability to tailor our loads to what shoots best from that firearm.
The factory loaded stuff has to be built so they will fit and function in any firearm, we don't.
I wouldn't worry about the cannelures esp. on blem bullets... I would however suggest measuring and sorting your bullets by size...MEASURE OFF THE BULLET OGIVE, NOT the tip. Hornady makes a tool that clips onto your Caliper for this purpose. When you adjust your bullet seater, do it for each lot of bullets that are the same size. Size will vary.
Find out where your bullets hit the lands in your barrel (there are many ways to do this), then back off .020 to .030 off the lands and test your loads. You don't want your bullets touching the lands, you want to find the position off the lands that gives you the best accuracy.
Also, I would highly recommend you buy the current Sierra and Hornady Manuals and rely on them vs the Lee Manual you already have. The Sierra Manual is the KING in terms of data, and the Hornady Manual is a good one esp when you are loading their bullets.
Hope this helps...and stay safe...
in my accuracy testing flatbase bullets were more accurate than boattails in my rifle at 100yds. depending on how far you are shooting you may want to try some boattails also. i did not load a max load with the 4064. i seat to the length of my magazine.
like Goose said they are a hard hitting light recoiling accurate round!!
Just know that as you approach close proximity to the lands, pressures can increase. That said, since pressures can increase when close too or jammed into the lands, I always start my load development with the bullets jammed .010" into the lands. By doing it this way, I don't have to adjust / decrease the powder charge at all while decreasing oal away from the lands. This also helps reduce the amount of components needed / used during the development process, and the development process goes a bit quicker too.
BTW, I've found that almost every rifle I've ever loaded for, has an accuracy node with the bullet jammed or touching the lands. You do lose a little bit of velocity though, but I'll trade a little velocity, for superior accuracy any day of the week.
This is the same method I use for the same reasons, with one exception. I start at 0.010" off the lands rather than into them. Since my primary purpose is creating the most accurate hunting loads I don't want to deal with the chance of the bullet staying stuck in the rifling when being un-chambered and spilling powder in the action. It simplifies things if you only have one direction to move the bullet when testing for optimal OAL.
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