How close to lands ?

[Lonnie]

Just picked up a new Remington 700 in 7mm Remington Magnum. Getting ready to do some loading for it. Will be loading 140gr and 150gr. Ballistic Tips for load developement.
What I would like to know is, from your experience, what powdes gave best accuracy? How close to the lands do you load the 7mm when useing Ballistic Tips?

Thanks

 

[nvbroncrider]

Generally you want to seat .003 to .015" of the lands. This is the rule of thumb. Some rifles you can't do this with as you would no longer be able to use your magazine. The #6 Nosler book has a perfect explination on how to do this.

 

[Elkman]

It is impracticle to seat the bullets against the lands in many rifles because of the magazine length. Start with the longest length that will function in the rifle then work shorter from there. If magazine length does touch the lands back off 10 and start from there.

Easy way to measure OAL to lands with a specifice bullet, take a fired case, crimp it ever so slightly as to be able to start a bullet with your fingers, gently chamber the round, gently remove and measure the AOL. Might take a couple of trys but it works.

 

[remingtonman_25_06]

140g NBT, 68.5g RL22, Rem case, Fed 215, OAL of 3.350" in my 700 custom deluxe 7 RM. Averaged 3200fps and 1/4-1/2 MOA.

Typically start .005" off the lands if possible, and work down to about .030-.040" in .005" increments, once you have the powder charge where you want it.

 

[Scott Spencer]

Typically start .005" off the lands if possible, and work down to about .030-.040" in .005" increments, once you have the powder charge where you want it.

I'm a crappy reloader suppose. :grin: I'm lucky if I can get my OAL to stay within .010 - .030 of each round. For example, if I want a 3.320 OAL my loaded rounds are usually wind up like 3.320, next will be 3.317, next will be 3.323, etc. No matter what I do I can never get every bullet to be 3.320 like I want it to be. I use standard Redding dies.

 

[ElmerThud]

Consistency of OAL is a combination of factors down to brass preparation. How you set the seating die in your press and the press itself.

e.g. All brass should be trimmed to identical OAL, the press ram should reach the full extent of it's 'cam over' (If possible) & you should always measure your OAL on the made up cartridge, using a comparator guage fitted to the micrometer.

If you can't get to the full cam over position with the ram, it's important to use the same seating pressure each time you operate the ram lever.
It's usually quite possible following the above to get accurate consistency, certainly to within +/- .001".
Cheers, ET

 

[NoelW]

I'm a crappy reloader suppose. :grin: I'm lucky if I can get my OAL to stay within .010 - .030 of each round. For example, if I want a 3.320 OAL my loaded rounds are usually wind up like 3.320, next will be 3.317, next will be 3.323, etc. No matter what I do I can never get every bullet to be 3.320 like I want it to be. I use standard Redding dies.

Scott, what I do is seat the bullet with the 1st stroke, lift the handle slightly rotate the case 1/4 turn or so and reseat. I do this 4 or 5 times and end up with a much more consistent seating depth and less bullet run out.

 

[NoelW]

Lonnie, the magazine box on my 700 Remington in 7mm Mag. with factory barrel is long enough to seat to the lands & that is where my rifle likes the 140's. I just posted my target from this weekend on another thread this morning. This target was with the CT's which is the BT's enhanced with Lubalox coating on them.

viewtopic.php?f=4&t=16859

 

[Scott Spencer]

Thanks, Noel. I'll give that a try.

ET, I check each piece of brass for consistency in length. I use an RCBS Rock Chucker press and I can get full cam over. I'll double check everything else but I suspect a part of my problem is the various lengths in bullets...especially in the lead tipped bullets like the Partition. I try to measure the actual bullets before seating them but they are like gold. I reload them and don't dispose of them... even if they wind up varying my cartridge in overall length

 

[NoelW]

Your bullet seater does not touch the tips of the bullets, it comes down on the rounded part of the bullet more like the area that touches the lands first. I find it hard to measure all the way to the tips of those pointy bullets accurately, almost impossible. A lot of the tips whether hollow points, soft points or even round nose soft bullets are deformed in some way. I use a Hornady Bullet Comparator for that. With it you you won't get the true overall length but your measurements from the case head to the area that hits the lands first will be much more accurate and consistent.

Maybe someone else has a different and better way but that's the way I do it.

 

[Scott Spencer]

Got it now, Noel!! It all just hit me and I've been doing the measuring wrong.
Thank you for making the light come on.