OAL question!

Deederswy

Well-Known Member
Joined
Oct 16, 2012
Messages
60
Location
Cheyenne, Wy
Hello all,
I have a quick question about COAL...Im shooting a 7mm mag(Remington 700) and im loading the 168 berger. I know that bullet seat depth plays a big part in accuracy with these bullets. According to SAAMI the COAL im supposed to have is 3.290...Ive been loading these rounds at 3.300 with no issues but I never knew how far out I could seat them. I just bought a hornady lock and load OAL gauge and I tested it 5 times, each time coming up with 3.450 for my OAL! That seems a bit long but its what I got. My question is, I know each chamber is different but is that a safe OAL? Also, ive only been pushing those bullets on average of 2850 fps(which I believe is slow) with 64gr of IMR7828 and federal 215 primers. By seating them out further, say .020 off, will I run into pressure issues and/or will I gain velocity? IMR7828 was my accurate load. I tried H1000 and couldn't get decent groups, could that be due to being seated too deep? I also have some Retumbo I was going to try. I feel like im starting back from square 1 with this!
 

brentc

Well-Known Member
Joined
Apr 3, 2009
Messages
2,525
Hello all,
I have a quick question about COAL...Im shooting a 7mm mag(Remington 700) and im loading the 168 berger. I know that bullet seat depth plays a big part in accuracy with these bullets. According to SAAMI the COAL im supposed to have is 3.290...Ive been loading these rounds at 3.300 with no issues but I never knew how far out I could seat them. I just bought a hornady lock and load OAL gauge and I tested it 5 times, each time coming up with 3.450 for my OAL! That seems a bit long but its what I got. My question is, I know each chamber is different but is that a safe OAL? Also, ive only been pushing those bullets on average of 2850 fps(which I believe is slow) with 64gr of IMR7828 and federal 215 primers. By seating them out further, say .020 off, will I run into pressure issues and/or will I gain velocity? IMR7828 was my accurate load. I tried H1000 and couldn't get decent groups, could that be due to being seated too deep? I also have some Retumbo I was going to try. I feel like im starting back from square 1 with this!

I'd load them up with your current powder charge using Berger's seating depth test, then work your powder charge up to the safe max for your rifle looking for the next higher accuracy node.
 

Corey Schwanz

Well-Known Member
Joined
Nov 10, 2014
Messages
191
Location
Indiana
Here is a link for the seating depth test mentioned: VLD: Making it Shoot | Berger Bullets. That will help you find where your rifle likes the bullets, then you can adjust your powders until you get the groups you are happy with.

There is nothing wrong with having the bullet seated out longer than SAAMI spec, other than it may not fit into the magazine area if you want to have multiple rounds in the gun for a hunt. All things even, a bullet seated out longer (but not touching the rifling) will have less pressure than one seated to SAAMI spec. The longer the bullet is seated out, the more space is available inside the case and with the same powders loads, there will be less pressure. This all changes when the bullet touches the rifling but that's a different story (and something I personally don't like to do for various reasons).
 

BIGJOHNT

Member
Joined
Sep 27, 2012
Messages
15
If you don't have a custom mag box on the gun? You may not be able to load .020 off . I went threw this and I just load a few thousandths off my mag well. If I have a problem down the road. I may add a extended mag.
 

pods8

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Joined
Aug 25, 2014
Messages
326
Location
Colorado
If you don't have a custom mag box on the gun? You may not be able to load .020 off . I went threw this and I just load a few thousandths off my mag well. If I have a problem down the road. I may add a extended mag.

In my 30-06 rem 700 I have no issues running a load that is 3.462COAL with a bit of room to spare. Mine is a 70s model, not sure if the newer ones have gotten shorter?
 

MudRunner2005

Well-Known Member
Joined
Oct 13, 2008
Messages
14,708
Location
Alabama
I run the same exact load as you do (I use Nosler brass, and my powder charge is different), but same components. I seat mine to 2.673" from base to ogive with a Hornady comparator.

Measuring OAL on cup & core lead bullets is not an easy task since the tips will almost always be slightly different in length. It's more precise to measure off the bullet's ogive, which is where the Hornady Comparator comes in handy.

Hornady Lock-N-Load Bullet Comparator Complete Set 14 Inserts
 

16Bore

Well-Known Member
Joined
Feb 14, 2010
Messages
146
Kiss the lands, work up pressure, shorten if needed. Better to work in 2 directions than starting in the middle and working sideways. You won't be going longer or adding more powder. Remmie LA mag boxes are nice and roomy and the 7MM is throated right. I'm kissing 162 Amax at 3.450 with plenty of room to spare.
 

davkrat

Well-Known Member
Joined
Sep 18, 2006
Messages
656
Location
The Motherlode
In my rem 700 7mm Rem Mag I can seat bullets way out there and still function from the magazine.

I used to seat my bullets .005" off until one day hunting in the snow I went to pull a round from the chamber and an empty case came. Bullet stuck in the throat and an action full of powder. Luckily the ETips I use now like .100" jump to the lands.
 

FEENIX

Well-Known Member
LRH Team Member
Joined
Dec 20, 2008
Messages
16,392
Location
Great Falls, MT
Hello all,
I have a quick question about COAL...Im shooting a 7mm mag(Remington 700) and im loading the 168 berger. I know that bullet seat depth plays a big part in accuracy with these bullets. According to SAAMI the COAL im supposed to have is 3.290...Ive been loading these rounds at 3.300 with no issues but I never knew how far out I could seat them. I just bought a hornady lock and load OAL gauge and I tested it 5 times, each time coming up with 3.450 for my OAL! That seems a bit long but its what I got. My question is, I know each chamber is different but is that a safe OAL? Also, ive only been pushing those bullets on average of 2850 fps(which I believe is slow) with 64gr of IMR7828 and federal 215 primers. By seating them out further, say .020 off, will I run into pressure issues and/or will I gain velocity? IMR7828 was my accurate load. I tried H1000 and couldn't get decent groups, could that be due to being seated too deep? I also have some Retumbo I was going to try. I feel like im starting back from square 1 with this!

Check out ...

Effects of COAL and CBTO | Part 1 | Berger Bullets Blog

Effects of COAL and CBTO | Part 2 | Berger Bullets Blog

Good luck!
 

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