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View Full Version : Bullet Seating Depth? (new reloader)



Chrazy-Chris
04-09-2014, 11:49 PM
I have a savage 11vt in 308 and sierra matchking 175gr bullets. I'm still trying to find powder but will hopefully get IMR 1460 or varget. I bought a modified casing to measure how far forward the bullet would be seated to be against the lands and grooves in my chamber/barrel. My question is: should I seat it to the Max length or slightly deeper? How much deeper?

Also, should I crimp at all?

Thanks!

Vince
04-10-2014, 01:58 AM
I would start at the reloading manual book COAL and find my most accurate powder and charge weight first.
Then, after finding my most accurate load, I's start playing with the seating depth to improve on that accuracy.

Texas Solo
04-10-2014, 02:19 PM
I pay no attention to the book COAL as it measures at the bullet tip, not the ogive.
Measure your chamber as you described, then minus .005". That .005" jump is a popular starting point and will keep you from approaching high pressure from jamming the bullet.
You will need new measurements for each different bullet you try as each different bullet has a different profile. I get a .020" difference between my 155's and my 168's.
I never crimp my rifle ammo. .002" neck tension is sufficient.
Stay with the same seating depth, whatever that is, during your load development for powder charge. You can play with different depths after finding your optimal powder charge.

wbm
04-10-2014, 02:29 PM
Personally I would forget the crimp.

I would start at 2.80" with the 175 Sierras or 178 Amax in the 308 and go from there. You might find that 2.80" is best for both....or not. 41.7gr of 4064 with the 175 Sierra Match King is the load used in the M118LR long range load and it is set at 2.80".....Very good load in every 308 I have used it in.

Another Great Load

Savage 10FLP.
Bullet: Sierra 175 gr. HPBT
Powder: Hodgdon Varget 43.0 grs.
Primer: Federal 210M
Case: Lapua
Velocity: 2582
LOAL: 2.805 (2.230 Base to Ogive with Stoney Point)
Comments: Ten shot group measured 0.815.

n4ue
04-10-2014, 05:55 PM
+1 on the great answers. I have a lot of Savages, Axis mostly, but also 4 M12s. I have found that seating each bullet as described above, will produce fantastic accuracy.
However, one last piece of the puzzle......
Will the length that provides optimum accuracy still fit in your magazine?? Most of my handloads don't. However, I just load one at a time and use the 'poly sled'. I don't hunt, so no biggie (for me)....

ron

Texas Solo
04-11-2014, 05:04 AM
Will the length that provides optimum accuracy still fit in your magazine??

ron

Maybe, maybe not. Some guys have found optimal accuracy with a .040" jump, so that probably would fit the mag. If it turns out to be longer than 2.800", it probably won't fit.

Chrazy-Chris
04-11-2014, 10:06 PM
I pay no attention to the book COAL as it measures at the bullet tip, not the ogive.
Measure your chamber as you described, then minus .005". That .005" jump is a popular starting point and will keep you from approaching high pressure from jamming the bullet.
You will need new measurements for each different bullet you try as each different bullet has a different profile. I get a .020" difference between my 155's and my 168's.
I never crimp my rifle ammo. .002" neck tension is sufficient.
Stay with the same seating depth, whatever that is, during your load development for powder charge. You can play with different depths after finding your optimal powder charge.

Thanks everyone for the great responses! I'm just getting started on my first reloading batch ever and I'm going to go with the .005" jump. I ended up getting IMR4320 and IMR4064 so I think I'm going to start out with the IMR4320 for the first batch. Thanks again!

limige
04-11-2014, 11:34 PM
Ok first of all crimps are for autos and large calibers.
second ideally you should start loading as long as you dare to shoot. Preferably jammed into the rifling.
Reason being this will show you max possible pressure for charge weight. As you work away from the rifling pressure will decrease.
if you are not a target shooter then chances are you will never run a bullet jammed. In this case I would start .005 off the rifling. Any closer things get erratic.
Work back from there...

If your space is limited in your magazine then load to the longest you can fit if your intent on using it.

Doing it this way you wont have issues with pressure spikes and most of the time these guns shoot best close to the rifling anyhow.

Of course some chambers just wont allow for this.