Start load development at SAAMI OAL? (308, 168, 4064)

[blockfort]

I have new projectiles (168 SMK) for my 308 WIN loads. I'll be using IMR 4064 and will work my way up from Hodgdon's minimum.

But what length should I seat to? If I make them 2.8" OAL, there's about 0.1" jump to the lands. Is that normal and ok?

[kcstott]

It is normal if you plan to feed your rounds from a mag. be it box or detachable.

Military went to the M24 rifle system which is a long action 700. they did this for two reason, one you can build a rifle in two caliber on one action, two you can now seat your bullets out where the need to be and still feed them from the mag.

Now all that said, I shoot 175 SMK's or Bergers and seat then to saami spec 2.8" and i can punch nice one maybe two hole five shot groups. The vlds like a little jump

[blockfort]

I plan to single load into my Browning A-Bolt Target, but charge weight and seating depth makes a 2-dimensional matrix (more if you experiment with other variables), and so there's just so many possibilities.

Will the best charge weight still be the best regardless of seating depth, and just get better when the depth is tuned?

[OpenSightsOnly]

I plan to single load into my Browning A-Bolt Target, but charge weight and seating depth makes a 2-dimensional matrix (more if you experiment with other variables), and so there's just so many possibilities.

Will the best charge weight still be the best regardless of seating depth, and just get better when the depth is tuned?

Buy this or make/fabricate a similar one - http://www.hornady.com/store/OAL-Gauges/

Buy a reloading manual like Sierra, try out their load then play with the seating depth with the Hornady gauge.

[Bill Steele]

I plan to single load into my Browning A-Bolt Target, but charge weight and seating depth makes a 2-dimensional matrix (more if you experiment with other variables), and so there's just so many possibilities.

Will the best charge weight still be the best regardless of seating depth, and just get better when the depth is tuned?

There was a similar thread on this very subject recently here. Some of the heavy weights (and not so heavy weights) opined and a lot of good data was exchanged. If I were better with the search function, I would just post the link.

Found it (on the front page, pretty easy): http://www.calguns.net/calgunforum/s....php?t=1213465

To answer your basic question, I have always found locating a wide node (charge weight) to be the first step, jump is usually one of the latter steps.

[blockfort]

Buy this or make/fabricate a similar one - http://www.hornady.com/store/OAL-Gauges/

Buy a reloading manual like Sierra, try out their load then play with the seating depth with the Hornady gauge.

I have a similar tool, but usually rely on a loose neck case and the actual bullet I'm loading. Regardless, I know my chamber dimensions now, but am trying to figure out what the best process is to find both charge weight and seating depth.

[blockfort]

There was a similar thread on this very subject recently here. Some of the heavy weights (and not so heavy weights) opined and a lot of good data was exchanged. If I were better with the search function, I would just post the link.

Found it (on the front page, pretty easy): http://www.calguns.net/calgunforum/s....php?t=1213465

To answer your basic question, I have always found locating a wide node (charge weight) to be the first step, jump is usually one of the latter steps.

Reading this now, thanks.

[OpenSightsOnly]

41.5 or 42 grains of IMR 4064 with a 168 SMK bullet. That is the accuracy load based on M852 match ammo. FGMM is similar to M852.

42 grains of IMR 4064 with 175 SMK is Mk.316 ammo.

If you have a chrono and a reloading manual, even better. This is 308 Win, don't sweat it.

[1badlvn]

41.5 or 42 grains of IMR 4064 with a 168 SMK bullet. That is the accuracy load based on M852 match ammo. FGMM is similar to M852.

42 grains of IMR 4064 with 175 SMK is Mk.316 ammo.

If you have a chrono and a reloading manual, even better. This is 308 Win, don't sweat it.

I agree with this 42gr of 4046 and 175gr smk loaded to 2.800 in FC brass gets me 2650fps out of my 24inch 5r and makes me jizz my pants up to 400 yards with the groupings. Gotta keep a spare pair just in case. I experimented loading to the lands at 1.915 and found no gain in accuracy, Just a funky looking round.

Sent from my SM-N910V using Tapatalk

[blockfort]

41.5 or 42 grains of IMR 4064 with a 168 SMK bullet. That is the accuracy load based on M852 match ammo. FGMM is similar to M852.

42 grains of IMR 4064 with 175 SMK is Mk.316 ammo.

If you have a chrono and a reloading manual, even better. This is 308 Win, don't sweat it.

I pulled one two days ago (FGMM 168 smk) and measured 43.3gr, could they have changed the recipe?

[OpenSightsOnly]

Were you able to confirm that the powder is IMR 4064?

They can change the powder charge in order to meet the velocity of 2650. For FGMM 175, I think its 2550? They work with different powder lots so I'm sure that they are blending the different lots.

Why don't you shoot/chrono the FGMM 168. If your rifle likes or doesn't like the load, then you have a starting point either way.

[JMP]

I have new projectiles (168 SMK) for my 308 WIN loads. I'll be using IMR 4064 and will work my way up from Hodgdon's minimum.

But what length should I seat to? If I make them 2.8" OAL, there's about 0.1" jump to the lands. Is that normal and ok?

The length depends on your rifle's chamber. 0.1" is fine if that is what the rifle likes to shoot. I use 168 SMKs, and I load them to 2.800" with 44.4gr of 4064 with CCI LRP, and that doesn't miss (well, a little bit now that my barrel is worn out). But, I have a tight chamber without a lot of freebore. You should load them to the lands and work backwards. If it is something like a Remington 700 factory barrel, you will probably best load them longer since the chamber is so big. If you are limited by magazine size, then start there; otherwise, start at the lands and work backwards.

[castgold]

Are you loading into a magazine that can accept a longer COAL? I try for 0.05" off the lands, or even closer depending on the rifle.

[blockfort]

Are you loading into a magazine that can accept a longer COAL? I try for 0.05" off the lands, or even closer depending on the rifle.

As I stated at the beginning of the thread, I am single loading through the ejection port. But if I load to be right off the lands, there's less than a tenth of an inch of bullet in the neck. If I load to 2.800 OAL for load testing, there's a tenth of an inch jump. I'm trying to figure out which of those scenarios I should use to test my charge weights, before moving to seating depth optimization.

[smoothy8500]

As I stated at the beginning of the thread, I am single loading through the ejection port. But if I load to be right off the lands, there's less than a tenth of an inch of bullet in the neck. If I load to 2.800 OAL for load testing, there's a tenth of an inch jump. I'm trying to figure out which of those scenarios I should use to test my charge weights, before moving to seating depth optimization.

My Rem 700 had a long throat too. Just load to 2.810" and call it good. When you rebarrel your rifle with a decent throat length then you can worry about depth.