Load Development Question?

[Brux]

On 308 load development would you just start your seating depth at factory specs or something different?
For instance if your rifle shot FGMM 168 which is seated at 2.800 and it's jumping let's say 40 thou would you start load test at that seating depth?

 

[hafejd30]

I like to start .020” off the lands unless need to run mag length limits that

 

[Steel head]

I usually start at 20 though off but that’s just habit.
I’ve found just start at what your comfortable with and run with it.

 

[Brux]

I usually do the 20 off thing also but like I said if your rifle shoots great at factory seated specs why not just load there and roll with it.

 

[ShtrRdy]

If you're using the same bullet then I would start with the same OAL.

 

[Ocean_Dweller]

I start at .020" also. Then after I find a velocity node, I'll try different seating depths until the groups tighten up.

 

[918v]

I start at .050”

 

[Doom]

I start at recommended seating depth.

 

[Choid]

I start at recommended seating depth.

For years I ran tests at ten, twenty, etc. Then, for shits and giggles, I decided to do load development at recommended depth, and what I found out was that unless the reamer was specced for something odd, recommended depth works really, really well most of the time. Especially true on SMKs, hybrids and ELDs from what I can tell so far. None of my last three loads required messing with seating depth, only charge weight. I think I have come to the conclusion that a lot of these ammo and bullet manufacturers actually have done their homework, lol.

 

[Baron23]

Ok, guys...old fart here but new to metallic reloading.

When you say 'recommended seating depth" exactly what are you referring to.

I'll be loading .264 Berger 140 gr Hybrid Targets in 6.5 CM in Hornady brass (cause I have a bunch).

I have recently determined distance to lands so I do think I can get .20 off of them to start....but what would be the manf seating depth. I can't seem to find such a thing?

Or are you taking about SAAMI spec?

 

[nn8734]

Across all of my loads where I’m using Berger hybrids I have found they like jump (.060-.090). YMMV. Also Hornady brass is thin walled so may require more powder vs Lapua, Starline or Pederson brass to achieve the same MVs. Federal brass has the thickest walls I’ve seen for 6.5CM

 

[6.5SH]

Ok, guys...old fart here but new to metallic reloading.

When you say 'recommended seating depth" exactly what are you referring to.

I'll be loading .264 Berger 140 gr Hybrid Targets in 6.5 CM in Hornady brass (cause I have a bunch).

I have recently determined distance to lands so I do think I can get .20 off of them to start....but what would be the manf seating depth. I can't seem to find such a thing?

Or are you taking about SAAMI spec?

What the maker lists as COAL for a particular bullet in a particular cartridge. As an example:

https://bergerbullets.com/pdf/6.5-Creedmoor-135gr.pdf

They don't have a pdf for the 140 Hybrid because they want you to buy their book (although I'm sure they'd tell you if you call or email).
We can likely get the same length they list from this:

6.5 mm Creedmoor 140gr Hybrid Target Rifle Ammunition

The Berger 6.5mm 140gr Hybrid target bullet is one of the top performing bullets in long range precision rifle target style competitions. If you want to get the best long range performance out of your single fed bolt gun chambered in 6.5 Creedmoor, this is the load for you.

bergerbullets.com

2.810" is what they load their own ammo to with that combo.

 

[hafejd30]

Ok, guys...old fart here but new to metallic reloading.

When you say 'recommended seating depth" exactly what are you referring to.

I'll be loading .264 Berger 140 gr Hybrid Targets in 6.5 CM in Hornady brass (cause I have a bunch).

I have recently determined distance to lands so I do think I can get .20 off of them to start....but what would be the manf seating depth. I can't seem to find such a thing?

Or are you taking about SAAMI spec?

Many manufacturers seating depth are set so they fit in a variety of platforms. Simply because the same ammo will be used by one guy in a savage 10, another in a Rem 700 and another in a Rock River LAR8 AR10. Most are loaded to fit in all mags for those rifles

The beauty of reloading and not loading to recommended length is generally you can find the sweet spot of what a bullet likes for jump. Certain designed bullets function better off the lands a little, a ways, or set into them

It also gives you the advantage when loading longer high bc bullets to seat them longer in the case to gain more powder capacity if you desire

 

[Baron23]

What the maker lists as COAL for a particular bullet in a particular cartridge. As an example:

https://bergerbullets.com/pdf/6.5-Creedmoor-135gr.pdf

They don't have a pdf for the 140 Hybrid because they want you to buy their book (although I'm sure they'd tell you if you call or email).
We can likely get the same length they list from this:

6.5 mm Creedmoor 140gr Hybrid Target Rifle Ammunition

The Berger 6.5mm 140gr Hybrid target bullet is one of the top performing bullets in long range precision rifle target style competitions. If you want to get the best long range performance out of your single fed bolt gun chambered in 6.5 Creedmoor, this is the load for you.

bergerbullets.com

2.810" is what they load their own ammo to with that combo.

Thank you! Yeah, no wonder I couldn’t find it...I was looking for the 140. Now, dumb shit me just got the Berger book and didn’t think to look there. Sorry, I do tend to try to do my own research before asking on the forum and failed this time.

 

[Choid]

My conclusion, after doing this a while, is that yes, sometimes you really benefit from seating out longer than SAAMI, especially if you are using a longer than standard bullet for caliber, say a 215 Berger with 300 Win Mag, but more often than you'd imagine, or at least more often than I'd have imagined, SAAMI length is really good for a lot of the new cartridges when shooting modern projectiles. And you have the bonus of not having a load so tuned to the lands, while the throat is constantly eroding. Not always, but sometimes staying simple this way saves a lot of hassle.

 

[Baron23]

My conclusion, after doing this a while, is that yes, sometimes you really benefit from seating out longer than SAAMI, especially if you are using a longer than standard bullet for caliber, say a 215 Berger with 300 Win Mag, but more often than you'd imagine, or at least more often than I'd have imagined, SAAMI length is really good for a lot of the new cartridges when shooting modern projectiles. And you have the bonus of not having a load so tuned to the lands, while the throat is constantly eroding. Not always, but sometimes staying simple this way saves a lot of hassle.

Thank you!

 

[nn8734]

My conclusion, after doing this a while, is that yes, sometimes you really benefit from seating out longer than SAAMI, especially if you are using a longer than standard bullet for caliber, say a 215 Berger with 300 Win Mag, but more often than you'd imagine, or at least more often than I'd have imagined, SAAMI length is really good for a lot of the new cartridges when shooting modern projectiles. And you have the bonus of not having a load so tuned to the lands, while the throat is constantly eroding. Not always, but sometimes staying simple this way saves a lot of hassle.

The paradigm of chasing the lands was applicable when folks were using VLD bullets with pure secant ogives back in the day to get a BC advantage over the tangent stuff…most modern projectiles are of the hybrid shape and like jump but you also get the high BCs.

If I’m unsure about where to start with a load for a given cartridge (usually because it’s new to me reloading-wise), I’ll buy a box of factory ammo that uses the bullet and brass that I’m considering and see how it shoots in my rifle.

If it groups ok and nothing weird is observed, I’ll buy that brass and those bullets, put my powder/primer combo together and start my seating depth mimicking what the manufacturer had done. Then adjust the seating depth in .015” increments if necessary once target minimum MV is met. Most often I don’t need to fuck with the seating depth too much if at all.

Hybrid bullets have really improved that aspect of load development.

 

[Baron23]

Thank to all for the replies....but stand by later for my stupid questions on load dev! LOL

but not tonight!

 

[Choid]

The paradigm of chasing the lands was applicable when folks were using VLD bullets with pure secant ogives back in the day to get a BC advantage over the tangent stuff…most modern projectiles are of the hybrid shape and like jump but you also get the high BCs.

If I’m unsure about where to start with a load for a given cartridge (usually because it’s new to me reloading-wise), I’ll buy a box of factory ammo that uses the bullet and brass that I’m considering and see how it shoots in my rifle.

If it groups ok and nothing weird is observed, I’ll buy that brass and those bullets, put my powder/primer combo together and start my seating depth mimicking what the manufacturer had done. Then adjust the seating depth in .015” increments if necessary once target minimum MV is met. Most often I don’t need to fuck with the seating depth too much if at all.

Hybrid bullets have really improved that aspect of load development.

This is exactly what I do. It certainly cuts down on load development time. I've found the ELDs, of both variety, SMKs and the various versions of hybrids both make life really easy this way.

 

[Baron23]

The paradigm of chasing the lands was applicable when folks were using VLD bullets with pure secant ogives back in the day to get a BC advantage over the tangent stuff…most modern projectiles are of the hybrid shape and like jump but you also get the high BCs.

If I’m unsure about where to start with a load for a given cartridge (usually because it’s new to me reloading-wise), I’ll buy a box of factory ammo that uses the bullet and brass that I’m considering and see how it shoots in my rifle.

If it groups ok and nothing weird is observed, I’ll buy that brass and those bullets, put my powder/primer combo together and start my seating depth mimicking what the manufacturer had done. Then adjust the seating depth in .015” increments if necessary once target minimum MV is met. Most often I don’t need to fuck with the seating depth too much if at all.

Hybrid bullets have really improved that aspect of load development.

Thank you very much. Berger 140 Hybrid loaded ammo does shoot very well in this barrel. They use Lapua brass and try to find that. But, I have a lot of Hndy brass so that’s that.

I do have Berger cartridges and can take CBTO from that to use.

But, as a new reloader, it might not hurt for me to get some experience and start closer to the lands and work my way off. Dunno.

but you guys have been a great help.

 

[nn8734]

Thank you very much. Berger 140 Hybrid loaded ammo does shoot very well in this barrel. They use Lapua brass and try to find that. But, I have a lot of Hndy brass so that’s that.

I do have Berger cartridges and can take CBTO from that to use.

But, as a new reloader, it might not hurt for me to get some experience and start closer to the lands and work my way off. Dunno.

but you guys have been a great help.

No need to reinvent the wheel with seating depth, the manufacturers have already done all the homework for you. Start at like .075” and plan on moving in or out by .015. (.060-.090). I’d be surprised if you didn’t find a good load in that range or just outside of it.

I’ll be perfectly honest when I tell you I have no idea how far I am from the lands on my two AXMC barrels (300N and 6.5CM). I just started at 2.130” CBTO for the 6.5 (FGMM 130 Berger) and 2.665” CBTO for the Norma (Norma brand w/215 Berger). Both shoot one ragged hole at 100m when I confirm zero when swapping them. For my Mk11 I just seat to just shy of mag length which is roughly .090 from the lands (175 smk).

 

[Choid]

No need to reinvent the wheel with seating depth, the manufacturers have already done all the homework for you. Start at like .075” and plan on moving in or out by .015. (.060-.090). I’d be surprised if you didn’t find a good load in that range or just outside of it.

I’ll be perfectly honest when I tell you I have no idea how far I am from the lands on my two AXMC barrels (300N and 6.5CM). I just started at 2.130” CBTO for the 6.5 (FGMM 130 Berger) and 2.665” CBTO for the Norma (Norma brand w/215 Berger). Both shoot one ragged hole at 100m when I confirm zero when swapping them. For my Mk11 I just seat to just shy of mag length which is roughly .090 from the lands (175 smk)

Ha, I have to start load development this weekend on my 300N AXMC barrel, and I started with the same ammo, but they actually jammed for me just a touch, so I moved back .070 to start. Hopefully it goes smoothly. I have a 30 inch barrel and am looking to hit right around 3000, so it shouldn't be pushing it too hard.

 

[nn8734]

Ha, I have to start load development this weekend on my 300N AXMC barrel, and I started with the same ammo, but they actually jammed for me just a touch, so I moved back .070 to start. Hopefully it goes smoothly. I have a 30 inch barrel and am looking to hit right around 3000, so it shouldn't be pushing it too hard.

With a 30” barrel, 3000 should be easy if using 215s or 230s. I’m getting 2996 out of a Proof SS 26” bbl using Norma brass/H1000/F215M. No pressure signs.

 

[Choid]

With a 30” barrel, 3000 should be easy if using 215s or 230s. I’m getting 2996 out of a Proof SS 26” bbl using Norma brass/H1000/F215M. No pressure signs.

Yeah, if I can keep the pressure a bit low, I'd like to. I'm using N570, and Quickload says I can get up to close to 3200, but I am not overly ambitious. I don't know what I really get with that extra speed.

 

[nn8734]

Agree, it’s not worth it.

 

[Choid]

Agree, it’s not worth it.

So, I end up around 3100. That is where the best accuracy seems to be, and the only velocity flat spot from 2950 up, and still no pressure. Factory ammo shows a little pressure, and up in the 3130s shows a little too, but very little.

 

[nn8734]

So, I end up around 3100. That is where the best accuracy seems to be, and the only velocity flat spot from 2950 up, and still no pressure. Factory ammo shows a little pressure, and up in the 3130s shows a little too, but very little.

Solid. That’s a good speed. What were the atmospherics?

 

[Choid]

Solid. That’s a good speed. What were the atmospherics?

60 degrees, calm winds, DA 6560.

 

[nn8734]

Should still be supersonic beyond 2k yards if using the 215 Berger. You going to take it to a mile (or beyond) soon?

 

[Choid]

Should still be supersonic beyond 2k yards if using the 215 Berger. You going to take it to a mile (or beyond) soon?

If I can get my ass away from fixing all the things ruined by snow this year.

 

[Choid]

Should still be supersonic beyond 2k yards if using the 215 Berger. You going to take it to a mile (or beyond) soon?

The only worry I have is that virgin Laupa brass is growing 8 thou on the first firing, so I might need to revisit the load on once fired brass.. On the good side, I am getting exactly 4 fps difference between my loads and the Berger factory loads, and identical POI, so I am likely to have a while before I actually get to my second loading. And they are all the same brass, so I will build a stable, because I have a pile of the Berger stuff.

 

[nn8734]

Reload 10 rounds using the 1x fired Lapua brass, 10 rounds with virgin Lapua brass then fire each batch over your chrono/lab radar and compare the data/poi shift on paper, if any.

 

[Choid]

Oh, I will, but that won't keep me from using this load with the 200 pieces of virgin brass I have. I'll just need to adjust as the time comes.