.308 Winchester

I've actually wanted to upgrade for a while since I have SAC's headspace comparators, but after seeing the disparity between the diameter measurements, I'm just going to switch everything over.
For me, the biggest reason that I changed was that the Hornadys are aluminum (relatively soft) and the SAC's are stainless (much, much harder).

And, I'm at the age where I want nice/good stuff. SAC fits that bill nicely.
 
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Does anyone have a CBO measurement of a 175 Sierra at a 2.800 OAL? I have a chamber set up for 168 Sierra's at 2.200 at that OAL jumping .010 so I'm wondering how the 175 compares before I buy some.
I just measured the BTO of my 168 and 175 SMK's and there was a .002 difference, the 168 being the longer. BUT. . . . keep in mind there can be a MUCH bigger difference within a lot AND an even bigger difference between lots (like .034"). So, that .002 difference really doesn't help you. Add to that, there's variations in different comparators.

I've measured and shot a lot of 168's and 175's. For the most part, the difference in BTO between the two tends to be small.
 
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I'm pretty restricted on the OAL because of the magazine. 2.830 is about max and I have no interest in single feeding.
You might think about trying the 169 SMK's??? The 169 SMK BTO's are ~.020 longer than the 168 SMK's and the COAL is about .105 longer. The 169's are tipped and works really well out to 1000+ yds . . . better than the 175's. They can be a little hard to find, but they're out there:

 
You might think about trying the 169 SMK's??? The 169 SMK BTO's are ~.020 longer than the 168 SMK's and the COAL is about .105 longer. The 169's are tipped and works really well out to 1000+ yds . . . better than the 175's. They can be a little hard to find, but they're out there:

Oh I know all about them. It was the first bullet I tried in the rifle in January with H4895 and it shot lights out, even jumping .117 at mag length, better than any M1A I've ever had, and was still shooting great up until about a month ago with that bullet until I changed lots of powder and the accuracy has gone to shit. Have tried everything, re-working up the load, seating depth changes, cleaning the gas system, barrel, different torque specs on the gas plug, yet the groups are inconsistent and all over the place. Even tried some Federal GMM that I know shot well and it still shoots so I figured I would try a different bullet and powder.
 
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Anyone have any experience with N140, Lapua cases, and SMK 169? I’ll be shooting out of a 24” MRAD. I was going to use the 168s for 600 and under, 169s for up to 1k (hopefully) and 338 Lapua for greater than 1k
 
The 168 SMK is in the Viht manual...N140 start 38.3 gr Max 42.9 gr.
I don't use this powder, and have shot the 169 gr with accuracy in the 16" 308 AR platform, with different powder and my barrel was super accurate with 168 ELDM.
 

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The 168 SMK is in the Viht manual...N140 start 38.3 gr Max 42.9 gr.
I don't use this powder, and have shot the 169 gr with accuracy in the 16" 308 AR platform, with different powder and my barrel was super accurate with 168 ELDM.
Thank you! I only have the newest Hornady manual and I was afraid the VV may not have the 169 data and I wasn’t sure how close the 168 would be. I greatly appreciate it sir!
 
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Anyone have any experience with N140, Lapua cases, and SMK 169? I’ll be shooting out of a 24” MRAD. I was going to use the 168s for 600 and under, 169s for up to 1k (hopefully) and 338 Lapua for greater than 1k
I don't have any direct experience with that, but I don't see any reason why it might not work for you.

Your velocities most likely will be different from what here:
24 in MRAD - N140.jpg
 
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Oh I know all about them. It was the first bullet I tried in the rifle in January with H4895 and it shot lights out, even jumping .117 at mag length, better than any M1A I've ever had, and was still shooting great up until about a month ago with that bullet until I changed lots of powder and the accuracy has gone to shit. Have tried everything, re-working up the load, seating depth changes, cleaning the gas system, barrel, different torque specs on the gas plug, yet the groups are inconsistent and all over the place. Even tried some Federal GMM that I know shot well and it still shoots so I figured I would try a different bullet and powder.
Different torque on the has plug ? That has that much effect on the m1a ? Interesting. My brother has one.
 
Just finished fire-forming my reformed SIG 6.8x51 Hybrid military cases. Got some new tear down cases with primers still in them for SUPER cheap. I reformed them Friday night, and then loaded them up yesterday. Went and shot them today, and will clean and polish them when I get ready to run another batch of brass in the US cleaner and tumbler.

Here they are after pushing the shoulders and necks back and reforming them for .308 Win. It's not a simple 1-step process to avoid the donuts or getting lube dents in the necks, so you have to use a body die and size down the case, then mandrel the necks to .30 caliber, and FL size them.

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I lube inside necks, then mandrel up first.
Size with the FL sizing die, don't lube where the neck is being formed.
Neck turn, and body die.
No dents, no donuts.
Here is the lathe neck turning operation.
It cuts the full 20° angle of the 308, but notice the sharp angle at the neck / shoulder junction. This takes away donut material.
Here is a loaded 308 win 215 gr Berger from the neck turned case.
A better close up of losing the donut.
This formed 338 RCM case necked from 6.5PRC ...note the neck/ shoulder junction sharper angle of the newly formed 338 RCM against the factory 6.5 PRC.
I always cut it completely, neck, radius and shoulder angle...cause I have a lathe.
But hand neck turned into the shoulder will accomplish most of what is needed.
 

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Different torque on the has plug ? That has that much effect on the m1a ? Interesting. My brother has one.
Fart wrong and it will have an effect on an M1A. One day it will shoot great groups and the next day it won't, very frustrating rifle. Yet I can't live without one.

A lot of the armorers from the 70's and 80's had some very interesting things to say about the rifles and what their shooting teams discovered. Gas plug torque, swapping out gas pistons and altering the dwell time by removing material from the plug or piston was all part of trying to squeeze every last bit of accuracy out of them. Problem is, you can waste a lot of time and ammo trying to figure out what combination of those, if any, would even show up on paper with any consistency.

I would love to have one of those guys at the range with me when I'm testing loads.
 
Fart wrong and it will have an effect on an M1A. One day it will shoot great groups and the next day it won't, very frustrating rifle. Yet I can't live without one.

A lot of the armorers from the 70's and 80's had some very interesting things to say about the rifles and what their shooting teams discovered. Gas plug torque, swapping out gas pistons and altering the dwell time by removing material from the plug or piston was all part of trying to squeeze every last bit of accuracy out of them. Problem is, you can waste a lot of time and ammo trying to figure out what combination of those, if any, would even show up on paper with any consistency.

I would love to have one of those guys at the range with me when I'm testing loads.
I've experienced some of the inconsistency with my brothers rifle. I think I've shot it more than he has.

A good friend of mine used to shoot service rifle matches and built match grade m1a's and garands. He was a wealth of knowledge when it came to the tricks to make an m1a shoot. His match rifle is for sale at the moment. If I can scape the funds together I'm going to buy it.
 
I've experienced some of the inconsistency with my brothers rifle. I think I've shot it more than he has.

A good friend of mine used to shoot service rifle matches and built match grade m1a's and garands. He was a wealth of knowledge when it came to the tricks to make an m1a shoot. His match rifle is for sale at the moment. If I can scape the funds together I'm going to buy it.
I shoot a lot of 5 shot groups with 4 touching and then one a half to three quarters of an inch away from the group. If I ever figure out how to tune that out, I'll let you know.
 
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I am trying to determine the best OAL for my rifle and am wondering if there is a recommended gap off the lands. Using the Hornady OAL gauge the total OAL is 2.94 in. Should I back it off .02?
Just so there's no confusion. . . Hornady's OAL Gauge is actually used to measure CBTO (Cartridge Base to Ogive) to find where the bullet it touching the lands. OAL is usually a reference to Over All Length.

I assume with you say "OAL is 2.94" you're talking about CBTO, where it's touching the lands???

No, I wouldn't start at .002" if that's what you mean. .020" off the lands to start is just fine. When closer than .010" to the lands, there tends to me substantial pressure spike effecting velocity. This could be an issue as the throat erodes, changing velocity enough to see on target. Therefore, I find it's best to start load development at .010 off the lands and move back incrementally to find a spot that produces the best results.

If one is limited to feeding from the mag, then that COAL (Cartridge Over All Length) for the mag is the place to start the load development.
 
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I guess I used the wrong terminology. Not using the mag, just single feed.

When powder manufacturers list a load amount for a particular round are they using a cartridge made for a magazine? How would the load amount change with a longer CBTO? I'm new to this so it might not make sense.
 
I guess I used the wrong terminology. Not using the mag, just single feed.

When powder manufacturers list a load amount for a particular round are they using a cartridge made for a magazine? How would the load amount change with a longer CBTO? I'm new to this so it might not make sense.
When you look at powder manufacturers page of data, how the cartridges are loaded is usually listed at the top along with COAL (C.O.L.) with the barrel length (often 24") for velocity reference purpose. They do not list CBTO since everyone's chamber can have a very different freebore and different comparator inserts have various diameters. Like what you see here on Hodgdon's website.
Hodgdon Load Data example.jpg
 
So back to my question. If the bullet is extending further into the chamber and leaving more room in the cartridge can the powder load be increased safely?
Yes. But when doing that you'll want to do it in small increments, starting well below the powder company's maximum recommendation (like ~10% below) and monitor for pressure signs as you increase powder charges.

Pressure signs:
-Stiff bolt lift
-Ejector swipe
-Ejector imprint
-Primer cratering (though some "cratering" is more from primer flow into excess space around firing pin)
1723669199680.png


FYI: the further you seat the bullet into the case the faster the powder burns creating a sooner release of the bullet letting gasses blow past the bullet before it's fully engraved. At the same time the increase in seating depth makes for a larger chamber volume for the blowby gasses to fill, which tends to reduce velocity a little. When you get closer to the lands, like less than .010" that chamber volume is small and tends to spike the pressure. Here's an example how that pressure curve works:
1723669144348.jpeg
 
So back to my question. If the bullet is extending further into the chamber and leaving more room in the cartridge can the powder load be increased safely?
In case you’re not aware, you will likely need to reduce your load in your gas guns from your bolt guns to avoid potentially dangerous pressures.
 
I never jam bullets into the rifling. That causes a big pressure spike of about 10,000 psi...plus if you unload it the bullet can stick on the barrel, making a big powder mess in the chamber and down the barrel.
Bullets have a variation on the ogive or radius of the point...some are better than others, and can change from lot to lot.
I am usually backed off .006" as close as I ever get but sometimes much more.
A long jump doesn't matter if the bullet don't care...shot some tiny groups with long jumps.
One can slowly add a fraction of a grain of powder for alot of extra COAL. Until ya hit the lands then the big pressure spike.
So if your looking for accuracy I wouldn't recommend adding powder above the max load, at longer than normal COAL for that cartridge but stay with book max requirements, until one has lots of experience and many thousands of rds down range.
Autos and bolts can take the same load....IF the AR is not one of those in the 6 ARC, Grendel, Valkyrie, Bushmaster, etc low pressure cartridges, weak and thin steel bolts, requires you keep the pressure down.
And IF your boltgun pressures are not quite a bit over max...as many are.
I shoot the same loads in 308, and 5.56 in boltguns as in ARs ...with normal pressure loads, even at book max, and a few +P.
Ya can't just seat a bullet out long and get performance with Varget, it's a good target powder, but not a performance powder, for maximum velocities these days. The magic ain't there, for super high velocity 308 loads.
And a 1/2 grain of powder will not net much more velocity as the extra space has to be filled with propellant gas and still stay inside pressure limits...not worth the squeeze, or worry.
Plus super high velocities are not needed for most shooting endeavors, at moderate to medium ranges...or a few excursions to 1000yds.
 
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Varget and the 168 ELDs is a great combo. One I use in my match rifle.
Yeah man, Varget and 178's have been great. Varget around here is getting spendy though. I think a one #'er was like 69 bucks at my local vs StaBall Match at 54.

Side note, and this may be a dumb question, but I got to thinking about bumping the .002/.003 shoulder off of fire formed practice. So, should all fire formed brass, regardless of brand, reloaded, factory, etc. be the same size to the same rifle in theory? In other words, how are you benchmarking what you are subtracting from? I'd imagine an over-pressured load vs a typical factory load could/would cook off and stretch differently, or is it all the same when it comes to brass heating up and stretching out in a blink. Does one get an average of 5, or is this totally dependent on specific brass? Does this make any sense? lol

Last, what's more important to get right, the case size or OAL sneaking up on the lands? Both? Is it all "test and learn"

Where I'm coming from is I've been reloading for a little while, but it's been pretty much to SAAMI. Would like to see if this makes a meaningful difference.
 
Yeah man, Varget and 178's have been great. Varget around here is getting spendy though. I think a one #'er was like 69 bucks at my local vs StaBall Match at 54.

Side note, and this may be a dumb question, but I got to thinking about bumping the .002/.003 shoulder off of fire formed practice. So, should all fire formed brass, regardless of brand, reloaded, factory, etc. be the same size to the same rifle in theory? In other words, how are you benchmarking what you are subtracting from? I'd imagine an over-pressured load vs a typical factory load could/would cook off and stretch differently, or is it all the same when it comes to brass heating up and stretching out in a blink. Does one get an average of 5, or is this totally dependent on specific brass? Does this make any sense? lol

Last, what's more important to get right, the case size or OAL sneaking up on the lands? Both? Is it all "test and learn"

Where I'm coming from is I've been reloading for a little while, but it's been pretty much to SAAMI. Would like to see if this makes a meaningful difference.

Check out some of the VV powders. They are cheaper and work well.

You are way overthinking it. You will be using the same brand of brass as if you aren't then you aren't loading precision rifle ammo. Doesn't matter if the brass was fired as a factory load or you loaded new brass. You measure the shoulder of the brass of the fired cases and subtract .001-002". Measure a few cases and work off the shortest one but they should all be very close as within .001".

You should be measuring the shoulder and the OAL and jump off lands, which .020" is a good place to start.
 
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Check out some of the VV powders. They are cheaper and work well.

You are way overthinking it. You will be using the same brand of brass as if you aren't then you aren't loading precision rifle ammo. Doesn't matter if the brass was fired as a factory load or you loaded new brass. You measure the shoulder of the brass of the fired cases and subtract .001-002". Measure a few cases and work off the shortest one but they should all be very close as within .001".

You should be measuring the shoulder and the OAL and jump off lands, which .020" is a good place to start.
Thank you, Rob.
 
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I recently purchased some reconditioned brass brand name-Topbrass. Anyone have any experience with this brand? I looks nice and the bag says it has been sized, cleaned etc. I noticed as I was resizing the neck small clippings of brass were coming off. I know they have not been annealed. Any input regarding quality or what I need to watch for is appreciated.
 
I recently purchased some reconditioned brass brand name-Topbrass. Anyone have any experience with this brand? I looks nice and the bag says it has been sized, cleaned etc. I noticed as I was resizing the neck small clippings of brass were coming off. I know they have not been annealed. Any input regarding quality or what I need to watch for is appreciated.
is "Topbrass" part of the head stamp ? or just what is on the bag ?
 
I use a lot of Lake City brass, along with just about every brand in range pick up braas, plus Lapua and hybrid cases in 308.
This 1000 pc order was pulled and contained the primer. Buffed off the sealant and loaded it in the Dillon progressive press, with old $20 per pound W 748 and 15 cent Speer 130 Varmint bullets.
First 5 shots from an AR 10 with an 18" Proof barrel was .3" the 2nd was .4" ....
So I did a little test with a 308 target rifle Lapua brass vs LC ...the Lapua was better by only .1" to .125" with no weight sorting and whatever the military used for primers.
A .1" difference won't make any difference in any informal shooting one is likely to do.
So I use thousands of LC brass in my 308s especially autos. It uses tbe same bushing as Lapua brass in the bushing FL die. It will take the same powder charge but the velocity will be higher because of slightly less volume and one should drop the powder charge about 1/2 to 1 grain, as the case heads seem softer in LC, the primer pocket will expand sooner.
For cheap plinking, get some some surplus powder cheap Speer bullets and a good AR 10 will still shoot 5 shots into .4 to .7 inches.
16" AR 10, 1/2" 5 shot groups all shot with LC brass, nice S/D LC brass.
And shit surplus 540 stick, whatever that is, cheap primed LC brass, still shoots nice groups.
So LC brass is pretty good stuff, it's very cheap, and no worries if ya lose a few.
 

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I lube inside necks, then mandrel up first.
Size with the FL sizing die, don't lube where the neck is being formed.
Neck turn, and body die.
No dents, no donuts.
Here is the lathe neck turning operation.
It cuts the full 20° angle of the 308, but notice the sharp angle at the neck / shoulder junction. This takes away donut material.
Here is a loaded 308 win 215 gr Berger from the neck turned case.
A better close up of losing the donut.
This formed 338 RCM case necked from 6.5PRC ...note the neck/ shoulder junction sharper angle of the newly formed 338 RCM against the factory 6.5 PRC.
I always cut it completely, neck, radius and shoulder angle...cause I have a lathe.
But hand neck turned into the shoulder will accomplish most of what is needed.
What dies do you use for the FL sizing? I read that we need a special die for the hybrid cases but haven't been able to locate them. TIA
 
What dies do you use for the FL sizing? I read that we need a special die for the hybrid cases but haven't been able to locate them. TIA
No special dies, for 6.8X51 hybrid cases just mandrel up and run through any commercial 308 die. Neck turn and anneal make headspace consistent, and neck turn eliminates donut, when done correctly.
American Reloading has them in stock.
Shellshock bi-metal cases for 9mm and 300 blkout need special dies, because of how they are made.
 

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No special dies, for 6.8X51 hybrid cases just mandrel up and run through any commercial 308 die. Neck turn and anneal make headspace consistent, and neck turn eliminates donut, when done correctly.
American Reloading has them in stock.
Shellshock bi-metal cases for 9mm and 300 blkout need special dies, because of how they are made.
Awesome thanks. Now I don't whether to load them in my 308 Win or consider trying them in my 260AI. Seems like a 260 AI would be doable since there is less body taper. I could create a false shoulder too and the 30 degree shoulder might make case forming easier.
 
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Has some wild S/D with weighed charges Varget... it was supposed to be a standard to judge the other powders for accuracy and velocity.
For some unknown reason it was the worst load ever...will revisit it one day.
 

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Aero Precision Solus Hunter rebarreled by Jon Beanland with a 20” 1:10 twist Bartlein 3b.

.308s are just so eager to please. I ordered some Berger 168gr Classic Hunters to try, as I had very good results from them in a previous .308. Also picked up a jug of N150. It is much more affordable than Varget and everything I’ve read about it says it performs well in the .308, particularly with heavier bullets. The burn rate charts put it close to H4350, but those who’ve used it claim it’s much closer to Varget, maybe just slightly slower burning. Anyway, as you can see, the combo is very stable. Any one of the four charges would be fine. All are 10 round groups. I’m going to go with the 45.2gr charge. 9 of the ten shots went into .445” and 8 of the ten went into .287”. Gotta love a good .308!

John

 
Speaking of Berger 168 Classic Hunters, these are 2, 10 shot groups shot on separate days with an M1A.

Both are exactly .90 MOA

Left Group
41.2 grs H4895
Virgin Lapua Large Primer Brass
CCI BR4
OAL 2.800"

Right Group
41.7 grs H4895
Virgin Lapua Palma Brass
Fed 205M
OAL 2.800"



Haven't even tried playing with seating depth yet.

20241028_184223.jpg
 
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Speaking of Berger 168 Classic Hunters, these are 2, 10 shot groups shot on separate days with an M1A.

Both are exactly .90 MOA

Left Group
41.2 grs H4895
Virgin Lapua Large Primer Brass
CCI BR4
OAL 2.800"

Right Group
41.7 grs H4895
Virgin Lapua Palma Brass
Fed 205M
OAL 2.800"



Haven't even tried playing with seating depth yet.

View attachment 8533975
What kind of M1A?