.308 Ammo

[P-12 Norm]

I have the 16" model ... like it a lot ... chambered for 308 Winchester

I have loooked for an SPS with a 20" barrel threaded for years. When this one popped up on Gunbroker at a reasonable price, and a local MD guy no less, I jumped. He bought it a few years back. Never shot it, decided to sell it because it had sat unshot. Has a black over-molded stock. Now I Have to select a good scope and decide if I want to go with a Magpul Hunter stock and mag well, or just go cheap and put the Howa Magwell and mag on it.

 

[Bountied]

I have loooked for an SPS with a 20" barrel threaded for years. When this one popped up on Gunbroker at a reasonable price, and a local MD guy no less, I jumped. He bought it a few years back. Never shot it, decided to sell it because it had sat unshot. Has a black over-molded stock. Now I Have to select a good scope and decide if I want to go with a Magpul Hunter stock and mag well, or just go cheap and put the Howa Magwell and mag on it.

I'd upgrade the stock. The Magpul is ok but there are better albeit more expensive options. The Viper PST gen2 is reasonable and will do everything you want on that rifle. 3-15 or a 5-25.

 

[E.Shell]

I use the 143gr in my 6.5 it's very accurate out to 500yds which is the furthest I shot with it. I was hitting a little 6" hanger at 500yds with ease using factory Hornady 143gr eld-x.

The 6.5CM is a completely different animal than the .308.

I worked up a couple different handloads and got better results with the factory ammo over my own. Better SDs and better groups. I tried very hard to get consistency but the factory stuff was still better. I was cutting the IMR 4064 to get them to within 0.01 grains of each other, measured case length and COAL and they still weren't as good as factory.

Many people seeking precision results end up chasing the wrong details and thus do not find the sweet spot. Many details people think are critical are purely theoretical factors and really do not have the impact on precision that people imagine.

Getting powder charges within 0.01 grain is a complete waste of time and contributes nothing to precision results. Seriously. Rhetorical question: Do you think Federal or Hornady weighs each charge for their 1/4 to 1/2 MOA match ammo? Hint: They do not, they dump it with a measure. Sacrifice a few factory rounds that outperform your handloads, pull the bullets and weigh charges. You will probably be surprised at the variations you will see. Even benchrest competitors do not chase weights to less than a tenth.

Case length is only critical when there are huge differences or when the cases are getting too long and some touch the end of the chamber. Otherwise keeping them someplace between the 'trim to' and 'max' lengths will satisfy requirements for safety and precision. You would be much better served by watching case neck tension via cleaning the inside of the neck each time and annealing. Champion 1,000 yard F-Class competitors anneal every time.

Due to bullet tip variations, OAL is much less important than consistent ogive position. If your seater matches your bullet, once your seating die is set and locked in, ogive position will not change, but OAL can and will vary several thousandths with no impact on precision. I usually started at 0.020" off the lands, found my OCW, then adjusted seating depth slightly each way to see if it mattered. Usually did not.

I have found IMR powders to be extremely sensitive to temperature variations. It can easily be enough to take you out of the OCW with any major temperature changes, including sitting in a warm barrel for a few minutes prior to firing. When I entered the long range precision arena, I had to give up on IMR powders completely and used Hodgdon exclusively for all of my precision long range loading. I'd still happily use IMR for short/mid-range loads and hunting, but not for long range (>500 yards) precision ammo.

For your 6.5 CM, I would suggest that you get some H4350 (not IMR), use Federal or CCI match primers, find your OCW and stay with a tenth or two of that and be happy.

 

[trickg]

I Know it takes a level of dedication to consistency to reload in a manner that give results exceeding today's factory loads, one that has be almost to an OCD level. I don't have that, so I didn't get into reloading. I have great respect for those who do. I wish I had that mind-set. I even looked into it. But decided against even starting. A man's got to know his limitations.

I can respect that. It's really not for everyone.

Keep us posted though - I'm curious to hear about the progression of this rifle - if you mod it with an aftermarket trigger, if you drop it into a different stock or chassis, change up your optics, etc.

 

[Bountied]

The 6.5CM is a completely different animal than the .308.

Many people seeking precision results end up chasing the wrong details and thus do not find the sweet spot. Many details people think are critical are purely theoretical factors and really do not have the impact on precision that people imagine.

Getting powder charges within 0.01 grain is a complete waste of time and contributes nothing to precision results. Seriously. Rhetorical question: Do you think Federal or Hornady weighs each charge for their 1/4 to 1/2 MOA match ammo? Hint: They do not, they dump it with a measure. Sacrifice a few factory rounds that outperform your handloads, pull the bullets and weigh charges. You will probably be surprised at the variations you will see. Even benchrest competitors do not chase weights to less than a tenth.

Case length is only critical when there are huge differences or when the cases are getting too long and some touch the end of the chamber. Otherwise keeping them someplace between the 'trim to' and 'max' lengths will satisfy requirements for safety and precision. You would be much better served by watching case neck tension via cleaning the inside of the neck each time and annealing. Champion 1,000 yard F-Class competitors anneal every time.

Due to bullet tip variations, OAL is much less important than consistent ogive position. If your seater matches your bullet, once your seating die is set and locked in, ogive position will not change, but OAL can and will vary several thousandths with no impact on precision. I usually started at 0.020" off the lands, found my OCW, then adjusted seating depth slightly each way to see if it mattered. Usually did not.

I have found IMR powders to be extremely sensitive to temperature variations. It can easily be enough to take you out of the OCW with any major temperature changes, including sitting in a warm barrel for a few minutes prior to firing. When I entered the long range precision arena, I had to give up on IMR powders completely and used Hodgdon exclusively for all of my precision long range loading. I'd still happily use IMR for short/mid-range loads and hunting, but not for long range (>500 yards) precision ammo.

For your 6.5 CM, I would suggest that you get some H4350 (not IMR), use Federal or CCI match primers, find your OCW and stay with a tenth or two of that and be happy.

I think I have some H4350 to mess with. These handloads were made using never fired new brass from Peterson, CCI BR2 primers 42gr of IMR4064. I usually load a few steps under max pressure. I think I chose 4064 because I could get more velocity than H4350. I only have 40 pieces of the Peterson brass so I didn't do a ladder test but I may to determine the OCW. I'll have to look up what Hornady loads their rounds to and with. I don't remember how I was shooting but I usually load one cartridge at a time and I may have shot the factory loads after the hand loads so the barrel temp was not consistent and that could explain some things.

I'm sure I can look it up but what is the process for annealing the case neck?

Are you still teaching long range classes?

 

[trickg]

I'd upgrade the stock. The Magpul is ok but there are better albeit more expensive options. The Viper PST gen2 is reasonable and will do everything you want on that rifle. 3-15 or a 5-25.

I think the KRG Bravo chassis is the cat's pajamas if you want a rifle that still looks like a rifle. It is more expensive than a Magpul Hunter - I looked into that one too - but I think it's a bit of a step up in just about every way. Your barrel will be completely free floating regardless of the contour, and the aluminum bedding block extends the full length of the chassis.

I got mine for a decent price - $320 due to military discount.

 

[E.Shell]

I think I have some H4350 to mess with.

These handloads were made using never fired new brass from Peterson, CCI BR2 primers 42gr of IMR4064. I usually load a few steps under max pressure.

I think you'll find cleanest ignition and most consistent results at the upper node of your OCW, which is often at or just below max pressure (for your rifle. not what any loading manual calls 'max').

I think I chose 4064 because I could get more velocity than H4350.

Small gains in velocity only serve to reduce drop and wind deflection by the tiniest amount. The real goal for long range is minimum SD coupled with best precision.

I only have 40 pieces of the Peterson brass so I didn't do a ladder test but I may to determine the OCW.

I do it, and suggest doing it like this:
1) Begin with your manual's starting load, and for a case capacity in the 6.5CM range, load a series of single rounds in 0.3 grain increments to just above your manual's 'max'.
2) Shoot each of these rounds through a chronograph while watching for excessive pressure and plotting velocities. Stop when you start seeing case head expansion/ejector marks.
3) Examine your velocity results and look for a spot where adding another increment did NOT show a corresponding velocity gain. This spot will be very close to your OCW.
4) Load a series of 3 shots per increment, starting two increments below the spot just described, to a point two increments above your sweet spot. This gives you five increments to test, theoretically surrounding your OCW.
5) Shoot these increments through your chronograph and watch for minimum variation within each series, and minimum /change/gain between increments.

When you find your OCW, you should see both minimum SD within each increment, as well as minimum change between adjacent increments. This process uses minimum components and two range trips.

Once you find your OCW, then vary your seating depth slightly to see if you get better results. Another variable is the primer, so you can also vary primers around your OCW to see if oen or the other makes your SD and/or precision better.

One thing I used to do that wastes a huge amount of time and components is to fight a bad rifle - i.e. trying to find a load it will group well, when most loads are not up to par. A well-built rifle will shoot almost any reasonable load well, so we are really evaluating loads based on velocity rather than group size.

I'll have to look up what Hornady loads their rounds to and with. I don't remember how I was shooting but I usually load one cartridge at a time and I may have shot the factory loads after the hand loads so the barrel temp was not consistent and that could explain some things.

When testing loads, I try to start with a clean bore and clean again before changing ammo with differing powder or bullets.

Hodgdon powders are very resistant to temperature changes and eliminating that one variation can make a big difference to long range precision.

I'm sure I can look it up but what is the process for annealing the case neck?

There are several ways to do it. I spin mine with a cordless drill and shellholder, heat the neck over a sharp torch flame and watch color. When the case neck starts to glow slightly and the color change comes down to the neck/shoulder junction, I drop it in cool water.

Are you still teaching long range classes?

No, very sorry, I'm physically unable to do it any more. Jumping up and down, yelling and screaming at students takes a lot out of you.

 

[ezracer]

Big fan of Federal Sierra Match King 168gr. A tad pricey

 

[Bountied]

I think you'll find cleanest ignition and most consistent results at the upper node of your OCW, which is often at or just below max pressure (for your rifle. not what any loading manual calls 'max').


Small gains in velocity only serve to reduce drop and wind deflection by the tiniest amount. The real goal for long range is minimum SD coupled with best precision.

I do it, and suggest doing it like this:
1) Begin with your manual's starting load, and for a case capacity in the 6.5CM range, load a series of single rounds in 0.3 grain increments to just above your manual's 'max'.
2) Shoot each of these rounds through a chronograph while watching for excessive pressure and plotting velocities. Stop when you start seeing case head expansion/ejector marks.
3) Examine your velocity results and look for a spot where adding another increment did NOT show a corresponding velocity gain. This spot will be very close to your OCW.
4) Load a series of 3 shots per increment, starting two increments below the spot just described, to a point two increments above your sweet spot. This gives you five increments to test, theoretically surrounding your OCW.
5) Shoot these increments through your chronograph and watch for minimum variation within each series, and minimum /change/gain between increments.

When you find your OCW, you should see both minimum SD within each increment, as well as minimum change between adjacent increments. This process uses minimum components and two range trips.

Once you find your OCW, then vary your seating depth slightly to see if you get better results. Another variable is the primer, so you can also vary primers around your OCW to see if oen or the other makes your SD and/or precision better.

One thing I used to do that wastes a huge amount of time and components is to fight a bad rifle - i.e. trying to find a load it will group well, when most loads are not up to par. A well-built rifle will shoot almost any reasonable load well, so we are really evaluating loads based on velocity rather than group size.


When testing loads, I try to start with a clean bore and clean again before changing ammo with differing powder or bullets.

Hodgdon powders are very resistant to temperature changes and eliminating that one variation can make a big difference to long range precision.

There are several ways to do it. I spin mine with a cordless drill and shellholder, heat the neck over a sharp torch flame and watch color. When the case neck starts to glow slightly and the color change comes down to the neck/shoulder junction, I drop it in cool water.

No, very sorry, I'm physically unable to do it any more. Jumping up and down, yelling and screaming at students takes a lot out of you.

Thanks for the info, yeah yelling at students can be tiresome.

I have tried a method to find the best seating depth. It involves cutting a slit in the case neck then putting a bullet in that case and closing the bolt. When the bullet touches the lands it will be pushed inside the case with little resistance. Then you measure that and back it off to what ever you want your jump to be, maybe .005 -.010" from the lands or less.

 

[Uncle Duke]

I think you'll find cleanest ignition and most consistent results at the upper node of your OCW, which is often at or just below max pressure (for your rifle. not what any loading manual calls 'max').


Small gains in velocity only serve to reduce drop and wind deflection by the tiniest amount. The real goal for long range is minimum SD coupled with best precision.

I do it, and suggest doing it like this:
1) Begin with your manual's starting load, and for a case capacity in the 6.5CM range, load a series of single rounds in 0.3 grain increments to just above your manual's 'max'.
2) Shoot each of these rounds through a chronograph while watching for excessive pressure and plotting velocities. Stop when you start seeing case head expansion/ejector marks.
3) Examine your velocity results and look for a spot where adding another increment did NOT show a corresponding velocity gain. This spot will be very close to your OCW.
4) Load a series of 3 shots per increment, starting two increments below the spot just described, to a point two increments above your sweet spot. This gives you five increments to test, theoretically surrounding your OCW.
5) Shoot these increments through your chronograph and watch for minimum variation within each series, and minimum /change/gain between increments.

When you find your OCW, you should see both minimum SD within each increment, as well as minimum change between adjacent increments. This process uses minimum components and two range trips.

Once you find your OCW, then vary your seating depth slightly to see if you get better results. Another variable is the primer, so you can also vary primers around your OCW to see if oen or the other makes your SD and/or precision better.

One thing I used to do that wastes a huge amount of time and components is to fight a bad rifle - i.e. trying to find a load it will group well, when most loads are not up to par. A well-built rifle will shoot almost any reasonable load well, so we are really evaluating loads based on velocity rather than group size.


When testing loads, I try to start with a clean bore and clean again before changing ammo with differing powder or bullets.

Hodgdon powders are very resistant to temperature changes and eliminating that one variation can make a big difference to long range precision.

There are several ways to do it. I spin mine with a cordless drill and shellholder, heat the neck over a sharp torch flame and watch color. When the case neck starts to glow slightly and the color change comes down to the neck/shoulder junction, I drop it in cool water.

No, very sorry, I'm physically unable to do it any more. Jumping up and down, yelling and screaming at students takes a lot out of you.

I think you'll find cleanest ignition and most consistent results at the upper node of your OCW, which is often at or just below max pressure (for your rifle. not what any loading manual calls 'max').

2) Shoot each of these rounds through a chronograph while watching for excessive pressure and plotting velocities. Stop when you start seeing case head expansion/ejector marks.
=============


Ed, comment on this for me please.


I don't dispute the validity of your statement regarding "rifle specific" pressure. Your contention is no doubt correct.

But....

What does concern me though, and I cringe when I hear it even though it's technically absolutely correct, is that readers may be inclined to dismiss published maximum charge weights. "They're lawyered." They're test barrel specific. Well, yes to lawyered in some instances perhaps. Absolutely yes to barrel specific. That one is a given. Yet for many and most, most may have no better tool than the manual so many are inclined to want to dismiss.

I say that for several reasons. One, because the chronograph tool isn't a part of most shooter's equipment. So that measurement option (sadly) doesn't exist for many and most. But more importantly, I think it safe to say that most shooters (and perhaps even most reloaders) genuinely struggle with being able to accurately distinguish and read pressure signs. And there exists no way for the casual reloader to accurately quantify pressure with lab accuracy, even assuming they knew and could positively identify how much is too much. So while certainly not a "be all and end all", not dismissing that manual is in most instances the best tool that most are going to have to try to keep themselves out of trouble.

Yes, ejector and similar case marks to be sure. A neon sign there. Curious also though, if you're using micrometer case head measurements as a pressure indicator, what case head measurement variation (versus a factory baseline?) would you say becomes cause for concern?

 

[P-12 Norm]

My next question for you who are far more knowledgable than I, is if I go with a Steiner 4.4-16 scope, does it make sense to get a 20 MOA base, or go with a 0 MOA?
Looking at the Nightforce Base (1 piece)

 

[Bountied]

My next question for you who are far more knowledgable than I, is if I go with a Steiner 4.4-16 scope, does it make sense to get a 20 MOA base, or go with a 0 MOA?
Looking at the Nightforce Base (1 piece)

Get a 20MOA base for sure. It will allow you to use more of your elevation. Even if you don't use it you will have it if you need it.

 

[Squaregrouper]

I think I have some H4350 to mess with. These handloads were made using never fired new brass from Peterson, CCI BR2 primers 42gr of IMR4064. I usually load a few steps under max pressure. I think I chose 4064 because I could get more velocity than H4350. I only have 40 pieces of the Peterson brass so I didn't do a ladder test but I may to determine the OCW. I'll have to look up what Hornady loads their rounds to and with. I don't remember how I was shooting but I usually load one cartridge at a time and I may have shot the factory loads after the hand loads so the barrel temp was not consistent and that could explain some things.

I'm sure I can look it up but what is the process for annealing the case neck?

Are you still teaching long range classes?

I have 47-48 pieces of twice fired Peterson brass you can have.
Their case volume is significantly lower than others, so they need their own load data. EX: 39gr in Peterson may equal 42gr in Hornady, 41.8 in Starline and 42.2 in Lapua. The difference is significant with the Peterson brass.

 

[Squaregrouper]

Get a 20MOA base for sure. It will allow you to use more of your elevation. Even if you don't use it you will have it if you need it.

100% this. You don't want to get good and then run out of elevation at 7-800yds.

 

[Bountied]

I have 47-48 pieces of twice fired Peterson brass you can have.
Their case volume is significantly lower than others, so they need their own load data. EX: 39gr in Peterson may equal 42gr in Hornady, 41.8 in Starline and 42.2 in Lapua. The difference is significant with the Peterson brass.

Are you referring to pressure differences or the amount before the powder becomes compressed? Or the total volume of powder it can fit? I think it's Peterson Brass it's been a while. It was a smaller company. Depending on what I have I may take you up on your offer, thanks.

 

[Squaregrouper]

Are you referring to pressure differences or the amount before the powder becomes compressed? Or the total volume of powder it can fit? I think it's Peterson Brass it's been a while. It was a smaller company. Depending on what I have I may take you up on your offer, thanks.

Peterson brass in 6.5 Man Bun holds significantly less water than other brands. This means you'll use less powder to get the same fps. The issue is if you use your load data from other brass on Peterson brass it could be dangerous. I will look up my records when I get home, but it is something along the lines of 42.4gr in Hornady brass does 2700fps as does 40.7gr in Peterson.
Bottom line- Peterson brass needs to be loaded with its own private data.
Caveat- My brass is from when Peterson was a brand new company ~8yrs ago.

ETA- Peterson is considered to be really high quality brass. If you have enough of it, it would be worthy of dedicating all your 6.5MB to.
.

 

[Uncle Duke]

6.5 Man Bun.

Tough group! LMAO every time I hear that!

 

[bibitor]

My next question for you who are far more knowledgable than I, is if I go with a Steiner 4.4-16 scope, does it make sense to get a 20 MOA base, or go with a 0 MOA?
Looking at the Nightforce Base (1 piece)

If you're looking at mounting a picatinny base and then rings, I would recommend rings direct to your receiver. I use the Talley rings on my Bergara and have found them to be fantastic. They have 20 MOA options as well. It's also a lot nicer on your wallet.

 

[Bountied]

Peterson brass in 6.5 Man Bun holds significantly less water than other brands. This means you'll use less powder to get the same fps. The issue is if you use your load data from other brass on Peterson brass it could be dangerous. I will look up my records when I get home, but it is something along the lines of 42.4gr in Hornady brass does 2700fps as does 40.7gr in Peterson.
Bottom line- Peterson brass needs to be loaded with its own private data.
Caveat- My brass is from when Peterson was a brand new company ~8yrs ago.

ETA- Peterson is considered to be really high quality brass. If you have enough of it, it would be worthy of dedicating all your 6.5MB to.
.
View attachment 404429

Gotcha. I did notice on one of my loads the bolt would stick a little after firing. I thought it might be due to high pressure but I didn't see any signs of high pressure on the cases, primer pocket not burnt, primer not flat, necks looked OK. I chalked it up to new brass sticking a little.

Disclaimer: I've never had a man bun, but I did have shoulder length hair in high school.

 

[Squaregrouper]

Gotcha. I did notice on one of my loads the bolt would stick a little after firing. I thought it might be due to high pressure but I didn't see any signs of high pressure on the cases, primer pocket not burnt, primer not flat, necks looked OK. I chalked it up to new brass sticking a little.

Disclaimer: I've never had a man bun, but I did have shoulder length hair in high school.

Do you wear skinny jeans or exclusively drink local IPA's? Either of those will qualify you too.