How deep to set a rifle bullet in case?

[slipknot]

I have a question regarding the reloading for .308 rifle cartridges. I have a Remington 700P bolt gun in 308 and I used the Hornady lock n load overall length gauge to measure my rifles' total bullet length and came up with total lengths for different grains to reach the lands and grooves of the following=

150 grain = 2.965" o.a.l.
168 grain = 2.948"
180 grain = 2.947"

these are Sierra match bullets HPBT

because of the boat tail, the 150 grain do not even make it into the casing, the chamfer just makes it to the edge of the modified 308 casing used in the tool.
The 168 only makes it in a little over an 1/8" on the flat part, the 180 goes in less than 3/8" total.

My question is how much of the bullet needs to be seated into the casing to be reasonable so I can avoid having to resort to needing longer heavier bullets like 200 grain or something? Should it be a percentage of the length of the bullet or what. Because it seems to me this factory brand new rifle has too much freebore for off the shelf ammo to come close enough to the lands and grooves to give me good results. I broke the rifle in, it has now over 130 rounds and groups at 100 yards are 4-5".
I plan on changing the trigger to a Timney I bought and that may help also but the jump with store bought ammo is significant it seems to me. The Federal sierra match 175 I have are 2.818" o.a.l.
I prefer to use reloads and have space of maybe 15 to 20 thousandths or less.

Any advice is appreciated, thanks

 

[josh2600]

I'm not sure where I picked this rule up, but I go by making sure that the amount of bullet seated is at least equal to the measure of the bullet across. So like if the width of the bullet at its widest point is .264 inch, try to have at least .264 inch of the bullet inside the case.

(Your measurements will obv be different, i just used a 6.5mm bullet as an example)

 

[josh2600]

Also, its not possible to seat to the lands in all guns, I'm not sure about .308, but its notoriously difficult in .260 rem

As the throat wears it moves the lands further and further out as well.

 

[EddieCoyle]

Like Josh said, as a general rule, one caliber's worth of the bearing-surface portion of the bullet should be in the neck.

 

[mac1911]

Some simple old school rules are hard to beat.
As deep into the case as dia. Of bullet...as noted above that's bearing surface.
Another rule is 2" high at 100 yards is a basic zero for most rifles to hit the kill zone on a deer...almost as far as you can see one.

You can also have some short fat bullets that will hit the lands also.

 

[Steve Marshall]

The one caliber seating is a truism. It makes sense until you look at it in a different perspective. For example, the .300 Win Mag has a neck on the case shorter than one caliber and is considered to be an accurate cartridge. But, you say, that has nothing to do with seating depth. Well then, what difference does seating depth make? Reliability, of course. You want to insure that working the action doesn't dislodge the bullet prior to the chamber. There even used to be a use for breech seating where the bullet was seated into the barrel and then the case was inserted. This was done for accuracy purposes in a target rifle. So, OP, seat the bullet however shallow or deep suits your need. In a hunting scenario, you'd need to seat the bullet where you can reliably work the action. If targets only, just deep enough to make it to the chamber straight enough for accuracy purposes.

 

[dgrafton]

4-5" at 100 yards is not acceptable at all! Off the shelf 700 with factory ammo should be well under 1.5 and I wouldn't be happy with anything over 1".


Sent from my iPhone using Tapatalk

 

[jtnf]

1:1 ratio of depth to diameter comes from engineering... Cylindrical slip fits need at least this to ensure the inserted member (projectile) remains coaxial with the outer member (case.)

 

[mac1911]

I have a question regarding the reloading for .308 rifle cartridges. I have a Remington 700P bolt gun in 308 and I used the Hornady lock n load overall length gauge to measure my rifles' total bullet length and came up with total lengths for different grains to reach the lands and grooves of the following=

150 grain = 2.965" o.a.l.
168 grain = 2.948"
180 grain = 2.947"

these are Sierra match bullets HPBT

because of the boat tail, the 150 grain do not even make it into the casing, the chamfer just makes it to the edge of the modified 308 casing used in the tool.
The 168 only makes it in a little over an 1/8" on the flat part, the 180 goes in less than 3/8" total.

My question is how much of the bullet needs to be seated into the casing to be reasonable so I can avoid having to resort to needing longer heavier bullets like 200 grain or something? Should it be a percentage of the length of the bullet or what. Because it seems to me this factory brand new rifle has too much freebore for off the shelf ammo to come close enough to the lands and grooves to give me good results. I broke the rifle in, it has now over 130 rounds and groups at 100 yards are 4-5".
I plan on changing the trigger to a Timney I bought and that may help also but the jump with store bought ammo is significant it seems to me. The Federal sierra match 175 I have are 2.818" o.a.l.
I prefer to use reloads and have space of maybe 15 to 20 thousandths or less.

Any advice is appreciated, thanks

When it comes to factory rifles they are going to cut the chamber free bore long enough to feed the longest factory fodder they think you may come across.
Are you going to single feed every round?
If not load to manufactures data or as long as the magazine can handle...
I have no idea of your skill set , scoped or iron sights
4-5" groups is a bit loose. Even a jump to the lands with good bullets and a good barrel should be doing a little better.
I have a 1903a4 clone sniper and the throat or lead is to me on the longer side. With 168gn noslers loaded to 3.3" feed fine and shoot darn close to MOA with me behind the trigger with a scope.
My 1903a3 I have loaded "off" the lands for single round loading. I'm .010" off and the bullet is probably about .230"ish into the case... I do not see any measurable increase in accuracy ? It's all fun.
Honestly though I will give this advice that was given to me.
Spend less time chasing loads and more time shooting.
I was chasing loads in my match AR for a while.
Then one of the better shooters said to me. That time you spent loading all those different rounds and testing would have been better time spent dry fire at home or liver fire practice. He put his money where his mouth is and shot 20 rounds of my ammo at 200 yards and scored a 200 9x with an extreme spread of 4.75" prone with sling iron sights.
So I say buy a box of 168 match ammo hand the rifle to someone you know that can shoot very well and see what he can post for groups. Might be something other than the ammo keeping you from getting good groups.

So load some known good loads and go practice.
Heck maybe your rifle and bullet combo doesn't like the short jump?

I'm not sure what to expect out of a rem 700 police.
I'm thinking these are not the most "accurate" line of remington 700's? I wonder what the factory specs are for acceptable accuracy. I'm going to gander it's more than people care to know... my guess is about 1.5 mean radius average?' Seems rem 700s are luck of the draw.
You either get a gem or a minute of deer rifle.

 

[dhuze]

If I had a .308 rifle that grouped 4-5" I wouldn't have a .308 anymore. Hell if I had any high powered rifle that couldn't hold under 1 1/2" I'd get rid of it or send it back.

My .22's do better than 4-5", some are 1".

 

[1919FAN]

I ck stuff old school I sacrifice a case that I plan on using whether neck or full lenght resized slit the neck ,take the head that i will be using install in case slowly chamand extract. By do this you will know where your lands are and amount of projectile in case just a quick way to ck and set a base line for setting depth of the lands.

 

[PatMcD]

Your OAL measurements are a little long if you ask me. Standard OAL for shooting out of M14 was always 2.8"

 

[johnN]

i hand load my 700 sps. I did the oal gauge with a 168 mk and it just about falls out of the case. but since it is mag fed does not matter. I load the 168's at 2.800 over 42.0 of 4064 in fed cases and get dime size groups WHEN I do my part. not bad since the inside of this barrel looks like the bed of a dodge truck. that same load in my ar10 with a new barrel looks like buck shot on paper.

 

[mac1911]

i hand load my 700 sps. I did the oal gauge with a 168 mk and it just about falls out of the case. but since it is mag fed does not matter. I load the 168's at 2.800 over 42.0 of 4064 in fed cases and get dime size groups WHEN I do my part. not bad since the inside of this barrel looks like the bed of a dodge truck. that same load in my ar10 with a new barrel looks like buck shot on paper.

You don't know until you try.
My friends son has become the 2nd best shooter I know.
22yrs old and shoots really well.
He has a rem 700 sps varmint with a 3x9 duplex ret: his pet load is Sierra 125 SPT 49.8 grains of H414.. 1/2 moa with boring predictability.
It's his 200 yard load and his coyote round out to 250.
His words...."it's miles from the lands"

 

[slipknot]

Thank you everyone, your input is appreciated

I will shoot some more Federal match ammo and see how it goes, then go from there and if I have to I will call remington again

 

[tysdad115]

Thank you everyone, your input is appreciated

I will shoot some more Federal match ammo and see how it goes, then go from there and if I have to I will call remington again

Knowing your skill set, you should probably have a semi decent shooter try it before you go too crazy...

 

[slipknot]

go catch a tuna Andy and stick with what you know
don't think I haven't thought of that already, are you offering assistance of your expertise?

 

[tysdad115]

go catch a tuna Andy and stick with what you know
don't think I haven't thought of that already, are you offering assistance of your expertise?

I'd be happy to burn through your ammo with the same results as you....maybe you should come to winter rifle in Pembroke on Sunday AM and have a talk with the guys there. They are always more than willing to show/help someone along. The collective knowledge there is amazing and they will sure give you guidance.

 

[mac1911]

I'd be happy to burn through your ammo with the same results as you....maybe you should come to winter rifle in Pembroke on Sunday AM and have a talk with the guys there. They are always more than willing to show/help someone along. The collective knowledge there is amazing and they will sure give you guidance.

this... I was there sunday looking to say hi andy. i love seeing some of the 22lr shooting 200 yards and posting high scores..
I still have not been ble to get there with my rascal!

 

[slipknot]

If I had a .308 rifle that grouped 4-5" I wouldn't have a .308 anymore. Hell if I had any high powered rifle that couldn't hold under 1 1/2" I'd get rid of it or send it back.

My .22's do better than 4-5", some are 1".

I shot some more with it before changing the trigger and did get a 1-1/4" group of 5 this time with 175 grain Federal match. Those 4" groups must have been with the 150 grain I used to break the barrel in.
Hopefully I can tighten up that group some more