Distance to Lands, Barrel Shot Out?

[Narf]

I recently traded for a 1990's rem 700 VLS .308 in very good shape. I've shot a box of factory loads through it and had .6 MOA results which I was very happy with. Before starting my load development I wanted to know where the lands were. I check by removing the firing pin and ejector from the bolt and seated the bullet a few thou at a time till the bolt dropped freely. this happened on two different .30 cal bullets at 2.268" to ogive. This puts the COL at about 0.145" over book value (2.945" vs 2.800"). This is my first Remington bolt gun. Do they have a reputation of chambering this deep or is this thing shot out? I've never worn out a barrel so I'm not even sure what to look for.

thank you, Nick

 

[Ru4real]

Not shot out, based on your factory group size.

Long free bore? Possibly.
Starting to shoot out? Possibly.

A borescope is one way to look to see rifling marks in the lands and groves. If so, long free bore.

Max COL is a suggestion only to ensure rounds function in nearly every chamber/magazine, etc. Going longer is fine for that gun, but may not be fine for other guns.

 

[JFrank]

Last I heard Remington had a lot of freebore to start with, no personal experience just skuttle butt.
Additionally if you wish to load magazine length start with a tangent ogive bullet as they are far more jump tolerant.
If you want a single shot with a different bullet then I would start on a jam /zero and complete a charge test then seating test , primer if desired also neck tension plays a part to optimize load

 

[Narf]

Follow up question, if not shot out, would you recommend loading to load data COL and forget the lands? Is there a limit on COL length? could I safely load to 2.935"? I believe I read somewhere not to seat less than bullet diameter plus boat tail length. I've only been reloading for a couple years and haven't encountered this before.

 

[Bill M.]

I do not know for sure what COL you should use. I have a Mauser in 6 mm Rem with a similar situation. I can not get the bullets far enough to engage the lands. I decided just to load to stay around standard COL and it shoots pretty good. I have been trying to load flat base bullets to get a little more grip area. But most of the bullets in this caliber are boat tailed.

 

[Laphroaig]

.6 MOA with factory ammo? I'd not be very suspicious of it being shot out quite yet. You could definitely play with the seating depth to see if closer to the lands makes a difference or not. I'd also see what mag length gives you. If the results are similar to factory ammo, I'd forgo single loading and accept <MOA accuracy.

 

[WVRJ]

My 700 VTR in 308 has a very long throat.My overall length if I load it .010 off the lands is 2.915.I guess they do that to make sure there's plenty of freebore for safety reasons,but it doesn't help accuracy.Some bullets are more length tolerant than others,and from my experience,bullets like the Sierra Match King and the Nosler Custom Competition,with their style of ogive are among the most forgiving.The long,tapered,sleek bullets seem to like to be close to or jammed into the lands.I wish Remington would have tooled up and made an action between their short and long actions.That would make rounds like the 308,260,7MM-08,6.5-284,6.5 PRC and others that need more than a 2.800 COAL a lot better.But,they stuck to their old design,just like they stuck to several other things that would have sold more rifles and would have made them more money.Instead they didn't innovate and keep ahead of the competition,which didn't help to keep the company out of bankruptcy.Almost all the gun manufacturers seemingly pay no mind to what their customers want.If Remington would have been as innovative as Ruger,we'd be calling the company Huge Green,or Giant Green because they would excell.

 

[Walkalong]

I started off at .010 to .015 off the lands in my brand new 6 Dasher barrel, it shot under 1/2 MOA pretty easily. After 1200 plus rounds the throat is looking poorly with the beginning of the lands partly washed out, but it is still shooting well, and I am not chasing the lands. I did give it a very thorough cleaning recently before a match (Most folks barrels are dirtier than they think, IMHO.), but after shooting around 100 rounds at that match, I came home, did some testing, without cleaning, with a new lot of powder, and it is still holding its own. Again, at the same OAL I started at.

Got sloppy (lost concentration/got in a hurry) on the fourth group (bottom left), then settled down again on the next one. Groups are 5 shots each

 

[AJC1]

Bullet shape is a big factor. The 175 smk will likely give you much shorter measurements. Jonnys reloading bench did a comparison on his 300 win mag video. Throat depth from the factory is also highly variable. Jump to the lands is no problem for most bullets. Some like solids recommend no less than .050.

 

[edwardware]

. . . on two different .30 cal bullets at 2.268" to ogive. This puts the COL at about 0.145" over book value. . .

Book value of COAL is approximately the most useless data in the book.

You have 3 relevant datapoints:
- Jam COAL, which you're measured.
- Magazine length COAL, which you will measure
- Factory COAL for a very promising factory load, which you will measure.

If it were me, I'd calculate jump of the factory ammo you like, and start there. Another option is to start at max magazine COAL, provided that's not into jam.

None of this involves book COAL, because it's nearly useless (unless you refuse to work up from start load).

 

[GooseGestapo]

OP,
Not likely. That’s nearly identical to my nearly new M700 Tactical.
I thought the throat/chamber long, but measured, it’s within .001” of SAAMI in every dimension.

Explains why 175gr bullets do so well, and are very popular.
My gun definitely prefers 175’s.

 

[z7]

Shoot it until it won’t shoot good, a 308 win barrel can last 5k-10k rounds without losing significant accuracy (some
May go sooner, some longer)

Because of the seating depth issues you may find some bullets work well (SMK) and some don’t, just shoot what works

if you can seat the bullets real long and still feed well, it doesn’t hurt anything as long as you know where you are from the lands and you start low and work up

one safe way to do it with rifle loads is to start at or as close to the lands as you can, and then seat slightly deeper as you tweak the load, this prevents pressure spikes going from a few thou off the lands to jammed

“Correct” seating depth is a twofold relationship, first, distance to the lands, second, what will feed well into your firearm. AR15 loaders are familiar with the trade off, sure I can be .01-.005” off the lands if I want to single feed my AR,

pick what shoots and don’t sweat it, 175g SMKs, 44g-45g of varget with winchester brass at 2.800” works pretty well for anyone, but start low and work up

 

[Walkalong]

Well said @z7

 

[sparkyv]

This:

Book value of COAL is approximately the most useless data in the book.

You have 3 relevant datapoints:
- Jam COAL, which you're measured.
- Magazine length COAL, which you will measure
- Factory COAL for a very promising factory load, which you will measure.