When do we stop chasing the lands

[oldno7]

We all know throats erode at varying degrees, depending on a multitude of scenarios.

So my question is--when do we stop chasing and re set a barrel/chamber or re barrel entirely?

One of my projects from last year is a 28Nosler. I started out touching the lans at 2.962.

After 215 rounds fired, I currently sit at 2.980

No problem, I extended my overall cartridge length but for how long?

I single feed so that doesn't enter the equation for me but might for others.

So using the .284 diameter, do we chase until we no longer have that amount of contact(.284) in the neck?(as a basic rule of thumb)

 

[Farmerboy78]

I'd say when the bullet isn't supported enough by the neck

 

[25WSM]

When you lose accuracy. When you lose to much speed. When bullets start blowing up. I always set my barrels back before it gets so bad it won't clean up with the reamer.
Shep

 

[J E Custom]

We all know throats erode at varying degrees, depending on a multitude of scenarios.

So my question is--when do we stop chasing and re set a barrel/chamber or re barrel entirely?

One of my projects from last year is a 28Nosler. I started out touching the lans at 2.962.

After 215 rounds fired, I currently sit at 2.980

No problem, I extended my overall cartridge length but for how long?

I single feed so that doesn't enter the equation for me but might for others.

So using the .284 diameter, do we chase until we no longer have that amount of contact(.284) in the neck?(as a basic rule of thumb)

You don't have to touch the lands to get accuracy and if you don't over size or bump the shoulder
and maintain proper head space, And unless the round wont chamber it will not do anything except maybe increase the velocity.

J E CUSTOM

 

[Alex Wheeler]

The barrel will be toast before you run out of neck. Chase until accuracy falls off, if you cant bring it back with a retune, its time to rebarrel. On your 28, expect about 700 rounds.

 

[6.5-300 BEE]

If you build on a magnum action you won't have the problem. Remember all the smart guys who built 257 Bobs on 06' actions ?

 

[rsmithsr]

I would say when you choose large cases and small necks you are asking to play a chasing game. at a much faster rate than larger bores with the same case volume. do as has been said. and then buy a new bbl. I do not think my 300 win mag with only top end loads with over 200 gr bullets has 25 thou in land movement. well over 800 rounds, not as precise as it once was. 18 in 200 rounds sounds like an early retirement. good luck

 

[rsmithsr]

listen to alex...gunsmith and hunter

 

[oldno7]

You don't have to touch the lands to get accuracy and if you don't over size or bump the shoulder
and maintain proper head space, And unless the round wont chamber it will not do anything except maybe increase the velocity.

J E CUSTOM

Thanks JE
This one came into accuracy ,030 off, I just extended my COAL by the amount of erosion.

So I'm still .030 off.
Appreciate the reply.

 

[oldno7]

The barrel will be toast before you run out of neck. Chase until accuracy falls off, if you cant bring it back with a retune, its time to rebarrel. On your 28, expect about 700 rounds.

Thanks Alex
This is a great shooting rifle, I suspect the loss of accuracy will be very noticeable.
So when it fails to regain accuracy after chasing lans, it's done.
Greatly appreciated.

 

[oldno7]

I wasn't planning on getting an excessive amount of rounds from this barrel, I knew that when it was chambered.

But I'm guessing I'll have more fun with it and occasionally laugh like a school girl(some more)at it's performance.

Heavy and fast is fun, it's not entirely my fault...

 

[dok7mm]

As a last effort, try extended jumps, looking for an accuracy node. This is common with overbore cartridges, the price we pay.

You can put it off a bit by proper bore care and barrel cooling between shots, but it's a given on barrel life.

 

[oldno7]

When you lose accuracy. When you lose to much speed. When bullets start blowing up. I always set my barrels back before it gets so bad it won't clean up with the reamer.
Shep

Thanks 25
as this throat has been eroding, I've been gaining speed, has made it a bit of a challenge to stay in the node.
currently node 3070fps with a 195 berger.

 

[25WSM]

28 no's is hungry on barrels.
Shep