Reloading - when your mag box limits your COAL

[med358-boise]

What amount of clearance do you use for your cartridge COAL? In other words, regardless of your desired distance to the lands; you always allow a minimum of X thousands under mag box length?

 

[FEENIX]

What amount of clearance do you use for your cartridge COAL? In other words, regardless of your desired distance to the lands; you always allow a minimum of X thousands under mag box length?

My Savage 11 in .300 WSM has a .030" magazine clearance, which puts me .080" off the lands. However, on my .338 Thor, it is at least .050" of clearance with the lands touching, but it is loaded .015" off the lands at the moment.

 

[xsn10s]

What amount of clearance do you use for your cartridge COAL? In other words, regardless of your desired distance to the lands; you always allow a minimum of X thousands under mag box length?

It all depends on the intended use. For the most part on hunting rifles I use tangent ogive bullets which are more forgiving on bullet jump. Even with some secant ogive bullets I still load to magbox length and am able to find sub moa loads.

 

[med358-boise]

My Savage 11 in .300 WSM has a .030" magazine clearance, which puts me .080" off the lands. However, on my .338 Thor, it is at least .050" of clearance with the lands touching, but it is loaded .015" off the lands at the moment.

FEENIX - do you use .030" as a rule of thumb or is that just the way it worked out? In other words, do you always like to .030 of clearance?

The reason for the question is I have a few rifles where my mag box doesn't allow me to get as close to the lands as I would generally like and am curious if others have similar situations so they have developed their own rule of thumb for minimum clearance.

 

[med358-boise]

Let me try to be clearer in what I am asking - Regardless of desired bullet jump, sometimes mag boxes are a limiting factor, so for those times when mag box is a limiting factor, do you have a minimum clearance for the mag box that use for reliability.

I suspect if someone's mag box was 2.900 inches and distance to the lands dictated a desired COAL of say 2.950 they would not load to 2.899 inches because only .001 clearance is probably a bad idea in a hunting rifle.

 

[xsn10s]

Let me try to be clearer in what I am asking - Regardless of desired bullet jump, sometimes mag boxes are a limiting factor, so for those times when mag box is a limiting factor, do you have a minimum clearance for the mag box that use for reliability.

I suspect if someone's mag box was 2.900 inches and distance to the lands dictated a desired COAL of say 2.950 they would not load to 2.899 inches because only .001 clearance is probably a bad idea in a hunting rifle.

When loading in a magbox my general clearance is 0.010". Then test for reliable feeding.

 

[RichCoyle]

med358-boise,

I never gave that dimension a thought. If I load a round and it doesn't fit, I seat it until it does. The system seems to work. The last three 300 yard groups were: .7". 1.3", and .93". My last wildcat I designed around the 3.4" mag box.

 

[FEENIX]

FEENIX - do you use .030" as a rule of thumb or is that just the way it worked out? In other words, do you always like to .030 of clearance?

The reason for the question is I have a few rifles where my mag box doesn't allow me to get as close to the lands as I would generally like and am curious if others have similar situations so they have developed their own rule of thumb for minimum clearance.

No, Sir! My .300 WSM was loaded with 215 Berger, where I found the best compromise between COAL and CBTO.

 

[memtb]

med358-boise,

I never gave that dimension a thought. If I load a round and it doesn't fit, I seat it until it does. The system seems to work. The last three 300 yard groups were: .7". 1.3", and .93". My last wildcat I designed around the 3.4" mag box.

Rich, Those are acceptable groups…..but, just barely! memtb

 

[FEENIX]

I suspect if someone's mag box was 2.900 inches and distance to the lands dictated a desired COAL of say 2.950 they would not load to 2.899 inches because only .001 clearance is probably a bad idea in a hunting rifle.

For me, yes! As @xsn10s noted, you need to make sure it feeds reliably. A .001" of clearance might also damage the bullet tip during recoil.

 

[memtb]

For me, yes! As @xsn10s noted, you need to make sure it feeds reliably. A .001" of clearance might also damage the bullet tip during recoil.

Another reason for a mono, especially in a heavy recoil rifle. Before I changed to mono's, by the time I got to the last round in the magazine……the bullet tips were so badly "flattened", I expected to see that the jacket had started to open! memtb

 

[VinceMule]

How many times in the past 5 years have you fired more than one shot at a deer?

Recoil is a major issue when considering mag length, and using a muzzle brake or other changes the equation on bullet tips getting beat up in the mag box.

 

[memtb]

How many times in the past 5 years have you fired more than one shot at a deer?

Recoil is a major issue when considering mag length, and using a muzzle brake or other changes the equation on bullet tips getting beat up in the mag box.

never said I shooting at game……merely shooting! Eliminating lead tips will also change the equation! memtb

 

[YZ-80]

For the most part, I don't have any bolt action rifles where this becomes an issue for me and I generally seat .015 to .020 CBTO. It does come into play with my AR style rifles. I think I make the COAL about.020" shy of mag length. And it feeds fine. This is just speculation but I think that it may be more forgiving when you use a ballistic tip with a plastic mag due to less friction, perhaps allowing you to get a bit closer. Here's how mine look and they feed great.