Measuring Case O.A.L.

[Guest]

I bought a StoneyPoint O.A.L. measuring set with the comparitor and the insert. I went and put a Barnes TSX 140 grain bullet in the measuring case. I follow the directions and when I measured the length with my caliper I got the Lenght of 2.808 for my chamber lenght. I said ok good reading so I did it 2 more times to double check which they came out the same. Then I put a Nosler Accu-bond in the test case and slided it in the bore of my rifle. When I measured that lenght I got 2.859. I measured it 10 times and got the same reading. For my reloading so far I have been setting my O.A.L. to 2.800 for the Nosler bullets just like it says in the book. But in the book it also states to set the bullets .015 to .030 from the rifling. I don't kow if I am doing something wrong or what? The Barnes bullet came out correct. So I do believe I am doing it correctly. Then it must be that the Nosler bullet have a smaller curve to the bullet making them set deep in to the barrel. But then how do I get them to be closer to the rifling but not past the 2.800 as it states is the MAXIUM CASE LENGHT. I would like to load accurate but safe ammunition.

If it makes a difference the rifle is a Savage 11gl in 7mm-08 Rem
The bullets are Barnes TSX in 140 grain, Nosler 140 grain Accu-bond

 

[shrpshtrjoe]

Howdy Bert. The max aol that's in the reloading manuals is a SAMMI length thats designed to fit in any chamber safely. Each chamber is different. Most of my hand loads exede the reloading books max oal. I use a stoney point gauge as well it's a nice tool. Sometimes to reach max oal for a rifle the rounds won't fit in the magazine so the oal is what will fit in the mag. Different bullets used will give you a different aol because of weight and the ogive length, aol must be determined for each rifle and brand , weight of bullet. Just remember what's safe in your rifle may not be safe in another rifle, every chamber is different. Hopfully I answered your question.
Joe

 

[Guest]

Yes, you are correct about the different lenghts. I did not realize it before how much difference there is. I went thru and rechecked both the Barnes bullet and the Nosler bullets. This time I use the Combined Tech 140 grain Ballistic tip and the Barnes TSX 140 grain and the Nosler 140 grain Ballistic tip.

The differences are alot. The Barnes TSX were at 2.800 and 2.805 which I got after checking it 20 times the split was about the same even 10 each. The Nosler 140 grain ballisitic tip was at 2.859 I rechecked this one 10 times and got the smae measurement. The Combined Tech 140 grain Ballistic tip was at 2.879 and was sampled 10 times.

The Stoney Point tool is very nice and easy to use. It just makes me nervous to load longer then waht the SAMMI says it should be. As you can see the Barnes bullet is what the SAMMI say, but the Nosler is .059 longer and the Combined Tech is 0.079 longer. How does this affect the bullet speed in reference to the listings that the Nosler reloading manual says. I think it would increase FPS as there is more time for pressure to build.

If I load to what Nosler says in the Manual to put the bullet .030 off the rifling I would be over on the Nosler ballistic tip by .029 and the Combined Tech by 0.049. The big thing is I just want to make sure that I don't blow up the rifle or do any other damage. The rifle is brand new so I don't have an issue with age of the rifle.


How many other Reloaders go past the spec lenght that the SAMMI says it should be? I like the Nosler brand of bullets, I had excellant results loading the reloads to 2.800 but I want to have better results. I will make a dummy round and check to see if it fits in the magazine.

 

[Blaine]

How many other Reloaders go past the spec length that the SAMMI says it should be? I like the Nosler brand of bullets, I had excellant results loading the reloads to 2.800 but I want to have better results. I will make a dummy round and check to see if it fits in the magazine.

Everyone I know who hand loads exceeds the max SAAMI specs for OAL in most loads. The SAAMI spec's are so that the load will fit EVERY chamber and magazine out there. The easiest thing to do is measure the magazine length of each of your rifles and record it. That way when you start loading for that gun, you will know how long the OAL can be. As Joe has said, each bullet brand, type, & weight, etc has its own base to ogive length. That's what makes this sport so interesting. :lol:

Blaine

 

[richcale]

[quote]I will make a dummy round and check to see if it fits in the magazine.

That has always been the limiting factor for me. I don't think I've ever loaded a round to .015" off of the riflings and had it fit in the magazine. Another limit is the amount of bullet in the case neck after it is seated. With some bullets, there is just no way you can go to the maximum because the bullets aren't long enough. Just remember that the round doesn't have to just fit inside the magazine, it has to move in there too. If you are going to load for bench rest shooting then .015-.030" is the way to go. There you can handle them gently and feed them one at a time. If you are going to load for hunting, they have to function and hold up to being loaded and unloaded several times.

 

[hvy barrel]

The manual list cartridge over all length (OAL). That is from where the head stamp of the case & the primer are,I will call it the base,to the tip of the bullet. When you are using a tool, such as the Stoney Point OAL gauge. You are measuring from the base of the cartridge to the point where the ogive of the particular bullet you are using meets the rifling in the particular rifle you are measuring.
If you are also using the Stoney Point bullet comparator that attaches to your calipers. You are then measuring from the base of the cartridge to the ogive of the bullet, not the tip.
I hope this helps.

 

[rick smith]

The extra part of the bullet that concerns you is just sitting in open space in the barrel, as long as it fits the mag box and is not in contact with the lands you are fine.Rick.