Does OAL really matter...?

[redneckmedic]

In rifle hand loading,
Loaded straight into the bolt action's chamber,
Not using mag size as a variable....

Isn't getting a measurement from the rim to the ogive much more reliable?

Especially for accuracy?

 

[EvilBlackGun]

Ogive-to-lands ...

... is a better variable to watch.

<snip> Isn't getting a measurement from the rim to the ogive much more reliable? Especially for accuracy?

 

[sloughfoot]

It depends. Usually on the bullet. Some bullets jump with no loss of accuracy. Sometimes Bergers and other bullets with J4 jackets like to be jammed into the lands.

Some people "soft seat" all of their rounds. In other words, the rounds are extra long out of the reloading press and they get their final seat when the bolt is closed and locked. This is only viable in a competition rifle IMO.

But lots of folks do it. I am one of them for my 1000 yard bolt guns. As the barrels wears, it becomes a non-significant issue because the OAL length changes and is not noticeable.

Lots of folks spend a lot of time agonizing over minor variations in accuracy due to OAL length when wind and enviromental issues have a far greater effect over accuracy than variations of OAL.

 

[redneckmedic]

ogive to lands... is a better variable to watch.

That's what I getting at, don't you need the OAL to the o-give, and it make contact when the bolt closes to know how far to back it off? I am starting to realize that I could care less about everything that is less than o-give diameter as different bullets are different lengths past that point.

 

[IndyGunworks]

I am starting to realize that I could care less about everything that is less than o-give diameter as different bullets are different lengths past that point.

Thats it exactly. The ogive is the only the thing that matters and what the jump to the lands is based off of. some bullets like to be closer than others, but its the OAL (to the ogive) that maters, not OAL to the bullet tip (unless you have magazine length restrictions)

 

[redneckmedic]

Thats it exactly. The ogive is the only the thing that matters and what the jump to the lands is based off of. some bullets like to be closer than others, but its the OAL (to the ogive) that maters, not OAL to the bullet tip (unless you have magazine length restrictions)

This is what I was fishing for, then why does reloading data specs never list the oal to the o-give as well since chambering is just as important as fitting a round in a mag?

 

[billybob44]

I like this tool....

You have a point there RNM. I bought one of these awhile back+it works for me..

http://www.sinclairintl.com/.aspx/pid=35491/Product/Sinclair-Bullet-Seating-Depth-Tool

I have used this tool for .222 through 30-06, with many in between.

Some of my rifles do get into the magazine limitations, so on those I can not just seat .010" off of the lands.

Matt, let me know if you want to use this tool sometime...Bill.

 

[IndyGunworks]

This is what I was fishing for, then why does reloading data specs never list the oal to the o-give as well since chambering is just as important as fitting a round in a mag?

Because not everbody understands that, nor do they want to take the time to buy the tools that attach to their calipers to measure properly, let alone finding out what the jump actually is.

standard AOL's are published that way because every rifle and reloader are differant. measuring from base to tip is always going to be the same.

 

[shibumiseeker]

This is what I was fishing for, then why does reloading data specs never list the oal to the o-give as well since chambering is just as important as fitting a round in a mag?

Because reloading specs are "lowest common denominator" and if you know enough and are a skilled enough shooter with a high enough quality rifle to know what sort of difference the jump to the lands makes for the round you are loading, you're ignoring the OAL published in the specs anyway.

 

[billybob44]

measuring from base to tip is always going to be the same.

Because not everbody understands that, nor do they want to take the time to buy the tools that attach to their calipers to measure properly, let alone finding out what the jump actually is.

standard AOL's are published that way because every rifle and reloader are differant. measuring from base to tip is always going to be the same.

Well,,IG,-NOT really.

I usually do not spring for Hi $ bullets=Bergers and others. I shoot a lot of Hornady, and their Spire Point bullets can vary quite a lot. Some of the Milt. FMJ bullets will have a different length-bullet to bullet.

The SP bullets can throw off your OAL measurement.

I use the Sinclair tool with a bullet that Mic's in at the center of the average of 10 of the bullets of that lot, and set up my seater to .008"-.010" off of the lands.
Seems to work well to me..Bill.

 

[top hat 45]

Well,,IG,-NOT really.

I usually do not spring for Hi $ bullets=Bergers and others. I shoot a lot of Hornady, and their Spire Point bullets can vary quite a lot. Some of the Milt. FMJ bullets will have a different length-bullet to bullet.

The SP bullets can throw off your OAL measurement.

I use the Sinclair tool with a bullet that Mic's in at the center of the average of 10 of the bullets of that lot, and set up my seater to .008"-.010" off of the lands.
Seems to work well to me..Bill.

but if you are loading for a clip, oal does make a difference as stated above. bill, i fully understand what you posted about different length bullets from the same box, but ogive to land jump or even touching is much more important than concerning about different length plastic tip bullets. don't you agree.....daryll

 

[billybob44]

but if you are loading for a clip, oal does make a difference as stated above. bill, i fully understand what you posted about different length bullets from the same box, but ogive to land jump or even touching is much more important than concerning about different length plastic tip bullets. don't you agree.....daryll

You're absolutely right d. From the way I gathered it, Matt was measuring the OAL of each load, with a different length shown. I do not find that so much in a V-Max as I do in a Spire Point(With the soft lead tip)

The Sinclair tool that I use is used in conjunction with the exact bullet that you are loading, with the same ogive length.
On my Varmint loads in my 22-250 I like Sierra BlitzKing and Hornady V-Max...They are both great bullets, but they have very different ogives, even with same bullet weights.
With most (Med.-Heavy weight)bullets of the loads in my 6MM Rem. I can not load too far out and still clear mag. well.

I think Matt is loading in a .243Win. Bolt gun. It should have a plenty long enough mag well to be able to seat his bullets out to the max and still clear...Bill.

 

[Hazwhopper]

I think that OAL is a great starting point. It agains depends on your experience with reloading and with the weapon you are using. There are a few ways to measure the throat length of your chamber. The value of the OAL is achieving the proper seating depth of your bullet into the casing. The length of barrel, powder and primer help deteremine what the length should be. After starting out with a minimum load and working it up to a load that proves to be accurate for your weapon, then a reloader might start working up the seating depth of the bullet.
That is when the jumping might have an effect on accuracy. So force a bolt action rifle to push the bullet into the barrel so far that the bullet is 10 to 20 thousands in. That could make for a very dangerous situation for a person who hasn't much experience or knowledge of what they are trying to do and most likely the outcome of their actions. My first year was reloading at the manual's suggestions. I used at least 2 books and 1 internet source for all reloading. The most common discrepancy was that the barrel length was not the same as the book. So I would start under the recommended powder loads. I had learned from forums that if you don't know the seating depth for your barrel that you should give 10% more room for error. So if I were loading a 45 and the seating depth was 1.200 that I would increase the seating depth to 1.210 or 1.212. There was times that I had the die too low and the bullet would push down to 1.180. That seems like very little error but I don't know if it was too much or too little. So I would remove the bullet and reseat.
I found that my 1911 would jam or FTF because of bullet seating depth. If the hollow point was seated too long and the mag was short, while the barrel hood was too short it would cause the hollow point to jam into the hood and case a FTF. Round point bullets didn't have this trouble but they didn't have the same seating depth. I know this isn't rifle reloading but it does apply.
I reloaded some 7mm magnums for a guy. He was shooting factory loads and after 20 rounds of shooting he had at 100 yds a target with 6 to 7" of grouping.
I reloaded the 7mm and started with a reduced load and 3 different seating depths. There were 4 rounds each at the 3 different depths. I set up 3 targets. The first was 2" group. The second 4 rounds were just .005 deeper and the grouping was under 1". The third 4 rounds were again .005 more than the first 2. The grouping was back out to 2". He stated how the rounds were pleasant to shoot and didn't cause shoulder ache and the results were like nothing he had at that point.
So I reloaded 20 more rounds with 4 foulers and he shot 5 round groups and repeated the 1" groups except for 1 that had a flyer. He felt that he yanked on the trigger during that group.
He was pleased and I was really excited. I didn't shoot them but I was apart of tuning a round that worked for his weapon.
I reloaded another 50 rounds with 4 foulers. They were all the exact same length and load. If you have ever tried to reload 50 rounds that are exactly the same, it is a thing of beauty to me. We are going to be working on a 300 Win mag next while I am working up a load for 308 for Remington 700.
Good luck

 

[U.S. Patriot]

When I started reloading for my .308, I did what sloughfoot refereed to as "soft seating". I set my neck tension just enough to where I could seat the bullet by hand, but it would not fall into the case. I chambered it five times and averaged my readings. Does it make a difference? Compared to results on target compared to factory ammo, I say yes, and I'm not using match bullets either. I'm new to reloading for a bolt action, so I'm learning as I go.

 

[Broom_jm]

Aside from the truly long-range shooters, to whom this stuff really makes a difference, a few other posters may be over-thinking this just a tad.

Most of the well-made bullets today are remarkably consistent in their length. If you're shooting anything with a polymer tip or copper tip, like the Sierra Match King bullets, the odds are good that a simple OAL measurement is going to be just fine. Now, if you're shooting bullets with exposed lead tips that aren't really intended for extreme long-range accuracy, then how much does OAL really matter? With the right bullets, OAL will be consistent enough...with the wrong bullets, it is not all that important. Your gun/groups will verify this.

@ Hazwhopper -- Seating .005" deeper and cutting groups in half is not unusual, but it is pretty darn rare to see groups go from 2", to sub-MOA, back to 2"...in increment of .005". That, IME, is a VERY picky rifle/load combination. Still, it illustrates that seating depth can, and does, impact accuracy quite a bit.

What most folks do not realize is that seating depth has an impact on starting pressure of the load, which probably has a great deal more to do with accuracy than how far off the lands the ogive is. If you don't understand this concept, consider that MOST loads are tuned to excellent accuracy using nothing more than minor changes in powder weight, not seating depth. The two measurements both impact pressure and barrel timing. Combined with a high-quality bullet, tuning pressure and timing are what results in better accuracy. Adjusting your OAL is like super fine-tuning a load, whereas charge weight is fine-tuning. Make sense?

NOTE: If you attempt to use a "soft-seating" technique, please be advised that there are serious potential pitfalls associated with it. This should only be done with loads that are not at maximum pressure to begin with. This should not be done with loads that will be used for hunting; they probably won't fit in your magazine, anyway. Be aware that IF you have to extract such a round from your rifle, you may find the bullet stuck in the lands and powder spilled in the action of your gun. Bottom line: Soft-seating is a highly specialized technique, with limited application, that is best left to people who fully understand the ramifications of what they're doing.

 

[Skip]

In rifle hand loading,
Loaded straight into the bolt action's chamber,
Not using mag size as a variable....

Isn't getting a measurement from the rim to the ogive much more reliable?

Especially for accuracy?

I thought this was the ONLY way to determine the OAL for YOUR rifle.
Yes, your rounds may not fit in the magazine BUT they will work really nice when you get them into the chamber and pull the trigger.