Home Forums Hunting & Shooting Ask The Gunwriters How do you determine COL?

I should add....when I work up loads in Quickload, I back off the max pressure quite a bit. No need to push it and it compensates for different burn rates in different lots of powders.

The few times I did use a chrono, my Quickload data was spot-on.

I do it similar, just backwards. I start by finding the lands and then check to see if it fits in the magazine.

I like the Lee collet neck sizers. Its easy to put a little squeeze on a fired case neck. Sharpie up a bullet and seat looong. Close bolt on round, remove, measure. I'll do it a few times.

I also like to take a drill and drill out the primer hole on the piece of brass im using. Makes it easy to push the bullet out if its seated a little tight. Mark and keep the dummy round.

I have never been told my advice is potentially dangerous, never by editors, powder suppliers, bullet suppliers or rifle and scope manufacturers who entrusted me with their products for review. No-one has ever had the gall to call me a puzzy to my face either. I suspect you would not either.

Read my bi-line. My comments are free to accept of dismiss, as incidentally, are yours. The readers will decide what is of interest to them and I am ok with that.

Time you wrote a book perhaps?
The End.

Too phugging funny - now you're going the Big Squeeze (AKA Big Puzzy) route.

Your publishers didn't have a probem cause you didn't write the same stupid advice like you did here. Why don't you publish an article telling people to develop pressure loads at reloading manual OAL, NEVER CHECK your rifle's MAX COAL then start walking their seating depth out. Let me know if you get that published with no disclaimers.

You might be surprised what I'd be willing to tell you face to face. Feel free to shoot me a pm, we'll see what we can work out.

David

Give it a rest buddy and stop ruining another thread.

I don't believe a single group like that tells anything for various reasons noted in prior posts, but a series of them can give one some data points to indicate a trend.

E.g., if one is working up a pressure series with a new rifle or new bullet, you might fire several three shot groups with incremental powder charge increases to let you know when you're getting near max pressure - I use a good Oehler 35 to do this. If one of those groups is 2 and 1, that means nothing. If all of them are 2 and 1, that is an indication that the bullet should probably be seated deeper. If they are all round but big, the bullet might benefit from being seated deeper.

But like almost all absolutes, there is no absolute. If you're working with certain powders like Ramshot TAC, a likely result will be mediocre grouping at starting loads right up until you hit a certain pressure, when all of a sudden they land in a tiny group with no other change in seating depth.

But like Mule Deer is saying, three shot groups are really only good for internet bragging. I like 4 shot groups even when starting a pressure series, and once everything gets to where I like it, then I'll fire a 5 shot group at least and sometimes a 10 shot group just to see what the rifle/load combination is really capable of over the long run.

It's like someone explained flying to me - science vs. art. The plane flies because of pure physics, flying it correctly is art. The rifle and load will shoot the way they do due to some ungodly number of physical variables, some of which are important and some less so and most I for one am at a loss to detect or analyze in minute detail. But the art is keeping an open mind and watching what trends seem to repeat themselves and then following that trend to a successful conclusion, whether or not I totally understand it.


Not trying to lecture you personally, since after 46 years of stuffing cases I'm still very much a student of the art, just philosophizing on a rainy Saturday morning.

Likewise.

I might have lied a little too..I've picked up several things from you over the years.

GFY

David

Only reason that I measure the distance to the lands is to make sure that I don't accidentally load a hot load into the lands. Magazine restrictions keep me from loading to the lands in every rifle that I own, but I always check again when using a new to me bullet. I try not to load hot on top of that. miles

That's a good point Miles.
I was once given a project to develop a common load for 3 rifles.

The cartridge was the .300 Winchester Magnum and the bullet provided was the 180gn Winchester Failsafe Bullet.
The 3 rifles were a Sako Finbear, Ruger 77 Stanless and a Remington 700.

Although it was relatively easy to find an accurate load that shot well in all rifles, it was the Ruger that determined the OAL for each rifle, as the intention was to use common load they could share.

The range I used had a single load policy so it was a slow process but concluded to the satisfaction of all.

John

Which is it? Seems like you're saying now it is imprtant to check MAX COAL for safety?

David

John,

Over the years I've often ended up with odds and ends of handloads, worked up for rifles loaned for testing, or that I no longer own. I used to break those down and "redistribute" the components, but anymore just tend to shot them up in other rifles. Sometimes I have to seat the bullets a little deeper, but often I don't--and generally they shoot pretty darn well!

Of course, a lot of factory ammo shoots pretty well in a lot of rifles, too....

A first year manufactor AccuBond compared to one manufactured a year or so later.





b

I've found Aussie's advice to work pretty often also.

I've also found that most load "workup" is moot until one gets the pressures about maxed out with any of the new powders.

Thanks Jim!

I'll be watching group dispersion more carefully.

I have failed miserably by assuming I'd found a great load based upon single groups...
For the record, almost anytime I have bragged about a 3-shot trifecta by posting it on the innerwet, it was not some random anomaly - just the best of the best. There not a thing random about a 22-250 pasting them in the tens, a 243 in the 2s or 30 cal cloverleafs. All factory barrels and self accurized. Now if I can just get my current fleet to shoot as accurate I'll have it made. Appreciate Everyone's input, as much as or more than ever. Whenever in question about something I'll do a little Google searching and find myself dismissing other sites, not always, but hopefully finding 24hourcampfire threads, new and old, reading those with most interest. Have learned a fair deal from many, some how to be a grade A asshat (which I have freely passed along to others), and other posts by men of decency sharing a wealth of information and reason. Thanks to all.

Of it all, I only feel one apology needed be offered, that's to jwp475 for a name calling rant a few years ago, not sure why I thought that necessary, was a piss poor attempt to make a needless point. Sorry.

Oregontripper

There is a lot of good advice on this thread but something is missing.....so I'll cover it.

There are actually 2 kinds of OAL.
The first kind, which is the most commonly asked, can and will vary from rifle to rifle and again from bullet to bullet and case to case (which effects the amount of bullet exposed from that case in reaching that OAL). This is commonly called distance to lands but it can also be distance from bolt face to lands if the case is slightly undersized and even if it is close enough to headspace safely.

This is the one I ignore because some rifles can have this OAL determined and the round will not fit in the magazine box, being too long to either fit or function without hanging up during cycling.

The second OAL which is infrequently spoken of, is the one I defer to.
As MD stated, you can shoot off old un-tailored loads in any rifle and most of the time they will shoot satisfactorily.

Some un-tailored rounds have a short OAL exampled by factory rounds which are designed to chamber and go bang in every rifle so chambered.

An example of that would be my .25/06 which has a custom throated chamber again, for which I have never measured, because I simply do not care what it is. It is a match grade barrel and will shoot with just about anything I put though it including the Vortex Factory loads provided to me from Barnes, with an OAL of 3.085" compared to my tailored handloads which have an OAL of 3.270".

The barrel is as I said, match grade so they all shoot together even with that disparity. Because shortening an OAL tends to decrease pressures and again as MD stated, if the slightly undersized case designed to fit "any" chamber yet still be safe, permits the primer to back out and re-seat upon case expansion to chamber, the primer will be flat in a case that is nowhere near dangerous levels in pressure so gives a false reading if you don't understand this.

The bullet seating depth which ultimately determines that cartridge OAL can vary in the amount of exposed bullet depending how tightly the case fits the chamber when resized or sized if a new factory unfired case.

Change the bullet and the ogive changes and alters the OAL again, distance from bolt face to lands. Batch to batch variation in bullets means that too, can alter the OAL if you check it that often.

For all the above reasons, I do not check this bolt face to lands OAL as it can generate a bullet seating length that may not fit the magazine for fit and function.

Hence my suggestion that using the group shape can better in my case and for my purposes, determine where an OAL needs to be to both fit and function in the magazine and also provide the optimum accuracy from that batch of bullets in that particular chambering and in that particular rifle.

Some rifles have acceptable accuracy to some and yet the same rifle in the hands of a "bullet tuner" such as myself, will make minute alterations to seating depth based on the 1/4 turns I described earlier, based on the shape of the groups being averaged. Not let me stress that some rifle fine tune in minute setting changes and a 1/4 turn is too much. How much you turn and what is acceptable accuracy is an individual choice.

A single group means little which is where most writers lost favor with benchrest shooters decades ago, but they look pretty in articles. Everyone has a good day but that is likely not a "representation" of how that rifle performs with that load.

I will continue to offer advice based on what I know to be true by qualifying that it is true. Most writers will not post on the net when they can get paid for the same words in print. There is a reason for that as demonstrated in previous posts.

There is another thread on here talking about the best contributors that have been lost because of the internet tough guys and their insults that contribute nothing to the discussion.

John Wayne once said, "a big mouth doesn't make a big man". Imagine what he would think of the internet?

Merry Christmas to everyone.

John

No disrespect meant...but I think it's reckless to say this without any detail as this goes against everything about COL and pressure that we've (or maybe I'm alone here) learned to date.

i.e.: Somebody trying to act on this statement and not knowing details could get hurt or killed.

Mule Deer talked about that in a prior post here. In a handgun round decreasing OAL decreases the combustion chamber (powder space) significantly and does indeed increase pressure.

But in a rifle decreasing OAL allows the bullet to build up more momentum before it hits the rifling so the pressure doesn't build as high - up to a point, and I think MD mentioned something like a 1/2" decrease in OAL as a good ballpark.

The Hornady manual has a good discussion of how seating depth affects pressure, pages 24-27 in the current 9th edition but previous editions have the same discussion and pictures going back as far as I've owned one.

Not reckless at and is an absolute fact in a rifle which is what we are discussing here. The closer to lands increase pleaser. This is well documented. Chub Eastman wrote an article about thus with pressure data to back it up.

John,

It's pretty simple - advocating increaseing COAL on a pressure load w/o first determing MAX COAL is stupid, unsafe and reckless. 14+ paragraphs in one post and you address all kinds of straw men, bit not the probelem with your first post in this thread - which is the ONLY thing I took issue with.

I know you were wrong, you know you were wrong, everybody that understands reloading knows you were wrong. Please, continue to swell up and blame me for your own stupidity and the inability to climb out of the monster hole you've dug in your own credibility.

One more thing - You were the internet tough guy that was making it clear " I wouldn't have the balls to say that to your face", not me...

David