Finding COL

[ksfowler166]

Does anyone have any tips or tricks for finding a rifles COL without destroying the brass or using a tool like the Hornaday Lock N Load Concentricity tool?

[Ben]

Is this for a bolt action rifle ?

[Dusty Bannister]

Cleaning rod/dowel method of finding cartridge OAL

This is what I use for my guns to determine the max OAL and this eliminates any question of the crimp, incorrect case prep, or other operator induced error.

This method works well on rifles and single shot pistols as well as Semi-autos. You can use a flat tipped cleaning rod, or flat tipped dowel rod. You will also need a sharp pointed pencil, a short dowel and a bullet sized but clean, of the type you are going to load.

For Rifles
Make sure the chamber is empty. Close the bolt, and be sure the firing pin is retracted into the bolt. Insert the dowel or cleaning rod and hold it against the face of the bolt. Mark the rod at the face of the muzzle. Remove rod, open bolt and remove it from the action. Insert the bullet into the breech and hold it snug into the rifling. While in that position insert the dowel or rod again, and with it firm against the nose of the bullet, mark the rod at the face of the muzzle.

The distance between the center of those two marks is the max cartridge OAL for that rifle, with that bullet sized to that diameter.

For Semi-autos
Remove the barrel from the slide and make sure it is clean and free of leading or other debris in the barrel and chamber. The dowel or cleaning rod needs to be longer than the barrel. Hold the barrel, muzzle up, and place the barrel hood on a flat surface like a table top. Insert the dowel or rod from the muzzle and mark the rod exactly flush with the muzzle. Remove the rod and insert the bullet you intend to use into the chamber and lightly press and hold it in place with the short dowel. Place the assy muzzle up on the flat surface. Insert the rod/dowel into the muzzle so it rests on the nose of the bullet and again mark the rod exactly flush with the muzzle. Remove and set the barrel aside. The distance on the center of the two lines is the cartridge OAL. Seat a dummy round to this length, or slightly shorter and begin to apply the taper crimp until the dummy passes the plunk test. This is the optomim cartridge OAL length for this bullet in this gun.

You may need to adjust the seater to shorten the OAL if this does not feed from the magazine, but generally this will be a great fit. Remember, if you seat and crimp in one step, you might force a slight ridge ahead of the case mouth and that will screw up your seating.

[aephilli822]

Cleaning rod/dowel method of finding cartridge OAL

This is what I use for my guns to determine the max OAL and this eliminates any question of the crimp, incorrect case prep, or other operator induced error.

This method works well on rifles and single shot pistols as well as Semi-autos. You can use a flat tipped cleaning rod, or flat tipped dowel rod. You will also need a sharp pointed pencil, a short dowel and a bullet sized but clean, of the type you are going to load.

For Rifles
Make sure the chamber is empty. Close the bolt, and be sure the firing pin is retracted into the bolt. Insert the dowel or cleaning rod and hold it against the face of the bolt. Mark the rod at the face of the muzzle. Remove rod, open bolt and remove it from the action. Insert the bullet into the breech and hold it snug into the rifling. While in that position insert the dowel or rod again, and with it firm against the nose of the bullet, mark the rod at the face of the muzzle.

The distance between the center of those two marks is the max cartridge OAL for that rifle, with that bullet sized to that diameter.

....

For testing how far the bullet jumps to the lands we used a very similar method. brass rod and 2 drill stops (collars with setscrews).
brass rod to the bolt and both stops on the rod at the muzzle. tighten the outer (away from muzzle) stop. gently push bullet into lands. tighten inner (closest to muzzle) stop, distance between stops is OAL to kiss the rifling.

[Hick]

I take a case and cut two slots on opposite sides near the neck, so that I can slip a bullet into the case and have it barely hold. Then put in a bullet with it barely in the case and carefully chamber it-- then take it out and measure COL. Do this many times and average and you can find out what COL fits your chamber.

[fast ronnie]

Hornady makes a tool with a sliding rod which screws into a case that has the primer hole drilled and taped. The case neck needs to be expanded so that a bullet will just slide. Bullet is placed in the case so it is a little on the deep side then tool is put into the chamber until it stops at the shoulder. The rod of the tool is then slid forward so the bullet just touches the lands. The tool is then locked and removed from barrel. The bullet usually stays in the barrel but can be pushed out with a cleaning rod or dowel from the muzzle. Place the bullet back in the case so it touches against the rod inside the case. This will be the true length touching the lands. It takes longer to explain it than to do it. The tool costs about $30 or so. The modified cases are less than $10. I made my own and was fairly simple to make. The tap was about $30 as I recall as it is a special thread. The thread is a 5/16 with 36 pitch. This is important because of thread depth being shallow. When doing this with a .223 case, the diameter under the extractor will be just enough to not break through. The threaded portion of the tool is partially cut away so that calipers can be used to check overall length or using an ogive diameter tool will give you the actual length from case head to the lands. Probably the most difficult part is holding the case reasonably straight to tap the rear of the case, but it isn't rocket science, either. It should be done in a lathe. Simple tool and can be purchased through any of the major suppliers. A fired case from that chamber is ideal, but not really necessary as long as the bullet can slide in the case mouth.

[Scharfschuetze]

Once you establish your OAL for a given projectile, measure your case base/bolt face to ogive length. You can now keep that length for use with bullets/boolits with different ogives without further machinations or OAL measurement. It involves measuring to the actual diameter of the ogive where it contacts the lands of the rifling. There are a couple of gauges available to do this.

Photos:

1. Stony Point ogive gauge (now marketed by Hornady)
2. Wilson ogive gauge
3. Cleaning rod stops for measuring the initial or overal length (OAL) of your round
4. OAL length of the example round

Once you get your initial OAL measurement, then it's easy to get the measurement of the bolt face to the beginning of the rifling with the Wilson or SP gauges.

The gauges are useful for any boolit design (jacketed or cast) as they give a measurement of diameter at the critical point and not of length. You can also use these gauges to measure throat wear of your barrel too. With them I have been able to track throat wear on several different .30 calibre match rifles as well as .223 calibre match and varmint rifles. You can then chase your lead forward (magazine length allowing) until the barrel is worn out.

Note that the base to lead measurement of this 7.65 Mauser is 2.700." First calibrate your caliper to read 1.000" by turning the dial to 0. The dial caliper will now read 1.000." Now insert your loaded round and measure. Both of these gauges now read 3.7000." Subtract the 1.00" of the gauge and you now have your base/bolt face to lead/rifling measurement. In this case 2.70."

The actual Overall length of the round is 3.049." This will not be the same for a different styles of projectiles, but the measurement to the ogive with the gauge(s) will remain constant from style to style. Just record the measurement in your loading data for each rifle and then set up your seating die to load to that length when changing boolit designs and you'll be good to go.

[eagle27]

The OP asked for tips or tricks for determining maximum COAL without destroying brass or needing to use tools purchased for this. Dusty B answered the question perfectly and is the only method I use. Quick and simple to do for every bullet you may want to use in your rifle. Use fine biro for your first mark and it will remain on your cleaning rod and is the set point from muzzle to bolt face, which by the way when measured from that mark to the tip of the cleaning rod is the true barrel length of that rifle.
To set your jump to the rifling for any bullet just subtract however many thou of an inch you want from the maximum COAL and that becomes your operating COAL.

The other answers involved destroying brass and using specific tools!!

[toallmy]

Magic markers on the bullet ,and play with the length until you see when the bullet touches the rifling .

[Hickok]

Keep seating the boolit until the round fits in the magazine!:bigsmyl2:

[Landshark9025]

Cleaning rod/dowel method of finding cartridge OAL

This is what I use for my guns to determine the max OAL and this eliminates any question of the crimp, incorrect case prep, or other operator induced error.

This method works well on rifles and single shot pistols as well as Semi-autos. You can use a flat tipped cleaning rod, or flat tipped dowel rod. You will also need a sharp pointed pencil, a short dowel and a bullet sized but clean, of the type you are going to load.

For Rifles
Make sure the chamber is empty. Close the bolt, and be sure the firing pin is retracted into the bolt. Insert the dowel or cleaning rod and hold it against the face of the bolt. Mark the rod at the face of the muzzle. Remove rod, open bolt and remove it from the action. Insert the bullet into the breech and hold it snug into the rifling. While in that position insert the dowel or rod again, and with it firm against the nose of the bullet, mark the rod at the face of the muzzle.

The distance between the center of those two marks is the max cartridge OAL for that rifle, with that bullet sized to that diameter.

For Semi-autos
Remove the barrel from the slide and make sure it is clean and free of leading or other debris in the barrel and chamber. The dowel or cleaning rod needs to be longer than the barrel. Hold the barrel, muzzle up, and place the barrel hood on a flat surface like a table top. Insert the dowel or rod from the muzzle and mark the rod exactly flush with the muzzle. Remove the rod and insert the bullet you intend to use into the chamber and lightly press and hold it in place with the short dowel. Place the assy muzzle up on the flat surface. Insert the rod/dowel into the muzzle so it rests on the nose of the bullet and again mark the rod exactly flush with the muzzle. Remove and set the barrel aside. The distance on the center of the two lines is the cartridge OAL. Seat a dummy round to this length, or slightly shorter and begin to apply the taper crimp until the dummy passes the plunk test. This is the optomim cartridge OAL length for this bullet in this gun.

You may need to adjust the seater to shorten the OAL if this does not feed from the magazine, but generally this will be a great fit. Remember, if you seat and crimp in one step, you might force a slight ridge ahead of the case mouth and that will screw up your seating.

This. ^^^

While the other methods likely have their uses, if the goal is to determine OAL, this is the easiest and cheapest method. At most you are out a fine point marker. MAYBE a length of dowel rod. It works well and it's cheap. Which I believe is the bullet caster's ethos.

[ksfowler166]

Thanks guys finding the COL for my Swiss K31 is driving me up the wall. I have tried several different methods and get different lengths for each. So far I have tried three bullets; Sierra 168gr MK HPBT, Sierra 165gr GK HPBT, Lyman 311466 160gr.

For the Lyman by using the method Dusty suggested I got 2.590", by loading a bullet into a new unfired case and closing the action I got 2.60" (this is corrected for bullet jump), by using a combination of the first two I got a couple thousandths larger than the second method.

For the Sierra 168gr using Dusty's method I got 2.728", by seating the bullet until the case would fall out of the rifle I got 2.770", by loading a bullet in an unfired case I thought that they were in the 2.775" to 2.790" range maybe 2.880" on the longest but when I just tried it I got 2.945". I tried smoking the bullet using a case set to 2.770" and could not see anything I definitively thought was the rifling.

For the Sierra 165gr by using Dusty's method I got 2.757", by loading a bullet into an unfired case I got 2.833", and by using a combination of the first two I got 2.830".

I am so confused I don't know what is up and what is down. I know that the other methods that I tried besides Dusty's are not recommended since using an unfired case the bullet's movement will be inhibited. Hence the recommendation for a cut case mouth or a fired case for an accurate reading. But the lengths I got using the method Dusty described seem and look awfully short especially when you take .020 off for bullet jump.

[aephilli822]

that's why I suggested the brass rod (could use cleaning rod, I guess, but it needs to be flat on the "bullet" end, and all of mine have female threads) and drill stops.
every time I used the "sharpie" method, the mark was wider than .010" - .020" and that was not accurate enough. (tying to get .005" to .010" off the lands)
whole setup cost me 10- 15 bux

[aephilli822]

http://www.sinclairintl.com/GunTech/Determining-Bullet-Seating-Depth-/detail.htm?lid=16131

like the pic under the scope, but at the muzzle end
the rod moves from touching the bolt to touching the point of the boolit, that's the (maximum)OAL, right?

[GunsAndHarley]

I take a case and cut two slots on opposite sides near the neck, so that I can slip a bullet into the case and have it barely hold. Then put in a bullet with it barely in the case and carefully chamber it-- then take it out and measure COL. Do this many times and average and you can find out what COL fits your chamber.

Dito! I dip the bullet in pink stuff calamine lotion I think, then cycle the dummy round. The pink stuff get a mark and you see where it start to touch the rifling. Work good for me.

[Stewbaby]

I've use the methods Dusty and Hicks outlined. For a K31 with the short throats, 2.8 is the neighborhood (can't go by the books that are based off GP11 and the 1911 &K11 chambers). 2.870 in what I ended up with in my two rifles and a Hornady 168.

162317

[eagle27]

Thanks guys finding the COL for my Swiss K31 is driving me up the wall. I have tried several different methods and get different lengths for each. So far I have tried three bullets; Sierra 168gr MK HPBT, Sierra 165gr GK HPBT, Lyman 311466 160gr.

For the Lyman by using the method Dusty suggested I got 2.590", by loading a bullet into a new unfired case and closing the action I got 2.60" (this is corrected for bullet jump), by using a combination of the first two I got a couple thousandths larger than the second method.

For the Sierra 168gr using Dusty's method I got 2.728", by seating the bullet until the case would fall out of the rifle I got 2.770", by loading a bullet in an unfired case I thought that they were in the 2.775" to 2.790" range maybe 2.880" on the longest but when I just tried it I got 2.945". I tried smoking the bullet using a case set to 2.770" and could not see anything I definitively thought was the rifling.

For the Sierra 165gr by using Dusty's method I got 2.757", by loading a bullet into an unfired case I got 2.833", and by using a combination of the first two I got 2.830".

I am so confused I don't know what is up and what is down. I know that the other methods that I tried besides Dusty's are not recommended since using an unfired case the bullet's movement will be inhibited. Hence the recommendation for a cut case mouth or a fired case for an accurate reading. But the lengths I got using the method Dusty described seem and look awfully short especially when you take .020 off for bullet jump.

Using my method (same as Dusty's) I use my PH yellow rod which I think is 30cal and it fits snuggly in both my 6.5 or 7mm barrels. Without a jag on the end it has a threaded flat end which when put down the barrel from the muzzle it bottoms out on the closed bolt face. Held firmly against the bolt face, spin the rod while hold a fine biro against the plastic coated rod at the muzzle end.

Now remove the bolt and insert a bullet of your choice into the chamber and push it in until it is firm against the rifling usually you can use your little finger to do this or a sized case will do the same. By alternatively pushing the rod and pushing the bullet back and forwards you will ensure the bullet is up against the rifling. While holding the bullet in place with the rod against the tip, mark the rod again with your biro or sharp pencil at the muzzle. The distance between the two marks can now be measured and set on your calipers. This is the OAL of a cartridge loaded with that bullet with the bullet touching the rifling. You can either set this as your usable OAL, bullet just touching the rifling or set the calipers for a few thou shorter OAL.

I have only ever used this method in loading for a range of cartridges over 40 odd years. Nothing convinces me I need any other.

[Tom Myers]

that's why I suggested the brass rod (could use cleaning rod, I guess, but it needs to be flat on the "bullet" end, and all of mine have female threads) and drill stops.
every time I used the "sharpie" method, the mark was wider than .010" - .020" and that was not accurate enough. (tying to get .005" to .010" off the lands)
whole setup cost me 10- 15 bux

Use a wood dowel and cut the marks into the dowel with a knife blade laid flat upon the muzzle. Then set the point of each caliper blade into the cuts. That should be precise enough for "Government Work".

[aephilli822]

Use a wood dowel and cut the marks into the dowel with a knife blade laid flat upon the muzzle. Then set the point of each caliper blade into the cuts. That should be precise enough for "Government Work".
:drinks:

[MostlyLeverGuns]

Are you shooting single shot or using the magazine. Magazine length may dictate COL if you are not loading single shots manually. The ability to extract a loaded cartridge should also be considered. Accuracy may or may not be better at 'maximum' length when only the bullet to throat/rifling length is considered. Measuring maximum length may help, but it is not the only factor to consider.

[porkchop]

Tom, I used your method before and if you are careful not to force the dowel it is a very accurate method. I use a sharp knife and the points of the caliper fit perfectly in it, much more accurate than metal rods and trying to hold calipers on same side of your mark on rod. I like your phrase "Government Work" ,for me repeating the measurements over and over is accuracy.
Stan

[JeffG]

Use a wood dowel and cut the marks into the dowel with a knife blade laid flat upon the muzzle. Then set the point of each caliper blade into the cuts. That should be precise enough for "Government Work".

this is what I do as well, use a razor blade. For those that only have a cleaning rod, just put a piece of electrical tape in places where you will make a light cut.

[Blammer]

I use a black magic marker.

simple, easy, effective

[Hickok]

I use a black magic marker.

simple, easy, effectiveAnd I have to use a good magnifying glass with the black magic marker. You can see the Oh so tiny little rectangles as the begin to fade out as you increase seating depth.

[toallmy]

Yep that's what I do . And my reading glasses .

[John Hill]

Thanks
John

[trapper9260]

Have any one try to do the OAL this way that is shown on this video?

https://www.youtube.com/watch?v=kaA3GECbbVA