Did some C.O.L. measuring this morning.

SAAMI is - 2.350"

Federal Factory round is - 2.310"

To my Rem 700 lands w/50 V-Max is - 2.530"

Questions ...

Where would you start and how much each time?

Example:

I'm thinking of starting out at C.O.L. 2.410" and easing up to 20 thousandths off the lands in .020" steps.

2.410"
2.430"
2.450"
2.470"
2.490"
2.510" (at this length, exactly .224" of the 50 grain V-Max is in the case mouth/neck)

Just for general info, what's your .22-250's C.O.L.?

And ... have you ever witnessed an accurate round become markedly more accurate when a certain C.O.L. was reached through stepped testing, as described above?

Thanks!

Mike TBC

[ 08-17-2003, 20:15: Message edited by: The Birth Controller ]

My Remington 700 22-250 shoots best at 2.42", touches grooves at 2.53". So?? go figure just play around with it. But, first try all same depth and different charge of powder and see which charge wt. works, then try .04" to each side of where you got those results. Burn up all that powder then try different ones. I like IMR 3031, but also got good results with H-380.

The OAL is one of the biggest factores in accuracy IMO. I`ve seen more than afew rifles drop a couple tenths with the right jump to the leade. I try varying the oal starting at the lands and working down instead of going up to the rifleing to avoid possible pressure spikes. I normally quit at .050 from the lands unless it appears the accuracy is improving at the shorter lenght. I load at .005" increments bracketing the lenght that seems the best with my first test to fine tune the load.
Remember too that the OAL will change with a new wgt, style or brand of bullet. The distance from the lands is what you want to record and load to. Some bullets may excede SAMMI OAL at this measurment while others will fall short.

Just noticed your post below. Work up your load then play with the OAL. Only change one thing at a time when looking for your best accuracy. I consider OAL to be a way of fine tuning your load, not a part of the work up process.

[ 08-17-2003, 20:28: Message edited by: Ol` Joe ]

If you want to be that precise I'd suggest getting a Stoney Point Overall Length Gauge and the related modified cases along with a bullet comparator from sinclair, stoney point or whoever. With the overall length gauge you will know exactly where the bullet is touching the lands and then you can reduce that measurement by a couple of thousandths and be in good shape to start. With the bullet comparator you can measure the bullet on the ogive and not have to deal with the exposed lead in some bullets being deformed in shipping and giving you different measurements. When you are talking about a few thousandths difference you cant get that kind of accuracy with each bullet's tip being deformed differently. Polymer tipped bullets are a touch longer (different ogive measurement) than spitzer type bullets and thus can be seated out a little longer before touching the lands. Hope this doesn't thoroughly confuse you because it sure did me.

[ 08-17-2003, 20:55: Message edited by: Hold 'em ]

Trying to measure col can be very tricky. Different bullets have different ogives and measuring deformed soft-nosed bullets is an effort in futility.

Get yourself a tool that measures col to the datum line of each bullet...that way you will reduce the margin for error. I happen to use a Stoney Point tool, but there are others. Also, don't be afraid to seat bullets one caliber deep; eg., .224 in the case of the .22-250 or about to the juncture of the neck and shoulder.

Here's an example of seating depths in my Browning 1885 single shot rifle. To the datum line NOT to bullet point.

Remington PSP 50 2.016"

Berger HP 50 2.052"

Nosler BT 50 2.050"

Shilen HP 52 2.070"

Sierra HP 52 2.062"

Speer HP 52 2.025"

HornadyVmax 55 2.075"

Nosler BT 55 2.065"

Sierra Sp 55 2.065"

My suggestion would be to start your chosen bullet .030" off the rifling, and then adjust depth closer or farther in .010" increments. If you find a marked improvement, go in .005" increments until you find what your gun likes best. I've never seen a dramatic improvement in group size when changing seating depth of .010" or less. Case brand and charge weight seem to matter more to my varmint rig.

I've all but given up on this aspect of reloading. I reload for 11 different calibers so I use Gawd only knows how many different bullets, probably close to 75. The chambers are ridiculously long with Remington being very long and Sako being closest to SAAMI specifications. Actually on many bullets I cannot even reach the lands. On most I'm reduced to shooting single shot since they become too long for the magazine. I'm switching more in recent years to European rifles since they at least follow the SAAMI specs. Our North American companies do as they damn well please. I don't know, or really care, how much of this is lawyer driven. Best wishes.

Cal - Montreal

The Birth Controller: Somebody once said "each Rifle is an individual"! I could not agree with anything spoken, more completely!
I have obtained best accuracy in many Rifles while seating the bullets several hundredths of an inch from the leades of the Rifling! And specifically to anwer your question about noticing best accuracy at a particular distance from the Rifling - yes I have noticed that many times! Conversely I have never taken a Rifle and obtained acceptable accuracy and then went back and started testing different O.A.L.'s for poorer accuracy!
I would estimate over the course of four decades trying to wring all the accuracy I can get out of my Rifles that about 80% of the time the closer to the leades of the Rifling the bullet is seated the better the accuracy! 20% of the time a Rifle will produce excellent accuracy with the bullet backed away from the Rifling. Bullet seating away from the lands is mandated by several different factors. Sometimes it just has to be tried/done! I have never tried a loading where the bullet is seated touching the Rifling! I do not endorse that practice for any Hunting or Varminting Rifle.
I use the WONDERFUL Sinclair bullet seating depth tool! My tool is still in the original packing tube and is marked $17.00! That my friend is the best $17.00 I have ever spent! I also use a bullet comparator tool and have for 20 years now. I had to have one specially made to work on 17 caliber cartridges but that also was a very modest and well spent amount of money.
I will add to the list of long throater companies out there the Ruger Company! They in my experience are the longest throaters of any factory - bar none!
I have several friends and acquaintances that always bemoan the fact they are not able to "seat out to the lands" of a particular Firearm! But they most often can get good to excellent accuracy from that Firearm anyway! Perhaps in the back of their mind is the nagging thought that the Firearm will magically start shooting one hole groups if they could only seat to the lands! I do not think so! I will repeat 80% of the time in my experience the closer to the lands the projectile is seated the better those Rifle/ammo combos will shoot - but not always!
I recently brought on line a splendidly accurate Remington 700 heavy barreled Rifle in 220 Swift. It has a Leupold 8.5X25 scope on it! I used my nifty Sinclair tool and set my dies up for bullet seating .002" off the leades, made up some test loads with a bullet I wanted to use! Wonder of wonders those test loads shot wonderfully (52 gr. Speer Flat Base Bullets) but I found out to late they would not fit down in the magazine! I should have checked right off but in my mind the 52 gr. bullets should have been short enough (at that weight) to fit in a magazine well for Petes sake! NO! So I had to return from the range with this bad thought in my mind - I hope the accuracy does not diminish when I have to seat for the magazine over all allowable length! Not to worry though my SIGNIFICANTLY shortened cartridges shot just wonderfully also in that Rifle! I am sure I shortened those bullets O.A.L. by .08"! I may have the exact figures downstairs. I will check and add if found later.
Anyway being unable to seat to the .003" jump to the leades as many advocate is not the end of the world accuracy wise. I have proven that to myself many, many times.
Good luck with your rig!
Hold into the wind
VarmintGuy

Varmint Guy ...

Your posts are a delight to read!

Thanks for the info!

Mike

I agree fully with Varmint Guy, in my 22-250 using the 55gr flat base Sierra bullet or the 52HPBT Sierra I just seat to the overall length that Sierra states. I get what I consider very good accuracy with the loads seated this way.

Good Shooting,
George