Howdy all,

Question on Overall Length for the Ruger No. 1

I'm fairly new to reloading, and I have some concerns. Hopefully someone could point me in the right direction and lend some experience. I've gotten a few ideas from another board, but more is always better.

My total chamber length, to the lands, is 3.850"

I'm using H4895, which I see from burn rate charts has a relatively mild if not slow burn rate. I would like to get the bullet fairly close to, if not touching the lands when working up a load. However, all the manuals I've seen shows a COL of 3.600"

So, I'm using a 270gr SP and I'd like to see if anyone else has loaded for the No. 1, what COL's are they using, and how are the results?


Many Thanks
EMC2

I don't know the Ruger #1's typical throat length in that caliber, but because it is a single shot you don't have to pay attention to OAL. OAL is important in the ammunition industry because loaded cartridges have to feed from magazines that are built for standard length cartridges. If you are feeding from a magazine a long round may not fit, even if it is the right length for best accuracy in that gun. No magazine, no OAL limit.

As to loading for best accuracy, this varies with the gun. Some shoot best with bullets just kissing the lands, while others want them backed away several hundredths of an inch. The measurement for the bullet off the lands is the distance it has to move from its seating position in the chambered cartridge case to it actually touch the lands on its way down the tube. So this is usually a matter of hundredths of an inch, but is usually given in thousandths (mils - a thousandth of an inch is an English system mil). Thus you may hear someone speak of a rifle that shoots best with the bullets seated 30 mils off the lands. This means the bullet only has to move 0.03" out of the case to encounter the throat (the start of the rifling) in the bore.

The easiest way to determine this seating position is with the Stoney Point seating depth gauge and a caliper. Gander Mountain carries these, as do numerous on-line gun stores. In the #1 you can use either the straight or the curved version that was designed for gas gun measuring.

Use the gauge to find the point where the bullet you are loading touches the lands. Pressure can go up significantly when you touch the lands, so I don't even like to start a load workup with the bullet in this position. Seat it 0.005" deeper, then fire a minimum load. Tip the gun up and lower it slowly before touching off each shot. This puts the powder where it gets the best ignition and creates the most pressure it is going to for that charge. You want that so you can't accidentally work up a load that works fine when the powder falls forward in the case, but generates too much pressure when it is rearward. This is why shooters like to find powders that just fill the case at best accuracy. Then they don’t have to worry about it changing behavior when they position the gun differently.

Keep seating the bullets deeper in 0.005" increments until you find what is the most accurate seating depth in that gun with that minimum load? Once you have the best bullet position, then start working up powder charges looking for the most accurate load. In the end you'll have the best combination for your gun. Any time you change powder and bullets you will have to do this over.

If you don't find the perfect seating depth using the above method, you may have to actually touch the lands. If you do, start your load workup with an extra 5% off the minumum powder charge just to be safe.

Nick

EMC2,
3.60 is Max OAL for the .375H&H, but with a spitzer bullet in a Ruger #1 you can go a bit longer. If you dont have the Stoney Point tools, you can still figure out your own gun's Max OAL with THAT PARTICULAR bullet.

First, I take and trim to length a fired, UNSIZED case.

Second, dimple the mouth slightly in one spot so that you can press with your fingers the bullet you want to use into the case and it will hold against light fingertip pressure. You want the bullet to hold position but move if meeting resistance. Leave the bullet seated longer than Max OAL. Start with +0.10", you may need more.

Third, carefully load your rifle pointed in a safe direction and close the breech.

Fourth, Open the breech and carefully extract the round.

Fifth, measure for overall lenght to nearest one thousandth of and inch.

Sixth, Repeat the whole sequence to get a good group of measurements.

This should show you how long that bullet and case combo should be to TOUCH the lands.

IMPORTANT!!!! BACK DOWN from that measurement to your optimal overall length.

This should be over the 3.60" OAL.

This will work to find where your lands begin in relation to the ogive of a particular bullet but in magazine rifles you can't forget magazine length.

Did I miss anything? If I did, there are others here who know this stuff better than I do who will catch it or give you more insight. They're so good, even I listen. :)

I like the idea behind MMichaelAK's method, but if you are shooting match or hollow point bullets, the noses won't be quite identical. It is just one of several problems with O.A.L. measurements, and why taking measurements off the ogive of a bullet is really more reliable.

The other old fashioned method is to make a standard dummy.

Resize and trim a disposable case. Do not prime it. Open the action and point the muzzle down, resting it on a piece of carpet scrap or other pad to protect the crown. Drop the case into the chamber. If you have a caliper, use the depth stem to measure the distance from some repeatable point on the back edge of the receiver to the case head. If you don't have a caliper, drop a dowel rod down in onto the case head and mark a registration line on it flush with some part of the back of the receiver. This establishes the case against its headspace determining surface. It is as far forward in the chamber as a sized case will go.

Adding no powder, seat a bullet too far out in the case. Drop the dummy into the chamber. Use the caliper or mark the dowel to show how much too far out it is. Adjust the seater die and further seat the bullet in steps until the case is almost, but not quite fully back into the position the empty case dropped into.

Color the bullet with magic marker or smoke it with soot or coat it with high spot blue. Drop it in again, then point the muzzle up and drop it out. You should see rifling throat marks on the bullet. Repeat this process, seating about 0.001" deeper every time (about 5° of turn on a standard 14 TPI die; on a competition seater die, just use the micrometer barrel graduations). The last time you do this, the marks should grow faint and almost, but not quite disappear. You should see them all around the bullet. The case head should measure all the way back into the position it was in when it was empty.

Load and mark a minimum load using the current seater position. Run a patch with acetone or Gun Scrubber down the barrel to clean away remaining marking color. Color the bullet on the new minimum load and drop it in. It should mark the bullet, but mark it a little more than the dummy did because multiple seatings will push a bullet a little further than a single stroke (it springs back slightly).

If the marks look too deep, run the same bullet into the seater again without adjusting the seater, and mark and check it again. If this looks good (adjust the seater if it doesn't), load 4 more rounds this way and mark them "0". Run the die in another 0.005" (25°) and load 5 more minimum loads and mark them "-.005". Run the die down another 0.005" and load 5 more minimum loads and mark them "-0.01", etcetera, until you have 50 rounds loaded.

Now go shoot groups of 5 with the cartridges of matcing seating depth. Note which group is smallest, and read the seating depth off its cases. If you have two adjacent groups tightest, pick a number in between. This is the best seating depth for this bullet in this gun. It won't necessarily be the ones touching the lands.

Reset the seating die to match the best grouping rounds. Seat the dummy with the die in this position. Tip the dummy nose down and squirt a dozen drops of superglue down in and let set up overnight upside down. Wipe any excess glue or white surface bloom that forms away with acetone or nail polish. This is now your reference dummy for this bullet in this gun. To set up your seating die for this combination in the future, just drop this dummy into the press and screw the seater down until it just makes contact with the bullet. Load away.

Now, using the newly found optimum seating depth, work up from the minimum load to the best grouping safe powder charge.

Nick

Nick, you are right.
Change bullets and you have to do it all over again with the new bullet. So long as you are off the lands and still have good neck tension on the bullet, you can use match bullets in the Number 1 as the method I descibe can be used with match bullets as well as RN or Spitzer bullets. Does anyone even make Match bullets in .375?
The steps don't change and it will work in a bolt action as well as the Ruger #1 but in a bolt you still have to worry about length through your magazine.

EMC2, my handloads with the 300 grain Sierra SBT for my #1 in .375H&H run 3.615. Mostly because I am running a lightly compressed charge of IMR 4350 and that is a long bullet.

Thank you very much for your detailed explanation.

Typically, I do measure using a comparator rather than a dial caliper. But, for the max C.O.L of this gun/cartridge/bullet combo, I have 3.850.

I intend to follow your theory of finding the best C.O.L. first, before working up a charge to best accuracy. I also hope to be able to transpose this C.O.L. to other bullets because the value I have will be from the ogive, and not the tip of the bullet.

You've all given me some very good food for thought, and I thank you. I'll post some results when I can get to the bench and the range.

Much abliged,

EMC2