I have been measuring this distance with the Hornady gauge, but double checked with a dummy round with a loose fitting bullet on my M70 in 30-06. The result was a difference of .035" meaning the Hornady gauge indicated the distance was .035" shorter than using a full lenght sized case and bullet against the bolt face. I remeasured several times with both methods. So is this possible and has anyone else seen this?

Impossible; the set screw on your gauge must be not holding; or something. I usually use the "bullet held in a partially sized case" method anyway.
Make sure your bullet is not so tight in the case that it gets pushed into the throat; are there marks on the bullet? You can't use a full sized case; the bullet will get pushed into the throat too much and give you a .035 long reading. I see your issue; just size the case enough so the bullet can slide in the neck when it hits the throat.

My brother slits the neck of the case to make sure there isn't too much pressure on the lands as the bullet seats against them. Seems to work for him.

I used a bullet puller die run the bullet in and out enough times to get a loose fit. I discovered the discrepancy when i found an old load that should have been long enough to hit the lands but chambered without effort so i started remeasuring.

I use the cleaning rod method and it has worked very well, although in each of my rifles I have used book OAL to find a load that shoots MOA. Dunno, makes my life easier though.

Good Luck

I use the cleaning rod method too.
Jumper, could be that the throat grabbed a bullet and pulled it out that .035.
You should try the cleaning rod method, and the Hornady tool works too but I do not have one. Check again; something went wrong.
Actually, for hunting, all I care about is will it feed and shoot into about 1 moa, depending on caliber.

I use the bullet in the case method with great results, both methods work.
Most times I repeat the process to insure that I'm getting a correct reading with out pressing the bullet too much into the lands or "dragging " it out.
Different brands, shapes, types and styles of bullets will have different points of contact due to the ogive or rate of radius to the taper on the bullet, I say this so that you know to measure every type style or brand bullet you are using.
Also be sure to measure your magazine box. Sometimes all this measuring to the lands stuff is for nought if your magazine is too short to let you seat your bullets out to or near the lands.

thanks all, I'm not sure what the cleaning rod method is, when i use the Hornady gauge i use a wood dowel to get a good light touch for the bullet against the lands. when i set up the case to get the distance i got the bullet pretty loose in the case. when i first started loading the ol salts had me sooting the bullet to see where the lands were, then we'd back off the die for the jump. Well I'll go back and remeasure as i just ran into this yesterday afternoon. I used to be in the forum 5+ years ago but hadn't been here and no longer had the PW.

I use the case and marks a lot method. Has always worked for me.

quote:

Originally posted by Texas Killartist:
I use the case and marks a lot method. Has always worked for me.

Same method I use

Jumper take a case fired in that rifle, deprime it and neck size.seat a bullet that will chamber and jamb slightly into the lands. measure the land marks length.and measure with bullet comparator. subtract the land mark length from your c.o.l. this should be bolt face to land length. seat bullets .010 deeper if this is where you want to start your load work. alot of my rifles shoot best at .010 off the lands, its a good place to start.

I will definitely try that, my 22-250 shoots very well at .020 off, the 06 I thought was shooting well at about .030 off until i discovered this discrepancy which may just be user error.

Sinclair Int has a nice tool or you can make one using Sinclair's cleaning rod stops and a piece of brass welding rod.

You can make one for measuring from the muzzle or from the breech and use a cleaning rod guide...much easier from the breech end and more accurate.

The larger the cal or the more mismatched the sized case is in relation to the chamber the closer you need to be to the lands and sometimes running the bullet into the lands 10 thou or so will center it, but start low and work up slow if you do this.

In actuality there are many nodes or seating points where the rifle will shoot with better accuracy or smaller groups...take a look at the reloading section on AR and you will see that varying the powder amount will give varying group sizes that is governed basically by velocity and barrel harmonics as a barrel has many null nodes and the same goes for varying seating depths.

EACH BULLET, EACH BRAND AND EACH WEIGHT will have a different "best group", except for monometallic or partition types which seem to like a bit of a jump.

Luck

I've used a fired case that I simply bend the mouth on against the table. Not near as pretty as a store bought gauge but has worked for 40+ yrs.

If you have the button type neck sizing die, use these to get just the right amount of grip.

As we load for so many wildcats with different neck requirements, we have all the different size buttons.

Well i feel pretty foolish, i looked at all the reply's especially the first from DPCD and this morning started again and discovered the bullet i was using i had probably jammed into the lands one two many times, so when i used the bullet i was using in the hornady gauge both ogive measurements were the same and i used a variety of bullets to double check. going hog hunting in a few weeks here in Ca so i'm happy to be over that self imposed hurdle. Thanks to all.

Good; glad you found it; You shouldn't feel foolish until you actually blow up a rifle (which is actually hard to do); until that is just called "learning".

I remove the firing pin from my bolt and use that to hold the long oal dummy in the chamber. the bolt of course won't close, so I use a rubber band to provide forward tension on the bolt handle. Works great and is fast and accurate. I prefer to use frosty scotch tape and put on enough to kind of center the rod in the barrel (this will depend on caliber of course).

Those Hornady tools are very rarely accurate. The reason is that they assume there is zero headspace, by jamming the "standard" case in the chamber. The true measurement comes from the BOLT FACE to the lands, not some case jammed into the chamber. Without the bolt face to measure against,(or from)you only have a close guess, unless you are using a case previously fired in THAT rifle. All of the other methods mentioned use the case closed in with the bolt.

as i thought about the issue logically a bolt face measurement should be the most accurate, and with the info from this discussion i think I'm setup for a better procedure. I spend much time tweaking loads for my 22-250.

The cleaning rod method:
I use a long wood dowel. Run it from the muzzle down to the closed bolt face, mark it at the crown of the barrel..Now stick a bullet just snug in the lands and run the dowel down the barrel until it touches the bullet and mark it at the crown. measure between the two marks, then back seat your bullets a few thosands deeper that the measurement. It's an accurate method and a cost saver. This has to be done with each change of bullet and its a pain.

I don't put as much faith in seating depth as some folks do. Over the years I have found that a rifles accuracy is mostly defined by its barrel. A good barrel will shoot no matter where the bullet rests..Bench rest competition possibly being the exception.

Seating depth can be useful with picky or iffy barrel to some extent, I hate a picky barrel that I have to play with for a month or two or load up all manor of loads to find one that shoots. I just rebarrel them, as do the benchrest crowd.

Ok thanks I will definitely try that technique, I agree about the barrel being the most important, but i have improved an already good loads with with seating depth changes. I pass near Filer on my way to Montana, but turn on 74.

There is a tool an entrepreneur (sp?) makes that I have used for years that perfects the "cleaning rod" method. It is the R-P Products C.O.L. E-Z Check tool marketed by a guy named Randy Reeves 318-424-7867 r_reeves61@bellsouth.net. Some of that information may have changed since it has been YEARS since I bought mine for $25.00

It is just a stainless rod shown here with the Stoney Point



it has 2 well made collets



and a removable brass tip (remove the tip for the smaller calibers)




You just put the tool down the muzzle to the bolt face (remember to cock it to retract the firing pin) and lock the outermost collet



remove the bolt and insert the bullet to the lands (the Stoney Point/Hornady works well for this), insert the tool back down the muzzle to the bullet tip and lock the innermost collet



measure BETWEEN the collets




One tool for ALL your calibers, best $25 I ever spent