Hornady OAL Gauge and Comparator

[Stevesdl]

I sent a question to DRMike and he answered nicely but I am still confused and DRMike has gone offline so I am posting here in case anyone comes online Satruday afternoon\evening. I want to reload according to any new spec for tomorrow morning load testing. (Please do not take offense DRMike and my sincere apologies if it is wrong to do that)

I have purchased the following:
1. Hornady OAL Gauge (straight)
2. Hornady Comparator and the 338 win mag insert
3. Hornady modified case for a 338 win mag

I have not seen anywhere in any instructions for this tool to do the following --> Subtract the length of the comparator" which is 1.000. (I just 0 it out with the comparator attached) Am I not correct in this discernment.

In a clean rifle:
1. Insert bullet into case and slide tube with case into chamber, giving it a slight turn till the case is seated properly.
2. Push the gray rod gently to contact the bullet and tap 2-3 times with forefinger to feel resistance only (Does this mean it is now JUST TOUCHNG the lands?)
3. Tighten the gray rod screw and remove gauge.
4. Tap the bullet out of the barrel witha wooden rod and place back in the case

Here is where I am confused:
5. Measure (base of case to ogive -- I have 2.765 (The Hornady 6 book mentions maximum length is 3.340 ???)
6. This will make my OAL (base to tip of bullet) 3.478
6. I have measured my magazine width and believe it to be 3.545

I need some additional help if this is all sounding right as well as where does the .020 off the lands come into play with that measurement.

Thanks
Steve

 

[Stevesdl]

Okay!!

DrMike responded as soon as I posted and I was able to give him a call.

I got some very clear knowledge and discernment.
I have measured 10 times to make sure my measuring technique is giving me a very close consistent measurement

My consistent measurement (base of case to ogive) is 2.754, I am going to seat my bullet at 2.734 at the OGIVE (test increment of .005 up to 2.744)
This will make my OAL (base to tip of bullet) 3.447 minimum to a maximum of 3.457 for maximum length

I have measured my magazine width and believe it to be 3.545

One of the things I found is to make sure that Case is 100% perpindicular to the caliper jaw, otherwise one can be off quite a bit which explains my first initial measurement statement.

Thank you DrMike and all
Steve

 

[rick smith]

Just a couple thoughts about the comparator/modified case. I make my own modified cases from brass fired in that rifle so most of my bullets slide through the neck, when they do that i insert the modified case with the bullet inside the case, muzzle up. point the muzzle down and let the bullet fall to the lands, drop the keeper rod and lock in place. If the bullet has to be pushed through the neck, i will barely seat the bullet in the neck of the case and slowly push the modified case into the chamber, drop the rod and lock it in place. If the bullet stays in the rifle with either method, I know I am not just touching the lands but far enough into the lands to hold the bullet. I then make a dummy round at the determined length, spin some 4/0 steel wool around the bullet, works better than a sharpie or candle smoking the bullet, chamber the dummy round. When removing the dummy round from the rifle I hold my fingers on the exit port to prevent the bullet from dragging on the exit port. Examine the bullet with magnification for land marks. If the bullet stuck in the rifling when I removed the modified case, there will be land marks on the bullet. If so, seat the bullet five thousants deeper, respin the steel wool, rechamber and check again.
Just added tose comments for the others that don't get to talk to Dr.Mike.Rick.

 

[Jim1 AB]

So Rick I'm not sure what your asking here. But I think the bottom line here is you get a base point here and then go up or down till you fine the sweet spot for that rifle. What the exact measurement really doesn't matter as long as all your measurements are consistent. I've had my comparator tool for a while, since it was called a Stoney Point comparator tool, and I use it to get a measurement of base to rifling and then to set seating depth after that. It's to bad Hornady hasn't come up with a seating die that you use the same inserts for. I do find that bullets will change the measurement in that insert when seated in the seating die of RCBS, Forster and Redding that I have. If that makes scene. Seat one bullet and do a run of 10 let's say remeasure the run and there will be inconsistencies with the comparator.

Jim

I also make my own cases. As 358 STA and 6.5/375 Ruger are not on their list of available cases. LOL Not really that hard. I thought I'd have to have a machinist co-worker do it for me but the brass is so soft it was quit easy to tap the cases.

 

[rick smith]

Not asking anything. Just adding to the conversation. The bullets can vary even in the same box. The seating stems vary from one manufacturer to another. That is one of the things that a comparator is good at showing.Rick.

 

[Jim1 AB]

Rick I think It only shows us how inconsistent most manufacturers are. Dam there goes the bubble. LOL

 

[Stevesdl]

When I was measuring COAL using the base to tip method, I was getting inconsistencies up to +- .004. I first started thinking my die (RCBS) was geting loose or incorrect since I measure every finished round. I then realized that the inconsistency was in the tip length. Well...... or maybe not or at least not all the time.

Once I started using the comparator in my measurements for a base to ogive method, I was expecting near perfection but then again found that not to be the result. I still am getting up to +- .004. I would think the average on 24 rounds was closer to +- .003 but I had 2 or three that were at .004. I am just believing there is no way around that with the exception of adjusting for every single round?

The very good thing is I learned an awful lot about COAL from you guys and from internet research and such. If not anything else, I understand it now. Any case, I am hoping that the COAL adjustment, which is much different from my original rounds will make a big difference in some of the accuracy issues. If not, I still just learned a whole lot over the weekend and will keep testing and having fun.

If I miss that big Bull this year, I am just going to turn and tell everyone, "Hmmm my COAL must be off."

Thanks all
Steve

 

[DrMike]

If I miss that big Bull this year, I am just going to turn and tell everyone, "Hmmm my COAL must be off."

A very common excuse, used by some of the finest hunters.

 

[Ryan46]

Setting the COAL is indeed a very important part of the reloading operation in producing quality ammo but I feel that setting the correct headspace is of equal or more importance. I know that one’s magazine limits the length of the cartridge and one may not be able to seat the bullet touching the lands or even within .010” to .015” to the lands.
The factory ammo I have measured usually has had .005” to .006” of headspace “slop” when .001” to .002” is more preferred. This extra “slop” allows the case to slam back against the bolt face & expand forward to fill the chamber at firing. This excess movement is detrimental to accuracy and leads to short case life. In that scenario the bullet will have a greater “jump” to make before engaging the rifling.
Therefore, I have found the Hornady LNL headspace tool to be very helpful when loading for my rifles. Once I get the headspace on my cases set then I seat the bullet at the length I want it from the rifling, usually at .005” off the lands.
This is just my two cents worth on the subject.

Happy Shooting
Ryan46

 

[Stevesdl]

Nice Point Ryan! Sounds like you have your science in reloading down to a beautiful fine art. :grin: :grin:

Before I invest too much more into that beautiful word called "accuracy", I want to see if the money spent ($80.00) for this last set of tools will do anything for me and my rifle. Still have not got to the range to justify. I just looked at that Hornady tool. Good ratings but like the other tools, just a tad expensive for a piece of milled and drilled aluminum. Precision or not. I started out life in Industrial Engineering but ended up changing in the mid 80's to Networking Engineering. I still know how to use the furnace, foundry, mill, lathe and drill press. Some of these prices are a bit steep. No insult to anyone intended but I might have to settle for my 1 1/8" accuracy at 100 yds. :lol:

Again thanks Ryan.

 

[Scott Spencer]

When I was measuring COAL using the base to tip method, I was getting inconsistencies up to +- .004. I first started thinking my die (RCBS) was geting loose or incorrect since I measure every finished round. I then realized that the inconsistency was in the tip length. Well...... or maybe not or at least not all the time.

Once I started using the comparator in my measurements for a base to ogive method, I was expecting near perfection but then again found that not to be the result. I still am getting up to +- .004. I would think the average on 24 rounds was closer to +- .003 but I had 2 or three that were at .004. I am just believing there is no way around that with the exception of adjusting for every single round?

This was my exact same findings. I've measured multiple boxes of bullets and found variations in bullet length which I presumed was just different tip sizes/lengths. I tried adjust every single round thinking my die was off but it was the actual bullet tip length itself that was the problem. Reading these threads makes me realize how little I actually know when it comes to cartridge reloading. :shock:

 

[Stevesdl]

Houston, we have a problem.

Weatherby Vanguard 338 Win Mag
O.A.L. 2.754 - Measured 10 consistent times with Hornady A.O.L. gauge
COAL 2.734 (Base to Ogive) - Measured in combination with Hornady Comparator and Vernier Caliper
COAL 3.447 (Base to Tip - COAL is above SAAMI maximum standards)
Magazine width 3.545

Top Target - 72 grains (Scrape on bottom right of top target from taking off stand - not a bullet)
6 round average - 2936 FPS (In the recent past with COAL at 3.334 - 2833 FPS)

Bottom Target - 73 grains
6 round average - 2976 FPS (In the recently past with COAL at 3.334 - 2921 FPS)

Accuracy was better for the 73 grain loads compared to 72 grain loads (see targets), but ....

Problems
1. FPS
A. FPS for 72 grains set with new COAL is faster than past 73 grains - 3 of the 6 rounds bolt were sticking very slightly but sticking nevertheless
B. FPS for 73 grains set with new COAL is faster than past 73 grains - All 6 rounds bolt were sticking slightly - 1 minute between each fired round

2. See Cases (Cases have been fired 4 times, the 4th being today)
A. First 3 from left are from 73 grains - serious issues
B. The next 2 are from 72 grains - look closely; hairline cracks as well
C. Unfired round show no remarkable issues before being fired


View attachment Sept280001.jpg View attachment Sept28.jpg

Should I keep the new COAL and reduce charge to 70 grains or 71 or should I forget this new COAL stuff?
All suggestions welcomed!

I really do believe in JD338 Motto --> "Speed is nice but Accuracy kills"

Thanks All
Steve

 

[DrMike]

Those are some pretty hot velocities with RL19 and 225 grain AB. I would consider 72 grains a maximum based on QuickLoad projections and velocities listed in the Nosler guide for a maximum load. It is entirely possible that your brass is fatigued after four rounds and you are seeing case separation, especially if you have been generating such high velocities. While velocity is not strictly correlated with pressure, there is an obvious relationship--you cannot get velocity without pressure, and as pressure increases, velocity will tend to increase. There will on occasion be a point where velocity seems to decrease though powder charge is increasing. You are tickling the dragon's tail at that point, and he may turn and bite you. I'd likely start with some virgin brass and drop back to work up the load again. If you don't stress your brass, you certainly should get more than four loadings with a 338 WM.

 

[Ryan46]

(Base to Tip - COAL is above SAAMI maximum standards)
Magazine width 3.545
Steve:

(Base to Tip - COAL is above SAAMI maximum standards)
Magazine width 3.545

I would not be worrying about your COAL. As long as your rounds feed freely from your magazine into your chamber and the bullet is not jamming into the rifling you are fine.
As I stated previously, I start at .005” off the rifling then move out in a ladder at .005” increments (.010”, .015”,.020”) until you find your rifle’s sweet spot.
Your pictures indicate your load is too hot! Back off a few grains or you and a plastic surgeon will become very good friends. Be safe my friend.
BTW, thanks for the compliment but what I stated about headspace anyone can do that with a Hornady LNL headspace tool along with your OAL tool; it ain’t rocket science. I am a journeyman machinist and can also make my own tools like the Hornady ones. I don’t know where you bought your OAL gauge but mine was nowhere near $80 bucks more like $32.00 from my local Bass Pro Shop.

Happy Shooting
Ryan46

 

[rick smith]

Steve, it appears that you are oversizing your brass and are getting case head seperation. It doesn't take a max load to seperate a case. You should be head spacing off the shoulder and not the belt. I neck size until the case gets snug to bolt closure and then PFL to bump the shoulder back 0.001-0.002".Rick.

 

[SJB358]

Steve, it looks like you are getting good accuracy and Mike is right, you are at your rifles max at 72gr's. I think with the new set of brass you are getting, you should start at 70, 70.5, 71, and maybe 71.5. I would also work at the length you have been getting your most accurate loads at. Work up slowly and I think you will have a winner. The Nosler brass is reported to have less internal volume than Winchester, so you might get top speeds much faster than with WW brass. Scotty