Bullet seating question

[Knopfplayer]

Novice reloader here. Loaded my first .22 Hornet shells over the weekend using new brass, Sierra 40 gr bullets, and H110 powder. I weighed every charge and was surprised at how consistently the Uniflow measure would drop powder. What was not consistent was the overall length of the finished round.

Since I don't have a bench yet, I used a basic Lee hand press and an RCBS seater die. The goal was 1.72", but a few were -.04/+.08". This sounds like a lot when I read of people loading to a tolerance of .02" or less. Should I be concerned? If I was consistent with the compression stroke and the die was cinched down, what are other things that would cause the odd case to come out long?

Thanks,

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[rick benjamin]

I think you are doing fine.
There are a lot of variables in reloading.
Does the bolt close on the cartridge?
Compare that with a factory round.

 

[Mark W.]

Are your cases all the same length? Never having used a Hand press. Was the bullet seater tight? Does the shell holder contact the base of the die?

As there might be some flex in the hand press its possible your as close as that system will get for tolerances.

 

[Goosebrown]

Sometimes the bullets vary some. Your seater doesn't push the tip of your bullet it has a ring and presses the side of the bullet below the tip. If that curve of the bullet varies s little it can seat lower or higher.

Really instead of measuring the length in total you might want to get the Hornady bullet comparitor which measures from where the bearing point of the bullet is to the base. The bearing point is where the angle of the bullet meets the lands in the barrel when the gun is in battery.

This measure is way more important than the overall length.

Good luck.

 

[Darkker]

Yeah, as has been said, you are working with a few variables.
REGARDLESS of what a manual says, you MUST know the distance to the lands in YOUR rifle, with EVERY different bullet you load.
So how big is your jump? And as Goose said, the Ogive is what touches the rifling, not the point, so that is a better measurement of fact.

 

[Knopfplayer]

I assumed the cases were all proper length as they were new from the package. (That's probably a rash assumption.) Everything was tight on the seating die, but it was set one full turn back from touching the shell holder to reduce the crimp on the bullet. (The instructions gave this as an option for bolt-action... what do I know?)

The 'distance-to-lands' part makes sense. I'll try to measure it and look up the Hornady bullet comparator.

 

[Otter]

If you measure off the tip your measurements are exactly what I would expect. Ideally get a comparator and use some method to find your lands. The Hornady tool is handy for doing that, but there other ways that are free.

Until then just load to the recommended COAL in the manuals and expect some variance.

 

[Goosebrown]

The hornady comparator is $30 and I use it all the time remember that each different type of bullet you try is going to be different worth the money.

 

[Certaindeaf]

As long as they're seated consistently and chamber without being jammed into the rifling and'll fit in a magazine, it's all good.. unless you want them jammed into the rifling and to not fit in a magazine.. a lot of people do just that on purpose though.
anyway yea, the lengths of the bullets vary unless they are essentially turned on a lathe

 

[AMProducts]

So I've been a commercial loader for years, the tolerance I load to is +/- .003" the biggest issue for me is tools and dies adjusting themselves as the machine heats up, or at least a dozen other factors. It's worth noting, when you're measuring distances this small, your skill with the tool could account for the slop you are seeing. If the die is secure in the press, and the lock screws are tight on the seating adjustment plug, there should be no noticeable variation unless you're crushing the bullet somehow (this does happen).

The number one thing I would suggest... make sure you're not crimping as you seat, unless your cases are bang on the same length, this perpetually becomes a very serious PITA. You didn't mention the make of the brass... if it was anyone besides winchester you're probably ok in this respect.

 

[Knopfplayer]

I used to work in commercial aircraft overhaul. I believe I'm pretty careful with calipers and mechanical stuff. The brass was new PRVI and I had the seating die backed off one full turn to minimize the crimp (so the instructions say).

I appreciate the information and will report back when I've had an chance to test fire some of this batch.

Thank you all,

 

[Rick4070]

Knopfplayer:

You said:
"a few were -.04/+.08". This sounds like a lot when I read of people loading to a tolerance of .02" or less."

Minus 40 thousandths to plus 80 thousandths is almost an eighth of an inch total. (.120")

I can't see how that much discrepancy is possible...

 

[Knopfplayer]

Rick,
The summary from what I learned in this thread. I'm sure someone will correct me if I'm wrong. (maybe even if I'm right...)

Measuring the finished shell with calipers gives us the overall length, but the bullet seater doesn't push from the tip. It pushes on a ring some distance back from the tip. When the taper of the bullets isn't identical, the same carefully adjusted seater will give different overall lengths. These were basic Sierra Varminter bullets, so I'm not expecting match quality. If we can measure to a predictable diameter closer to the base, the distance from bullet to rifling lands will be more consistent, improving our groups on target. The Hornady bullet comparator is a tool for this. Some rifles will group more accurately with the bullet a specific distance from the rifling and this is a way to help measure this. If we change to a bullet with a different taper, we'll need to readjust our seating die to achieve the length we want. (I also used a light duty press, but the small 22 Hornet shells don't take much pressure.)

I hope this helps. Most of my rounds measured close, with just a few at the extremes.

 

[orygun]

but a few were -.04/+.08".

That's a 12 hundredths spread, are you sure you don't mean -.oo4" and +.008"? Like mentioned above .120" is a lot. No, on second thought, it's like 10 miles! I can't imagine a Sierra bullet having that sloppy of a tolerance, especially on a bullet that's only .223" (or maybe .224") in diameter. Also, the case length will affect your crimping, but it won't change overall length unless you are squashing cases.

A 12 thousandths swing, though, wouldn't worry me too much for the reasons stated by Goosebrown.

 

[Knopfplayer]

@orygun Well. I now understand your skepticism. I did miss a zero in each number before.

I checked all 200 rounds again tonight (partly to take my mind off work). My goal was 1.720". If the margin is +/- .002", then 147 passed. When the margin is +/-.003" ala AMProducts, then 185 passed. Difference between shortest and longest was .01". Much better for my first serious effort with inexpensive equipment.

I'm looking forward to testing them first on paper, then on the little ground squirrels in Wallowa County..

 

[Rick4070]

"I did miss a zero in each number before."

Ahhh, that explains it.

Pesky decimal points.....

 

[ChiefStealth]

I understand trying to be as accurate and precise as possible. I know a couple of people who try for an OAL of +/- .001. Personally, I'm getting good usable .223 Rem varmint ammo at +/- .005. IME, powder type and charge weight and bullet quality make the biggest difference in accuracy. OAL makes much less difference than other factors. At shorter shooting distances, it doesn't matter so much. Not a lot of difference between .7 MOA and .8 MOA at 200 yards, or less.