I have been reloading for over forty years but I'm new to precision rifle reloading. I'm working on loads for 223 with Sierra 69 GR HPBT. When I seat the bullets a few thousandths off the rifling the bullet only contacts about half the case neck. Is this normal? Is this enough to hold the bullet straight when feeding from a mag or will I need to load them one at a time? Thanks in advance for any and all opinions.
Dan

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Old Age Ain't For Sissies

Well for starters, Matchkings are not particularly jump sensitive so having them close to the lands may not be necessary.


What I would do is an OCW test with what ever powder you are going to use and start with the published COAL for your combo. Once you find a node that works well then do the same basic thing with cartridges of different COAL's until you find the next node.
You have to have the OCW first or you're just beating your head against a wall.


OCW=Optimum Cartridge Weight

Given bullet weight and balance uniformity, bullet jump to the rifling is the most important determinant of grouping performance, and of course jump vs. COAL depends largely upon the nose profile. About all you can do is start out with what is generally considered to be a good load for that cartridge, and by experimentation find what the best-grouping COAL is for that specific bullet and load, regardless of case neck engagement.

My precision loads are for a Shilen Barreled AR-15 in 223 Wylde, so I load everything to an overall length of 2.250 inches and don't worry about getting the bullet that smidgen short of the rifling. For one thing the 223 Wylde chamber features a longer lead intended to allow the use of 77 and 80 grain bullets. At this point I haven't even purchased any of these heavy weight bullets, my precision loads use a 68 grain Hornady BTHP or the Sierra 69 grain bullet you are using. Mainly I use the Hornady bullet because they cost less and are easier to find locally.

Now for the results of using a round that is well short of the rifling. BTW, both the Hornady and Sierra bullets produce the same level of accuracy. On my better days I have managed to shoot consecutive 3 shot groups at 100 yards under 0.30 inch at 100 yards with the average group size being 0.285 inches. To be honest I suspect a better shooter could get down to 1/4 inch or less but for an old fart under 3/10 moa is just fine. Unfortunately I do have good days and poor ones and the poor days do seem to outnumber the good ones. On a poor day I'll shoot between 1/2 and 5/8 moa. I'll also note that 5 shot group performance isn't quite as good and the stringing I've observed seem to indicate the barrel strings vertically as it warms up.

Conclusion to me is that fussiness about getting the bullet an exact distance from the rifling is a complete waste of time for most shooters. While it may improve accuracy by a fraction of an inch, 99.5% of us just aren't good enough to ever observe the improvement.

Note, at this point I've tested IMR 4064, Varget, and CFE223. My very best results have been with Varget with the CFE223 a very close second. As for the 4064, rather so so in 223 but very good in 308. I will also note with the Nolser 60 grain Ballistic Tip the CFE223 is a complete failure, I tried every weight between max and min at 1/10 grain increments and could not get one single group under 2 inches at 100 yards. With Varget and the Nosler bullet the average group runs about 0.45 inch. Really do wish the CFE would work with the Nosler bullet because it meters well enough to just "throw and go" where Varget requires hand adjusting every charge thrown. I will also note that Copper Fouling Eliminator actually does make it much easier to get a barrel 100% copper free.

There is an old "rule of thumb" that seating depth should not be less than the diameter of the bullet. Depending on your desired COAL and OCW, it can be a balancing act, quite elusive. My 204 is that way. Especially with a 32gr pill. Sometimes OCW does not give optimum accuracy. Good luck chasing the perfect load!

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CERAKOTE Svcs.
Class 01 FFL

There is an old "rule of thumb" that seating depth should not be less than the diameter of the bullet. Depending on your desired COAL and OCW, it can be a balancing act, quite elusive. My 204 is that way. Especially with a 32gr pill. Sometimes OCW does not give optimum accuracy. Some bullets perform better with more "jump." Good luck chasing the perfect load!

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CERAKOTE Svcs.
Class 01 FFL

Can anyone recommend a good book with the what to and how to for precision reloading?

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Old Age Ain't For Sissies

Thanks to all for replies.

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Old Age Ain't For Sissies

The Mcpherson classic.

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Front sight and squeeze

Imo, you need more bullet bearing in the case neck. Many will say a full caliber is a minimum. Usually easy to attain that. It helps align the bullet in the case neck & keep it there during feeding. In a ss rifle, you might get away with less, but feeding from any mag, i want more bullet bearing in the case neck.
Btw, the mythical 0.010" off the lands is just that. Every bullet will have a sweet spot. I start at 0.01" off if possible, then work it up or back. In most AR, some internal mags, you arent getting that close the rifling without single feeding.

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NRA Cert. Inst. IDPA CSO

Are cartridges long enough to approach the lands actually short enough to fit in your mag?

mtgianni
Thanks I have one on order.

Twoboxer
Yes i have about .050 in. to spare in the mag.

Thanks again to all for your help.

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Old Age Ain't For Sissies

Another book that is somewhat dated, but still has good info in it is Warren Page's "The Accurate Rifle"

I find in precision rifle shooting, that while not having excessive bullet jump is desirable, I find case volume and case preparation, and powder charge weight and type of powder used for a particular rifle bullet combination, far outweigh the depth of bullet seating to some degree. I get .25" out of my .308 and .30" out of my .223 @100 yards. I guess for me charge weight and bullet choice and a lot of experimenting with the combinations till I get it right seems to work out pretty good.

I load .223 with 69gr Sierra Match Kings also.
Before loading that load I had very good groups with Black Hills reman and factory 69gr SMK`s.
When experimenting with Hodgon OAL data and using the OAL of the Black Hills loading I got better groups using the Black hills OAL which was the longer of the two.
2.245" is the average Black Hills OAL
2.235" is from Hodgdon Data
I shoot the loads in an Axis XP 2 and a Sport 1 1/8 5R.
Both shoot MOA or better.
YMMV
Jim

In my rifle the 68 gr match king touches the lands at 2.410" I loaded some test rounds at 2.400 witch is not deep enough but I wanted to see what they would do. They did fit in the mag but they did not feed well at all. I shot five different loads a 100 yards and to my surprise they all shot sub moa with the smallest being .486". Four of five in that group was .206". With my old eyes and body that may be as good as I can do. My next load I'm seating the base of the bullet down to the base of the case neck witch is 2.340 OAL and see how that works out. Thanks again to all for your input.

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Old Age Ain't For Sissies