223 overall length measurement question

J

Jeff

Guest
I am about to start loading fro a new 223 and am trying to measure where the bullet hits the lands. In the past I have used a Stoney Point Bullet Compartor and never gotten repeatable measurements. This time I took a piece of brass and slit the neck so I could push a bullet into the neck. After slightly pushing in the bullet I then place it in the action and close the bolt expecting the lands to stop the bullet and force it back into the neck. After ejecting I measure the total overall length for the bullet.

The problem is that four trys gives the following measurements, 2.271, 2.268, 2.272, 2.269 and 2.271. AM I expecting too much accuracy and with these measurements what would you guess to be the length where the bullet hits the lands.

I guess I could start with a total overall length of 2.25 or 2.28 for this bullet but wanted to get others openions.

Thanks I am looking forward to this new to me rifle and hope to make progress a little faster by asking for help.

Jeff
 
You have a total variation of three thou, about the tickness of a piece of paper on your desk.

Call the length to touching 2.270 and go from there.

I'd ignore the stoney point concept, you will not get any better results than what you got doing it with the split case method.
 
BJS6 said:
You have a total variation of three thou, about the tickness of a piece of paper on your desk.

Call the length to touching 2.270 and go from there.

I'd ignore the stoney point concept, you will not get any better results than what you got doing it with the split case method.
Click to expand...

That's right, and not only that, you'll drive yourself nuts trying to get consistant C.O.L. because the bullet shapes at the ogive and overall length vary at least that much. :)
 
I noticed that Jeff was listing lengths of 2.268 and 2.27 which is really close to the max SAAMI recommended spec...I just checked out my LRPV and found that I was getting avg lengths of 2.370 with 55gr spitzers...is this a large amount of freebore. The barrel is new with 140 rds thru it
 
AZ_Win52 said:
I noticed that Jeff was listing lengths of 2.268 and 2.27 which is really close to the max SAAMI recommended spec...I just checked out my LRPV and found that I was getting avg lengths of 2.370 with 55gr spitzers...is this a large amount of freebore. The barrel is new with 140 rds thru it
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Is just the barrel new or is the whole rifle new? The reason I ask is because the headspace might be set on the long side. When I change barrels I like to keep set the headspace on the tight side of spec.
 
New rifle. I also tried doing a minimal neck size...just enough so that the bullet will slide in the neck but still have friction to stay there after extraction. Seated the bullet part way and closed the bolt. The COL came out around 2.377 to 2.380. I tend to believe the Stoney point gauge since I was pushing the bullet gently til it reached the lands.
 
Reply to question on seating depth.

Dont put all your faith in the bullet seated just off the lands theory. Some rifles like it and a lot especially sporters dont. Try five shots the thickness of a layer of candle soot off the lands, five a tenth of an inch deeper and five a tenth of an inch deeper again. Mix the individual batches around so that there is no placebo effect and see which shoots best. I have four sporter weight rifles,three shoot best with the deep seated bullet the other one likes them almost touching the lands with most handloads. One of my rifles is a.223 and this rifle shoots about 1/2 m.o.a two tenths of an inch off the lands. Good luck with your testing Murphy.
 
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