.308 precision mic results??

czechitout

czechitout

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Yes .. I am a newb! I used my new precision mic to determine the optimal OAL for my 700 P. In doing so, I found that although the internal mag allows me to seat my 168 gr. Sierras about .030 off the lands, the ogive of this bullet is so far from the tip that it only allows me to just BARELY seat it into the neck, no where near the depth required (at least .308, right?) So I basically seated the bullet into the neck about .300 and left it at that. So my question is .. what was the point of that exercise? I can't seat the bullet far enough out to do any good!! Do I have to change to a different bullet?
Suggestions?

thanks in advance!

:D
 
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Your barrel has an unusually long throat. You could get a different barrel, have yours set back and rechambered, etc.

You can also get by with .200" of seating, at least for target work. That's what I do.

Or try a heavier (longer) bullet or one with a stubbier (lower radius number or a secant ) ogive.
 
John Y Cannuck said:
Just because it won't seat close to the lands doesn't mean it won't shoot. Try it!
Click to expand...


X2

The advice to seat close to the lands is very overrated.
It will sometimes help a rifle with a poor chamber shoot better but in most cases all it results in is pressure spikes and lower over-all velocity.
As long as the jump to the lands is shorter than the bearing surface on your bullet you are good to go.
 
thanks guys .. I just can't believe the throat is that long! Does that vary from rifle to rifle within the production run? I already purchased a Rock M24 barrel for it .. just don't have the $$ to get it installed yet! I keep thinking that I have maybe screwed up the mic measurements, but they continue to come out the same. I could go to .200 of the lands .. but that is as far as i can go for sure.

I will just go shoot the OAL i have now and not worry at this point.

thanks again!

:D
 
I've got two Rem 700s -- a 30-06 sporter, and a .308 Win heavy barrel. Both of these rifles have throats so long it's just silly. I have read before that it's a characteristic of the Rem 700, as if the factory deliberately chambers them that way to allow for extra case capacity for handloaders. Uh-huh. I've read that, but I don't believe it -- not in this day and age of litigation and class action suits.

That said, I don't know if my two rifles are an anomaly or the rule.

The point was made earlier in this thread, however, that one should just got out, shoot, and see what the groups look like. That's very sage advice. Both of my rifles shoot very well -- so well that both are on my "don't even think about selling" list.

Neo
 
A quick ? here folks;
How does deating the bullet, futher out, create a pressure spike ?
It make sence to me that seating a bullet, deeper, would spike
pressures, but not further out. .

Maybe I'm off.
Anyone have something on this

....WW
 
WithoutWarning said:
A quick ? here folks;
How does deating the bullet, futher out, create a pressure spike ?
It make sence to me that seating a bullet, deeper, would spike
pressures, but not further out. .

Maybe I'm off.
Anyone have something on this

....WW
Click to expand...

Because the bullet encounters resistance a bit quicker during ignition if the bullet ogive is very close to the lands. If the bullet has a little momentum when it hits the lands it levels out the pressure curve a bit as well as reducing the peak pressure spike somewhat.
 
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