Oal with smk

[Bubb]

Okay I fully understand OAL, but with match bullets they vary? When the jacket is swegded? the tips are not uniform. You just don't get accurate measurements? Now unless we are all measuring off shoulder with stoney point oal gauge this wouldn't be a problem. But how do you guys feel about the varying tips on match bullets? I hate measuring to the tip with calipers and the tips are differnt?

 

[Rob01]

Re: Oal with smk

Measure off the ogive. It's a better way to figure you OAL and length to lands.

 

[schwim]

Re: Oal with smk

Yea, measuring off the ogive is the best. Check out the Sinclair sleeve, bullet comparator and a micrometer. I've recently discovered that with 175 smk, I can easily load into the lands and be magazine compliant... not so with the Lapua 155 Scenars.

 

[Bubb]

Re: Oal with smk

So most time your finding you length to lands not TRUE oal? Really what matters is mag length or to the lands. High BC bullets that are much more pointed it doesnt' matter how far the tip is in the bore. It just where the ogive hits the lands?

 

[nova-birdman]

Re: Oal with smk

I always measure with the compartor (Ogive OAL or OOAL as I write it in my book), then measure COAL to ensure it will fit in the magazine with adequate clearance (Idue to tip non-uniformity of 0.01" or so, I typically want 0.02-0.05" of cleanance), and load to my preferred length to get the right jump, or the magazine length, whichever is shorter. If the magazine is the driver, I'll determine the proper OOAL that corresponds to that COAL, and load/measure to the Ogive still. That ensures the best possible consistemcy of firing, without worrying about magazine feed problems.

That being said, I'm lucky in that the magazine for me 110BA will hold a COAL that is longer than any of the COALs I'm using (even when loaded to the lands)--making it purely a concern of proper jump, and thus OOAL only.

 

[Rob01]

Re: Oal with smk

The ogive measurement is important as that's where the bullet first hits the lands and grooves. Anything sticking past that is only important as to whether it will fit in your magazine or not.

If you wanted to measure to the tip then a bullet like the AMAX which has a polymer tip will be easier but i would still recommend using the ogive as the measurement point.

 

[marduk185]

Re: Oal with smk

you can trim the meplats...but ogive is the way. wanna get real ocd like me and measure yer bullets for base to ogive, weight,and then overall length. sort them this way then load to a known ogive measurement. when yer done check for overalls under mag length.

 

[Jerkface11]

Re: Oal with smk

bullet comparator That's the one I use nice and simple .Once you get the bullet the right distance from the lands. Just put the bullet through the right sized hole measure and there you go. That measurement is the length you will want for EVERY bullet.

 

[schwim]

Re: Oal with smk

Here's the other tool you may find helpful. Use it with the appropriate modified case to measure your actual chamber dimension, from the case head to the lands (each bullet make will measure differently due to varying curvatures). When used in conjunction with a bullet comparator, you will know where you are seating the bullet's ogive as it relates to your specific rifle's chamber. Good luck.

http://www.midwayusa.com/viewproduct/?productnumber=570611

 

[Jerkface11]

Re: Oal with smk

Oh as for the varying tips on the bullets that doesn't really matter unless there is something majorly wrong with one. Now if the base of the bullet is messed up that's a different story.

 

[decider]

Re: Oal with smk

yea, well I reload under black light in order to prevent oversight of the slightest anomoly on my bullets.... plus there is an added benefit of identifying blood....

 

[marduk185]

Re: Oal with smk

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Decider</div><div class="ubbcode-body">yea, well I reload under black light in order to prevent oversight of the slightest anomoly on my bullets.... plus there is an added benefit of identifying blood.... </div></div>
i thought the black light was to csi any awkward pink sweater fuzz one may have collected dancing with unknown butterfaces?