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OAL PROBLEMS

Posted: Fri May 06, 2011 9:37 pm
by MUSKY
Hi all!
Recently bought myself a Howa 1500 Axiom in 204 Ruger!
Problem is I am struggling to get a consistent reading of my oal useing my oal guage and compariter.
I am trying to get a load going with 32gr v max's.
Just got some 35gr Bergers but hav'nt tried them in the gauge yet.
Anyone else had similar problems?
Cheers!!! :wall:

Re: OAL PROBLEMS

Posted: Sat May 07, 2011 3:11 am
by Joe O
Exactly what problem?If you are getting different readings when measuring bullets with the comparator,then sort your bullets into groups of sizes,before seating.

Re: OAL PROBLEMS

Posted: Wed May 18, 2011 4:21 am
by GaCop
I've found that even Berger's can fluctuate up to .002" from base to ogive. I sort my bullets by length AND weight for all the benchrest calibers I load for. Some of the worst measurements (base to ogive) I've ever gotten were older Hornady A-Max that I've had for about 6 years, they varied up to .004". The new ones I've measured are far better.

Tom

Re: OAL PROBLEMS

Posted: Wed May 18, 2011 6:05 am
by Joe O
You would be hard pressed to find any box of commercial bullets fall within .002-.004.I've had as much as .015 difference with Match bullets.So I sort,when working up loads for accuacy.

Re: OAL PROBLEMS

Posted: Thu May 19, 2011 10:39 am
by Wrangler John
There isn't any sense in chasing dead-on OAL with commercial bullets and reloading equipment. If measurements are made with a dial caliper and a comparator, pressure on the slide can change the reading depending on the "feel," too heavy and they are short, too light and they are long. A range of +/- .002" is good accuracy for varmint hunting and a factory rifle. The only time I obtained greater accuracy with OAL was using my own swagged jacketed bullets. Each was formed in the same dies using precision jackets at a slow production rate (boring, sleep inducing repetition). Yeah, I won a lot of useless trophies - but eventually factory bullets became so good there was no point to making my own.

Some Barnes bullets vary by up to .007" base to tip, but when seated by the ogive they are much more uniform - and shoot exceptionally well. You can try sorting by length, but I did that and came away with no appreciable gain in accuracy.

One thing I used to do is smoke the bullet (or Use a Sharpie) to mark the ogive, then use Sinclair's OAL depth gauge to mark the ogive against the rifling lead. Next I'd carefully contour the seating stem to seat only as close to that line as possible (seating stems can be returned to most manufacturers with some sample bullets for modification). If the bullet tip touches any part of the stem, then longer bullets would be seated deeper, and vice versa. OAL still varies when measured from the case head to the bullet tip, but is uniform to the ogive. After tinkering with all this rigamarole, I found that any accuracy gain was minimal, and superfluous for varmint hunting. Also be sure the primers are seated below the case head (up to .004") so they don't interfere with cartridge OAL measurements. If you are getting groups under .75" you are in the ballpark, and anything .5" or under is hard to beat.

Sounds to me like you are doing well.

Re: OAL PROBLEMS

Posted: Thu May 19, 2011 9:14 pm
by sharptailhunter
Well said John!