Tuning Cartridge OAL

[woojos]

It's probably been asked 100 times over, but I've seen a handful of guys posting original OCW targets and none posting OCW targets playing w/ OAL after choosing a charge weight.

I have 2 rifles: .308 and .223 both shooting about 1/2 MOA consistently and the .308 is a little better than the .223 probably because the trigger is tuned. The loads for both rifles have been loaded to SAAMI OAL for both cartridges. Both were approximately the result of OCW workups.

I picked up a Stoney Point gauge and just measured the .223 to see where it was at and I'm about .0350 off the lands w/ 77gr SMK and a stock 700 chamber. I'm waiting on a .30 cal comparator die to look at the .308.

Is it worth taking it further and playing w/ OAL if I'm happy with the performance of both rifles? Has anybody noticed significant accuracy increases after playing with it?

Most of my practice so far has been limited to <~220 yards or so. I'm opening up dates in my schedule to make the drive to stretch them out a bit, and I want to make sure everything is squared away so I don't find out something is off when I finally get out.

 

[LRDD]

If I was "consistently" shooting half minute groups I would call it done and don't mess with anything.

 

[woojos]

If I was "consistently" shooting half minute groups I would call it done and don't mess with anything.

"consistently" = probably approximately 1/2 moa... 90% of the time I can shoot 4/5 <= half minute at 100 yards

 

[HodgdonExtreme]

I'd definitely adjust seating depth and see what happens. Why not? Sometimes it makes a big difference. Two of my rifles will shoot almost anything 1/2-3/4 moa, but when the jump is "in tune", will bug hole.

 

[wrangler5]

Here's something I posted a couple of days ago on another thread: Here's an article on a quick way to find what works best for your specific setup Berger Bullets Seating Method for VLD Bullets - A "Sweet Spot" with a Long Bullet Jump will give the best accuracy.. But read this, too, for the cautions about high pressure from "too much" setback in small cases Berger Tips for Loading VLD Bullets « Daily Bulletin .

Using this technique, I found best accuracy for my particular 223 rifle and components to be with a bullet setback of 0.063 from the lands (interestingly, with both SMK 69g and Berger VLD 70g bullets) which gives my loads an OAL of ~2.225. Your mileage almost certainly will vary.

 

[wilecoyote]

It's probably been asked 100 times over, but I've seen a handful of guys posting original OCW targets and none posting OCW targets playing w/ OAL after choosing a charge weigh....

tha real bonus of the LADDER test is the focusing of the attn. on the powder charges only,at first, allowing to work on the COAL as next step_ that's the reason because I like it better_

[/QUOTE] Is it worth taking it further and playing w/ OAL if I'm happy with the performance of both rifles? Has anybody noticed significant accuracy increases after playing with it...[/QUOTE]
yes, it worth it, and worth it even more w.the increasing of the shooting distance, exponentially,of course_ (you can chose to be being happy, happier,or the happiest, I would say)_

 

[Pinecone]

I don't remember if I posted my OAL targets, but when I worked up my .308 load, I did the OCW for powder charge. Then I loaded 5 each starting 0.010" shorter in steps (I don't remember what the steps were) out to max mag length (Manners mini chassis).

I shot the rounds round robin, like an OCW, with 2 minutes between shots.

The groups got smaller as the OAL got longer, so I load to max mag length for my rifle.

 

[fastex500]

Tuning Cartridge OAL

Same thing here as Pinecone stated. I just worked up loads on 308 with 178's and Pro2000. Did OCW test with powder charges, then took accuracy node and adjusted .010 up to lands. All decent groups under 3/4moa, but at .010 off lands I shot the best group I have ever put on paper (close to a single hole). Just loaded up 10 more to take to the range and verify this weekend.

So.... Yes, it does make a difference in 6 rifles and 3 calibers I have loaded for. Will be adding 300 WM to this process in August.


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[fx77]

Def. try adjusting OAL to ogive of bullet..
Get the best powder group and then load with ogive just touching or .001 short of the lands
Shoot a group and reload each time reducing by 1.5 thousandths til the groups stay tight, get tighter, or start to open U will have your answer

 

[tylerw02]

If you plan on using it as a field rifle and don't intend a ton of neck tension, do not touch the lands. Do not jam into them. Keep them at least .005" off.


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[oldfatguy]

I use the OCW method to find the best jump distance, usually 0.025 to 0.035 for my rifles. Does not hurt to retest as the throat wears.

OFG