Over All Case Length

Pumpkinslinger · Posted: Wed Dec 26, 2007 7:59 pm Post subject: Re: Over All Case Length

Info on the BOSS from Browning:

www.browning.com/faq/d...asp?ID=107

I've never seen any claim that the BOSS increased velocity, only that it allowed you to tune the barrel vibrations to your selected load.

By the way, what's "OCW"?

bobdds · Rookie Member Joined: Dec 27, 2007 Posts: 1

ome.earthlink.net/~dannewberry/dannewberrysoptimalchargeweightloaddevelopment/ there is excellent material about the concept. You can also practicalrifler.6.foru.../index.php if you like to understand shooting you will find this interesting and helpful.

hunterjoe21 · Posted: Wed Dec 26, 2007 9:01 pm Post subject: Re: Over All Case Length

Pumpkinslinger wrote:

Info on the BOSS from Browning:

www.browning.com/faq/d...asp?ID=107

I've never seen any claim that the BOSS increased velocity, only that it allowed you to tune the barrel vibrations to your selected load.

By the way, what's "OCW"?

Start here:

www.huntingnut.com/ind...amp;sid=17

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

Hunter Joe....

Been pretty busy with my boy layin' in a supply of meat.

Finished up now with that and am fixin' to R&R with hurtin' some steelheads if things don't ice up too bad, and blastin' X's thru some woofs....

Did make a trip Down South with the boy and scored pretty well on his first go 'round.

He out did me by one down there, and that do.....do me proud.

Spent a lot of time during bow season tryin' to put the Ninja Sneak on a HOG black bear....came close twice but he's pretty good at stayin' alive.

Gonna change up what I've got on a few things here as well with some moly'd X's....been hearin' good things about that (grins).

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

OCW rocks................

Pumpkinslinger · Posted: Thu Dec 27, 2007 8:01 pm Post subject: Re: Over All Case Length

Thanks Hunterjoe!

PaulS · Posted: Mon Dec 31, 2007 7:43 am Post subject: Re: Over All Case Length

The whole bullet seating as long as you can is to get the last bit of performance out of your cartridge. I have a rifle that cannot be loaded with any but the heaviest bullets anywhere near the rifling. I seat the bullets at the length listed in the reloading data. If there isnt a length listed I use the longest length listed in other loads. I then tune the powder charge to the most accurate load I can get. I do this with three powders and pick the most consistantly smallest groups. I always end up with loads that shoot average groups of at or very near 1/2 MOA. There is no reason to seat the bullet longer unless I want to find that load while using more powder. The accuracy just doesn't get any better no matter what I do. I can gain one last 100 fps that the game and I would never notice.

steve4102 · Member Joined: Feb 24, 2005 Posts: 38

I found the article by Barnes. It also has some interesting reading on "Crimping" if you are interested.

www.barnesbullets.com/...-bullet-n/

woods · Member Joined: Oct 15, 2005 Posts: 89

steve4102 wrote:

I found the article by Barnes. It also has some interesting reading on "Crimping" if you are interested.

www.barnesbullets.com/...-bullet-n/

Good link, steve

No earthshaking conclusions but at least those guys are thinking about it.

For me, there are 2 bullet types that I seat differently. The all copper bullets like the TSX and the regular cup and core, whether bonded or unbonded.

I have found the TSX doesn't show an appreciable and consistant change in accuracy between .025" and .075" (the limits of my tests). Oh sure, there are the occasional one hole groups at certain seating depths but they haven't shown to be consistant. So I seat the TSX at .050" like Barnes recommends.

The other bullets (mostly Accubonds, but some NBT's, Partitions, Scirrocco's, Interbonds, etc) have shown 2 distinct accuracy groups base on seating depth. One is jammed -.005" to just off at .005" and the other is .010" to .035". Mine is still a work in progress but I have been having outstanding results in most rifles most of the time by seating to just touch the lands (let's call it .000"). When I do this I always drop back at least a grain if not 2 grains and work up watching the velocity and looking for pressure signs like hard bolt lift and ejector groove brass flow on the case head. I started jamming bullets on belted cases with new brass in order to mitigate the effects of case thinning at the pressure ring that leads to case head separation and found some guns will shoot very accurately with new cases and jammed

Once the cases have expanded fully and I start to Partial Full Length Resize then I have found good results seating to just kiss the lands.

But, what I have found to repeatedly important for accuracy is that all the bullets must be seated to the exact same depth. Notice the change in point of impact in this test

Now if you have a set of bullets that have different seating depths then groups will expand because of the POI change due to seating depth.

So as to not hijack this thread, I would recommend that if you can not seat close to the lands then at least seat to the exact same depth. You will need a Competition or Benchrest Seating Die to do this.

JMHO