Lands are WAY OUT THERE??

[Whiterabbit]

So, I've read some folks here test their OAL limit by seating a bullet halfway then chambering the round to see where the bullet contacts the lands. OK.

So I did exactly that and basically I never hit the lands. I can seat the bullet less than a quarter inch, leaving the OAL something like a half inch too long (I don't remember the exact lengths) and it chambered just fine. No stiffness, no problems. The round ejected just fine, no problems whatsoever. I saw what could be land marks on the bullet, but since the OAL didn't change, I'm skeptical. I did this three times, I can't fake-seat the bullet any farther out to test, it'll fall out of the cartridge before I get the assembly into my rifle.

Is this normal?

SAMMI ammo of course fires just fine. I've had MOA groups with factory ammo sometimes though I'm an inexperienced shooter.

---------------

This is all coming about because I'm prepping to work up my lead free hunting load, and it's not like .223 where I can load hundreds of rounds cheaply to see what will work best. The bullets are too expensive, I've gotta maximize development efficiency.

So Barnes (TTSX) tells me OAL recommended is 2.94", SAMMI is 3.06", and calguns (which is always right, right??) tells me barnes is sensitive to OAL and should be loaded to .05 off the lands.

So I'm at a conundrum for the starting OAL to start working up the pressure. Do I start at Barnes recommendation? at SAMMI max spec since I'm still a mile and a half off the lands (my factory ammo is all around sammi spec)? Is there something I missed with the bullet-seat test that makes the data I collected meaningless?

[Sky_DiveR]

What rifle are you loading this into?

[Whiterabbit]

Can't imagine that would make the difference, but it is an Interarms Mark X bolt rifle, I'm told it is based off the mauser action. The cartridge is 7mm mauser.

The ultimate goal is to develop my hunting cartridge. That shoots as accurate or better than factory lead ammo using the best non-lead bullet I can get my hands on.

[Pthfndr]

Most all factory rifles have long throats. This is too make sure that no matter what factory loaded ammo is used it won't be jammed into the lands and cause pressure spikes, possibly causing damage.

Thank the lawyers for that.

[Whiterabbit]

Cool. I'll start with barnes spec then. Just seems odd to be so short.

[buffybuster]

Most all factory rifles have long throats. This is too make sure that no matter what factory loaded ammo is used it won't be jammed into the lands and cause pressure spikes, possibly causing damage.

Thank the lawyers for that.

This probably goes double for the 7x57. Chances are the chamber specification was for 175gr RN bullets, which would put the throat way out there.

[Whiterabbit]

Nope. I have some of those. (and some 160's, and some 140's, and some 139's.... )

All around saami spec of 3.06-ish

[ejor]

yes I have a 7x57 mauser like that, I can't hit the lands with any bullet. most all others calibers I have are much shorter in the throat, on the opposite spectrum I have a 6.5 swedish that pmc factory ammo wouldn't chamber in because it was hitting the lands. I agree with buffy buster it was due to the original 7mm military loading having a long 175 grain bullet.

[Slash2]

My advice, don't sweat the overall length. Buy some factory copper ammo, sight it in to those rounds. Load up regular ammo and adjust loads so you're hitting near your copper rounds. Every time you go to the range use one of your copper rounds for your first shot to confirm that you are still sighted in with the copper on a cold bore shot. Now practice with your reloads striving to get tight groups where ever they hit relative to the bulls eye.

if you're set on doing your own copper reloads, first go to this site http://www.jbmballistics.com/ballist...culators.shtml, plug in the numbers on the stability calculator and see if the copper bullet you want to use will even stabilize with the rate of twist of your gun.

[mif_slim]

Try putting a bullet backwards into the brass. As in, tip of the bullet inside the case and send the bolt home with that round. You'll know if it hits lands or not. If it does, it'll usually push tue bullet in and you'll know how far the lands are in.

But, honestly in your case, your not usin it for 10x at 1000 yards so you should focus more on powder charge for accuracy. You'll fine that just that you can get sub-MOA if your gun can do it. When you want sub-sub-MOA you start playing with OAL, brass sizing etc etc..

[Whiterabbit]

My advice, don't sweat the overall length.

But, honestly .... should focus more on powder charge for accuracy. You'll fine that just that you can get sub-MOA if your gun can do it. When you want sub-sub-MOA you start playing with OAL, brass sizing etc etc..

You guys got this right for sure! I'll try to post pictures later, but I did not expect the results to be as drastic as they were. Not sweating the overall length and working up the load by .5 grain increments, I found the rifle shoots barnes full load recommendations. I then shot three groups of five.

After drinking a pot of coffee and using factory ammo, my rifle shoots 3 MOA and I'm OK with that. My third group of handloads loaded to within .5 grains of powder and OAL that's equally loose shot two one hole groups .75 inches apart.

All I need is pie-plate accuracy but getting just-sub-moa while measuring powder on a bench in the wind with 10 other shooters shooting off it is an amazing result to me.

I am shocked that I could get such drastic improvement in ~ 20 rounds of loaded ammunition. I am completely sold on the concept of boutique bullets, and excited at the prospect of bringing the press back into the wind-and-vibration-free garage to put together a bunch of .1 grain accuracy tight-tolerance OAL rounds to test again.

I'm ->||<- this close to posting my target in the range report forum to tell everyone they should be reloading, even if they are just interested in hunting.

[Whiterabbit]

I suppose I should mention slash, that I'm definitely set on copper handloads. It started as my thought that factory 7mm mauser non-lead didn't exist, but just after buying all the components I found a boutique online seller that will make me some. For $92 per 20!

At that price, my reloading equipment pays for itself after I load 62.5 rounds (and that's at reeds component prices). crazy.

[J-cat]

Factory freebores are loooooong. I load to mag length and see .5 MOA accuracy.

[Whiterabbit]

This is how drastic the results can be. Keep in mind I've loaded a smidge under 200 rounds of ammunition in my life, and didn't start shooting centerfire until maybe one year ago.

The factory ammo group is a 6 shot group that I can lay down any day, drink-a-pot-of-coffee, or meditate to slow the heart rate, doesn't matter. On good days (I think I'm just getting lucky with the actual catridges) I could put down an MOA group.

The handload group is 5 shots. My scope is set to ~3" high at 100 yards. If I rotated the rifle when aiming for the bullseye that could have been enough to get that second grouping.

Given my extreme lack of experience I am very very impressed with the potential of handloads with good bullets.