7mm-08 troubles procedure

[Divr6347]

So im trying to load some 120 gr Barnes Tsx rounds for my sons axis compact 7-08

i measure his chamber with Stoney point oal gauge and micrometer with the Tsx and it measures 2.785 in

look in my nosler manual and it states that the max coal for the 7-08 is 2.80 in

measured the chamber oal 6 times just to make sure I wasn't missing something and got the same numbers

I don't get it but I do know that if I were to load to max coal I would probably not be able to close the bolt on this rifle

also Barnes recommends seating the Tsx .050 in off the rifling as a starting point so at 2.785 if I seat them .050 off of that I would have a round that measures 2.735 oal at .070 off that would be 2.715 never seen a round loaded that short so I'm kinda scratching my head a bit anyone have any idea if it's safe to load rounds that short seems like quite a jump to the rifling at .050 still wondering why the chamber oal is shorter than the coal stated in the manual this is kinda puzzling me
anybody have any ideas about what might be going on with it ??

Thanks for for any info
dive6347

[Robinhood]

Bullets of different construction like solids often defy common reloading dimensions. Make sure you have enough bullet in the neck to keep the run out to a minimum. I would not concern myself with OAL. the 2.800 is a number that was conceived out of a range of bullets that fit in a SAAMI spec chamber. certain manufacturers mag length may have also been a factor. Fred probably can answer that one in detail. savage will let you seat a heavier bullet much longer in their magazine.

Remove the internals of the bolt. If you can, remove the ejector. Take a sized case and do not put a primer in it. Stick a bullet into the neck and seat the bullet into the case about an 1/8 inch. Place that into the bolt face where the rim is behind the extractor, chamber and see if the bolt will close easily. DO NOT APPLY FORCE. repeat until the bolt practically falls closed with no effort when you get close your increments should be a couple of thousands at a time. This method will give you the exact location of where your ogive meets the land.

From there you can work for your happy medium of jump and seating depth.

For what it is worth your findings are not unusual to me.

[rbp75503]

When I am doing load development of a new bullet/powder combination I will begin the process by loading .010" off the lands. After finding a good accuracy node I will then try different distances from the lands in an attempt to tighten the group up. I do not rely on the recommended COAL to drive the process, but rather view it as a recommendation. Yes Barnes and Bergers like to jump to the lands.

[gbflyer]

How does it shoot?

[Divr6347]

Thanks for the info guys
I ended up loading three different charges of varget to try in it. 42 gr 42.5 gr and 43 gr kinda split the difference on the seating depth and seated the bullets to 2.740 in about .040 off the lands. Hopefully it's a safe place to start guess we will see

divr6347

[Haiku_Rodney]

I do what Robinhood recommends. I then use a bullet comparator to set the seating depth of the bullet. My current hunting load will group consistently under 2" at 200 yds.

[Zero333]

Short and tight freebore is nothing new from Savage.

Load it 50 thou off the lands and shoot it !!! By seating the bullet deeper into the case you might reach pressure signs a little sooner but not much sooner.

When it comes to accuracy, it doesn't matter how deep the bullet is seated inside the case.

The freebore/lead might loosen a bit after a few hundred rounds.

[m12lrs]

Just my opinion. load devopment for a hunting rifle. of course i enjoy load development. just remember if your rifle doesn't like that powder/bullet combination you can't force it. know when to try something different.

start with a seating depth .010 to .020 off the lands. Or shorter for mag length.

run a OCW or if you have the room a ladder test to find 2 or 3 charge weights with little vertical change and.where you start to have pressure signs. now you have a starting load and know where your max is.

pick a charge in the middle of your findings and run a seating depth test. with a hunting rifle i start.just off the lands and keep backing up at .005 increments until i find the magic. the berger seating depth test works too and it is much faster. i found my seating depth with my .308 and berger hunting VLDs 0.120 off the lands. a suprise to me.

then do a final charge weight test. that final charge may be quite different then the one you started with.

you can even tweak seating depth after that

[RC20]

You can do all the match but the reality is that there is variance from chamber to chamber.

I have used the Hornady bullet check, it always come up short of true lands contact. Ok for hunting and dropping it .020 or so.

I just take a case that has been size, seat a bullet long and very gently move the action forward.

Usual what happens is it sticks before full closure. but if you are gentle, barely sticks , tap it gently back with a plastic handled (screwdriver ) and it come out and bullet is not changed (I cross check it going in and when I get it back out with the Ogive checker)

If it was a long way from closing , then seat the bullet .030, if it was close to or the bolt start to close, 010.

Repeat until you get a closure with no sticky. Drop it back another .010 and you are good baseline.

You can fine tune it or just accept another .005 is probably sticky again.


I use .010 as I have had bullet ogvie vary and an occasionally sticks one in the lands.

You really don't want to stick in the lands at least to start with. It causes a pressure pulse. Seating deeper is no issue unless you are way up there and a compressed load.

Then as noted I run a string of loads fr5om lo2w3 to high and see where it looks good for accurate.

I then load up a group of 50 usually of 3x 4 x 3 below, middle and above it by 3 to 5 tenths . I may do 4x 3 x 3 or 3x 3 x 4. Just depends on where the decent looking rounds fell.

I write that measurement down for THAT bullet.

I always take a RCBS junior to the range with me, the first 10 of a close trial group are set at .020 or so from the lands, if it looks good I then custom seat the rest of the bullets out a bit or deeper to see if it makes any difference.