I was working up a load for my 308 I worked it up to 45.5 grains of varget and decided to stop I was happy with the velocity, But a few days later I decided to see what Kind of velocity I could hit workin it up a bit more. The max load is 46 grains, But when I fired one with 45.7 grains it considerably flatten the primer alot more then it does with 45.5 grains, but when I fired another this time with 46 grains the primer was only flattened like it did with the 45.5 grains. what does this mean??? why am I getting a good sign of pressure increase with 45.7 grains and not with 46 grains?? I'm am confused with this one

I would never use the look of a primer as a true pressure indacator. I read that it takes lots of pressure to flatten a rifle primer.
The ways I use and I am no expert at it , just what I have read .
On lifting the bolt handle ,dose it stich or any extra resistance ?
I mik. the case just in front of the web ,is it the same or less exspansion as factory ammo ?
What bullet and load data are you using ? I looked at my Hornady book and Varget with 150 gr bullets tops out at 44.9 gr

The bolt doesn't stick and no resistance at all, I tried using my micrometer to measure the case there on the web but I cant use factory ammo for reference since I use fire formed brass and only size the neck. I did use some of my once fired casings from the same batch as the now twice fired cases for reference and there was no difference if there is any variation its within .0005. My load data is:

Bullet: Sierra 165 grain BTHP gameking Case:winchester Primer: fed 210m Powder: 46 grains varget MAX

I used remington brass instead and a fed 210 primer also that is why I wanted to work up the load to be on the safe side since remington brass has a little less case capacity then winchester.

Asfar as the load data for a 150 grain bullet that you have 44.9 grains sounds like a start charge. All My data I have all shows 44 grains as a start charge for a 150 grain bullet with varget and shows 47 grains as MAX. that was both in Sierra rifle and pistol reloading data manual: 5th edition and Hodgdon's 2002 annual reloading manual.

Let me ask what would you do would you go ahead and use the max load or would you keep it backed off a bit? I was told by a friend here in arizona because it can be very dry and hot the max load isnt really the best idea because on hot days of shooting the barrel warms up faster and if I have nice hot barrel put a new cartridge in the gun and wait a few minutes before firing and the new cartridge with a max load warms up to the tempature of the barrel then you might have a problem and could blow the gun up when fired.

The chronograph I used in the begining to work up my load to the 45.5 grains wasnt very accurate half the time it would just read 0000 when shot through it, my buddy did tell me it was old and not very good. I'd like to think i was getting 2700+ fps with the 45.5 grain charge. Can anyone tell me that uses the same load as I do what charge they use and what kind of velocity they get from a better chronograph then the one i used. I know even with the same loads but different guns velocity can vary but I just need a general ball park idea. the velocity I want needs to be at the least 2700 fps.

Q:?
Did you use new brass on your first series of load workups, and then reload the brass by neck sizing it to do your later loads?

A neck sized piece of brass is going to fit the chamber of the rifle alot tighter than a new piece of brass. A new piece of brass is likely to leave a bit more headspace in the chamber where the brass needs to expand to fill it out. When this happens, the base of the case is pushed backward fairly hard and can flatten the primer. The force pushing back on the necksized cases isn't going to be quite as high as the headspace will be less, and you won't get the false-positive high pressure signs of the primer flattening.

This would be my best wild -ss scientific guess as to what might be happening.

That just showes the differance between load books and bullets Hornady 5 edition says 44gr with a 165 -168 gr bullet is Max . Have fun and be safe!

While performance is always a goal of reloaders, trying to beat (considerably) the velocity of factory loads is a futile exercise filled with the promise of future trouble. It's just not worth it.....even if you succeed in beating factory velocities by 150'/sec there still isn't any game animal in the world that will notice. Further doing so can be a very difficult task.....if you really need that additional velocity trade the gun for a .30-06 or a .300 Mag.....you have a very fine gun in a .308.....enjoy it "as is"!!!

I have an older Remington M700 mountain rifle in 308 win, A rare one I think its the only one I have ever seen chambered in .308 win.

The brass was factory ammo first, then I neck sized it and thats what I have for brass. I dont see any reason to buy brand new brass.

A factory load for a 165 grain bullet pushes right at or a little above 2700 fps from most data I have looked at. I am just wanting to hit factory velocity, what charge weight would give me factory velocity? the extra velocity is unimportant to me all i want is to be at or slightly above 2700 fps. My load data from hodgdon states the 46 grains of varget hits a velocity of 2773 fps from a 24 inch barrel, My rifle has a 22 inch barrel.

If its just factory velocity you want to match, don't bother worrying about it. Factory velocity ratings are based on on of their test rifles- comparing this to what it will do in your rifle is like comparing apples to oranges. Reloading manuals- pretty much the same deal, you can't accurately predict velocities unless you already have data for your personal rifle.

This is also the reason why you want to work up a load- in some rifles you load a little hotter than the maximum load, in others somewhat less to get to the point of high pressure signs.


If you just load for velocity- especially blindly without a good chonograph, you are ignoring the biggest virtue of the cartridge, which is accuracy. A .308 that shoots cloverleafs is alot more fun and useful than a .308 that shoots 100 fps faster and shoots 1.5" groups.

johnch,

that hornady load data you have what brass are they using in it?

Birman,

I'm not looking for more velocity i'm after accuracy thats why I am lookin to push the bullet at about 2700 fps. I think I'm just gonna stick with the 45.5 grains and call it good for now untill i get a good chrono. or if i can find some helpful info that might steer me i the direction im lookin for.

well i just found some info for the 165 grain bthp game king the info shows the best accuracy for a 20 inch barrel with 1 in 10 twist nearly the same as what my rifle has (22 inch barrel 1 in 10 twist) is a charge weight between 44 and 45 grains those charges in a 20 inch barrel produce between 2600 and 2670 fps. So i think I will back off my charge to 45 grains and give it a try id imagine in my barrel with 2 inches more barrel should produce a little closer to 2700 i'm guessimating 2,680 fps. which is about the velocity for a factory match loading. Thanks guys for giving a little more to think about if you have anything else to share you are most welcome I would love to read more ideas that might help.