7mm-08 AI Reloading Data

[arthursc]

Hi,

I am about to start reloading my 7mm-08 AI. I have some questions regarding this that I would like some input on.

I need to know what I should trim the cases down to as I have 40 degree AI.

I know the loads as I have this data but I have no data on "trim to length".

I am using;
Fed Cases
VV N140 Powder
Nosler 140 Ballistic Tips
CCI Benchmark Primers

Rifle is Sako 75 with wirther 19" Barrel with 9/14 twist.

If anyone has some data I would really like to know.

Regards
Colin.

 

[flyingfisherman]

Hi Colin,

You got back ok then?? We saw you pass us on the motorway going a lot better than us! What is the difference between a 7mm08 and 7mm08 AI? Im intrigued! Ive just been on the phone to Steve Kershaw about a custom 7mm08 as a christmas present to myself!

Ben

 

[DL]

There's a couple of links to similar threads about Ackley Improved at the bottom of this page.

 

[Muir]

I am not sure the exact dimensions but, since factory 7mm-08 ammo/brass is used to fireform the IMP brass, then 7-08 trim-to length would seem reasonable.~Muir

 

[gitano]

51.96mm or 2.046 inches.

Paul

 

[arthursc]

51.96mm or 2.046 inches.

Paul

Hi gitano,

Are you sure this is correct as the 7mm-08 non ackley case length is 2.035. When I have measured ALL my fire-formed cases, they are between 2.027 - 2.035. I even have some that measured 2.010 - 2.017. SO I am sort of stuck as to what I should be doing for datam on my trim to length case size.

Regards
Colin

 

[long shot]

Hi,

I am about to start reloading my 7mm-08 AI. I have some questions regarding this that I would like some input on.

I need to know what I should trim the cases down to as I have 40 degree AI.

I know the loads as I have this data but I have no data on "trim to length".

I am using;
Fed Cases
VV N140 Powder
Nosler 140 Ballistic Tips
CCI Benchmark Primers

Rifle is Sako 75 with wirther 19" Barrel with 9/14 twist.

If anyone has some data I would really like to know.

Regards
Colin.

obvioulsy you have a custom chamber so once you have fireformed your brass,sacrifise 1 case and get yours a chamber lenghth gauge which will give you the exaact chamber lenghth,they only cost a few pounds,I think I may still have one I made for my 7mm,you can borrow it if it helps.
dont trim your caes untill there all fireformed to AI as you will be allowing the brass to stretch to were it wants to be,if your chamber is a lot longer than your brass just trim to the shortest case of the average case length which may mean you scrapping a few cases if there far to short,but to be fair in a hunting rifle it wont make much difference just batch them

 

[gitano]

What long shot said....

Paul

 

[arthursc]

All

Many thanks for the advice. Wanted to let you know what the outcome was of my 1st test load;

I think the 3 rounds of the same load speaks for them selves.

Regards
Colin.

 

[gitano]

If that's at 100 meters, !!! and

Way to go!

Paul

 

[arthursc]

Hey Paul.

I nearly fell off the landrover after the second shot! I did 15 rounds, All of groups of 3 set 5thou off lands starting at 27:11. That 1st load was clover leafing, I thought that was good. The other rounds were all VERY close sub 1inch. The one above was 26.69 off lands. I couldn't believe it. So make-up was;

140gr Nosler Spitzers BT.
42gr of N140
Fed Cases from factory ammo fireformed
CCI Bench Rest primers.
100 Meters from target. No Wind, Cool autumn temp.

No point in messing with the setup now. I will make some more up just in case it was a freak of nature....

Regards
Colin.

 

[gitano]

As often as not, I get so excited after a second shot that touches the first one, that I blow the third one.

Now that the gun's not an issue, you can't blame it for misses. Last year I was hunting a friend's farm, and uncharacteristically using his rifle instead of mine. (The first time in my life I didn't have my own rifle at hand.) I missed a VERY nice white-tail buck. Since I "don't miss" when I shoot at big game, I wanted to test fire the rifle at his range. The first shot from the rifle cut the X at the center of the bullseye. No blaming "the gun" after that.

You've got a 'live' one there. Don't turn it loose.

Paul

 

[arthursc]

As often as not, I get so excited after a second shot that touches the first one, that I blow the third one.

Now that the gun's not an issue, you can't blame it for misses. Last year I was hunting a friend's farm, and uncharacteristically using his rifle instead of mine. (The first time in my life I didn't have my own rifle at hand.) I missed a VERY nice white-tail buck. Since I "don't miss" when I shoot at big game, I wanted to test fire the rifle at his range. The first shot from the rifle cut the X at the center of the bullseye. No blaming "the gun" after that.

You've got a 'live' one there. Don't turn it loose.



Paul

Hi Paul,

Made some more up to this evening. 4 rounds by the headlamps of my landrover, as you say, I have got a live one here;

 

[scotch_egg]

At 42gr of powder I really don't think you are taking advantage of the AI case. My normal load is the nosler 140gr BT over 43.5gr varget achieving 2800 fps out of my 20 inch barrel. I have not chrono'd the n140 load yet and wont seeing as I only have 50 round left and am not keen on the feel of the rounds. The varget shoots much smoother.

I think you should try rl17 and also some 162gr A-max to get the most out of that fireforming. For a stalking rifle I don't see the need to go AI for the reason of less case stretch. Now stoke it up and let us know how you get on........

 

[arthursc]

Hi scotch_egg,

Chrono'd at 1635 average. Will load up when I am back from arran to 43 & 44. Did load up by accident at 47 and was showing pressure signs....

But even with that silly error they were still grouping the same.

Will let you know.
ArthursC

 

[arthursc]

What hodgson powder are you using? I know it's varget but what are the "H" numbers?

 

[arthursc]

If that's at 100 meters, !!! and

Way to go!

Paul

Revisiting this thread as for sometime I have been worried about the drift and drop to the right I have been getting with this load.
Today I made some more loads up but upped the powder from 42gr to 45 & 46. The results were very impressive.

The 46gr load was absent of the drift and the lift was fine but the grouping alittle spread for me.

The 45gr, was what I settled on. Tight groups at 100, 200 & 300 yards. 100 & 200 yards were smack on the bull with each bullet passing through or touch the previous shot. But the 300 yard shot had me Here is the pick at 300 yards;

 

[longrangestalker]

im looking into this caliber

 

[Humpy]

Unless something has changed I believe you are going to find the seating resistance of the primers being seated is going to feel much looser on the 2nd reload. If you keep loading them with progressively larger primer pockets you will get gas leakage around the edge of the primers and see a circle getting burned into your bolt face. I load my Federal cases three time and leave they laying.