243win/95 bergers drops

[midwesthunter]

Ok so rifle is Rem 700 varmint with 26" barrel. Ammo is hand loads I had from another rifle and have lost all load data. My chrony is broke so I shot two different 3 shot groups at 480 yards. Both held 3" group with vertical variance only 1/2". With 100 yard zero, 2" scope height, temp was 80* 54% humidity and elevation of 800 feet. What's puzzling me is groups only dropped 24-1/2". When run through ballistic program I have to use a 3550 fps velocity? That seems really high to me. Using .48 for BC what am I doing wrong?

 

[wbm]

Just a guess but probably the parallax on your scope.

 

[westcliffe01]

Use a G7 BC instead of a G1 it is more accurate.

 

[westcliffe01]

Using a 0.246 G7 BC the numbers look very close to my own. Are you sure there was not a slight slope involved ?

 

[angus-5024]

If I use the data from my .243 profile (these are confirmed several times) I come up with 44.16" or 9.2 MOA. I am shooting the 95 grain bergers @ 2790 fps with a 24" barrel (I know its slow). So if your running things hard and a 26" tube you should be around 3000fps, which would give you about 7.5 MOA or 36" of drop.

I think you may have mis-measured you drop or possibly your scope height. 2" is usually high rings though.
If I had to bet, I would say probably something with your scope set up.

 

[westcliffe01]

My setup is a 26" Shilen select match with 1:8 twist 243 AI chamber. But the numbers I posted are shooting virgin 243 brass with 41gr of H100V powder, in other words my "fireforming" load. My loads are to sami OAL spec of I believe 2.71".

When the brass is fireformed and loaded the second time I am loading them with 105gr bergers and am still doing load development on that one. I have not yet found the optimum jump for that bullet, nor the ideal powder load.

 

[Methow Packer]

My setup is a 26" Shilen select match with 1:8 twist 243 AI chamber. But the numbers I posted are shooting virgin 243 brass with 41gr of H100V powder, in other words my "fireforming" load. My loads are to sami OAL spec of I believe 2.71".

When the brass is fireformed and loaded the second time I am loading them with 105gr bergers and am still doing load development on that one. I have not yet found the optimum jump for that bullet, nor the ideal powder load.

What is a 243 Ai chamber? Do you always need a faster twist than 1-10 to shoot 95Gr VLD?

 

[westcliffe01]

An "Ackley Improved" chamber. Holds about 10% more powder after it is formed than a regular cartridge.

My original barrel was the model 12 26" varmint barrel 1:9.25 and the 95gr bergers would not group with it.

Just looked and they have 2 different 95gr hunting bullets

95 gr Match Grade VLD Hunting G1:0.480 G7:0.246 length:1.150" Twist: 1:9″ berger #:24527
95 gr Match Grade Classic Hunter G1:0.427 G7:0.219 Length:1.070 Twist: 1:10″ berger #: 24570

What I can tell you is that the higher BC Match grade hunting shot no better than 2MOA from my Savage Barrel which was a 1:9.25 and now shoot 1/2 MOA in my 1:8 barrel. To get any real advantage from shooting VLD's one is typically going to shoot the heaviest one that one can from your barrel. Poor grouping is how you can quickly tell that they are not going to be working for you in a given barrel. I wanted to shoot the 105's and the data listed for them is

105 gr Match Grade VLD Hunting G1:0.532 G7:0.272 Length:1.235 Twist: 1:8″ Berger #: 24528

So I let the spec for the 105 dictate which barrel to buy.

Looking at the 115:
115 gr Match Grade VLD Hunting G1:0.545 G7:0.279 Length:1.365 Twist:1:7″ Berger #:24530

You will note that there is only the slightest BC advantage in going to the 115 and it requires its own special twist rate and look at the length of that thing ! Not easy to accommodate in the typical short action 243 rifle.

 

[midwesthunter]

I was thinking I was around 3175 out of my other rifle. I will double check slope height.