Barrel length vs. powder burn

[Canhunter35]

I agree with CanHunter 100%. I'd only add that the comparison should include wind as well because velocity affects wind drift too.

I'm just not sure why he likes cans over game....... LMAO!

Lol I didn't feel like typing Canadianhunter when I made my name.

 

[Susquatch]

Lol I didn't feel like typing Canadianhunter when I made my name.

Sorry, I couldn't resist.

I actually figured exactly that eh!

 

[frostop]

Very good points! I would love to be able to shoot that far more often, unfortunately right now I am lucky to get 100yds without Paying $500 to be a member! I can shoot 100 yds at the house and there is a place I can shoot 400 but I am not sure if I can get to that spot yet!

That being said, I will take your advise and load up some different loads and try them all at that range. Right now I have some 7828ssc that I am going to try and eventually more loads of H1000 and will probably try the Retumbo again if necessary.

 

[gator378]

I felt this was good discussion BUT let's say in my 6.5x 284 a load reaches 2950 and shoots a constant 3/8 group yet case capacity is only 85% and could stuff in 8 more grains be just off the lands slightly compressed load, no pressure or primer sings reaching 3250 But the groups is 3/4" The Question is speed or accuracy?

I tend to go with accuracy since if you don't hit the target all the speed in the world is useless.

 

[therifleman556]

It's all about expectations and how far you plan to shoot. I'll take .75 moa @ 3150 over .5 moa @ 2950. At some point that decision needs to be made. If the .3 moa load clocks 3075, well then things might be different. An 8" kill zone is much greater than .75 moa even beyond distances I want to hunt at. Your application may be different.

 

[Susquatch]

I tend to go with accuracy since if you don't hit the target all the speed in the world is useless.

So just to be clear, I usually go with accuracy too. However, this is a "Long Range" forum so accuracy needs some defining. You really can't take accuracy at 100 yards and translate that to accuracy at 1000 because SD and velocity starts to play a much more significant role at longer distances.

Let's take the example that CanHunter suggested and allow me some liberties using his example.

For the 3/8 load at 2950, the linear extrapolation of 3/8" at 100 out to 1000 yards yields a 3.75" group. And the 3250 0.75" group yields a 7.25" group. On that basis, the 3/8 appears to be the clear winner.

However, if the 3/8 group has a hypothetical SD of 10fps, the SD adds another 4.4" of group size solely due to the difference in the group size caused by the shot to shot velocity difference! So the 3/8 group actually prints 8.2 at 1000.

If the SD on the 3250 is zero (just to make the point), then the group size will be 7.25 at 1000.

Even though the slower load has a group that is half that of the faster load, the faster load actually out shoots the slower load at 1000.

I only used the same numbers that CanHunter used. In reality, the faster load will not have zero SD, and wind and other factors will amplify the effect.

But the point is that short range accuracy isn't as important at long range as is velocity and SD. So, if I'm hunting at long range, I might prefer a high velocity low SD load over a smaller group at lower velocity and higher SD.

I could easily pick loads that show this effect to a much greater degree. I just used what I was given.

The bottom line is that you have to shoot the rifle at the ranges and conditions you plan to hunt in if you really want to know which load is best.

 

[frostop]

Well, I was able to find some H1000 and put together a load which worked out pretty well! Mag length load 270wsm, 62gr. H1000, CCI BR-2 primer and Matrix 165. Ended up to be an average velocity of 2912 and an SD of 9. I got it all zeroed this morning and went out and shot it at 395yd. It was a windy day, gusty from all direction!
Not to bad but not exceptional!

 

[Susquatch]

....... I got it all zeroed this morning and went out and shot it at 395yd. It was a windy day, gusty from all direction! Not to bad but not exceptional!

All depends on the conditions. Regardless of that, it's definitely a very dead deer........!

The clustering on your 100 or 200 yrd group (whichever it is) looks like the rifle might have a bedding problem or you and your shooting rest might have some inconsistencies that would be worth exploring. What do other groups at that range look like?

Edit - the 400 yrd group shows similar clustering......

 

[frostop]

It's a Ruger M77 MkII in a M2 Tactical stock that I just picked up and has not been bedded! That being said it could be me as well! The only other group that I have on paper is the one that went over the Magnetospeed, which was probably a foot higher poi and to be honest I wasn't really shooting for a group but it was still inside a minute at 100 yds! All groups were shot prone off a bipod and I am still getting used to shooting that way but it's something that can be duplicated out hunting!

 

[Susquatch]

It's a Ruger M77 MkII in a M2 Tactical stock that I just picked up and has not been bedded! That being said it could be me as well! The only other group that I have on paper is the one that went over the Magnetospeed, which was probably a foot higher poi and to be honest I wasn't really shooting for a group but it was still inside a minute at 100 yds! All groups were shot prone off a bipod and I am still getting used to shooting that way but it's something that can be duplicated out hunting!

OK, that isn't really enough to make a good call. But if I were you I would keep an eye on it. If it turns into more than a coincident, it is worth investigating.