Let's talk muzzle velocity....

[jrebel]

So....I have been handloading for quite some time now and have never really paid that close attention to my muzzle volocity.  I was always hand loading for hunting purposes and based my final load off of accuracy. 

Well, a couple weeks ago, I finally broke down and bought a Magnetospeed V3 to see what my muzzle velocities are. 

This was the data with a 7 shots out of my .270 which, if I do my job, will shoot well under an inch groups. 

Shot #1  2681
Shot #2  2733
Shot #3  2694
Shot #4  2719
Shot #5  2712
Shot #6  2750
Shot #7  2751

SD 26.7
Max Spread 70 fps
Average 2720

My question is....is this acceptable or can I tighten it up a little?  What reccomendations would a person have to tighten this up without any major changes as the accuracy is there. 


My .308 is quite a bit better

Shot #1  2778
Shot #2  2807
Shot #3  2805
Shot #4  2772
Shot #5  2804
Shot #6  2776
Shot #7  2789

SD  15.1
Max Spread 35
Average 2790

[Duckslayer89]

So....I have been handloading for quite some time now and have never really paid that close attention to my muzzle volocity.  I was always hand loading for hunting purposes and based my final load off of accuracy. 

Well, a couple weeks ago, I finally broke down and bought a Magnetospeed V3 to see what my muzzle velocities are. 

This was the data with a 7 shots out of my .270 which, if I do my job, will shoot well under an inch groups. 

Shot #1  2681
Shot #2  2733
Shot #3  2694
Shot #4  2719
Shot #5  2712
Shot #6  2750
Shot #7  2751

SD 26.7
Max Spread 70 fps
Average 2720

My question is....is this acceptable or can I tighten it up a little?  What reccomendations would a person have to tighten this up without any major changes as the accuracy is there. 


My .308 is quite a bit better

Shot #1  2778
Shot #2  2807
Shot #3  2805
Shot #4  2772
Shot #5  2804
Shot #6  2776
Shot #7  2789

SD  15.1
Max Spread 35
Average 2790

My 308 only shot 2520 with a 165 grain bullet factory nosler trophy grade ammo 22 inch barrel

[JimmyHoffa]

You could get more precise in your loading, sometimes that can help get a closer spread.  Things like:  Weighing and sorting the bullets right out of box (for example the box of Hornady 200 gr that I have consists of bullets from 197 gr to about 202 gr).  Using all powder from one lot/container, or even trying to separate powder from within the container to get more similar grain sizes (like putting on the table near the tumbler--not on in right against; seems to work the larger grains up to the top).  Brass prep.  Etc.

So, with your shots--what was the sequence like?  Is first measured from cold/clean bore?  Approximate same temp of barrel for each shot?  A warmer cartridge gives higher pressure/velocity than a cooler identical one.

[Jason]

What are you using for a crimp die? I tightened up my velocity spread with the Lee factory crimp die.

[jrebel]

So....I have been handloading for quite some time now and have never really paid that close attention to my muzzle volocity.  I was always hand loading for hunting purposes and based my final load off of accuracy. 

Well, a couple weeks ago, I finally broke down and bought a Magnetospeed V3 to see what my muzzle velocities are. 

This was the data with a 7 shots out of my .270 which, if I do my job, will shoot well under an inch groups. 

Shot #1  2681
Shot #2  2733
Shot #3  2694
Shot #4  2719
Shot #5  2712
Shot #6  2750
Shot #7  2751

SD 26.7
Max Spread 70 fps
Average 2720

My question is....is this acceptable or can I tighten it up a little?  What reccomendations would a person have to tighten this up without any major changes as the accuracy is there. 


My .308 is quite a bit better

Shot #1  2778
Shot #2  2807
Shot #3  2805
Shot #4  2772
Shot #5  2804
Shot #6  2776
Shot #7  2789

SD  15.1
Max Spread 35
Average 2790

My 308 only shot 2520 with a 165 grain bullet factory nosler trophy grade ammo 22 inch barrel

This is a Kimber Mountain Ascent and it hated 165/168 grain bullets but loved the 150 grain accubonds.  It is quite the shooter....though I have to 100% due my job as it is such a light rifle.  If I mess up just a little it really is magnified in the results. 

[jrebel]

What are you using for a crimp die? I tightened up my velocity spread with the Lee factory crimp die.

I have never crimped my rifle bullets....maybe I should??  Does it make that big a difference? 

[jrebel]

You could get more precise in your loading, sometimes that can help get a closer spread.  Things like:  Weighing and sorting the bullets right out of box (for example the box of Hornady 200 gr that I have consists of bullets from 197 gr to about 202 gr).  Using all powder from one lot/container, or even trying to separate powder from within the container to get more similar grain sizes (like putting on the table near the tumbler--not on in right against; seems to work the larger grains up to the top).  Brass prep.  Etc.

So, with your shots--what was the sequence like?  Is first measured from cold/clean bore?  Approximate same temp of barrel for each shot?  A warmer cartridge gives higher pressure/velocity than a cooler identical one.

Shto sequence with the .270 was 3 shot (10 seconds between shots)....Waited for barrel to cool and then shot 4 with 10 seoconds between.  Was a little curious how the heated up barrel would react and I agree....appears the warmer barrel produced the highest volocities. 

The .308 is a super light barrel and heats up fast.  Did the same shot sequence to see if I could replicate the results and it didn't appear to effect it as much even though the barrel was heated up pretty good with the second shot volley. 

[Curly]

Must be 150 gr bullets in the 270.

H4831 or RL26 is probably where you want to be.

[jrebel]

Must be 150 gr bullets in the 270.

H4831 or RL26 is probably where you want to be.

Yes 150 grain partition being pushed by H4350.  Not sure changing powder is the way I want to go based on my accuracy.   Here is my 5 shot group (the flyer is my fault  )

[Duckslayer89]

So....I have been handloading for quite some time now and have never really paid that close attention to my muzzle volocity.  I was always hand loading for hunting purposes and based my final load off of accuracy. 

Well, a couple weeks ago, I finally broke down and bought a Magnetospeed V3 to see what my muzzle velocities are. 

This was the data with a 7 shots out of my .270 which, if I do my job, will shoot well under an inch groups. 

Shot #1  2681
Shot #2  2733
Shot #3  2694
Shot #4  2719
Shot #5  2712
Shot #6  2750
Shot #7  2751

SD 26.7
Max Spread 70 fps
Average 2720

My question is....is this acceptable or can I tighten it up a little?  What reccomendations would a person have to tighten this up without any major changes as the accuracy is there. 


My .308 is quite a bit better

Shot #1  2778
Shot #2  2807
Shot #3  2805
Shot #4  2772
Shot #5  2804
Shot #6  2776
Shot #7  2789

SD  15.1
Max Spread 35
Average 2790

My 308 only shot 2520 with a 165 grain bullet factory nosler trophy grade ammo 22 inch barrel

This is a Kimber Mountain Ascent and it hated 165/168 grain bullets but loved the 150 grain accubonds.  It is quite the shooter....though I have to 100% due my job as it is such a light rifle.  If I mess up just a little it really is magnified in the results.

That's what happens to me. If I mess up a tiny bit the bullet goes haywire. Frustrating. But off hand I took a shot at a steel target hit dead nuts where I was aiming. Sometimes I wonder if the bench messes me up.

[b23]

Do you keep track of how many times you reload a piece or brass?  In that seven shot string,  had every piece of brass been reloaded the same amount of times or were they a mix of different amounts of times they all had been loaded??

[jrebel]

Do you keep track of how many times you reload a piece or brass?  In that seven shot string,  had every piece of brass been reloaded the same amount of times or were they a mix of different amounts of times they all had been loaded??

Haven't kept track.....All are under three times reloaded with most being second time as they were mostly factory loaded rounds to begin with. 

[Magnum_Willys]

The good news is you are on a node - but you knew that.  With that deviation in speed having little impact on accuracy you are in the sweet spot.   Watch temps. Are u sitting rounds out then putting in single just before shot?  Or are they warming in mag?  Loading to .1 grain accuracy?

[jrebel]

The good news is you are on a node - but you knew that.  With that deviation in speed having little impact on accuracy you are in the sweet spot.   Watch temps. Are u sitting rounds out then putting in single just before shot?  Or are they warming in mag?  Loading to .1 grain accuracy?

I was placing 3 rounds in the mag.  Is it better to have them out or in?  I do load to +/- .1 grain, measuring every load with a lyman electric scale. 

I am going back up today and will shoot one round, let cool for 3-5 minutes, shoot another, etc....  Little more time between shots.  I was also going to buy a crimp die before I go back today.  I want to crip 5 rounds and see what happens. 

[Magnum_Willys]

Ive wondered myself if rounds in mag were warming up but have never checked.  Just going from 50 to 75 degrees might explain some if they actually warm up?