getting the most out of light bullets.

[johnmventers398]

I am looking for advice from people with a better understanding of internal ballistics than I.

I have a 7mm rem mag that I typically shoot 150's from but also have the notion that I would like to shoot the lightest of bullets such as the Hornady 100gr gmx.

my friend and Smith tell me that long case body does not produce the most efficient burns with light bullets?

how do I go about getting the most out of the light rounds? slow powder fast powder? mag primers non-mag primers?

I am reasonably competent in reloading and have my tried and true methods of getting an accurate load but lack powder knowledge.

pointers would be gratefully received.

thanks

john

 

[243winxb]

Your Smith gave good advice.

Large amounts of powder require magnum primers in large cases. Even more so using ball powder and midrange loads.

Faster burn rates of powder are better then super slow powders.

Do use .002" neck tension , if using bushings.

Trying to reach the rifling with an extra long COL is not always a great idea.

Example, with photos. https://thefiringline.com/forums/showthread.php?p=4928827#post4928827

 

[johnmventers398]

Your Smith gave good advice.

Large amounts of powder require magnum primers in large cases. Even more so using ball powder and midrange loads.

Faster burn rates of powder are better then super slow powders.

Do use .002" neck tension , if using bushings.

Trying to reach the rifling with an extra long COL is not always a great idea.

Example, with photos. https://thefiringline.com/forums/showthread.php?p=4928827#post4928827

thanks.

this is what logic was telling me but I thought I would check.

I tend to jump my rounds a fair amount as I will always be loading from a mag.

the reason I am interested in this is pure and simple to do with new up and coming policy from my employers. less lead contamination in carcases for humans and carrion to ingest.

hoping I can make up for poor B.C with pure velocity in order to achieve similar flight curves. I also understand that the hydraulic piston action in the nose of the harder copper bullets generally requires velocity to work reliably.

 

[Toby Bradshaw]

...hoping I can make up for poor B.C with pure velocity in order to achieve similar flight curves.

You'll find that for any given bore and case size, with similar bullet shapes, lighter bullets are going to have a flatter trajectory, and heavier bullets are going to have less wind deflection.

 

[Zero333]

Hornday doesn't make a 100gr GMX... their lightest 7mm bullet is 120 gr Vmax, then the 139gr GMX.

Barnes makes a 100gr X S monolithic.

According to Quickload, RL-17 will get the 100gr Barnes X going at 3,650 fps with a charge of 70 gr.

Reduce and work up.

I shoot 130gr TTSX in a 300winmag. It goes at 3,550 fps. Awesome point blank.

 

[johnmventers398]

Hornday doesn't make a 100gr GMX... their lightest 7mm bullet is 120 gr Vmax, then the 139gr GMX.

Barnes makes a 100gr X S monolithic.

According to Quickload, RL-17 will get the 100gr Barnes X going at 3,650 fps with a charge of 70 gr.

Reduce and work up.

I shoot 130gr TTSX in a 300winmag. It goes at 3,550 fps. Awesome point blank.

yes, you are correct. I had the 270 box checked on there website, not the.284

 

[Davidb187]

Why not staying at 150gr but with an all copper bullet. Less lead is still lead.

 

[johnmventers398]

Why not staying at 150gr but with an all copper bullet. Less lead is still lead.

I have had experience of copper bullets not expanding more times than I am happy with and I have discovered that speed seems to solve this.

I use my 7mm for everything so it has to expand on the smallest targets.

I think all coppers 150's would work on the stags but I would be less confident on the hinds, calves and foxes.