Hi Guys,
Need your advice again.

For a newer shooter/reloader shooting up to 600 yards using a heavy barrel/gun and a muzzle brake

Assuming all the bullets stays supersonic to the target and the barrel likes 168, 175, 180 and 190 equally well - would using 190 gr bullets make things "easier" for a new shooter/reloader?

By easier, I mean 190 grain won't be as sensitive to wind or if the powder weight is slightly off

The trade off is more recoil but weight of gun and muzzle brake should help mitigate it.   And a few cents more per bullet

My friend will be testing 168 and 175.  I'm thinking of testing 180 and 190.

Tnx!

(Why use 308 for just 600 yards?  I bought it for 1000 yards and found out afterwards that civilians aren't allowed on the 700-1000 yard range at Puuloa.)

175 grain BULLETS

I'm confused. Cast boolits or jacketed bullets? For novice, stick with jacketed. These work really well in my 300BLK.

http://www.shootersproshop.com/nosler-30-cal-190-gr-custom-competition-hpbt-over-run-1000ct.html

AFAIK, the weight of the bullet has no direct correlation to powder accuracy. Generally, the heavier the bullet, the more pressure created in the case, the less powder you use.

You can try the Stability Calculator. Don't tell ren. He'll get mad at me again.

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

I'm confused. Cast boolits or jacketed bullets? For novice, stick with jacketed. These work really well in my 300BLK.

http://www.shootersproshop.com/nosler-30-cal-190-gr-custom-competition-hpbt-over-run-1000ct.html

AFAIK, the weight of the bullet has no direct correlation to powder accuracy. Generally, the heavier the bullet, the more pressure created in the case, the less powder you use.

You can try the Stability Calculator. Don't tell ren. He'll get mad at me again.

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

Boolits are cast

Powder accuracy? I'm not mad nor get mad at you. Just don't shoot no less than 5 tables away from me and we'll be fine.

AFAIK, the weight of the bullet has no direct correlation to powder accuracy. Generally, the heavier the bullet, the more pressure created in the case, the less powder you use.

I have no idea what you're trying to say here. Please rephrase.

I like 175gr smk bthp . I’m not currently pressing but just buying again . I did play around with different sizes and brands . To me  and that’s just my opinion but the 175’s held better at greater distance. It also gives good stopping power for deer out at 500+

For example, the 190gn BTSP in my 300BLK takes up to 17.8gn of A1680 powder while the 150gn takes up to 22.0gn, per the Hornady Manual.

Have you looked into the Berger 200-20X?  Don't know your twist but many F-T/R guys are using it.


Sent from my iPhone using Tapatalk

For example, the 190gn BTSP in my 300BLK takes up to 17.8gn of A1680 powder while the 150gn takes up to 22.0gn, per the Hornady Manual.

I know that there is a correlation between powder charges and projectile weight, but I need you to tell me more about this "powder accuracy."

OP: "By easier, I mean 190 grain won't be as sensitive to wind or if the powder weight is slightly off".

OP: "By easier, I mean 190 grain won't be as sensitive to wind or if the powder weight is slightly off".

powder weight variation
That depends on case capacity. A few kernels may matter in a small case versus a bigger case.

OP: "By easier, I mean 190 grain won't be as sensitive to wind or if the powder weight is slightly off".

wouldn't the larger projectile have less available space in the case, making it more sensitive to powder weight variation?

Probably. Match shooters seem to prefer the larger bullets (such as 80gn 5.56) but not exactly sure why. I doubt it's because the larger bullets are more forgiving to powder weight variations.Using my Hornady Bench Scale, I'm confident at 0.2 gn increments but not so much at 0.1 gn. Match shooters use a +$1,000 scale with sliding door like the ones I used in chemistry class. I'm nowhere near ready to spend that much on reloading.

https://www.amazon.com/Torbal-AGN200-Readability-Auto-Internal-Calibration/dp/B009S7CAVI/ref=sr_1_26_sspa

Probably. Match shooters seem to prefer the larger bullets (such as 80gn 5.56) but not exactly sure why. I doubt it's because the larger bullets are more forgiving to powder weight variations.Using my Hornady Bench Scale, I'm confident at 0.2 gn increments but not so much at 0.1 gn. Match shooters use a +$1,000 scale with sliding door like the ones I used in chemistry class. I'm nowhere near ready to spend that much on reloading.

https://www.amazon.com/Torbal-AGN200-Readability-Auto-Internal-Calibration/dp/B009S7CAVI/ref=sr_1_26_sspa

I can tell you why I shoot 80s because of the higher BC. I don't use any fancy scale. I load on a Dillon 550B. Prime, charge and seat all on the Dillon. The Palma team did it and many other highpower shooters do.
With 80s they are seated farther out and will not fit in a magazine.

Cool. What twist rate do you have?

1x7

Hi Guys,
Need your advice again.

For a newer shooter/reloader shooting up to 600 yards using a heavy barrel/gun and a muzzle brake

Assuming all the bullets stays supersonic to the target and the barrel likes 168, 175, 180 and 190 equally well - would using 190 gr bullets make things "easier" for a new shooter/reloader?

By easier, I mean 190 grain won't be as sensitive to wind or if the powder weight is slightly off

The trade off is more recoil but weight of gun and muzzle brake should help mitigate it.   And a few cents more per bullet

My friend will be testing 168 and 175.  I'm thinking of testing 180 and 190.

Tnx!

(Why use 308 for just 600 yards?  I bought it for 1000 yards and found out afterwards that civilians aren't allowed on the 700-1000 yard range at Puuloa.)

tim, going back to your original question--

as you correctly pointed out, the choice to use 155, 168, 175/178, 180, 190, and even the bullets above 200, are largely dependent on the yardage at which the bullet goes transonic.

like you, i'm also learning about bullet choice and ballistic coefficient.  typically the long range shooters will prefer high ballistic coefficient bullets because they hold their supersonic velocities out to longer ranges, and are also less sensitive to wind drift.

regarding your Q about sensitivity to powder weight variations, this will be largely dependent on the charge weight you choose.  a lot of the newer reloading theories that i've been reading into have to do with choosing a charge weight that provides very little variation in velocity for charges +/- 0.1gr or +/- 0.2gr.  basically, you want a charge weight in the "flat spot" on a velocity graph.  ideally, that charge weight will also have a low standard deviation and low extreme spread in velocities.

I'm actually playing with 168, 175, and 190 loadings right now.  i'm attaching a pic of the velocity data from a recent session to show you the "flat spot" that i'm referring to for a 175gr Nosler OTM and Varget test.

i'm still in the process of learning about this so take my post with a grain of salt.

"41.0 of IMR 4895 pushing a 168 Sierra Match King won Gary Anderson the Olympics in 300 Meter rifle.

42.0 of IMR 4064 pushing a 175 Match King is an "Index Load" -- if your rifle doesn't shoot it well there's something's wrong with your hardware.

44 grains of Varget will push most bullets accurately in a bolt rifle. Stick around 42 to 43 for autoloaders. "

from the former CDR of the AMU. I'd heed his advice.

Nice data. Barrel mount chrono?

Hi Guys,
Thanks for all the good info!  Much to digest and share with my friend.  In hindsight I should have put "reloading for idiots that suck at making precise loads and wind calls" in the subject line. 

Pew - that is pretty impressive.  Are you using a magnetospeed?  What program are you using to make that spreadsheet and graph?

I think I've been reading the same postings/articles as you regarding finding a "plateau" where speed stays same while powder increases.  (I was planning on finding the "plateau" for my 223 rifle and then throwing the charges instead of weighing them)