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Old 04-18-2021, 12:59 PM
EricPope EricPope is offline
 
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Default Load Development, Accuracy, Velocity

Hello shooters.

This question / comment originates form another string in which many NM shooters were saying not to bother with load development for Service Rifle competition. That it wasn't worth the reduced barrel life. They went on to say list several loads as standard for NM shooters. 24 and 24.5 of Varget with 77 SMK and the same for H 4895. and R 15. Slight variations, but not necessary for this string.

I never wanted to be a scientist about this stuff. I just want a MOA load, but recognize that I need max velocity for the 600.

In the course of some load development I noticed an accurate node at 2600 fps with several powders, propelling 75 HPBT bullets, but didn't test past that very far. My 2600 node was good enough for my 200y matches and I knew I wasn't going anywhere because of COVID.

My question is: Has anyone recognized a MV / accuracy convergence? Something like 77 SMKs are sub moa at 2800 to 2850 with multiple powders.
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Old 04-18-2021, 03:51 PM
Gewehr43 Gewehr43 is online now
 
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I've found that the 77's (any type) seem to settle in well at around 2750.
The 80's (SMK and Nosler) settle in around 2700fps.
Again SR shooting.

I'd say that you don't need "max Velocity" for 600yds, ..... yes velocity is important but low ES/SD is also.

Likewise I wouldn't say that load development isn't needed to save on barrel life but instead the AR is "figured out" and so not really needed as you can pick one of the combinations and be done.........

ie I Shoot SMK's with H4895 at the velocities I mentioned above, 77's at mag length.
Done.
Shoot better than I can.

PS... I'll look again but IIRC my H75 load was just over 2750fps........... See a pattern?
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Last edited by Gewehr43; 04-18-2021 at 03:53 PM.
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Old 04-18-2021, 04:43 PM
EricPope EricPope is offline
 
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Location: Arizona
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Yeah, I was hoping to discover a node like that to make load development easier. So if I know 77 SMKs settle in around 2750 then if I have to switch powder or I get a new barrel I load one round at 3/10 workups until I get to 2750ish, and check for signs of over pressure, then fine tune.

In the past I skipped the chrono and shot for groups but that doesn't help any when you have to switch powder. Also, without knowing the MV I used too slow of a load at the 600 on an EIC and got killed.
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Old 04-21-2021, 06:47 PM
Belltower0351 Belltower0351 is offline
 
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Location: Northwest Ohio
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Through all your load development, you will most likely end up at those same proven loads... 24 of varget or RL 15 or 23.5 H4895 for 75s and 77s. Add a half grain for 80s if you want, but you don't have to to keep it in the 10 ring. There are more loads with other powders, but the work has already been done. Those loads will put you in a velocity node that will work with almost any barrel, which should be right around that 2750 mark noted above. If you have to switch powders in today's climate, search for loads on the national match forum and you're set.

If you enjoy playing with loads, have fun. If not, load a proven load and shoot. And you can use a measure, no need to weigh powder for every round. Plus or minus a tenth isn't going to show on the target at 600 and under.
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  #5  
Old 04-24-2021, 09:07 PM
hebes405 hebes405 is offline
 
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Quote:
Originally Posted by EricPope View Post
Hello shooters.

This question / comment originates form another string in which many NM shooters were saying not to bother with load development for Service Rifle competition. That it wasn't worth the reduced barrel life. They went on to say list several loads as standard for NM shooters. 24 and 24.5 of Varget with 77 SMK and the same for H 4895. and R 15. Slight variations, but not necessary for this string.

I never wanted to be a scientist about this stuff. I just want a MOA load, but recognize that I need max velocity for the 600.

In the course of some load development I noticed an accurate node at 2600 fps with several powders, propelling 75 HPBT bullets, but didn't test past that very far. My 2600 node was good enough for my 200y matches and I knew I wasn't going anywhere because of COVID.

My question is: Has anyone recognized a MV / accuracy convergence? Something like 77 SMKs are sub moa at 2800 to 2850 with multiple powders.
Yes. The convergence is around 2700 fps ie* 24 grains of varget loaded mag length.
There's no reason to load develop for short line ammo. That wheel has been invented.
There is some gains in tuning a 600 yard load. But I recommend shooting 80 grain bullets at 600. Your not limited by magazine length and can play with seating depth to get your groups tighter.
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