SRP vs LRP Creedmoor Brass - R16 vs H4350

[WestMOhunter]

I broke down and did a budget 6.5 Creedmoor build to have a common caliber handy. I’ve been resizing .308 brass and have had decent results - BR2s w/ H4350 and R16. The R16 has been giving me 0.9” 10-shot groups at 2750-ish. As is typically the case, the R16 has been 50+ fps faster. Fast-forward to buying Alpha SRP brass…

5-shot groups ~1/2 grain under max w/ 140 ELD-M:

H4350 - 2710 FPS SD 7.3 0.5”
R16 - 2650 FPS SD 11.7 1”

I’m rounding group size, but I’ve consistently seen 1/4” tighter w/ H4350. It’s the ~100 FPS drop with R16/SRP vs the stable velocity of H4350/SRP that has me perplexed. Regardless, looks like it’s H4350 going forward.

 

[codym]

They like what they like. I have a 25 creed I kept trying to get to shoot h4350, tried a couple different lots and was consistently inconsistent maybe like 3/4 Moa. Switched to rl 16 velocity stabilized, groups shrunk completely different barrel now.

 

[Pickettpuncher]

Unless you have a huge supply of the r16, it seems it won’t be carried anymore. Keep that in mind

 

[WestMOhunter]

They like what they like. I have a 25 creed I kept trying to get to shoot h4350, tried a couple different lots and was consistently inconsistent maybe like 3/4 Moa. Switched to rl 16 velocity stabilized, groups shrunk completely different barrel now.

Yeah, for sure. I have used H powders for years, but R16 and R23 have magic dust in them, so I bought some. The R16 is better than H4350 in my .280 AI w/ Absolute Hammers and the R23 seems to be a tick hotter than H4831sc. I like Alliant powders. I’m gonna try N555 as an alternative to H4350 just in case, but I’m pretty happy with my results.

 

[codym]

I haven’t had any luck with h4350 In a few barrels now, always got velocity but not consistency. Varget 4895 and h1000 have been money for me. Have had good luck with rl16 and 23 as well. Also n565 in my 7saum and 300 prc. I’ve really changed the way I approach loaf development. I usually have two know powders and 2 know bullets and if I can’t get those combinations to shoot pretty quick I scrap the barrel. With the cost of components and the value of my time I’m not going to chase anymore

 

[WestMOhunter]

Welp, I gambled and bought 8# of N555. Got lucky because my 22” Criterion Palma loves it. Like, crazy stable. I did a pressure test over 2 grains in 0.3 increments and shot a nice group. Shot a 0.482” 5-shot with an extreme spread of 2 @ 43.0 gr @2,689. And that was consistent with several 3 shot groups at different charges (43.0 is well over book max). The craziest part is this was with Midway 140 HPBTs that shot mediocre with the other 2 powders. Looking forward to what ELDMs will do.

My takeaway from the testing of new Alpha SRP brass is that bulkier powders like R16 and even bulkier N555 suffer velocity compared to LRP. H4350 won the velocity test with SRP, but is the slowest with LRP. The other takeaway is N555 is the most accurate (in my rifle) with either SRP or LRP. As long as it stays so available and slightly less expensive than H4350 it will be my new go-to.