Is there a way to tighten up velocity, ES, & SD?

[larks99]

first thing that comes to mind is your powder. Sounds like to me your powder thrower is not consistent with each load. Try weighing each charge and load up 10 rounds to see if it's more consistent for you.

 

[FlGunner]

So here's what I've done this evening. I shot some new bullets that I've bought and been playing with. I paid close attention to my case length and lightly brushed the case mouths. Did the usual in primer pocket reaming and deburring flash holes. I shot a couple of groups with Hornady brass, 162 grain SST, CCI #250M , and 67.0 of H1000. Velocity average was 2925 with Es of 40. Didn't do the numbers on ad yet. Group was very tight for no better rest that I had being I left my bag and bipod at home. I shot this group of 3 shots 3 times. Basically laid rifle across a bag of shelled corn lol.

 

[FlGunner]

Next I used the federal brass I had with some new Nosler 168 grain Accubond LR with 71.0 grains of Retumbo, same primer and case prep. Shot 6 rounds to what I found to be the most accurate and consistent in working up. Velocity was 3000, 2998, 2998, 2994, 2998, 2986. I do feel the load will shoot better than what's pictured with a better rest even though I shot the sst's tighter. I think confirming my powder charge on the rcbs 10-10-10 I just got from a friend is a major help. I do use a trickier as well. I do weight sort brass and bullets as mentioned. Haven't sorted by capacity yet on the brass. I do also measure base to ogive and this load is .050 off the lands. Again, thanks for all of the replies and suggestions guys. They're much appreciated.

 

[jshepherd61]

Next I used the federal brass I had with some new Nosler 168 grain Accubond LR with 71.0 grains of Retumbo, same primer and case prep. Shot 6 rounds to what I found to be the most accurate and consistent in working up. Velocity was 3000, 2998, 2998, 2994, 2998, 2986. I do feel the load will shoot better than what's pictured with a better rest even though I shot the sst's tighter. I think confirming my powder charge on the rcbs 10-10-10 I just got from a friend is a major help. I do use a trickier as well. I do weight sort brass and bullets as mentioned. Haven't sorted by capacity yet on the brass. I do also measure base to ogive and this load is .050 off the lands. Again, thanks for all of the replies and suggestions guys. They're much appreciated.

Can you stretch it out? My 7 STW likes the 168 ABLR's about 0.13 off the land.

 

[FlGunner]

Can you stretch it out? My 7 STW likes the 168 ABLR's about 0.13 off the land.

I will try to this weekend but I'm limited to just over 500 yds where I can shoot. But I will try and get ya response on how they do at some longer distance.

 

[Hatrick]

Fl, He means closer to the lands to tighten your group.

 

[toliver]

I tried a little experiment this weekend. I fired ten rounds of exactly the same load. The only difference was 5 had a very light crimp. About the best I could measure was .001 of crimp. The other 5 no crimp at all. No crimp had an es of 21. Crimp had an es of 6. I was a little surprised that the crimped cases were slower across the board as well. I will do a more comprehensive test soon, as the results I believe intriguing.
This was a .308 w/175 berger over 43 of varget.

 

[toliver]

Oh ya measured over a labradar.

 

[FlGunner]

Fl, He means closer to the lands to tighten your group.

I must've missed that lol. Yeah I plan to use same charge weight and lengthen in .005 increments and shot 5 at each length. I've read the accubond LR like jump and actually didn't do much seating depth work with them. So maybe this will improve thing as well. Thank guys for all the good help.

 

[RedSnake]

Neck tension... Anneal and FL size with bushing dies

 

[WalksLikeADeer]

not sure if anyone has mentioned but barrel will make a difference.... some are tighter some not so much. the sensitivity the powder has to heat will affect it as well!!! I have quite a few 7mmRM that I load for from stock to custom and I load the same in all and they all shoot 1/2moa @100 the custom does a lil better. In the propellant profiles book max charge of 75gr of h1000 was a little much. I load 74gr with WW, hornady and Nosler brass all hit in the same exact place. bullets are 160gr hornady match or eld, hunting 160 nosler partition. Fed 215match primers. As others have said anneal your brass, I trim everytime!! also I took my expander ball out and polished it( heat it up til is orange, let it cool, polish, then heat it back up to orange and quench) if you remove a few thou thats ok. primer pockets all uniform and flash hole de-burred.

the propellant profiles book is a good tool I suggest everone have one!! lots of different powders and testing done with them. good luck!!

 

[WalksLikeADeer]

I assume when you mentioned the the Hornady 160 gr match and Eld, you were referring to the 162 gr? I load the 162 gr ELD-X (.284) for 7mm Rem Mag but the Hornady manual states a max load of 68.5 grains of H1000.

I'm unfamiliar with the propellant profiles book but if it is stating a max load of 75 grains of H1000, that is a huge discrepancy. No wonder you were seeing pressure signs!

 

[FlGunner]

I assume when you mentioned the the Hornady 160 gr match and Eld, you were referring to the 162 gr? I load the 162 gr ELD-X (.284) for 7mm Rem Mag but the Hornady manual states a max load of 68.5 grains of H1000.

I'm unfamiliar with the propellant profiles book but if it is stating a max load of 75 grains of H1000, that is a huge discrepancy. No wonder you were seeing pressure signs!

The Hornady bullet I was referring to is the 162 sst using 67.0 of H1000, I've been using a couple different loads but settling in with the 168 Nosler Accubond LR with Retumbo. I don't push past book limits. The velocity I'm seeing is at or just above book values from a 26" tube. Sorry if I may have been a lil confusing with the post. Too much rain to shoot this afternoon and tomorrow looks the like the same forecast.

 

[bpcrshooter]

yes sorry 162gr. The propellant profiles book fifth edition states 160-162gr, 71.0gr for 2983fps with 50300 cup. max load 75.0gr for 3129fps and 55500cup.
168gr 69gr-2896fps/ 73gr 3055fps
175gr 68gr 2812fps/72gr 2978fps
I started well below and worked up. max on all gave signs of pressure Remington cases sucked!! the three I use ww,hornady and nosler all worked well and group Very well into the 1/2 min area the partitions were a lil bigger and low past 300yrds. Also cci primers did not work for me in any gun fed215 I found 2k match primers so that's what I've been using lately. I shot 74gr/ 162gr yesterday and had 3in group @ 600yrds with my custom 7mmRM. I know we all don't need a new loading book but I go to this book more than any of them, lots of data on lots of different powders. Its a good read!!