Grendel loads with large accuracy nodes

[sniper79_98]

Good evening,

What weight bullet has the largest accuracy node? I know a lot of work has been done with the 123s. I’m wondering what bullets (in your experience) has produced the largest accuracy node? I’m going to shoot some 100s and 107s tomorrow. The 123s seem to have a narrow node of about 1/10th grain using ar-comp in my mini. Do any of the bullet weights offer a larger node? Say .3-.5 grains? Shooting with a suppressor I’ve reduced my load by .2 to get my groups tightened back up. Thank you for sharing anything that may be helpful! Side note, any calibers that have larger accuracy nodes are welcomed as well.

 

[FCS]

100 & 120 SMK, 100 & 120 Nosler BT, 120 Berger Match BT have all worked well. I have found that 8-11, maybe 12 radius ogive works better than does 13-17 radius ogive profiles found on 107, 123s.

"Problem" with 107 SMK, 123 SMK / Amax / ELD-M / Scenar is that ogive profile means jumping more but since mag limits OAL you've buried bullet in case. Limits case capacity so this forces you to a bit faster burn rate powder, that can cause load to be a bit more peaky / temperamental.

AR-comp works okay with lighter bullets but getting a little faster in burn rate then I like with 120-123 gr bullets.

IMR8208
H4895, velocity is slower but accuracy has been great
Viht N-135, N-530 or N-540 are in "right" burn rate.

3-3.5X charge weight for bullet weight, once bullet weigh is above that it tends to become more difficult to find a wide node.

How gas system was set up for the mini is also going to influence behavior. When rifle was built, was it set up for 120-123 gr bullets or set up for lighter bullets?

 

[sniper79_98]

It’s simply a Howa mini action. Not an 11.5-12” barrel ar. The 3-3.5 is interesting. I was wondering if there was a rule of thumb so to speak. I wish I’d have gotten more H4895. I’ve got 8#s of the xbr and ar Comp. I’ve got 500 of the 107s and about that in 123 eld(s) and nosler cc(s). Thank you for writing that. You’ve given me something to study.

 

[FCS]

Ahhhh, Howa mini not Mini-14.
Howa mags still have you pretty short but I think the Howa mags allows for slightly longer OAL than AR magazine.
100 /120 Nosler BT have done well for me from AR, I’d expect same from Howa.
120 Berger Match BT is a favorite. Berger discontinued 100 gr Match BT, was a great AR bullet.

I’ll find my Howa magazine, see what OAL it will allow.

 

[bobke]

Interesting, as I’ve found AR Comp to be quite forgiving across 6 different Grendel barrels, from 18-24”. 27.2-27.4 works very well with 123CC’s and 123 Sierras, and is more temperature insensitive than most ball powders, which could easily affect the breadth of your nodes in a positive manner as cooler weather comes.

 

[sniper79_98]

That was my experience with AR Comp as well. I had excellent accuracy with 27.6-27.8 grains with Nosler CC or the Hornady ELD in 123. Since hanging a suppressor on the end of it, I’ve had to reduce that loss to 27.5 to achieve the accuracy I had without it. Thinking my velocity would’ve been similar when I put them over a chronograph... the velocity dropped from 2475 with 27.8 grains of AR Comp/ no suppressor to 2400 with 27.5 grains ar Comp with a suppressor. The bolt was noticeably Sticky after using my old load of 27.8 ar Comp and 123 nosler cc. I’ll buy some more 120s. I had some but shot them all up and moved to the 123s (this was before I’d bought a suppressor).

 

[bobke]

From all I've heard about the 120gr Sierra MK, that's about the most forgiving of all of the bullets out there. I have some I'm holding in reserve, but with the accuracy I'm getting with either CC's or 123 Sierras, have found no reason to dig into my stash. Strykervet reports excellent accuracy with 120gr Nosler BT's, and I've seen same, just reserve them for hunting and not general usage.

 

[Tacovrd]

Sub'd to follow thread.

 

[FCS]

Looks like 2.34" inside magazine, probably 2.330" OAL will feed without issue. What OAL are you running with the 123s?

Loaded to a longer OAL, I'd be looking at IMR8208, H4895, VV-N530, possibly Benchmark, RL-15 / N-203B.

 

[FCS]

120 Berger Match BT is really great bullet for the 6.5 Grendel, more expensive but is my favorite 6.5 Grendel bullet. I really liked the 100 Berger Match BT, felt it was the ideal weight for 6.5 Grendel but Berger discontinued that bullet about decade back.

100 / 120 Nosler BT work very well.
120 SMK is a great bullet also. I've been meaning to test some with the 100 SMK, just haven't found the time to get that done yet.

120 Barnes from CZ527 does very well accuracy wise, will have to find chrono book, look up velocity as I don't recall.

 

[sniper79_98]

I found that the Nosler meplat varied a little so I’m measuring base to ogive. I’m a 1.760 on that. I’m thinking close to 2.265? I can certainly seat them out further but I’ve got an AR as well that I’d like to run them in. I’ve never shot any Bergers... at all. Mainly Nosler, Hornady and Sierra. If I can find a deal on the Bergers, I’ll buy a few hundred. I’m done buying 100 only to wish I’d bought more and now can’t find them lol.

 

[FCS]

I abandoned one load for two platforms.
Bolt gun load is longer so won’t mistakenly go in magazine, then optimize load for what bolt gun allows.
AR you have too many dynamics at play, limits choices vs what one can do with bolt gun.

I fully understand the desire for one load, two platforms and when I’ve done that in past it was purpose built AR using same barrel Mfg’er and chamber reamer as bolt gun, very specific port location, port size, buffer weight, buffer spring K.
Still can’t quite get gas gun to deliver same performance as bolt gun, I just migrated to dedicated load for each. Easier and both run better than compromise load that works reasonably well in both.

100 / 120 SMKs are knee of curve, Berger Match BTs are better but 40ish % more.
Nosler BTs shoot really well but are more expensive.

 

[6.5SH]

@FCS any experience or advice for the Nosler 100 gr Custom Comps in Grendel (for AR if that matters)?

 

[FCS]

I haven’t tried 100 NCC.
Benchmark & 100 Amax / ELD-M was a winner, 18” bbl with rifle gas.

 

[6.5SH]

Thanks for the reply

 

[FCS]

What barrel length?
Gas system length?
Any idea of port size?
Buffer weight?

 

[6.5SH]

What barrel length?
Gas system length?
Any idea of port size?
Buffer weight?

A bit of an oddity, I use an AR pistol for local PRS format gas gun matches.

12.5" 1/8 twist
Carbine length gas, .068" port
Vltor A5H3 buffer
I get 4:00-4:30 ejection with 123 Gr Hornady American Gunner.

I have 8 lbs of Benchmark, so was pleased to see you suggest it. I was going to start with Nosler's 100 gr BT data.