Grendel finally delivered...

[Bronsonburner]

Since buying my PSA Grendel upper back in December it has been a troublesome beast. Mediocre groups with everything. Finally out of frustration I rebarreled it with a Criterion 18" tube. First few outings were also disappointing. Finally after paying more attention to brass prep and seating depth I finally think I have it shooting like it should. These were the best two groups form today (none were really bad though). 8208 XBR under 123 ELDMs.

IMG_2288.jpg



Penny in pic for scale. Weather couldn't be much worse either. Overcast with gusty winds in my face at 20MPH of so. Temps rapidly dropping and I was becoming chilled. Man I'm pumped up. I guess I can start playing around with seating depth now to try and milk out a little better accuracy.

Edit to add I called the minor flyer in the second group.

[ricsmall]

Nice looking groups! I’d say you figured it out.

[FRB6.5]

Looking good! Any velocity measurements?

[Massey9556]

That's awesome. Congrats. So what are you gona do w that barrel? You had a 18 inch Psa on it right? I'm just curious.

[Popeye212]

I think you got it.

[Cornbread]

You should be able to get to 28 gr.

[Bronsonburner]

Looking good! Any velocity measurements?

26.6 averaged 2372 with a pretty high SD of 18.6. I did have one round that read way high so I question the reading.
26.9 avg 2385, SD 11.2.

I might try a few at 27.0 as I'd like to hit 2400 or so. I tried 27.2 grains but the group opened up at that charge.

[Bronsonburner]

That's awesome. Congrats. So what are you gona do w that barrel? You had a 18 inch Psa on it right? I'm just curious.

Not sure yet. I know having spare AR parts laying around seem to turn into whole new guns though lol. I may end up giving it another chance someday or I may sell it. Thanks in part to this forum I have learned more about working up loads in the last few months than I thought I knew after years. I was spoiled rotten with my FN barreled 5.56. It shoots most everything well and I never really had to work to make it shoot.

[slip357]

good shooting

[Massey9556]

Curious if your going to hunt with those eld-M bullets? Some say they work good on deer coming out of the Grendel cartridge because they're not blazing saddles fast.

[kcb38]

Nice. Shame it took replacing the barrel to get there.

[Arkhangel5]

I am with Cornbread. I would see if you can get to 28gr. If no pressure signs, am betting you will see the groups tighten back up.

The barrel will tell you what it likes, if higher doesn't shoot tight, there you go.

As an example, I am at 2465fps with 28gr of 8208, sub moa all day long, I think Cornbread is in the same ballpark(18in barrel).

Just an FYI.

SY

[Popeye212]

For me 8208 seems to tighten up on the groups and Sd's on the upper end. YMMV

[Bronsonburner]

I am with Cornbread. I would see if you can get to 28gr. If no pressure signs, am betting you will see the groups tighten back up.

The barrel will tell you what it likes, if higher doesn't shoot tight, there you go.

As an example, I am at 2465fps with 28gr of 8208, sub moa all day long, I think Cornbread is in the same ballpark(18in barrel).

Just an FYI.

SY

If I found any data that listed 28.0 as a max I might go farther with it. The latest Hornady manual has no data for this bullet/powder. Major fail if you ask me. I used Sierra's data for the 123 grain SMK. It maxes out at 27.5. I loaded up to 27.2 and saw no pressure signs at all. I have a feeling I would hit another node beyond that but I am leery "going out on my own". I really wish for CFE velocities with an extruded powder's temp and SD stability. Is there such an animal? I would love to give AR Comp a try but it's not available locally to me.

[Londerko]

Hogdon lists 28.5 as max with a 123