Thread: 6.5 Grendel load trouble shoot

So tested my luck with reloading recently, apparently not so good.
Though getting easy MOA or sub but the speed was way low. With 6.5 Grendel I was aiming for above 2500fps and I was getting around 2200fps.

So the details of load is as below:

Howa mini action 22" barrel suppressed
123gr Amax projectiles
Once fired Hornady brass trimmed to 1.519 to 1.522 inch
COAL 2.327 (I suspect this might be the culprit, as this is a fair bit longer than most COAL I've seen on internet)
IMR8208XBR powder.
I've loaded 28.0gr to 28.3gr, and the fps ranged from 2201 to 2254 fps, on average about 13fps increase per 0.1gr powder increase.

The speed is way too low considering I want a hunting set up. With my limited experience I can only suspect my COAL is fair bit longer than standard 2.250 or 2.260, but would that really create a 300fps drop though?

Dilemma1: My current COAL fits nicely into the magazine and is close to the rifling, I've learnt that's apparently good for accuracy. But I'm really close to the 28.5gr max recommended load, so not sure if it's safe to increase powder above 28.5gr to reach 2500fps.
Dilemma2: I'm running hella low on pills so I don't want to just experiment around and waste what's left. Had piss poor luck on that, even lost a box to postage so if anyone can supply some 123eldm or amax I'd be much obliged. Can pay cash or swap 6.5 147eldm or 308 168 eldm.

Sorry about the lengthy post, any advice or pills would be really appreciated, cheers.
Michael

What chrono? I've had no trouble getting "about" 2500 with 123s and 8208 from a 16" for a mate. Dud lot of powder or dud chrono?

Or ya barrel is 6 inches too long

Id suggest try one over the chrono at 28gr at the 2.250", you might find out some useful information. I dont see it gaining an extra 300fps however. If your happy with .1 gr increments, keep going up until you hit pressure signs( sticky bolt lift, flattening of the primers, ejector stamping, bolt face swiping etc) often book max charge weights are pretty reserved, find your rifles pressure and work with that. You might find a great node over book that is safe in your action.

Gordons Reloading Tool reckons you should be getting more velocity than that (2560fps, but really need actual case capacity). It predicts a shorter COAL of 2.25 would give you another 80fps or so, but would be well overpressure. I would be trying a different chrono as a first step.

It could be the powder lot, or age/humidity exposure.

You have the right components for good rounds. About the best you can get for the grendel in that weight range. Surprised you are getting that length into your mag. I have the same set up and can't get that I don't think from memory.
Have you tested your load vs the expected drop at long range. If you are shooting high it might be your chrono

Im using 26gr 8208 in mine with same projectile for 2350 fps. and out to 350 meters its a real killer! I could go a bit hotter, but from memory .5 gr more showed pressure signs, and as said the terminal performance has been exceptional, so Im not going to worry about it.

Is this the same Howa Mini you purchased from me?

Ive just checked my reloading note book. I used 123gr eldms and 8208.

I have notes saying max mag length was 2.310"

I have data on powder testing from 27.9gr to 28.5gr, all the velocities were 2500+ fps.

It also appears from my seating depth tests it shot tighter groups at oals shorter than max mag length.

Best i tested was a oal of 1.661" base to ogive using my comparator. Which shot under .5 inch at 100 yds. It wasnt suppressed when i had it, so the seating depth tuning of it may well have changed after suppressing, but suppressing it wont have reduced velocity, in fact it should have slightly increased it.

Thanks a lot team
I've checked the chrono, a guy on site put his labradar next to my rifle and the reading was consistent. @GWH yes it's the one I bought from you, it's shot factory ammo amazing, I just wanted to reload for it to squeeze out every last bit of its potential. And yeah suppressor is new.
I might grab a mate that's more experienced and see if I got all my measurements right. Double check I didn't make some silly mistake somewhere.

QuickLOAD 123 gr AM, 28 gr 8208, 2.327" COAL

QuickLOAD 123 gr AM, 28 gr 8208, 2.250" COAL

QL almost agrees with Gordon's. QL and Hodgdon Reloading Centre say you are getting up near max.
QL doesn't always perfectly predict velocity but its never out by 300 fps.
Likewise would get a more accurate prediction if cartridge water capacity is entered. But for the sake of the exercise these predictions are good enough.
What velocities were you getting with factory ammo?

What scales are you using and are they calibrated? Might be a whole lot less powder going in than you think.

Originally Posted by zimmer

QuickLOAD 123 gr AM, 28 gr 8208, 2.327" COAL
Attachment 187865
QuickLOAD 123 gr AM, 28 gr 8208, 2.250" COAL
Attachment 187866
QL almost agrees with Gordon's. QL and Hodgdon Reloading Centre say you are getting up near max.
QL doesn't always perfectly predict velocity but its never out by 300 fps.
Likewise would get a more accurate prediction if cartridge water capacity is entered. But for the sake of the exercise these predictions are good enough.
What velocities were you getting with factory ammo?

Thank you very much and this Quickload looks like an incredibly useful tool.

Originally Posted by feratox

What scales are you using and are they calibrated? Might be a whole lot less powder going in than you think.

Hornady 1500 G2, I know it is not that flash but could it be out by that much though?
I did rattle the cartridge after loading them and I gotta admit they sounded like they had a lot of space in there.

I had a set and found they drifted quite a bit between start and finish. Got so pissed off with them they leapt off the bench and flew into the opposite wall.