H4350 and the Grendel

[cory]

I've been playing around the 140gr projectiles for a little while now. I got to wondering if the 140gr projectiles would respond to a slower burning powder. Long story short I did some research where H4350 popped up a couple of times. Lucky me I came across a #.

I loaded some a couple of months ago and just got to the range with them today. I was a little nervous going into uncharted territory. After every round fired I stopped to exam the case. I expected to see pressure signs that would lead me to stop before I finished the loads I developed. That didn't happen.

Precision Firearms Grendel Rifle
Barrel Type- Lilja
Barrel Length- 24"
Barrel Twist- 8"
Primer Type- CCI 450
Brass used - hornady
Bullet Type/Ballistic Coefficient - Hornady 140gr SST 0.520
Bullet seating depth- OAL 1.675" COL 2.294" 0.010" jump to lands
Powder Used- H4350
Charge(gr) ..... Average Velocity(fps) of 3 rounds
C27.1 ..... 2029.7
C27.4 ..... 2078.3
C27.7 ..... 2113.3
C28.0 ..... 2128.3
C28.3 ..... 2147.0
C28.6 ..... 2177.3

Weather Conditions::
Altitude- ~800' above sea level
Temperature- ~63F
Wind/(Direction of wind in relation to your shooting)- In my face for the most part
Results-
IMG_20140405_234303_485.jpgIMG_20140405_154647_736.jpg

The OCW was done at 205 yards. I had my scope in a new mount, the target in the center is what I used to zero in my scope with some hand loaded Nosler 123gr CCs (CFE 31.2gr).

Unfortunately I couldn't fit anymore powder in the case. I'm sure I was well under 50ksi. I'd be interested in seeing how H4350 would work for the 6.5x45 stretched out Grendel for a Military prototype that has been discussed in the military section

[LRRPF52]

I could have told you that. H4350 is too bulky for the Grendel, but is great in .260 Remington. I use it to push the 130gr VLD at 2820fps from my 22" AR10. It's a pretty impressive load.

What distance is your target at?

[lilharcher]

Yep, I use it in my 22" JP 6.5 Creedmoor and get similar velocity mention above. Thanks for sharing.

[Bwild97]

Wow! Im thinking you may have a very nice sub sonic suppressed load right there! How did your rifle function with these loads? Any cycling issues?

I have been wanting to play with IMR 4007ssc for some time now, havent had the opportunity to pick a pound of it up or time to load and shoot it.

[cory]

I could have told you that. H4350 is too bulky for the Grendel, but is great in .260 Remington. I use it to push the 130gr VLD at 2820fps from my 22" AR10. It's a pretty impressive load.

What distance is your target at?

Yea others had told me the same. However I had gotten the idea in my head, and it was going to bug me to no end until I saw exactly what the velocities were.

My bad I forgot to mention it. The distance was at 205 yards.

Wow! Im thinking you may have a very nice sub sonic suppressed load right there! How did your rifle function with these loads? Any cycling issues?

I have been wanting to play with IMR 4007ssc for some time now, havent had the opportunity to pick a pound of it up or time to load and shoot it.

The rifle functioned beautifully. I didn't think about a subsonic load with the H4350, but you may be on to something. Decrease the charge by a few grains and maybe.

[JASmith]

The powder is a tad slow, and might explain the group sizes. H414 is close to the same burn rate but you might be able to squeeze a grain more of it and bring the pressures closer to where the powder likes to work at.

[cory]

Yea it was, but it had started to show potential at 28.6gr. The winds were all over the place, so the horizontal dispersion you're looking at is skewed.

H414 I'm going to look into that now. I'd really like to get my hands on some N540.

[arnie]

One problem with using slower powders in AR's is that the pressure spike is farther down the barrel so your bolt might get slammed open too hard and put undo stress on it .Garand's will have this problem .

[Bwild97]

One problem with using slower powders in AR's is that the pressure spike is farther down the barrel so your bolt might get slammed open too hard and put undo stress on it .Garand's will have this problem .

Adjusting for too much gas is easier than adjusting for not enough gas. I imagine that 27.4g load in a 14-16" brl. Would be sub-sonic

[cory]

IDK about 27.4gr, you're looking at 1700-1800 fps MV I'd think. I was thinking more in the 25gr range.

[JASmith]

There are reports of episodes of slow-burning powders causing disastrous pressure spikes when reduced loads are used. If I recall these were mostly in overbore cartridges, but that experience suggests some caution is due. IIRC, 4831 was one of these and it is slower that 4350, but caution should rule.

Might be a good idea to research the literature, check with Hodgdon and be safe.

The Hodgdon folks might even be able to suggest a powder that is both safe in partial fills and is happy enough to produce good accuracy.