338 Sherman Build (This Is My Boomstick!)

[benchracer]

Thanks Brad! I guess I missed some of the earlier data. It was likely too late at night for my old brain......Rich

Nope. You didn't miss a thing! I just went back and added the data this morning.

 

[elkaholic]

Whew! So I am not quite senile yet

 

[benchracer]

I finally got around to doing some accuracy work. I started with the Berger 250 EH and RL-17. As you can see, best accuracy showed up @ 62.0 grains. The 62.0 group measured just under .900". That was OK, but I felt like there was more to be had.

Under normal circumstances, I begin load development by testing seating depth. However, since the Sherman is a wildcat cartridge, I had begun my work by seating .010" off the lands and generating a load map for the cartridge. With best powder charge figured out, it was clear that I needed to tune the load by testing seating depth.

Here, I found myself on the horns of a dilemma. My normal procedure is to begin testing seating depth @ .040" intervals, as recommended by Berger. However, for the sake of performance, using every bit of available case capacity in the 338 Sherman is critical. Moreover, I knew the 62.0 grain charge to be very near to max with this combination. I was concerned that .040" intervals might be too coarse of an adjustment, both in terms of available case capacity and in terms of safety.

I decided to discuss the matter with Rich (elkaholic), who recommended that I test .020" and .030" off the lands...

 

[benchracer]

After giving the matter further thought, I decided to test five different .010" increments, with the idea of casting a wide enough net to give myself the best chance of finding an accurate seating depth. With that in mind, I decided to back the throttle down to the next node for the sake of safety.

As it turned out, I only needed to back off an additional .010" from my initial seating depth of 3.565". I found what I was looking for at 3.555 and .020" off the lands. At its widest point, the group measured .232 center-to-center.

From here, I intend to throttle back up to the vicinity of 62.0 to fine tune the load.

Rich initially designed the 338 Sherman around the Berger 250 EH. I'd say he nailed it AGAIN! I expected this cartridge to shoot, but wasn't expecting results like these!

 

[elkaholic]

That is pretty impressive Brad! Goes to show what a little tweaking will do before you have coffee Mine shot really well right around 3.560" coal I think?

 

[elkaholic]

That is pretty impressive Brad! Goes to show what a little tweaking will do before you have coffee Mine shot really well right around 3.560" coal I think?

 

[benchracer]

HORNADY 285 ELD-M/MISC NOTES

I also ran a MIN-MAX test with the Hornady 285 ELD-M and RL-26 awhile back. When I measured the OAL to the rifling with this bullet, I was surprised that it measured only 3.530 vs 3.575 for the 250 EH. I perceive this as yet another data point that indicates how good the 250 EH design really is. Loaded .010 off the lands @ 3.520, the 285 ELD-M maxed out near 2650. OBT calculations predict the center of the accuracy node would show up just above 2600.

RL-26
65.0 2581
65.5 2564
66.0 2594
66.5 2608
67.0 2634
67.5 2649 Light ejector mark.


I also loaded a short MIN-MAX series with the 252 CE and RL-17. To my surprise, the 252 CE maxed out at about the same muzzle velocity as the 250 EH, with one grain higher powder charge. I am astounded by this. With virtually every other CE bullet I have tested, the MTH will typically show a gain, over a comparable cup and core bullet, of 40-70 fps at max powder charge. The fact that a low-friction bore rider bullet design shows no velocity advantage over the Berger EH speaks volumes about how right Berger got that design. Again.

 

[benchracer]

Hornady has released two new .338 ELD-X bullets in 270 grain and 230 grain weights, respectively. Hornady lists the 270 ELD-X as having a .757 G1 (.381 G7) bc and the 230 ELD-X as having a .616 G1 (.310 G7) bc. I view .338 bullets above the 250 grain class as being best suited to larger cases, so I won't be testing the 270.

The 230 ELD-X, however, looks like it could have serious long range potential. I have a box of these on order and intend to test them as soon as I possibly can (which, alas, will probably be after the first of the year). I am hoping this bullet will have a shorter bearing surface than the 225 SST, allowing it to be pushed faster before pressuring out. If it can be pushed fast enough, it may well rival the long range potential of the Berger 250 EH...

 

[elkaholic]

+1 on the 230

 

[benchracer]

Hornady has released two new .338 ELD-X bullets in 270 grain and 230 grain weights, respectively. Hornady lists the 270 ELD-X as having a .757 G1 (.381 G7) bc and the 230 ELD-X as having a .616 G1 (.310 G7) bc. I view .338 bullets above the 250 grain class as being best suited to larger cases, so I won't be testing the 270.

The 230 ELD-X, however, looks like it could have serious long range potential. I have a box of these on order and intend to test them as soon as I possibly can (which, alas, will probably be after the first of the year). I am hoping this bullet will have a shorter bearing surface than the 225 SST, allowing it to be pushed faster before pressuring out. If it can be pushed fast enough, it may well rival the long range potential of the Berger 250 EH...

I received a box of the Hornady 230 ELD-X bullets today and proceeded to take some measurements and compared it to the other .338 bullets I have. My initial impression is that the Berger 250 EH's Long Range crown is safe. It looks to me like the extra 5 grains went into a longer boat tail. From what I can tell, the nose profile and bearing surface are identical to the 225 SST.

225 SST
Length: 1.426
OAL To Lands: 3.452

230 ELD-X
Length: 1.514
OAL To Lands: 3.445

So, a bullet that is .088 LONGER has an OAL to the lands that is .007 SHORTER than the 225 SST. For all practical purposes, the OAL to the lands is effectively the same, given that a .007 difference could easily be seen lot-to-lot in the same bullet.

In real world testing, the 225 SST was maxing out around 2900 with both RL-17 and H100V. After plugging the measurements into QL, the 230 ELD-X looks like it will max out around 2850. The OBT predicted nodes for both bullets are within 20 fps of one another. I am prepared to believe Hornady's stated bc for the ELD-X. In comparison to the 225 SST, it does appear to be a better bullet. For your money, you are getting roughly a .100 bump in G1 bc, a longer boat tail, and the new non-melting tip.

Though the ELD-X appears to be a genuine improvement over the SST, it sure looks like Hornady left a lot of performance on the table. As always, actual shooting will have the final say, but it is looking like the ELD-X will only be about 50 fps faster than the Berger 250 EH. Relative to what I was hoping for, this looks pretty disappointing.

 

[elkaholic]

I received a box of the Hornady 230 ELD-X bullets today and proceeded to take some measurements and compared it to the other .338 bullets I have. My initial impression is that the Berger 250 EH's Long Range crown is safe. It looks to me like the extra 5 grains went into a longer boat tail. From what I can tell, the nose profile and bearing surface are identical to the 225 SST.

225 SST
Length: 1.426
OAL To Lands: 3.452

230 ELD-X
Length: 1.514
OAL To Lands: 3.445

So, a bullet that is .088 LONGER has an OAL to the lands that is .007 SHORTER than the 225 SST. For all practical purposes, the OAL to the lands is effectively the same, given that a .007 difference could easily be seen lot-to-lot in the same bullet.

In real world testing, the 225 SST was maxing out around 2900 with both RL-17 and H100V. After plugging the measurements into QL, the 230 ELD-X looks like it will max out around 2850. The OBT predicted nodes for both bullets are within 20 fps of one another. I am prepared to believe Hornady's stated bc for the ELD-X. In comparison to the 225 SST, it does appear to be a better bullet. For your money, you are getting roughly a .100 bump in G1 bc, a longer boat tail, and the new non-melting tip.

Though the ELD-X appears to be a genuine improvement over the SST, it sure looks like Hornady left a lot of performance on the table. As always, actual shooting will have the final say, but it is looking like the ELD-X will only be about 50 fps faster than the Berger 250 EH. Relative to what I was hoping for, this looks pretty disappointing.

Dang! I had high hopes for something of that weight but I guess 2800 plus with the 250 should keep us happy anyway

 

[benchracer]

Dang! I had high hopes for something of that weight but I guess 2800 plus with the 250 should keep us happy anyway

I am still ecstatic to be able to push a high bc, very accurate, 250 grain bullet to 2800+ fps. I like the idea of having alternatives, though. The problem seems to be that the Berger 250 EH really is in a class by itself. As problems go, I suppose that's not an entirely bad one to have...

 

[elkaholic]

When I was testing, I had pretty well determined that the 250 might be best all around and also saw some usefulness in the 200 AB at 3100+. I would also see a lot of guys using something like the Hammer monos.

 

[benchracer]

When I was testing, I had pretty well determined that the 250 might be best all around and also saw some usefulness in the 200 AB at 3100+. I would also see a lot of guys using something like the Hammer monos.

Yes, so far, the ONLY bullets I have seen that can keep up with the Berger in terms of velocity, drift, and drop are monos. Accuracy and terminal performance are still open questions.

The only other .338 bullets that even make sense to me are in the 200 grain range.

I'm not sure why it's such an issue in the .338 diameter, but a LOT of .338 bullets seem to be designed with a long bearing surface, which limits velocity potential. That may not make much difference with the larger cased .338's, but it matters when trying to extract efficiency from cases on the smaller end of things.