338 Sherman Build (This Is My Boomstick!)

[benchracer]

Finished fire forming today. I now have 50 Norma and 50 PRVI cases ready to go. Next step will be establishing max with each bullet and powder. I hope to be tuning loads by next Sunday.

During the fire forming process, there have been quite a few 5+ shot groups hovering around MOA, out to 200 yards. This is with NO load development. This rifle acts like it really wants to shoot. I can't wait to see what it does when the tuning starts.

It has been a lot longer than I had hoped for, since my last testing session. Range time has been at a premium over the course of the last month. Life keeps getting in the way of my hobbies!

I have not yet progressed to accuracy tuning, but I have done enough testing to develop a pretty good idea of where MAX is, with several different bullets and powders, in my rifle.

Regrettably, the FIRST thing I learned is that PRVI brass isn't going to cut it. My high hopes for this brass were dashed when I started getting hard bolt lift and difficult extraction at starting loads, with no other pressure signs. My best guess, without sectioning the cases, is that there isn't enough material in the case head. That may also account for the extra capacity in the PRVI cases vs Norma cases.

I continued my work, using only Norma cases, and they are working out well, though they are taking a beating. By the time my testing is complete, I will have to fireform a new batch of cases for field use. At some point in the future, I intend to obtain some RWS brass and work with it. It has a reputation for Lapua-like toughness, which I expect to prove useful, despite reduced capacity relative to the Norma cases.

BERGER 250 ELITE HUNTER

i am starting with the 250 EH because elkaholic designed the 338 Sherman around this bullet and because it is showing itself to be an excellent bullet. The more I shoot it, the more it impresses me. I measured COAL to the lands @ 3.575 and loaded my test rounds .010 off the lands @ 3.565.

RL-17
60.0 2730
61.0 2751
62.0 2804 Light ejector mark.
63.0 2839 Bright, shiny ejector mark.
64.0 Did not shoot, based on pressure signs @ 63.0.

H100V
61.0 2701
62.0 2754
63.0 2776
64.0 2818 Shiny ejector mark.
65.0 Discontinued test.

RL-26 (Win LR Mag primers)
68.0 2751
69.0 2805
70.0 2813
71.0 2852 Light ejector mark.
72.0 2881 Heavy bolt lift. Hard extraction. Bright, shiny ejector mark.

 

[benchracer]

It has been a lot longer than I had hoped for, since my last testing session. Range time has been at a premium over the course of the last month. Life keeps getting in the way of my hobbies!

I have not yet progressed to accuracy tuning, but I have done enough testing to develop a pretty good idea of where MAX is, with several different bullets and powders, in my rifle.

Regrettably, the FIRST thing I learned is that PRVI brass isn't going to cut it. My high hopes for this brass were dashed when I started getting hard bolt lift and difficult extraction at starting loads, with no other pressure signs. My best guess, without sectioning the cases, is that there isn't enough material in the case head. That may also account for the extra capacity in the PRVI cases vs Norma cases.

I continued my work, using only Norma cases, and they are working out well, though they are taking a beating. By the time my testing is complete, I will have to fireform a new batch of cases for field use. At some point in the future, I intend to obtain some RWS brass and work with it. It has a reputation for Lapua-like toughness, which I expect to prove useful, despite reduced capacity relative to the Norma cases.

BERGER 250 ELITE HUNTER

i am starting with the 250 EH because elkaholic designed the 338 Sherman around this bullet and because it is showing itself to be an excellent bullet. The more I shoot it, the more it impresses me. I measured COAL to the lands @ 3.575 and loaded my test rounds .010 off the lands @ 3.565.

RL-17
60.0 2730
61.0 2751
62.0 2804 Light ejector mark.
63.0 2839 Bright, shiny ejector mark.
64.0 Did not shoot, based on pressure signs @ 63.0.

RL-26 (Win LR Mag primers)
68.0 2751
69.0 2805
70.0 2813
71.0 2852 Light ejector mark.
72.0 2881 Heavy bolt lift. Hard extraction. Bright, shiny ejector mark.

HORNADY 225 SST

The SST bullets have long been among my favorites. I have found them to be inexpensive, easy to tune, and destructive. I have also found that many SST, AMAX, and VMAX bullets tend to have shorter bearing surfaces, relative to comparable bullets from other manufacturers, typically allowing me to push them a bit faster. Because of that, I was surprised at how quickly these bullets pressured out. I wasn't able to push them much faster than the Berger 250 EH's. IMO, that speaks volumes about how good the Berger design really is.

I don't see the 225 SST's as offering anything special in the 338 Sherman. I am sure they would work well for hunting at normal ranges, but I don't see them as useful long range bullets. I will use the remainder of them to fireform brass.

I seated both of the SST bullets .040 off the lands. OAL for the 225 SST was set @ 3.410.

RL-17
62.0 2840
63.0 2903 Light ejector mark.
64.0 2944 Heavy bolt lift. Hard extraction. Bright, shiny ejector mark.
65.0 Discontinued test.
66.0 Discontinued test.

H100V
63.0 2834
64.0 2898 Shiny ejector mark.
65.0 Discontinued test.
66.0 Discontinued test.
67.0 Discontinued test.

 

[elkaholic]

Good data and pretty much backs up what I have seen so far. I was a little disappointed in the 210 swift for the same reason (bearing surface too long). The 200 AB did show serious promise though.....Rich

 

[benchracer]

HORNADY 225 SST

The SST bullets have long been among my favorites. I have found them to be inexpensive, easy to tune, and destructive. I have also found that many SST, AMAX, and VMAX bullets tend to have shorter bearing surfaces, relative to comparable bullets from other manufacturers, typically allowing me to push them a bit faster. Because of that, I was surprised at how quickly these bullets pressured out. I wasn't able to push them much faster than the Berger 250 EH's. IMO, that speaks volumes about how good the Berger design really is.

I don't see the 225 SST's as offering anything special in the 338 Sherman. I am sure they would work well for hunting at normal ranges, but I don't see them as useful long range bullets. I will use the remainder of them to fireform brass.

RL-17
62.0 2840
63.0 2903 Light ejector mark.
64.0 2944 Heavy bolt lift. Hard extraction. Bright, shiny ejector mark.
65.0 Discontinued test.
66.0 Discontinued test.

HORNADY 200 SST

Like the 225 SST, the 200 SST isn't a useful long range bullet. I think it would make for an outstanding, inexpensive bullet for use on lighter-bodied game at normal hunting ranges. This bullet also showed signs of pressuring out much earlier than I expected, causing me to discontinue testing after the second shot showed an immediate flat spot in the velocity curve, along with a light ejector mark. Based on what I have seen in past testing with RL-17, a flat spot (or a drop in velocity) is a pressure warning sign. The shot(s) that follow tend to be unpredictable.

OAL for this bullet was set approximately .040 off the lands @ 3.380.

RL-17
64.0 3071
65.0 3080 Light ejector mark.
66.0 Discontinued test
67.0 Discontinued test
68.0 Discontinued test.

H100V
65.0 2997
66.0 3008
67.0 3080 Shiny ejector mark.
68.0 Discontinued test.
69.0 Discontinued test.

 

[benchracer]

CUTTING EDGE 252 MTH

Applied Ballistics testing has established a G7 bc of .366 for this bullet, which is slightly higher than the Berger 250 EH. Based on prior testing with MTH bullets in .375, it has also been my experience that these bullets can typically be driven faster than comparable cup-and-core bullets, because of their seal-tite band and bore rider design. With that in mind, my test results with the 250 EH and RL-26 had me expecting the 252 MTH to pressure out in the low 2900's. In this case, with this powder, I believe the low bore resistance of the MTH design prevented it from building enough initial pressure to reach the velocity potential of this bullet. Packed with every last kernel of RL-26 that would fit in the case, a highly compressed charge of 72.0 grains topped out at 2865, with a shiny ejector mark, but no heavy bolt lift or hard extraction. I intend to re-test the 252 MTH with RL-17 to see how it behaves with a faster powder.

RL-26 (Win LR Mag primers)
68.0 2770
69.0 2777
70.0 2815
71.0 2852
72.0 2865 Shiny ejector mark.

 

[benchracer]

CUTTING EDGE 225 MTH

With an un-verified G1 bc of .651, it is difficult to assess the long range usefulness of this bullet. However, consistent with the behavior of other MTH bullets, I was able to drive this one considerably faster than its 225 SST counterpart, topping out at 2970 with a shiny ejector mark, but no heavy bolt lift or hard extraction. If its bc is anywhere near accurate, it looks like it would have some long range potential. I would expect the Lazer version of this bullet to fly pretty well, while boosting terminal performance. I think this could be an attractive option for anyone hunting in an area where non-lead bullets are required. Paired with tougher RWS brass, the 225 MTH or Lazer could offer a pretty good all around combination.

RL-17
62.0 2862
63.0 2923
64.0 2970 Shiny ejector mark.

ETA: Applied Ballistics has since established a .304 G7 bc for the CE 225 MTH, which is roughly equivalent to a .595 G1. Not bad, but no real advantage over a cup and core bullet such as the Hornady 230 ELD-X. Accuracy node from a 26" barrel will appear around 2880 fps, for either bullet, using RL-17.

 

[benchracer]

CUTTING EDGE 200 MTH

Like the 225 MTH, this bullet's G1 bc of .570 is un-verified, making its long range usefulness difficult to evaluate. Unlike the 225 MTH, there is no Lazer version of this bullet, which I would expect to shorten its useful range. However, it can be pushed fast enough to keep it shooting flat to a considerable distance, even if the real world bc is lower than stated.

RL-17
63.0 3019
64.0 3063 Light ejector mark.
65.0 3117 Shiny ejector mark.

ETA: Applied Ballistics has since established a .224 G7 bc for this bullet, which is roughly equivalent to a .435 G1 bc. Using RL-17 from a 26" barrel, the accuracy node will show up around 3080. I don't consider this to be a useful long range projectile.

 

[waspocrew]

Thanks for the great write up! It's been nice to see the results and load data that's been collected. Would definitely be a fun round - I've thought about doing a Savage pre-fit in 338 Sherman (would be cheapest route for sure), but the stock options for LA savages are definitely skimping compared to the SA.

 

[elkaholic]

Brad.....I would be interested in seeing how Hybrid100V works in yours. I think you will get the same velocity as RL26 and with a std. primer,,,,,,,Rich

 

[benchracer]

Brad.....I would be interested in seeing how Hybrid100V works in yours. I think you will get the same velocity as RL26 and with a std. primer,,,,,,,Rich

I do have limited data on H100V. I need to go back and edit my posts to include that data, along with OAL info for some of the bullets. So far, I have only tested H100V with the SST's and the Berger 250.

H100V is pressuring out at, or slightly below, the same velocity as RL-17. It seems to behave in a more linear, predictable fashion than RL-17. When it does pressure out, it seems to do so more gently. RL-17 has tended to signal it is near the top end with a faint ejector mark, immediately followed by a bright ejector mark, hard bolt lift, and hard extraction, all at once. H100V has tended to show a bright ejector mark at the top end, before it reaches a level that produces hard bolt lift or hard extraction.

I haven't tested any of the CE bullets with H100V because it isn't showing me anything particularly distinct from RL-17. I have done quite a bit of load work with RL-17, in various chamberings, which has given me a pretty good feel for where the accuracy nodes are going to show up. Based on what I have seen with the Berger 250's, so far, I am confident that the accuracy node with RL-17 will show up right at 2800. Though H100V is producing similar velocities, I am not sure if the nodes will show up in the same place. Once I have some accuracy nodes pinned down with RL-17, I intend to re-visit H100V with certain combinations.

For now, I need to narrow my focus to a few combinations. Testing to find MAX with 6 different bullets and three different powders is taking a toll on my brass. PRVI brass not working out put a big dent in my testing plans, leaving me with half as many cases to take the testing workload. I need to get some accuracy nodes pinned down with my most promising combinations before I start losing cases and have to start over by fireforming a new batch of brass.

On the back end of all of this, I plan to do some additional work with RWS brass and my established accuracy nodes.

 

[benchracer]

Thanks for the great write up! It's been nice to see the results and load data that's been collected. Would definitely be a fun round - I've thought about doing a Savage pre-fit in 338 Sherman (would be cheapest route for sure), but the stock options for LA savages are definitely skimping compared to the SA.

Glad to help and I am happy to know that the subject has drawn your interest! Hopefully, you will find a LA stock that suits you. I really like this cartridge and feel like it was a build that was absolutely worth doing. In terms of action length and parts availability, a Rem 700 LA would probably be the ideal choice for the 338 Sherman. I know there are some folks out there anxiously waiting for Rich to introduce the SS version of this cartridge, which could broaden available options somewhat.

 

[codyadams]

I know I'm just waiting on money to build a 338 SS. I have a savage short action that I can load to 3.00", that is begging for a big bore on it. Once I get more money, I will be building one. But being newly married, wife in nursing school not able to work, and 2 kids soak up pretty much all funds ha ha.

 

[benchracer]

Brad.....I would be interested in seeing how Hybrid100V works in yours. I think you will get the same velocity as RL26 and with a std. primer,,,,,,,Rich

Edited prior posts to include H100V data...

 

[elkaholic]

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