338 sherman field test

[elkaholic]

2860fps in a 24" barrel. Do you think you could use Lapua 06 brass?? I know RWS is very nice as well but I cannot order brass oin line in my state(sucks)

I wish I could but it would end up WAY short in the neck..........Rich

 

[elkaholic]

I loaded up some more for tomorrow, if the rain quits! I picked up some RL15 for the 200's to see what kind of velocity I can get. If it works out well, it is supposed to have good temp stability. I also loaded a couple with N540 to compare. (200 AB's)
After shooting the 250's with 67 grains of H100V yesterday and clocking 2860 (a little hot for the Norma brass) I decided to run a ladder test with RWS brass and charges from 63-66 grains in 1/2 gr. increments. I figure 2 grains less than yesterdays charge should yield 2800+ and be within useable pressure with the RWS cases.
Interestingly, the 200 AB's at 3.400" coal are positioned nicely just above the base of the neck just like the 250 Bergers are at 3.560". They are much shorter but the far less aggressive ogive compensates..........Rich

 

[elkaholic]

Made it out to do some more testing but the rain never stopped so I could only run a few 200's over the mag speed to test velocity. The ladder test with H100V will have to wait. RL15 turned out to be a little disappointing as it would not reach 3000' without pressuring out. N540 has some promise, but I REALLY need some N550!
Below is 63 and 64 grains of N540 with a 200 AB. I think 63.5 is max and the 2 shots went into pretty much the same hole.

 

[nvbowhunter]

Rich,
Thanks for the progress reports on the rifles' performance. Why is it the Lapua 30-06 brass would be too short in the neck area after forming, and is the RWS and Norma brass you're using not formed from 30-06 brass?
Just trying to get this all figured out as my son and I gather rifle parts and reloading components for two builds of our own in this chambering.

 

[huntinherrrington]

Rich,
Thanks for the progress reports on the rifles' performance. Why is it the Lapua 30-06 brass would be too short in the neck area after forming, and is the RWS and Norma brass you're using not formed from 30-06 brass?
Just trying to get this all figured out as my son and I gather rifle parts and reloading components for two builds of our own in this chambering.

Because his Sherman line is not based on the 30/06 but rather the 270 win or 280 rem brass. You can use either 270 or 280. They are slightly longer than 30/06 which is why he uses them and not the 30/06.


30/06, 300 Sherman, .270 win

 

[elkaholic]

That is correct! The 270 or 280 brass is approx. .046" longer which is huge in this case........Rich

 

[nvbowhunter]

Thank you both for the info. So, it's the same reason we're using the 270 brass in the 6.5S! I guess I was all hung up on the 30-06 as it is the standard size action it's able to be used in.
Thanks again!, Les

 

[elkaholic]

Thank you both for the info. So, it's the same reason we're using the 270 brass in the 6.5S! I guess I was all hung up on the 30-06 as it is the standard size action it's able to be used in.
Thanks again!, Les

Yes, it is 'o6 head size only.............Rich

 

[elkaholic]

I think one thing of note in testing is that the RWS brass has been fired about 6 times now with loads at 2800, and above at times, and the primers are still TIGHT!
This is a very positive sign for the cartridge going forward.........Rich

 

[elkaholic]

The weather improved today and I was able to get back out and complete the ladder test for H100V with the 250 Berger. I was hopeful that it would work out because H100V is known to be more stable than RL17. Both powders are pretty much equal velocity wise but H100V takes about a grain or so more to achieve equal pressure. Temp was 45 degrees with the wind at 5-10 mph from about 7:30. It looks like it has a nice node between 2710 and 2760 fps. and another coming in at max pressure around 2860'. I had shot this load at 100 yards previously and was not surprised that it showed up in the ladder. 2860" with a 250 in a 24" barrel is considerable whallop!
Another thing to point out is how critical barrel harmonics are and higher velocity does not always mean higher POI! The ladder from 63, 63.5, and 64 grains CLEARLY shows this with a jump in POI starting at 64.5 grains. The 100 yard group below was with Norma brass earlier, but the RWS today with 1 grain less equals the velocity and handled pressure a little better...............Rich

 

[elkaholic]

I loaded up some virgin 270 Norma brass today for fire forming so I thought I would post pics of the process and field results.
I simply necked the cases up first with an '06 die and then to 338 with the Sherman. I loaded a WW primer behind 51 grains of RL15 and a 250 Berger jammed .020 into the lands to insure proper head spacing. I chose this load because I felt it was about 6 grains below max. It chrongraphed 2420' so I think it was pretty close.
This rifle shoots VERY well with whatever I stick into it. It is not at all fussy and is an easy cartridge to work with.

 

[elkaholic]

Another trip to the range today. I re tested the 65 grain load of H100V behind the 250 Berger with a WW primer with great results! I also ran a max load test on the 200 AB with N550. I had planned on testing the Hammer bullets in 260 and 236 grain but had to stop after running 3 of the 260's over the chrono at around 2695'. This was not max but it looks like they will easily make 2750'. I will run the 236's next and shoot both for group. Below are pics of the results. The chrono #'s on the 65 grain load of H100V are not an error........Rich
View attachment 74158

View attachment 74159

200 AB 67 N550 This was just a little hot

 

[bb204]

How is the temperature stability of the N550 and the H100V ? I am going to have to build one of these. This would be great for the 180-210 gr bullets. This and the 6.5 has got my attention more than anything in a while. This is with a 24" barrel, right ? Keep the info coming.
Thanks, bb204

 

[elkaholic]

Stability on the H100V is said to be pretty good but I don't know much about N550?
I shot the 260 Hammers for group this p m and they shot pretty well for no load developement. The N550 is faster burning than the book says (faster than RL17). It shows potential, especially with the lighter bullets, but pressures out faster than RL17 or H100V with the heavies.