338 sherman field test

[elkaholic]

I have been going crazy with being homeless with the move going on but brought my new 338 Sherman to Utah with me while I stay at the outlaws for a while. I clamped my press down on my father-in-laws table saw bench with some c-clamps and proceeded to load a few rounds for a ladder test.
The rifle is my old 6.5 Sherman which "bigngreen" just re barreled. It is a 700 LA trued with a 24" Bartlein 5r, 10 twist with a 3 port Little Beast brake. It has a H-S Precision thumbhole sporter with Remington BDL bottom. The trigger is a Jewell. Scope is 4-20 2moa S-Tac with Burris Extreme rings and Leopold MkIV 20 moa rail. I had already chrono'd some 250 Bergers before I left so had an idea on what to load. Rhian and Cliff had also run some over the mag speed when he finished the build.
I used RWS brass and F210M primers with RL17 powder and 250 Berger Elite Hunter bullets. I loaded 2 each of the following charges at .005" off the lands:
61, 61.5, 62, 62.5, 63, 63.5( i.e. 61=shots 1 and 2) I did not bother to chrono as this had been done by Rhian and Cliff earlier. 61 was around 2730' and 62.5 was at 2802', and according to Cliff, was not max so my 63.5 load should have been right around 2850'.
I had fired a few rounds with some Norma brass earlier to see how they compared with 3 grains more capacity. I figured that 64-64.5 grains was max useable at a little over 2800'. The Norma brass started getting ejector marks at 64.5 grains.The RWS brass is much tougher and I showed no significant pressure signs with the 63.5 grain load! On with the test: Temp was 42 degrees with 10-15 mph wind and RAIN, so I will run the test again later but felt that I got some decent data given the conditions. I also noticed a couple of the rounds had significantly different seating pressure when I loaded them and I am pretty sure that shot #8 was one of them. The target was placed at 400 yards and I laid on the WET gravel with a bipod and rear bag. If you throw out shot #8, I felt that there was a pretty good node in the 7-10 area, and below. This would be in the 2800'-2825' velocity range. It is VERY obvious that the top load of 63.5 jumped the node! Recoil, shooting prone, was very manageable and similar to the old brakeless 6.5 Sherman. The 5 lower groupings, minus shot #8, all were in 5".

 

[codyadams]

Looking good. I'm going to keep this cartridge in mind for upcoming builds for a big elk thumper. I think with a 28" barrel, braked, on a heavy gun would make a good long range rig with big energy, and you can skip the high cost of brass for something like the Nosler cartridges or magnums, and less powder consumption as well.

 

[elkaholic]

Looking good. I'm going to keep this cartridge in mind for upcoming builds for a big elk thumper. I think with a 28" barrel, braked, on a heavy gun would make a good long range rig with big energy, and you can skip the high cost of brass for something like the Nosler cartridges or magnums, and less powder consumption as well.

So far it has at very least met expectations. It is a pleasure to shoot and shows great accuracy potential with WM performance. Barrel life should be LOOOOOOOOONG and it feeds like a dream in my std. 700 mag box. I have some 200 grain AB's that I may try this week as well. I'm betting 3150 or so with the right powder......Rich

This was 3 different charges at 110 yards. Walked right up the ladder!

 

[elkaholic]

After completing a ladder test yesterday, I loaded up some 250's with 62.8 grains of RL17 for todays test. I also loaded some 200 and 225 AB's to get an idea what max might be with these bullets. I had thoroughly cleaned the barrel, which took little effort, (this Bartlein is great)! I figured I would shoot the AB's for velocity to get the barrel fouled for some accuracy testing with the 250's.
I picked up some N540 for the 200's as I was unsure whether or not the RL17 would pressure out? The N540 turned out to be FASTER than advertised in my rifle and it cranked out 3198' with the 200 AB but was over max!!
I then moved on to the 200's with 67 grains of RL17. It rolled up 3140' on the mag speed and showed no signs of high pressure. It sounds crazy but I am pretty sure that I can reach 3200' safely with this powder!
Next I tried the 225 AB's with RL17. It is obvious that the long bearing surface built pressure more quickly. I was able to reach 2976' but that load was just a little hot. It looks like 2950 will be about max with that powder. I want to pick up some N550 if I can find it.
Now for the 250's: I fired 3 shots over the magspeed that averaged 2776' with a 6 sd. The velocity is down a little (25-30') since when Cliff fired it which is no surprise with break in. I will probably end up bumping the charge 1/2 grain later and shooting for accuracy.
I set up a target at 400 yards with the wind at 8:00 o'clock between 10-15 mph. I fired 5 shots at a 3" bull and the picture speaks for itself! I am sure the 5th shot was a result of the wind letting up a little. To say that I am pleased with this build would be an understatement! Thanks again Rhian!!

 

[benchracer]

Looking good. I'm going to keep this cartridge in mind for upcoming builds for a big elk thumper. I think with a 28" barrel, braked, on a heavy gun would make a good long range rig with big energy, and you can skip the high cost of brass for something like the Nosler cartridges or magnums, and less powder consumption as well.

My 338 Sherman is under construction. It will have a 26" barrel. I had anticipated the optimum burn rate range would fall somewhere around RL22/MRP/RL26.

Initial real world results strongly indicate a preference for powders similar to RL17 in burn rate. Based on Rich's initial results, I don't believe I will see significant gains from the extra barrel length on my rifle.

It looks to me like 24" will prove to be about the ideal length for the 338 Sherman. In such a configuration, the 338 Sherman looks to be a versatile cartridge in a carry weight rifle, yielding external ballistics very similar to the 300 Win Mag/Berger 215/H1000 combination, with a bit more frontal diameter and bullet weight.

200ish grain bullets @ 3100 will make for a flat shooting, hard hitting open country deer/pronghorn setup, while 250's @ 2800 will lay the smackdown on elk, bear, and moose. All of this from a standard bolt face, 30-06 length action.

Going with a long barrel, heavy rifle configuration with this cartridge is unlikely to yield much of a performance gain, while trading away the virtues of the 338 Sherman in a carry weight rifle.

Of course, those decisions are yours to make. Just food for thought...

 

[huntinherrrington]

What muzzle brake are you using Rich?

 

[elkaholic]

What muzzle brake are you using Rich?

Little Beast from Brakes and More..........Rich

 

[hseII]

What is the total weight of the Rig as pictured above?

Ready to shoot.

 

[elkaholic]

What is the total weight of the Rig as pictured above?

Ready to shoot.

Haven't weighed it but close to 9 lbs.?

 

[IdahoCTD]

Little Beast from Muzzle Brakes and More..........Rich

Who dat?

Sounds and looks like it's shooting pretty sweet Rich. What's next? a .358/.375 or a 6mm?

 

[elkaholic]

Who dat?

Sounds and looks like it's shooting pretty sweet Rich. What's next? a .358/.375 or a 6mm?

I have too many to test now That brake works pretty nice Nathan........Rich

 

[elkaholic]

I made it back out today to test a 200 AB for velocity and try some H100V behind the 250's. I also shot 3 rounds of yesterdays load at 1100 yards and managed moa but it was pretty windy. The H100V shows promise and is known to be pretty good as far as temp sensitivity. The 200 grain AB turned up 3166' and was getting close to max.
I may run a ladder on the H100V with the 250 Bergers. I appears like velocity will be on par with RL17 with a couple grains more charge and equal pressure. The load below was about 1 grain over max with the Norma brass but I might be able to get close to that with RWS..........Rich

 

[elkaholic]

I made it back out today to test a 200 AB for velocity and try some H100V behind the 250's. I also shot 3 rounds of yesterdays load at 1100 yards and managed moa but it was pretty windy. The H100V shows promise and is known to be pretty good as far as temp sensitivity. The 200 grain AB turned up 3166' and was getting close to max.
I may run a ladder on the H100V with the 250 Bergers. I appears like velocity will be on par with RL17 with a couple grains more charge and equal pressure. The load below was about 1 grain over max with the Norma brass but I might be able to get close to that with RWS..........RichView attachment 73497

The H100V had pretty good sd for that high of pressure

 

[Capt RB]

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)