SHERMAN MEGA LINE

[ButterBean]

500, 1K, 1.5K does make a difference to me. I'm in the thread and I'm a Max customer already. Was planning a 30 or 338 Mega, but maybe I can justify the 7 for 195's.

I understand that completely, I'm simply stating that the folks here that are running are not building them for barrel life as they are Hot Rods, these are hunting Rigs and in all probability you will never wear a barrel out, I haven't heard of one being shot out yet so I doubt seriously you will get a reply and once again I mean ni disrespect but if your that concerned with barrel life this aint road you wanna be on

 

[highdrum]

I understand that completely, I'm simply stating that the folks here that are running are not building them for barrel life as they are Hot Rods, these are hunting Rigs and in all probability you will never wear a barrel out, I haven't heard of one being shot out yet so I doubt seriously you will get a reply and once again I mean ni disrespect but if your that concerned with barrel life this aint road you wanna be on

My 6.5max looks freaking ROUGH running 156s at 3120 w/ N570. My round count is about 500y. Flyers have started to be come a norm in 4 shot groups so I'm starting to look for solids to see if it changes my accuracy. Takeaway: don't run N570 on a 6.5mm bore and expect any kind of throat life!

 

[Rich Coyle]

I mean no offense but no one in this thread is concerned with barrel life

Apparently, someone is!

 

[Monkeygoat]

My 6.5max looks freaking ROUGH running 156s at 3120 w/ N570. My round count is about 500y. Flyers have started to be come a norm in 4 shot groups so I'm starting to look for solids to see if it changes my accuracy. Takeaway: don't run N570 on a 6.5mm bore and expect any kind of throat life!

I'm running N570 in mine, but with the 153.5's @ ~3170. Also have a lighter load with 8133 and 145 Match Burners @ 3K. Less than 200 rds on a 28" Bartlein and she's shooting really well. I'll keep an eye out for flyers once above 500 rds. Thanks.

 

[highdrum]

500, 1K, 1.5K does make a difference to me. I'm in the thread and I'm a Max customer already. Was planning a 30 or 338 Mega, but maybe I can justify the 7 for 195's.

Staying away from double based powders like rl26/n565/N570 will show a much better erosion rate/bore condition. Running a heavy contour and letting the rifle cool completely between strings helps a lot too.

 

[ButterBean]

Apparently, someone is!

Not me Brother,

 

[elkaholic]

Have you measured / can you give an expected barrel life for your 7Mega running those pressures?

No idea yet on barrel life? With the number of firings on the case so far though, Im not at all concerned about what the pressure number is!
Guess on barrel life would be 1000-1200 rounds based on the 7 SS and 7 Max.
It would be better with powders cooler burning than N570, but velocity would be lower.
Here is what I know so far:
This barrel had 300-400 rounds through it as a 7 max running mostly 570 and has around 250 more as a MEGA. It hasn't been scoped but shoots .2 at this time with no drop in velocity. Not all that meaningful, but what I have to date.

 

[Northkill]

After some setbacks and troubleshooting the 338 Mega is up and running! After actually measuring the barrel it is only 21.25". My testing has shown that this round does well with a shorter barrel also. My barrel is chambered with the "long" reamer which has a longer freebore. Rich was kind enough to get me a bit of the ADG 300 WSM brass to use for initial testing until the proper length brass is done.

So far I have basically just been able to run pressure tests, with very little accuracy testing, using the 250 grain Berger, 265 grain Long Range Accubond, and the 285 grain ELD-M. Powders tested so far include RL 26, N555, RL 16, Hybrid 100V, and IMR 4451.

Disclaimer: All loads with RL 26 and 285 ELD-M and 265 LRAB used a drop tube and with bullets seated .005-.010" off lands. 250 Berger was seated .080" off. All speeds taken with Magentospeed. These were just pressure tests in my rifle an not to be taken as load data. I stopped at pressure signs that were obvious to me (extractor marks, extra bolt lift, cratering or flattening of primer).

285 ELD-M Fed 215 primer RL 26
72 grains 2635 fps
73 grains 2666 fps
74 grains 2706 fps
75 grains 2747 and 2735 fps
75 grains was max pressure and capacity. Only the faintest shadow of an extractor mark

265 LRAB Fed 215 primer RL 26
74 grains 2741 fps
75 grains 2770 fps
76 grains 2807 fps
77 grains 2845 and 2856 fps
77 grains was also max pressure and capacity. Faint shadow of extractor mark but harder bolt lift

250 Berger Fed 215 primer RL 26
79 grains 2987 fps
80 grains 3013 fps
Both these loads were hot. I will post a picture of the 80 grain load case head. 80 grains was excessive and 79 grains is where I would normally stop and go 2 grains lower to start playing.
View attachment 314048

Fed 215 primer N555
72.5 grains 2758 fps
73.5 grains 2780 fps
74.5 grains 2810 fps
I could have possibly fit 1-2 more grains in but basically out of capacity. Didn't pressure out.

Fed 215 primer RL 16
69.5 grains 2791 fps
70.5 grains 2811 fps I made a jump to find pressure next.
73.5 grains 2915 fps This just had a slightest shadow of extractor mark. Basically out of capacity also.

Fed 215 primer Hybrid 100V
72.0 grains 2922 fps
I have used 100V quite a bit and had a good idea where to start which seemed right on. This seemed like no more pressure than where I stopped with other powders.

Fed 215 primer IMR 4451
71 grains 2852 fps
72 grains 2860 fps
73 grains 2905 fps pressure didnt seem bad but has to be close to top

I'm going to concentrate on groups when I get a chance next and possibly try another powder or two. Can't wait to try and smash a spring bear with this rifle since it missed my elk season this fall.

What about n560?

 

[elkaholic]

What about n560?

It usually pretty much mimics RL 26, but maybe Ryan will have info?

 

[Deleted member 109523]

It usually pretty much mimics RL 26, but maybe Ryan will have info?

my 338 max loves n560 with 225 badlands BD-2's and 250 bergers
pic below is 225 BL BD-2 from a couple days ago. I'm hopefully gonna put one these in a spike elk in a couple weeks.
This was 74 gr with a drop tube. Powder just touching the base.
It holds this angle out to 945 yds so far.

 

[Tac-O]

So what is that actual difference for this mega case vs the wsm case?

 

[elkaholic]

So what is that actual difference for this mega case vs the wsm case?

MEGA is longer in the body and much longer neck. It has less body taper and a 40 degree shoulder.

 

[Tac-O]

MEGA is longer in the body and much longer neck. It has less body taper and a 40 degree shoulder.

So it's sort of like a mega version of Wheeler's 300 saum imp?

And even though I read through this whole thread, maybe I missed it. What brass are you forming from?

 

[elkaholic]

So it's sort of like a mega version of Wheeler's 300 saum imp?

And even though I read through this whole thread, maybe I missed it. What brass are you forming from?

Yes. Wheelers saum improved is my 300 max!
The brass is new but is an elongated wsm