300 Sherman Shortmag (SS)

[Korhil78]

Very awesome!

Let me ask you, did all loads tested that you did with RL26 show very marginal accuracy and then all of a sudden shrink down to a very small group like the one shown? Or were they all fairly accurate and that one was the best? RL26 with the 143 ELD-X in my 6.5 Sherman was pretty finicky for me until I found the EXACT right seating depth/powder combo and then it shrunk considerably. I have never worked with a powder quite like it. I have used H1000 pretty extensively in a lot of rifles and it always shot well with a seating depth and different charges and you just had to pick the most accurate out of the bunch. RL26 was not so for me haha. I had 1 MOA or more for different powder charges and then at the higher pressure end, it just shrunk to 1/3 MOA all of sudden.

Just trying to gather your thoughts on the powder because I'm thinking either it's the powder or the bullet. Since you are shooting a different bullet, I thought I might ask.

 

[Idaho Trecker]

All I've done for this load so far is a pressure test (3 shots) then loaded up the 4 at a charge I thought might be ok for pressure (this rifle is incredibly accurate!). They are a little hot and I will back them down at a later time after hunting season. As for RL 26 by itself I have seen some of what you are talking about with the pressure and accuracy liking the top end and smaller windows for accuracy. I have done the most testing with RL 26 in my 270 Sherman. I have been following your 6.5 Sherman thread from the beginning also.

I dont want to get this thread to far off track if you want more info you can PM me and I'm more than happy to answer any questions.

 

[Korhil78]

Yup...sorry!

Been learning a lot just from reading your posts. Thanks for being so in depth!

 

[WiscGunner]

Any updates on how this cartridge is performing? Thanks

 

[Rocky Mountain]

Yes very interested in how R26 is going in the 300 SS.

 

[Idaho Trecker]

I havent been out with it much lately but I'll be either taking that or my 270 Sherman out for deer next weekend. I'll have the 300 taken apart for a few days but should have it back up and with a little improvement sitting on top
I'll get some pictures up with the new toy and hopefully an amazing group with the extra magnification. I may drop a half grain which would still be somewhere between 2920 and 2930 fps. Still not to bad considering the amount of powder used.

 

[TheDerkster]

Now your talkin'! RL26 is the best I have found in both the Sherman AND SS cases with just about any bullet. There was some ?? as to whether the 300 had too much bore, but it looks like it's the champ again. Good job with testing Ryan. 3010' with 67 grs. of powder. HOTDANG!............Rich

Dangit, Rich. I thought the 7mm SS was the unicorn. Now you got this one out and Im gonna have to get another barrel so I can play too!!

3010' with a 215 is nuts. Im getting 2900 with the 195 eol. I might out run ya in the long run but hunting with a 215 at 3000' and outperforming the 7mm unless out to extreme yardages due to BC is crazy good. I mean sure, I can run a hot load like it takes to get that 300 up to 3000 and probably get 2980-3000 with some decent primer cratering, but forget it. Ill just build a new gun now >

 

[1hornhunter]

Maybe this has been discussed already and I missed it. Any idea on how the barrel life looks with this caliber? I know there are a lot of factors regarding this but in general what is a guy looking at before the gun needs a new barrel?
Thanks, 1hornhunter

 

[Idaho Trecker]

I'm not sure what the actual round count would be but judging by the relatively small amount of slower burning powder used I would say it a very high amount. I'm sure Rich will have a better idea on a number estimate.

 

[Idaho Trecker]

Scored!!!!!!!! Went out yesterday to sight back in after changing scopes and came up with this killer group (i'll have to post separate pictures from my phone). This gun just shoots!!! I shot this group at 4:23 pm and at 5:57 pm I got to take it out the distance on a nice whitetail.

After sighting in I went and posted up in the field where I do my shooting since its been producing alot of deer. I watched a bunch of does start feeding out of the timber into the field about half hour before shooting ended. After a few minutes of them being out they got nervous and a smaller buck came charging out after them making deer scatter all over. I knew there was a big buck up there but he wasnt it so I just watched the action... until just before dark I saw the big boy come sauntering out of the timber. After ranging him 4 times to confirm distance with my Leica I dialed up the 24.25 moa and held the 2 moa for the 90 degree 5mph crosswind and let 'er fly. He lurched forward then turned straight away and over the horizon out of view. I was solo like usual so after my hike in the dark over to were I saw him last I found him piled up in the field about a 100 yards from where he was hit.

I was ecstatic as this was my furthest kill to date!!! The one shot with the 215 Berger was perfectly behind the shoulder and had a racket ball sized exit at 1110 YARDS!!!
All my numbers for this load were confirmed with this shot being perfect. This load with 65.8gr of Rl 26 is doing 2978fps and sure did the job for me. While gutting him I found a rather large hole in the heart and the lungs were also pretty hammered. It always amazing me how these animals can make it so far with a blown heart and lungs.

 

[Idaho Trecker]

 

[Capt RB]

Awesome stuff right there. Great Buck and even better story line thanks for sharing!!!

 

[Idaho Trecker]

I'm still on cloud 9!!! To make it even better... I made the shot 10 seconds before a disrespectful tresspassing ingrate drove through the farmers field which I have permission to hunt below this buck! I wish he would have seen what I got
He came flying up and jumped out of his truck and threw his rifle over the hood trying to find a deer in his scope to shoot but never did and drove off before I got to him to give him a piece of my mind!!!

 

[Rocky Mountain]

A great write up with a new case, powder bullet combo 2970fps with a case that small will make alot of guys take note well done. I wonder what it would do in a 22-24 inch barrel the perfect woods rifle?