300 Sherman Shortmag (SS)

@elkaholic Do you know which 300 sherman short reamer you sold preferred barrel blanks? They are not sure which one they purchased. If not do you have a print of the new shorter reamer they can use to compare?
 
Pretty sure they have the original long FB of .180"
The newer short FB is .110".
Both are in useful depending on your application.
 

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Pretty sure they have the original long FB of .180"
The newer short FB is .110".
Both are in useful depending on your application.
Thank you, i wanted to shoot some 200 gain bullets (probably eld-x) that would fit in my ai type magazine (internal length of 2.97). So I assume I would want a chamber cut with the shorter reamer.
 
Thank you, i wanted to shoot some 200 gain bullets (probably eld-x) that would fit in my ai type magazine (internal length of 2.97). So I assume I would want a chamber cut with the shorter reamer.
Probably so but the ELDX may load shorter than the 215 Berger that the reamer was designed for?
It MIGHT work even with the .180 FB reamer.
 
Has anyone tried H4350? I have a couple pounds of it and figured i'd give it a try since its similar to IMR4451(which others mentioned did ok).
 
I don't post here much, but Ive read all these threads over and over. I've got a 338 ss that shoots like nothing I've ever seen, and compensates for my lack of ability, still waiting on a 338 Mega barreled action that I should have had 4 months ago, and I now have a mid length action and 24" 30 cal Proof cf blank in route to me now. I'll have action and barrel by the end of next week. Pretty sure you guys can see where this is going. Im planning on running 215's. With a medium length action I'm not gonna be limited by mag length, but throat length. A question I've got is how much more free bore does the long reamer have over the standard reamer? My 338 ss has the long throat, and with 250 gr Bergers seated out to its best in accuracy, the bullet is about to fall out of the neck. That's ok for what that rifle is set up for. Weighs 18# loaded, and does nothing more than punch paper and steel. It will get another barrel in the not too distant future, and live the rest of its life as a hunting rifle. I'd like some room to play with seating depth with this 300 ss, but I don't want my bullets about to fall out of the neck, and I also want to be clear of the neck shoulder junction. I need to run some #'s and see what I've got for wiggle room with the standard shortened reamer.
Another question is what is everyone using for primers? I noticed Idaho Trekker is using 210's. Out of curiosity and lack of knowledge, I'd ask does mag vs non mag primers by chance have any affect on burn rates?

Chris
 
I don't post here much, but Ive read all these threads over and over. I've got a 338 ss that shoots like nothing I've ever seen, and compensates for my lack of ability, still waiting on a 338 Mega barreled action that I should have had 4 months ago, and I now have a mid length action and 24" 30 cal Proof cf blank in route to me now. I'll have action and barrel by the end of next week. Pretty sure you guys can see where this is going. Im planning on running 215's. With a medium length action I'm not gonna be limited by mag length, but throat length. A question I've got is how much more free bore does the long reamer have over the standard reamer? My 338 ss has the long throat, and with 250 gr Bergers seated out to its best in accuracy, the bullet is about to fall out of the neck. That's ok for what that rifle is set up for. Weighs 18# loaded, and does nothing more than punch paper and steel. It will get another barrel in the not too distant future, and live the rest of its life as a hunting rifle. I'd like some room to play with seating depth with this 300 ss, but I don't want my bullets about to fall out of the neck, and I also want to be clear of the neck shoulder junction. I need to run some #'s and see what I've got for wiggle room with the standard shortened reamer.
Another question is what is everyone using for primers? I noticed Idaho Trekker is using 210's. Out of curiosity and lack of knowledge, I'd ask does mag vs non mag primers by chance have any affect on burn rates?

Chris
Love the idea, this one has crossed my mind a couple of times, I'm curious how it will work out for you
 
The 180 was the original freebore. He now has a 110 as another option. If you're running an xm action you will have plenty of room. With the 215 Berger seated properly with only the boat tail below the neck/shoulder junction is 2.952". I believe with my first 300ss with the 180 freebore the 215 Berger was around 3.030". I'll have to check my notes later. With my new 300ss I have a custom throat that's is about 140. I'm also using cci 250 primers in this one.

Here is the new one
20220629_163138.jpg
20220629_163054.jpg
 
Thats correct
The .110 fits the 215 pretty well but .180 gives a little more performance at about 3.03 coal
So, it sounds like with an XM action .180 is my best option. Anybody out there have that reamer, with the reamer ground down to the new chamber dimension specs? I believe that would be my best option.
 
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