300 Sherman Shortmag (SS)

[Idaho Trecker]

I've been storing a few boxes of some lighter weight bullets for a couple months now to test and finally got around to it since I scored on a bear and ended my season (unless I buy a second tag )

So for those of you who were wondering how this case does with the "lighter" bullets here is some initial information.

As always these are in my rifle and not recommended for others and should start lower.
(Although I'm the only one with the 300SS as of now) It still blows my mind nobody else has chambered this. It is unreal how efficient this case is!!!! I can basically run the same speed as 300 win and right there with my 300 Dakota but with around 20 grains less powder.

The bullets:
195 grain Hornady ELD-M
180 grain Berger Elite Hunter
200 grain Sierra Match King

Just to get a baseline of what powders to pursue I only shot 1 round of each at what I figured would be towards the top end of pressure.
With the reamer that chambered my rifle (Rich may alter dimension if more interest comes to keep COAL of 208 and 225 Eld-m and 215 Berger under the magic 3") my max COAL to lands:
195 ELD-M 2.875"
180 Berger Elite 3.021"
200 Sierra MK 3.167" (They are javelins!)
If you compare the Coal to where they "should" be with the boat tail below neck shoulder junction it is a different story (other than 195 eld-m).
195 Eld-M 2.860"
180 Berger Elite Hunter 2.815"
200 Sierra MK 2.990"

Here is what I found today( all speeds from Magnetospeed) :
195 ELD-M 2.860" COAL
IMR 4451 59 grain 2980fps Towards top end, good working max
RL-16 59 grain 2964fps Towards top end, good working max
RL-17 61 grain 3091fps Definitely max pressure hard bolt lift
Hybrid 100V 61 grain 3060fps Hard bolt lift, max pressure, extractor mark
RL-22 65 grain 3042fps Max pressure, extractor mark
RL-23 63 grain 2948fps Max capacity, good on pressure
N560 61 grain 2794fps Very low pressure
65 grain 2978fps good working load, at top end

180 Berger Elite Hunter 2.982" COAL 2.250" BTO
RL-16 62 grain 3110fps close to max, max working load
Hybrid 100V 63 grian 3131fps max working load
N560 67 grain 3089fps easy bolt lift, some room to increase
RL-26 68.3 grain 3159 fps max load but would be good with.5 grain less
(I just had to try the magic Pixie dust again and it was a winner)

200 Sierra Match King 3.120" COAL 2.250" BTO
RL-16 60 grain 2966fps good working max
Hybrid 100V 60 grain 2934fps can work up little more. good on pressure
N560 65 grain 2973fps upper end, ok on pressure

All these were 1 shot only for pressure and speed base line. After the first round of testing on the 195 I figured I would focus on the powders I felt had the most potential and better temperature stability. The 180 and 200 grain bullets were both pretty impressive for speed. The seating depth of these bullets were both around .040" off lands and had about 1/2 a bullet diameter of the bearing surface held in the neck. When I get around to testing groups and seating depth I will update my findings. After running the numbers of the 3 bullets with a speed I felt would be comfortable to run the 200 gain SMK carried the most energy and only had .5moa more drop than the 180 Berger at 1000 yards. That being said all 3 bullets carried more than 1270 ft lbs at a 1000 yards.

WOW!!!! that was way to much typing!!!

 

[elkaholic]

Good write up as usual Ryan! Some of these bullets are getting as long as my little case
I have considered shortening the coal a bit for some time now; as you know. I don't think it would significantly affect velocity with the fill ratio of some of the powders used.
We have all asked for high b c bullets with the long range craze in both hunting and target. Manufactures have really started to grease the sgueaky wheel! Subsequently, now the barrel makers, mag box manufacturers, etc, are playing catch up. I guess its all part of the fun!.......rich

 

[Idaho Trecker]

You are right on all points you made! The 200 grain SMK is 1.545" long! If i had a faster twist barrel I would have bought some of the 230 grain SMK which I'm sure would be longer than the case haha. I don't know why I didnt fire a load of RL26 with the 200 SMK but I'll probably do that today just so I know if the pixie dust works with this bullet to. I'm sure it will smoke it out there.

 

[cjl2010]

Ryan, with a 215 seated where it should be, what would the COAL be?

 

[Idaho Trecker]

Ryan, with a 215 seated where it should be, what would the COAL be?

The optimum length with the boat tail of the bullet at neck shoulder junction is right at 2.990" COAL.

In the current reamer I touch the lands at 3.034" COAL.

 

[Idaho Trecker]

I had a free minute to stuff a case full of pixie dust (RL 26) under a 200 grain SMK. I was able to put 66.7 grains of RL 26 under the SMK. This load was pretty stiff and not a working load at all. It was max which is what I was looking for anyway. This load came out of the pipe at 3067 fps! Again RL 26 will be the winner for speed and working velocity. I'm confident that a working load at 3000-3015 fps would be a good working load.

 

[hgh1969]

I've been storing a few boxes of some lighter weight bullets for a couple months now to test and finally got around to it since I scored on a bear and ended my season (unless I buy a second tag )

So for those of you who were wondering how this case does with the "lighter" bullets here is some initial information.

As always these are in my rifle and not recommended for others and should start lower.
(Although I'm the only one with the 300SS as of now) It still blows my mind nobody else has chambered this. It is unreal how efficient this case is!!!! I can basically run the same speed as 300 win and right there with my 300 Dakota but with around 20 grains less powder.

The bullets:
195 grain Hornady ELD-M
180 grain Berger Elite Hunter
200 grain Sierra Match King

Just to get a baseline of what powders to pursue I only shot 1 round of each at what I figured would be towards the top end of pressure.
With the reamer that chambered my rifle (Rich may alter dimension if more interest comes to keep COAL of 208 and 225 Eld-m and 215 Berger under the magic 3") my max COAL to lands:
195 ELD-M 2.875"
180 Berger Elite 3.021"
200 Sierra MK 3.167" (They are javelins!)
If you compare the Coal to where they "should" be with the boat tail below neck shoulder junction it is a different story (other than 195 eld-m).
195 Eld-M 2.860"
180 Berger Elite Hunter 2.815"
200 Sierra MK 2.990"

Here is what I found today( all speeds from Magnetospeed) :
195 ELD-M 2.860" COAL
IMR 4451 59 grain 2980fps Towards top end, good working max
RL-16 59 grain 2964fps Towards top end, good working max
RL-17 61 grain 3091fps Definitely max pressure hard bolt lift
Hybrid 100V 61 grain 3060fps Hard bolt lift, max pressure, extractor mark
RL-22 65 grain 3042fps Max pressure, extractor mark
RL-23 63 grain 2948fps Max capacity, good on pressure
N560 61 grain 2794fps Very low pressure
65 grain 2978fps good working load, at top end

180 Berger Elite Hunter 2.982" COAL 2.250" BTO
RL-16 62 grain 3110fps close to max, max working load
Hybrid 100V 63 grian 3131fps max working load
N560 67 grain 3089fps easy bolt lift, some room to increase
RL-26 68.3 grain 3159 fps max load but would be good with.5 grain less
(I just had to try the magic Pixie dust again and it was a winner)

200 Sierra Match King 3.120" COAL 2.250" BTO
RL-16 60 grain 2966fps good working max
Hybrid 100V 60 grain 2934fps can work up little more. good on pressure
N560 65 grain 2973fps upper end, ok on pressure

All these were 1 shot only for pressure and speed base line. After the first round of testing on the 195 I figured I would focus on the powders I felt had the most potential and better temperature stability. The 180 and 200 grain bullets were both pretty impressive for speed. The seating depth of these bullets were both around .040" off lands and had about 1/2 a bullet diameter of the bearing surface held in the neck. When I get around to testing groups and seating depth I will update my findings. After running the numbers of the 3 bullets with a speed I felt would be comfortable to run the 200 gain SMK carried the most energy and only had .5moa more drop than the 180 Berger at 1000 yards. That being said all 3 bullets carried more than 1270 ft lbs at a 1000 yards.

WOW!!!! that was way to much typing!!!

Have you shot these for group? Just curious.

 

[TG-5150]

What an amazing thread, took a whole pot of coffee to get through. Thank goodness I am self employed. I'm late for work.
Glad it got dug up.

 

[Idaho Trecker]

Have you shot these for group? Just curious.

I have not shot groups but winter is setting in and so will the boredom so I will eventually. I'll post when I get some trigger time.

 

[Idaho Trecker]

What an amazing thread, took a whole pot of coffee to get through. Thank goodness I am self employed. I'm late for work.
Glad it got dug up.

That's good stuff! It still amazes me I have the only one after 3 or so years! Especially after hammering my Mike deer and nice bull elk over 1100 yards this year. The first year I got another 1100 yard deer.
Find my 270ss thread and another pot of coffee lol

 

[WiscGunner]

I am new to wildcats and was initially most interested in the 300ss because the 300wsm does seem to have much info available from people using the 215Berger in a true short action. What little info is available seems to be people running the 300wsm long in a long action. I have since shifted to the 7ss simply because I have a short action and the info for medium or long action chambers of short action cartridges doesn't really pertain to me personally.

There are lots of long action factory options and even better long action wildcats so if I have to buy a long action, I personally don't see any reason for me to run any short mag cartridge.

The main appeal to me, personally, is to swap barrels on my short action TL3 using cartridges that fit in an AICS magazine. I know this may not be the case for other people and that is ok. I also understand I could guess close enough by taking 100fps off the velocities but then the 7ss really pulls ahead.

Still following your success with unnatural interest as I haven't taken it completely off the table.

Thank you very much for sharing you awesome results and excellent data!

 

[ruby76]

I read this thread several times and used it for reference. At the time I had a 300wm so didnt really "need" another 30. Once I heard a whisper of a 338SS I was off to the races and my 300wm was on the chopping block.

 

[WiscGunner]

I read this thread several times and used it for reference. At the time I had a 300wm so didnt really "need" another 30. Once I heard a whisper of a 338SS I was off to the races and my 300wm was on the chopping block.

I have followed 338ss quite a bit as well.

Going to order a Proof Barrel and need to decide....2850ish with 250 Berger(338ss), 2900ish with 215 Berger (300ss), 3000ish with 180ELDM (7ss) for long range hunting. Decisions, decisions, decisions.

 

[elkaholic]

One of each is the way I would go!
Go get a count on your wifes shoes first.