The Old Becomes New Again

[RealMuddyboots]

So in another thread, @mtmuley mentioned I built a 30-06 that hit 3100 with 180HH so I thought be interesting to discuss what in hell are you doing?

With all the latest whiz bangs that come out, what is the number one rule? Buy enough of the rare brass to keep it going. Otherwise its a purty safe queen. My thoughts started to go down the same road of new cartridges but with the older generation in mind. Build with faster twists, provide greater magazine COAL, add sufficient freebore for longer, heavier, higher BC bullets to match how new cartridges are being launched today but with readily available brass.

So I was at range shooting my 1968 Savage 110C in .270 Win and thinking about it "what's so different between this old girl and the new whiz bang? The .270 is one of the few 65K cartridges so it has horsepower but running with a "governor" with 1:10tw and SAAMI cartridge dimensions. Got thinking, why not fast twist it, 1:8tw, add sufficient freebore, and use a 700 long action to take advantage of the magazine maximum COAL of 3.67". So found a donor rifle which some think I'm nuts to take apart 30-06AI but 1:10tw. Contacted Preferred Barrel and sent Bryce 2 dummy rounds of 156HH set at 3.63" for 0.020 jump. The Remage barrel was Light Palma, 27", 5R, 0.290 freebore to marry up to my 700LA. PBB nailed the dimensions and the rifle turned out fantastic! I had never shot the 156HH before but I built this rifle to shoot them. RL26 Pixie Dust delivered the velocity far greater than anticipated. The initial load topped out at 3284 but barrel has since sped up quite a bit since then. My hunting load is now 3250fps with the 156HH. Magically I killed my biggest whitetail (161 7/8) that year with it. Performed perfect!

The initial dipping toe turned to an article I read from German Salazar on the 30-06 Serengeti bore rider reamer he designed to allow him shoot longer heavier higher BC bullets in his 30-06. I have good friend who is also a gunsmith and he was onto the Serengeti reamer with his tweak. So early 2024 ordered a 26", 1:9tw, Sendero contour for another 700LA again to maximize the magazine COAL. So sent him the dummies and he worked his magic with the Serengeti bore rider reamer. MDT just came out with new Field stock which matched up perfectly. Triggertech trigger and very nice affordable high performing rifle. This rifle is still green but 180HH@3100 with W760 powder was right on from get go. I am now running 181HH ladders with Ramshot Big Game and will probably be closer to 3150.

So what's the point? The older generation rifles have built in governors that restricts their full capability IMO. The best part you are using "standard" brass that is available everywhere at reasonable prices using very common powders. No fire forming, just go shoot.

My next build is 300WM rebuild. I have Gen 1 Sendero 300WM with 1600+ down tube. Still shoots sub MOA at 300 with 196HH@3150. But I want to shoot some heavier monos and cup and core so 1:8 is next with Serengeti treatment.

After the 300WM, the .270 is going to get the Serengeti treatment to squeeze a little more out of it.

.270 dummies

 

[mtmuley]

Awesome. And the mad scientist over at Hammer are at it again. mtmuley

 

[RealMuddyboots]

To clarify bit more, the Serengeti Bore Rider reamer design reduces pressure which then allows you to take full advantage of maximizing the case capacity for more powder. The other part of this process is there are far more higher energy powders to take advantage of the increased case capacity by seating bullets out further.

So used my trusty Dremel to make some cartridge cut aways to show case seating depths of various bullets (AKA my whistle collection) I am a visual guy and using these cut aways has been enlightening where bullet base/heel ends up in case depending upon COAL.

It also helps on powder selection relative to powder type versus potential case capacity.