95 SMK in 223, anyone try yet?

[davidjoe]

curious what freebore you tried with the 95’s ?

I’m actually using just the SAM standard PTG .223 reamer, with zero additional throating. The rationale for not increasing the freebore is mentioned above. Basically, I wanted to see if shooting it in would work, by itself, so as to be accurate at a short throat and accurate at the ideal longer throat, but the round count accurate free bore life approaching both, combined. If I burned in a longer throat with the longest bodied bullet there is, starting at optimal freebore, I could see that barrel having a short life.***

I actually did get 23.5 grains of Varget to not ring the nose much, on fire formed brass. The primers indicated that was all I need at this point, unless and until I get more case capacity from a longer throat later on.



Standard reamer lets me seat them before jam, just like this. The 95’s have a long body. The VLD 90’s are the Moly bullets in the center.




The light in this bottom picture reveals the relative body better without my estimated indicators.



*** I watched a video documentary just last evening of one of the WWI German super guns, which utilized individually numbered “bullets”, each pre-rifled and made a little bigger in diameter than the prior one, specifically to offset the bore erosion caused by each, single firing. It reminded me of the experiment here to shoot in the ideal throat. I have been reluctant to push a bullet body into the case where pressure could be squeezing it and the boat tail instead of pushing it forward, but apparently that isn’t close to being an issue yet, until the proportional intrusion is more extreme.

 

[Jdne5b]

curious what freebore you tried with the 95’s ?

Fwiw I had something close to a .170 and added .130 to it with a unithroater when I first tested them. The next barrel wasn't quite as long. Maybe 30k shorter. As usual, Nedd is pretty spot on with .250-.270 probably being ideal.

 

[avidflyer]

Fwiw I had something close to a .170 and added .130 to it with a unithroater when I first tested them. The next barrel wasn't quite as long. Maybe 30k shorter. As usual, Nedd is pretty spot on with .250-.270 probably being ideal.

I remember you and I talking about that, seemed to shoot ok but was way to long for 88.5’s or 90’s was curious to see what Dave was doing also. Turned a couple barrels (Wayne did) for a Panda one with a 70FB and one with a 170 FB for 90’s just debating if the 70 FB was worth messing with. Have several thousand 80 smk’s and 77 tmks thought I’d burn through. But with that much BC difference is it worth it? just may go to the 170 FB and 90’s

 

[avidflyer]

Fwiw I had something close to a .170 and added .130 to it with a unithroater when I first tested them. The next barrel wasn't quite as long. Maybe 30k shorter. As usual, Nedd is pretty spot on with .250-.270 probably being ideal.

what did you end up doing with the 88 eld’s wasn’t that about the same FB as the 95 smk’s??

 

[Jdne5b]

what did you end up doing with the 88 eld’s wasn’t that about the same FB as the 95 smk’s??

Yes, the 2nd barrel is what I was able to also use 88s in. I currently have something (3rd barrel) that is shorter than you could do 95s in and 88s are marginal. I'd have to dig @Dos XX out of retirement to check the freebore of his 223 Meyers reamer.

Seems you could do:
85.5 and 90s
88s and 90s
88s and 95s

but not all 4 in an ideal chamber unless you want to run bearing surface below neck\shoulder junction or jump the shorter ones .050+

 

[Ned Ludd]

FWIW - I found very early on that the 90 VLDs in my setups shot well at ~.018" to .024" off the lands. So that's where I have always seated them, rather than into the lands. The unfortunate part about that is that the PTG .223 Rem ISSF reamer that cuts 0.169" freebore was designed in conjunction with shooters that were seating the 90 VLDs as far as .010" into the lands. So one way of looking at it is that by seating 90 VLDs around .020" off the lands, I just effectively gave up about .030" worth of the freebore cut by that reamer relative to the folks seating them .010" into the lands.

In my hands, the 90 VLDs seated at around .020" off the lands in a brand new barrel chambered with the .223 Rem ISSF reamer (0.169" fb) have the boattail/bearing surface junction right at, or just barely above the case neck/shoulder junction. That is part of the reason why I had a .223 Rem reamer made that cuts 0.220" freebore. Seated at the same relative depth, the 90 VLDs have the boattail/bearing surface junction something more like 1/4th of the way out the neck. In a .220" fb chamber, the 95s seated at -.024" have the the boattail/bearing surface junction well below the neck/shoulder junction (see attached image below). The alignment in the image is far from perfect, but it should give a rough idea of where these bullets will be seated in a chamber of given freebore.

Given where each of these bullets is situated in the case neck when seated at -.021"/-.024" in a chamber with 0.220" fb, you could easily extend the freebore by another .050" (i.e. 0.270" fb), seat either bullet at those respective seating depths, and still have bullet shank gripped by at least half of the neck (or more). With the 95s, the BTO dimension (average of 10 bullets from a single Lot#) is ~.064 longer than the 90 VLD, the BS dimension is ~.057" longer. Depending on how little bullet shank in the neck you were willing to accept, you could probably even use a .300" fb and still seat the 90 VLDs with the 1/3 shank gripped by neck. I personally prefer not to seat bullets that far out in the neck, but you could if you wanted to and it would probably work just fine.