More 7-08 varmint meds

Intheshop

Well-Known Member
Not sure "conjecture" is the right word on this next part?......gut feeling maybe?

OK,I don't have "that many" moulds,maybe 20-30? On every GC mould we have,once seated,there's a very noticeable gap between the top of GC and where the lowest drive band begins. It's precisely this gap that is being lubed on my HV bullets. Which is a .30(.06 and .308),a .22(.223 and 22-250),and a 7-08 . It's the whole "less is more" thing meaning,less lube=higher velocity.... a little more involved but that's for a different day.

On the "inbred" 7 ,there isn't any gap. Now the "conjecture"..... these see the top of the Hornady GC's not only closing the gap but,depending on height of the base milling,you can.... very lightly bury the GC into the drive band. Which is part of the last post's "soft seating".

Does it help? Beats the snot out of me but.....

Nobody is gonna convince me otherwise, that the only reason there's a gap is because of production tolerances "built in" by mould makers. One more big check mark to milled bases though.... this gap is now EASILY set to whatever floats your boat. I will say,it looks good.
 
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Ian

Well-Known Member
There's a gap because that's where all the lead and carbon the gas check scrapes off the bore ends up. No gap at HV = lead wash like a sumbeach. If you use plastic buffer it won't lead. Found this out the hard way with the Swede and cutting down the Lee cruise missile. Now you're gonna prove me wrong I bet, and I hope you do and that it works for you.
 

Spindrift

Active Member
Nice work, Intheshop!
Very interesting concept you have there. Hope they shoot well for you! Please keep us posted on your results with your special bullets!
 

Intheshop

Well-Known Member
Well,ain't holding my breath for hitting 3k with this,the more I read on the loading dope.
And that's OK... this whole project kinda leapfrogged a 22-250 that got put together that I would take bets on,hitting that milestone.

Am looking forward to shooting these though.....from a having fun standpoint. The subsequent splatter effect on varmints is really what's this is about. The larger diameter "should" come unglued better....leastwise that's where my thinking is.
 
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Intheshop

Well-Known Member
Going tomorrow a.m. to find a box of factory loads..... will pull the bullets. Don't want to use my R700 cases,and these will be fresh. Been going round and round on what load to start with.....going with 41g of H4895 load from table below.Screenshot_20190409-084721_Chrome.jpg
 

Spindrift

Active Member
Exciting! I usually start with more modest speeds when getting familiar with a new bullet, really cool that you go directly to warp speed. Best of luck!
 

Intheshop

Well-Known Member
Well that,WAS fun.Pretty hot load....

Luepold is a fine scope,no two ways about it but,they ain't exactly the most.... click friendly. Meaning it takes awhile for the adjustments to "set".

I bore scoped the rig with an old reliable Japanese Bushnell which got me on paper. Shot first 3 @50... reasonably quick. These were the first CB's down this barrel. The P.O. had done a fab job of cleaning the brrl before shipping. Doubt he shot 40 rds through it? So the little bit of vertical in these early shots means nothing. Sent the next 2 down to 100 cause,that's where we're headed. Then went to the cleaning bench.

But first,the cases looked VG-exc. By the 3rd round the brrl was cooking hot. Primers look great. Haven't completely checked over the cases....will do that later. By the 5th round there was a tiny bit of what I call "pimples" on the case necks. Not as bad as some.... will say it's a bit of backwash. Don't need to go into detail right now because,I've seen it before...it's very manageable,just not a big deal. There was NO,nada,nothing to speak of going on IN the barrel. One sopping wet patch( viva kitchen towels,ripped/wrapped around a .25 brush) with shooters choice. Then dry mop watching how long it takes for a clean patch. Then started my normal,break in procedure of wearing it out hard with grey JB bore polish/paste.... it's the "milder" of the two JB's.

This will be ongoing.... keep dialing in the Luepold 3-9,keep cleaning whilst warm with JB and/or Remington 10X. It's going to take 50 rounds before it "normalizes"....

But cases look fab,brrl is brite,and its showing.promise on the groups. These were pretty "cully" bullets BTW...and just getting started on seating depth. I'd say the lack of any sort of "leade" to the rifling,whilst kinda doo doo in theory..... and not how I think it should be.... don't seem to be holding anything back? Heck,with this load,it ain't gonna take long for it to erode anyway?

I wasn't THAT concerned with dialing in the fit.... because I knew about the break in process which just takes a little time.... time,that gets also spent on the fit,amongst a few other things?

Alloy seems to be up to the challenge of 40k+ cup,on the pressure,leastwise initially. I didn't check for a lube star but looking at how brite the bore was,and experience says its fine.

Storm brewing.....and there's more than one. Weather front and 3k fps "Inbred" 7,haha.
 

Intheshop

Well-Known Member
OK,big check marks for Weaver mounts and Savage,adjustable headspace.

But backing up the truck just a bit. The FL sizing die for my R700 is set so that cases go back to what "they" came from the factory. That chamber is a cpl .002 over,so the bump is happy. When I set the Savage up the other day I sorta on purpose erred on the long side of headspace.... thinking safety.

Part of the strategy was to set the Savage up so that the FL die setting,worked for both.

So,pop the scope off the Weaver's....pulled the action,checked and rechecked. By measuring the fired cases,it looks like I needed to shorten up the headspace .004".... takes about as long to write as it does to effect the change.

Made notes.....

Speaking of scopes; I don't know what it is about these "spud" mounted bore sighters that get some folks so riled up? I mean if you can't slip a spud carefully into a barrel...come on,it's pretty durn easy. Is it in anyway a substitute for checking zero? That's a rather ignorant position...... of course you have to check zero.

BUT, what it does do.... is; if you've ever looked through one mounted it's a grid system of lines with a darker set like a crosshair in the center... got it? Now here's the interesting part. There is a pretty well thought out theory,that honestly.... if you've ever turned a handle on a mill or lathe you should be aware of how the scales don't play nice with backlash..... well scopes ain't a whole lot different. The theory is that the spring/s that apply resistance to the erector tube.... oh,how you say? pretty much suck at killing backlash. OBVIOUSLY, some scopes are better than others.... Luepold is in the "others".

Now,back to why a borescope can cut to the chase just a bit faster. If you know that we always want to turn the knobs "in"..... killing backlash,even if that means turning "out" an extra 6-10 clicks..... then count back "in",minus what your intended correction was. When I use a borescope,always set it so that the subsequent zero,sees me turning the screws,"in".
 
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Intheshop

Well-Known Member
It takes 4 minutes.... and that's at a smooth,almost lazy pace...

To mill 5 bullet bases from start( picking bullets out of the box)...... to finish,putting them back in the box,as sets of 5.

Once on the loading bench,they're the same as the parent,130's.
 

Ian

Well-Known Member
I've tuned dozens of pianos, maybe over 100, and countless guitars. The rule of backlash applies there too, always tune in the direction of increasing stress (up); if you overshoot, back down half a step or more and come back up to it. A really good match sight on an M1A is sort of the exception, being that it has a precision platen for a foundation and a monster spring that always keeps the backlash tight in both adjustment directions. The armature springs in scopes can't compare.
 

Spindrift

Active Member
I’ve never really thought about the role of backlash in scope adjustment. It makes absolute sense. Very useful tip, thank you!