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Topic: 260 Creedington...lol (Read 686 times) previous topic - next topic

Re: 260 Creedington...lol

Reply #15
I kind of quit the GRT because I was getting pressures that could no way be right even after tweaking parameters on my 7-08 AI
Dave

Re: 260 Creedington...lol

Reply #16
With the 44.9 load the GRT said 66000 and the velocity was in line in that 2980 neighborhood.
Seeing nothing as far as pressure it makes me think when we do see signs we are way over book.  Conservative manuals are way under but I'm guessing that factory ammo is sometimes also way over saami numbers.
Another question; first time of used br-2 primers, are they harder & stand more pressure than std or mag primers?  Or just more consistent?

Edit: just primed up the cases for the next test. Pockets were all tight except for one, the one that boasted the 3101....it was snug but way looser than the rest....that was firing number 3.
Won't be going there again!...lol
11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #17
I think you are EXACTLY right about pressure! When we see the signs we're way over not getting close.

On the primers the BR 2s are harder and more consistent than standards. The BR 2s and the mags are the same cup as I understand it but possibly not as close QC as the BRs as I understand it.
Dave

Re: 260 Creedington...lol

Reply #18
First seating test pretty much inconclusive.  I can't see well enough to keep a good target picture after a few shots.  Between floaters, cataracts & mirage off the barrel I have to shoot at the "blurr"!  I thought the color of the orange 3/4" squares might help.

.003 jam shot the tightest but I really didn't see any pattern.  One got totally away from me in .006 off, my panic mode, so I can't even discount that depth.

I saved the final load (44.9) for the mag speed and shot it at the foulers target....2984 exactly what 44.8 & 45.0 had on the second velocity check.

Wishing that it wasn't so heavy, otherwise I would definitely hunt with it.
Now I'm debating whether or not to run that reamer in another barrel.  Have a 22" Savage take off  sporter that I already re-chambered from 260 to Creedmoor.  It shot "ok" and probably has a 100 rounds on it now.  Thinking that it might end up like something in between the CM & the 260 AI with the CM throat.

Edit: the group size numbers of .009 & .012 are just the opposite.
11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #19
3 in & 3 out look good considering POI and elevation to me. 
Dave

Re: 260 Creedington...lol

Reply #20
3 in & 3 out look good considering POI and elevation to me. 
I did call number one right on .003out.  May try those again and also 015 on out a ways.
Thought about looking through all my "poor mans" scopes.  This is the viper 6.5-20 "capped" version is that the "hs"?  I've got two of them.  My best scope glass wise is the  3-18 leupold.  Clear but cross hairs are too thick for fine work (or my eyes are too thin).
Also have a Bushnell elite 4200 6-24 that has fine crosshairs and AO (no sf) but worked great for me in the past. 
My plan was to have those cataracts taken care of during this past winter.  Covid has put a damper on that and getting an appointment now will put me too close to hunting season I think.   We will see (pun).
11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #21
Update: Throwing another dart on the board, decided to try this in one of my sporter contours.  Have a take-off 260 that I had set back and made a Creed out of.
So the reamer came back out and I lengthened the hole.  Figured I could turn it back into a regular Creed if need be.
Well, that Shilen shot good for me right off the bat.  Not so so far with this railroad track Savage.  No decent targets or groups to show.  This short barrel (22") also reaches pressure quicker.  Tried an assortment of bullets so far to see what might "stick".  Some 140 Federal fusions that were on the shelf show the most promise but groups just under an inch is all.  Pushing them with h4831sc at 2770.

Also shot the very worst group of three in my 68+ years.  There is almost 300 Speer 'hot cor' 140s on the shelf that wouldn't shoot in anything else I have so I gave them another try.  Now there are three less back on the shelf.  They might make a good 20 yard bullet but didn't try that.

Frustrating, almost time to move on to something else....lol
11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #22
I'm moving on on several as we speak  :))
Dave

Re: 260 Creedington...lol

Reply #23
https://www.65creedmoor.com/index.php?topic=2173.0

I got the new version of GRT loaded today.
Low & behold it now has a few more powders including H4831.
Also in the caliber list is a wildcat 6.5 Super (SLR).
Well other than neck length it is the virtually the same as the Creedington.  The SLR kept the same case length as the 260 so the neck is approx. .040 longer than mine.

The link above is from this forum (2014).  Surprised I didn't see it before.  Mine requires the extra trimming but no special reamer or dies.

Any rate I'm working on the third one now, the 19 inch Shaw barrel now on its 4rth & final caliber.  It looks like the speed is not going to be there (even less than expected).  The barrel itself was never quite right from new and with the bore cam I see the shadows of the original chamber. It was a tad off from center so each "improvement" followed suit.

I will "play" with this one a few days and hopefully there will be something worthwhile to report or post.

11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #24
Here's another picture I found in searches for the 6.5 Super.


Btw; I am renaming the "Creedington" to
6.5 CML (creedmoor long)  so I can have room to etch the barrels that I have changed.
11X Grandfather
Part time Savagesmith

Re: 260 Creedington...lol

Reply #25
Randy, you act like you still have snow up there and nothing to do.  :o
I like the looks of it.  As soon as you perfect it, sell it to Nosler or someone
with deep pockets.

Re: 260 Creedington...lol

Reply #26
I want to see what's just beyond  46. She really tapered off from 45.6 to 46, looks like the proverbial " long wide node" to me. I bet you're about to the top end of it.
Dave you were correct again todays tests at 48.7 grains of imr 4831 with the 140 hornady match seconds showed supprising velocity. No target to confirm anything though.

Seems like I had no trouble getting to 2900 + with the 20" Savage barreled Creedmoor and was running 2950 with 123s

With the 135 Atips in my 28" Criterion I've been as fast as 2940 on 42.3 grains with no pressure.

42.6g was 2934, 2931 & 2927 with no pressure but it seemed like it was getting bigger. If I ever get happy with a seating depth I'll run it up to pressure and see what's left up there.
11X Grandfather
Part time Savagesmith

 

Re: 260 Creedington...lol

Reply #27
Similar velocity today with 48.5 gr charge. 3067 averagefor 5 shots these were the 140 deep cirl HBN coated seconfs. My 6.5-06 would never get up to 2950  which was supposed to be optimal for it and 6.5-284.
This IMR4831 WITH THOSE DEEP CURLS SHOULD MAKE THAT 6.5'06 THE THUMPER I TouGHT IT WOULD BE.if i can breakk 3000 fps. Maybr it might knock them down as good ad my 25-06s did i always thpught the 3000 mark was magical for drt shots. The 25 rarely failed kocking the feet from under them. The 6.5 Ackley did too with 120s at 3000.
11X Grandfather
Part time Savagesmith