The Creedmoor Forum

As the title says, these are available now at Brownells and Midway (maybe others).
http://www.midwayusa.com/product/714503/magpul-pmag-5-ac-l-magazine-aics-long-action-standard-5-round-polymer-black
I have been tweaking an Accurate mag AICS long, for my Sweedmoor, and am not happy enough with the feed to bed the DBM in a "final" resting place. Hopefully, by mid week, I'll have some of these, and have that solved.

Here's hoping

Terry

I received the new tube for the next phase of the Sweedmoor saga. Bought a 27" Excaliber barrel, and a fresh 6.5 Creedmoor reamer from PTG. Hopefully, the weekend will afford me enough time to spin it up, and screw it home. Have plenty of fresh brass sized and trimmed, ready to fireform, but can probably use the fireformed brass from Rev. 1 if need be.

Have gathered a lot of good load data from the original barrel, that should prove useful in the new. This time I'll be starting with a fresh tube, of more recent manufacturing vintage/material. Should be interesting, could be disappointing.
Will update all, as it progresses.

Terry

CTF and whoever else is looking.

http://www.grafs.com/retail/catalog/product/productId/6184

Terry

I'm starting this thread to allow anyone to post about powder availability, when they see it. Might be helpful, may die a quick death, we'll see.

TAC in stock at Wideners (1#'rs) 12/11/14

Terry

Any one interested in trying long round nose bullets in a creedmoor, need to seriously look at throat/bullet relationship. The guns that originally were chambered for these long projectiles had a"generous" throat, to say the least. In the creedmoor, a lot of the bullet will reside in the "boiler room". Shouldn't be a problem, as the heavier projectiles, will be launched slower anyway, just something to be aware of.

I made a short, ogive/throat/shoulder relationship "quick check", from a short piece of barrel, and the creedmoor reamer. Shown below, with a pic of a creedmoor case with a 160 RNFMJ projectile, placed to just clear the lands.



Coincidently, since my Sweedmoor was reamed with the Creedmoor reamer, I can utilize this tool with it as well.

Terry

I am trying this just to see if the engineering behind the Creedmoor neck, shoulder, and body taper, will translate to a slightly larger case, with any gains. I was originally trying to base this off the Lapua 6.5x55 case, as I wasn't sure of the additional taper diameter of the base, resulting from running a Creedmoor reamer in to an additional 0.235" depth(1). The depth was chosen, because it allows a 6.5x55 headspace gauge to be used, allowing formed 6.5x55 LENGTH(2) brass to headspace correctly, allowing fire forming to be conducted with no real forward movement, upon firing pin strike. If you have ever fire formed cases, you can appreciate some of the methods employed to keep this from happening, and the results good/bad.

(1) The body taper (near base) is close to the Swede diameter, but a little too snug for reliable feeding, so I used the 6x57(Rem) or 7x57(Mauser) case, as it had more than enough length, with near perfect body diameter, for the extended depth of the Creedmoor reamer, as I chambered with this iteration of the Sweedmoor. The Lapua neck is a little thicker, and doesn't work well with the reamer neck dimension of the Creedmoor, which is 0.296" at shoulder, tapering to 0.295" at neck opening. My experience with Lapua 6.5x55 brass finishes at 0.296" at neck when loaded, a little tight.

(2) As the accompanied pic shows, the x57 case is longer than the x55 (Huh!), so after running the 7x57 case through the 6.5x55 die, the neck requires a bit of trimming. 6.5x55 brass (when next reamer is finished) needs to be trimmed about 0.020", as the Creedmoor neck is shorter than the 6.5x55.Once trimmed, 6.5x55 could be fire formed as is. I gave up the small gain in neck length, to be able to headspace the 6.5x55 with only the trim.

I am going to nail down all of the changes required for a reamer and resize reamer to be made, but will try to get some real life results/data, out of the present chambering first, to see if it's worth all the effort.

I say that because the 6.5x55 is a fine cartridge as is, with the 6.5x57 possibly better, requiring little to no case forming to be up and running. Will keep you up to date.

Pic shows L to R   7x57, 7x57 sized to 6.5x55, 7x57 sized to 6.5x55 trimmed to length, Fireformed Sweedmoor, 6.5 Creedmoor.




Terry


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Basic premise for this whole exercise, is to see if I can approximate the loading density of a Creedmoor with slower powder in a larger case, to see if the "benefits" enjoyed by Creedmoor shooters can be taken to the next level.

Time will tell, might be a big waste of time (I doubt it, but..........).

Terry

I got a chance today (however fleeting) to test some more loads in my 788 Rem CM. I loaded 48 & 48.5 gr of Ramshot Magnum today. My previous standard seating depth was jumping 0.080". Both my CM's liked that jump with my H414 load. The barrel I am using on the 788 has typically shot 0.5 moa (not as good as my Mauser CM)
I loaded both charges, at 0.080", 0.065", 0.050", and 0.035" jump. Only got to shoot the upper charge(s) due to time constraints.
All shot at 0.5moa or better, with no real "outstanding" winner, however as might be expected, velocity crept up as jump was decreased. I may try even closer to lands. I also need to duplicate this exercise in the Mauser, as it has repeatedly shot in the 0.2moa range.

The good news, is Magnum can hit 2800fps in the CM with a 139 Scenar with no real pressure signs. It also ran ES of 24fps, and SD of 8.5, in 10 shot strings.
Don't say this too loud but these were dropped charges from a RCBS Uniflow. Magnum flows REALLY well.

Got to shoot my last 5 rounds at 600yds, and managed a 0.52moa cluster despite gusting wind.

I'll try to show more sophisticated data as I go, but today showed great promise.

Terry