PDA

View Full Version : 6.5 Creedmoor project



bruce drake
05-12-2012, 11:09 AM
So I have a spare 260 Remington Large Ring Barrel (the one I buggered the chamber up a few months ago) and I decided that it wasn't going to waste the barrel so I had a friend with a lathe trim the end back .250" and recut a new shoulder on the barrel as well (it still has 4 complete threads) to rechamber it for the shorter 6.5 Creedmoor.

So yesterday while I was waiting for the movers to come do the site survey of the house for the move to Kansas I was in the garage puttering around putting things to order and I saw the barrel just laying there on the shelf with the other spare barrels and I figured the only way I was going to move forward with the project was if I actually spun on it on an action.

So out comes the barrel and out comes the Yugo 48 Action that it will be going on (the same one I originally had setup for the 260 Rem project) and I proceeded to spin the old 8mm Mauser barrel off (anyone need a nearly new Large Ring Yugo 48 Mauser 8mm Mauser barrel?) and cranked on the 6.5 barrel. I have a barrel wrench and barrel vice mounted on my work bench so swapping barrels is just a matter of time getting it setup properly.

Afterwards, I knew the chamber was close to the proper 6.5 creedmore dimensions already but I wanted to do a quick check but I didn't have the dies yet (dies and brass are due in next week from Brownells. - FFL Collector discount dropped 10% off the price of Midway's and Midsouth's ) so I then took a 22-250 case out of a box on the shelf and then necked it up with a 260 Rem sizer die and then seated a 120gr Hornady A-Max with the 260 Rem seater die to make a 6.5x250 dummy (the 260 Rem dies did nothing to the shoulder angle of the original 22-250 case). So I then placed the 6.5x250 cartridge into the magazine of the assembled Mauser and cycled the bolt to feed the dummy case into the chamber. The bolt would not close on the cartridge (which I expected, but I figured I'd see if it headspaced immediately - a proverbial luck of the draw sometimes) but the bolt is only a couple of thousandths off from headspacing as the bolt stops at about the 12:30 position so the remaining bit will be shaved out of the chamber later this week to allow the bolt to fully close at the 3 o'clock setting. Of course this was taking eyeball measurements with the modified 6.5x250 case which has a different shoulder angle than the 6.5 Creedmore (its also about .008 of an inch shorter than the Creedmoor) but since the 22-250 is one of the parent cases of the 6.5 Creedmoor it should be pretty close.

The 6.5 Creedmoor was designed to operate in AR10s and Short Action rifles so the shorter cartridge length should operate well in this rechambered barrel. Most of the production rifles in this chamber have 1-8 twist barrels but this barrel is set at 1-9 from the original setup for 260 Rem but it should operate just fine with the same bullet weight range as the 260 Rem (90-140gr). My personal 6.5 mold is a Lymans 266469 at 140gr but I also have a Herters 257 caliber 90gr mold (thanks to TwoTrees for the mold) that someone had recut two of the driving bands to .266 at sometime in the past that throws a 105gr boolit out as well to experiment with.

Cycling and loading the 6.5x250 dummy cases in another Yugo 48 8mm Mauser that I have showed no problems with the feeding from the magazine into the chamber so I expect that once the rifle is headspaced it should be a light, trim woods/target rifle. I have a Lyman 57 rear sight and Springfield 03A3 front sight mounted on the Creedmoor rifle and barrel so it should be a nice rifle to play with on Kansas ranges and woods.

Of course I realized afterwards I should probably have been taking pictures of the rifle and for the forum, but I'll try to make up for that when the rental reamer and gauges show up next week.

Bruce

buyobuyo
05-14-2012, 10:08 PM
Sounds like a fun quick project. I really want to give the 6.5 Creedmoor a try sometime, but I can't afford new guns/calibers right now.

Haggway
05-14-2012, 10:29 PM
I have an AR-10 in 6.5 creedmoore. It shoots way better than I can.

bruce drake
05-14-2012, 11:45 PM
Well, the largest investment came in the new dies/brass and renting the reamer and HS gauges. I traded some extra small parts I had laying around with my friend for the lathe time and the barrel was one I had on shelf already. I'm just hoping to reset that chamber and make the barrel functional after messing up the original chambering 5 months ago. The reamers and dies shipped today so they should be delivered by Friday by the latest so perhaps I'll be able to pop off to the range this weekend to do a quick range report.

Bruce

danski26
05-14-2012, 11:58 PM
I love my 6.5 Creedmoore. My 1-9 twist shoots the 142 SMK's just fine.

bruce drake
05-15-2012, 05:49 PM
Danski26,

Have you played around with any 120gr loadings?

My jacketed supply has 90, 100, 120 and 140gr so some assistance in the various weights would be helpful.

Bruce

bruce drake
05-16-2012, 07:44 PM
Ok, so the reamer and gauges came today and I cut the chamber and now its ready for proofing this weekend. The dies and brass are due to be delivered tomorrow so either tomorrow night or Friday, I'll build my first cast loads for the Creedmoor Mauser.

Bruce

danski26
05-16-2012, 08:16 PM
I have not tried a 120 gr projectile Bruce. I will be working up a reduced course load soon. Probably will go with a projectile around 100 gr for that. I'm loading Varget with the 142's and I get the velocity that i need however I believe there are powders that will give it more velocity. 120 gr projectiles should give you good performance out to 300 on paper and possibly farther. Should be a good deer bullet too.

bruce drake
05-17-2012, 10:46 PM
Ok,

So the Hornady dies and brass arrived today from Brownells.

First off - (pro) The dies are nice and very well finished. They easily resized trimmed down 308 Win and 243 Rem cases into 6.5 Creedmoor cases. (con) The seating die had to be assembled and the recapping die had to be readjusted to the proper height for the cartridge and then tightened down.

Secondly - (pro) The Hornady 6.5 Creedmoor brass came packaged in a nice box and was bagged as well. All the brass were within the length specifications as set out by SAAMI. no flattened cases or oval necks. (con) The cases come with annealed necks. Out of the 50 cases I lost 5 to collapsed necks when I was seating my Lyman 266469 140gr gaschecked boolits. THere wasn't any difficulty in seating the 50 cases but the 5 came out with crushed necks which makes me figure the annealling process softened the brass too much. Still that is a 10% loss rate out of a brand-new set of cases. This required me to enquire how easy it would be to form 6.5 Creedmoor from 308 Win parent cases which turned into a positive as it was an easy process to trim .11" off the neck and then reform the neck and shoulder angle. I think future cases for this rifle will be cutdown 308 Win cases since they easily reformed and fit the chamber without having to neck turn the cases.

Attached below is a photograph of three different 6.5 cartridges so people can compare the new 6.5 Creedmoor(6.5x49mm) in the center to 6.5x57mm (left) and 6.5 Arisaka (6.5x50) on the right.

Tomorrow, I intend to shoot the rifle if I can get off work in time so I can see some preliminary shot groups before the rifle gets packed up next week for the move.

Bruce

danski26
05-18-2012, 02:02 PM
If you bumped up the inside neck diameter of the Hornady brass a bit with a mandrel die I bet that would solve the seating problem. I haven't been able to get the 243 brass formed into 6.5 creedmoor that will work in my chamber yet. Although....I have only put about 30 minutes into the attempt.

bruce drake
05-18-2012, 08:16 PM
Dan,

I went to the range today and got several five-shot 1.5" groups at 50yards with the Lyman 266469 and 9gr of Unique.

My chamber reamer was rented from www.reamerrentals.com. They use PTG Reamers so perhaps our reamers were from different makers. My rifle chambered and fired the 308 Win and 243 Rem reformed and cutdown cases without an issue this afternoon.

Now I need to get a photo of the targets uploaded.

added text:
All my shooting gear is now boxed up for the move so additional benchtime with this rifle will have to wait until next month.

This target photo shows my last group at 25 yards (#5) and my first group at 50 yards (#6). All shooting was done offhand with a Lyman 57SME rear sight and a Springfield 03A3 front sight. It would probably be tighter with a scope but I'm holding off on putting one on at this moment.

Fitting five into the magazine was a hit or miss proposition depending on where the cartridges were placed on whether the first round got picked up neatly or not. There will have to be some adjustment of the sidewalls of the action to convert from a 57mm case length cartridge to this shorter but fatter cartridge.

Loading 4 or less gave the rifle no problems but since I'd like to shoot this rifle in NRA Highpower matches with jacketed bullets, I need it to reliably feed 5 at a time during the rapid-fire stages. I'm not in a mood to do load 4-4-2 for a 60 second 10 round string :)

Right now, she is all set up for a hunting rifle for deer or smaller animals so either way, it is nice to know I recovered from my earlier chambering problem with this barrel.

Bruce

bruce drake
05-20-2012, 06:05 PM
All my shooting gear is now boxed up for the move so additional benchtime with this rifle will have to wait until next month.

This target photo shows my last group at 25 yards (#5) and my first group at 50 yards (#6). All shooting was done offhand with a Lyman 57SME rear sight and a Springfield 03A3 front sight. It would probably be tighter with a scope but I'm holding off on putting one on at this moment.

Fitting five into the magazine was a hit or miss proposition depending on where the cartridges were placed on whether the first round got picked up neatly or not. There will have to be some adjustment of the sidewalls of the action to convert from a 57mm case length cartridge to this shorter but fatter cartridge.

Loading 4 or less gave the rifle no problems but since I'd like to shoot this rifle in NRA Highpower matches with jacketed bullets, I need it to reliably feed 5 at a time during the rapid-fire stages. I'm not in a mood to do load 4-4-2 for a 60 second 10 round string

Right now, she is all set up for a hunting rifle for deer or smaller animals so either way, it is nice to know I recovered from my earlier chambering problem with this barrel.