Thread: 6.5 Creedmoor load development

Thanks for taking the time.
With the increased popularity of the 6.5CM this will be down the path of many and may save some ‘Headaches’!
Many calibres are far from their potential best and while most are happy it’s a great feeling ‘cracking’ some extra FPS or accuracy and knowing it’s safe as a house on fire.
Hope you post again soon...

Loving it. Keep it coming.

Yeah @Wingman this is a good thread reading with interest

Question on brass. If I have stamped brass in a previous rifle but it still chambers etc. fine in a new one, would you still bin it? What damage has been done would you suspect? That link has got me thinking all sorts of things about the way I treat brass

@Wingman, are you able to provide a lot number for the AR2209 you were using?

Thanks

Originally Posted by Wingman

....The 2209 on the other hand was just disappointing in both early pressure signs and accuracy. Although slower burning than the 2208 it is a little bulkier which meant anything over 41gr had the projectile up against it and bordering on a compressed load......

Just goes to show how much variation there is between different rifles. With my Tikka T3x 6.5 CM 45gns of 2209 will only reach slightly below the neck shoulder junction with Lapua fire formed cases. My overall cartridge length with the 140gr ELD-M is 2.940 and the base to ogive is 2.240 - both measurements seated .010" off the lands. I don't use 45gn 2209 in my rifle but have done so safely.

The best thing I did after I bought my 6.5 Creedmoor was to ditch my old CHRONY as it was very inconsistent in it's accuracy and buy a Labradar. Currently testing the Peterson SR brass too.

Please keep up the excellent reports Wingman - very interesting.

@Wingman you have an excellent writing style, thanks for posting all this.

Originally Posted by Gibo

Question on brass. If I have stamped brass in a previous rifle but it still chambers etc. fine in a new one, would you still bin it? What damage has been done would you suspect? That link has got me thinking all sorts of things about the way I treat brass

If by stamped brass you are referring to extractor marks it really depends on severity and how you go about prepping that brass for the new chamber.
Pressure high enough to give you that kind of marking can be minor with little lasting effects or like in the link I shared it may look minor but lasting damage has been done to the brass that has in turn shortened its life regardless of the chamber its fired in. it depends on where that brass has take the pressure damage and each piece should be inspected for tightness of primer pocket and over all dimensions.
Brass flows and will be migrating every shot regardless of pressure so all cases have a lifespan... just what than span is depends greatly on the user and honestly Creedmoor and I are still not intimate enough in our relatively fresh relationship for me to even guess and average number of firings the Lapua brass will yield at any given load data. My Lapua brass is on its 6th load and it took a punishing with ADI 2209 tests so Ill watch it closely an retire it when it once its had a few OAL cuts or when the primer pockets lose their tension which is the norm with this thicker small rifle primed Lapua brass in most cals.
Many people over work their brass when full length sizing or even neck sizing by bumping back the shoulder excessively. it only need a couple of though to headspace correctly and chamber with a smooth bolt closure. The shoulder does blow forward to a certain extent if you keep up with your annealing and full lenth cutting etc but it also stretches the thicker cup out at the base of the case which runs a much higher risk of case head separation. This excessive shoulder bumping practice alone will kill your brass quicker than a few hotter loads will.

Use light loads to reform the usable brass to your new chamber and inspect it again. A good s/s or media tumble will hide old ejector kisses but dont let this give you a false sense of security. Keep a close eye on the post fired dimensions above the cases thick section at the base.. if its bulging each time and then just getting resized, there is a good chance it getting thin and brittle.

Originally Posted by Flyblown

@Wingman, are you able to provide a lot number for the AR2209 you were using?

Thanks

Originally Posted by Wingman

If by stamped brass you are referring to extractor marks it really depends on severity and how you go about prepping that brass for the new chamber.
Pressure high enough to give you that kind of marking can be minor with little lasting effects or like in the link I shared it may look minor but lasting damage has been done to the brass that has in turn shortened its life regardless of the chamber its fired in. it depends on where that brass has take the pressure damage and each piece should be inspected for tightness of primer pocket and over all dimensions.
Brass flows and will be migrating every shot regardless of pressure so all cases have a lifespan... just what than span is depends greatly on the user and honestly Creedmoor and I are still not intimate enough in our relatively fresh relationship for me to even guess and average number of firings the Lapua brass will yield at any given load data. My Lapua brass is on its 6th load and it took a punishing with ADI 2209 tests so Ill watch it closely an retire it when it once its had a few OAL cuts or when the primer pockets lose their tension which is the norm with this thicker small rifle primed Lapua brass in most cals.
Many people over work their brass when full length sizing or even neck sizing by bumping back the shoulder excessively. it only need a couple of though to headspace correctly and chamber with a smooth bolt closure. The shoulder does blow forward to a certain extent if you keep up with your annealing and full lenth cutting etc but it also stretches the thicker cup out at the base of the case which runs a much higher risk of case head separation. This excessive shoulder bumping practice alone will kill your brass quicker than a few hotter loads will.

Use light loads to reform the usable brass to your new chamber and inspect it again. A good s/s or media tumble will hide old ejector kisses but dont let this give you a false sense of security. Keep a close eye on the post fired dimensions above the cases thick section at the base.. if its bulging each time and then just getting resized, there is a good chance it getting thin and brittle.

Thanks mate

Geez this has sort of put me off the Creedmore, was on my maybe list at some time.

Originally Posted by viper

Geez this has sort of put me off the Creedmore, was on my maybe list at some time.

The 6.5 Creedmoor has a reputation for being an easy cartridge to develop an accuracy load for. I've found this to be true in my case, however that's with the caveat of only trying five powders and nine different bullets of various brands, weights and designs for only 800+ shots. Even the worst groups were well under an inch at 100m regardless of load I tried. Obviously though, Wingman's experience differs and he's done a very fine job of explaining his intelligent and methodical approach to come up with an accuracy load that suits his particular rifle. You may find your 6.5 Creedmore, if you obtain one, equally as frustrating or equally as easy I did to find a good accuracy node for the bullet you want to use.

So a quick search of small primer brass available for the Creedmoor came up with Starline Brass and Peterson match brass. I ordered both.
Unfortunately while waiting for my Peterson brass from the USA I was notified the Starline brass was sold out.. I figured Ill try the Peterson first.

The weeks went by and I had an "all else fails" fall back load I was happy with that pushed the 139gr to 2890fps with 44gr of RL16 that was continuing to cut fantastic groups and would be a great hunting round too.

Now this is the part where I was torn.. to cut or not to cut... 24" was getting just enough velocity and great accuracy with the load I had, but my bullpup chassis was almost complete and I need to make a desision.

Again I hit the internet and stumbled across this great bit of informative experimentation.

https://rifleshooter.com/2016/02/6-5...p-a-creedmoor/

I wasnt too interested in velocities and temperatures etc but I did take one valuable piece of data from it.
his barrel at 24" long shot the 142gr SMK at 2683fps and when cut back to 20" shot it at 2609fps.
A drop of 74fps using H4350, now that I could live with knowing my velocities are already respectable and I could still use the 130gr TMK if velocity truely fell apart with the shorter barrel and RL16. So.... off it came..



I was very happy to find only lost 62fps with the same load. The rifle felt a lot more balanced and lighter in the MDT chassis too so I was really keen to get the pup chassis finished for it to bring the weight back even more.

The Peterson match brass finally arrived after getting lost in transit and re-sent but I was impressed with what I recieved. Ive never used this brass before now so had no idea what to expect.
Very nicely packed in its own foam lined plastic box with anti-corrosion protection and a bunch of papers.









So back to brass prep with a debur and a fire form then neck size and shoulder bump.
The first thing I noticed was this brass was much thicker an weighed more than the Lapua brass. That's a positive thing for the tendency of high pressure in this Creedmoor case.

My load of 44gr of RL16 in the Lapua case was not compressed and was just under the top of the case shoulder. The same 44gr in the Peterson brass was well compressed and was in the base of the neck.

Instantly I could see this would follow the trends of high pressure as the case got closer to the full mark or was compressed by the projectile while seating.

However I ran another ladder test with a much lower start load of 42.4gr and right up to 44.2gr. in 2gr increments. (my max safe charge in the lapua case is 44.5gr)

I reached the state of mild powder compression at 43.2gr and this is where the velocity dropped a crazy 100fps over the next 0.4gr.
This is where I should have stopped the ladder test and called my max load with this brass at 43gr. Interestingly the last velocity with the 43.2gr RL16 almost matched my load of 44gr in the Lapua brass at 2884fps.
The compressed loads continued to climb in velocity all the way to 2972fps at the max charge but also showed consistently increasing pressure signs of flatter primers and ejector rings the eventually turned to smears in the last two loads. I must mention that even though these loads were hot non of them had any inkling of a sticky bolt lift, a case stretch or primer failure..... many match shooters would still shoot them this way and just drastically reduce the working life of their brass.
This is not an option in my platform as I have talked about earlier.





So this new brass runs the same velocities and pressure as the Lapua brass does with 1gr less of the same powder and the added brass thickness was a welcomed upgrade.
Now I just needed to find the answer to lower pressure while keeping as much of this available velocity that teased me at the upper end of the ladder tests...

Very interesting reading but please get a better chronograph

The Peterson brass is now available from Workshop Innovation.

Have you tried RE26 Wingman? Not easy to obtain though.