Thread: 6.5 Creedmoor load development

Originally Posted by viper

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

I’d caution against being out off Viper - haven’t digested everything above yet, will go through it this evening - but neither my experience or that of my business partner (who I copied) were anything like this. We’re not benchrest fussy, far from it, but achieving 2800fps and sub MOA was easy.

I’m also with @10-Ring, my AR2209 has behaved itself and I’ve also been quite high but not as high as him before selecting a node that worked for my purposes. Haven’t checked the lot number yet, will do later.

Love the detail @Wingman, already got a long list of questions, sure others will to.

I’ll also throw out a bone and say that I’ve already told @Wingman by pm that my Creedmoor load dev was done with a dodgy chrono that was proven wrong by drop testing first time out in the field.

Originally Posted by Kiwi Greg

Very interesting reading but please get a better chronograph

I understand your concern but after many crossover tests with other chono's and rifles and matching my ballistic charts to its read outs, it is "bang on the money".. even if it didnt cost me much money

In the even of a chrono giving bad readings it is still valuable for shot string consistency and your true velocity can be tracked and pinpointed through a ballistic program.
It can also be checked with sub loads with a known altitude and speed of sound. In this case my old trusty checks out.
Ive owned many chronos over the years , some better than others but I trust my left nut on this one

Originally Posted by Wingman

I understand your concern but after many crossover tests with other chono's and rifles and matching my ballistic charts to its read outs, it is "bang on the money".. even if it didnt cost me much money

In the even of a chrono giving bad readings it is still valuable for shot string consistency and your true velocity can be tracked and pinpointed through a ballistic program.
It can also be checked with sub loads with a known altitude and speed of sound. In this case my old trusty checks out.
Ive owned many chronos over the years , some better than others but I trust my left nut on this one

Having owned several Ohlers, a shooting cronie, magneto speed, now a Labradar & soon to be two I'm glad I'm not your left nut

Originally Posted by 10-Ring

The Peterson brass is now available from Workshop Innovation.

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

I did have RL26 on my radar when I first saw the Sierra load data but after reading about its temperature instability and the fact I was intending on running an 18" or 20" barrel the RL 16 was just a better first option. RL26 was nil stock when I bought the RL16 too so that decided it.

I dont want to discourage anyone buying this cal or trying other things here, this is just a documentation on my rocky creedmoor journey.
To be honest if it wasnt for that early one 5 shot ragged hole group with the ADI 2208 at 2730fps (and a few others around 2550fps) I would have either sold the rifle and/or built a more suitable 6.5x47 on the bullpup chassis. those early groups showed that this cheap rifle could perform but my early high expectations of this cal fell short on velocity.

Id agree, 6.5 Creedmoor is a reasonable easy cal to work up loads for (even in my rifle) but I was trying to push it to limits I thought were the norm and falling well short with pressure problems. How ever I stand by what I said saying this cal is possessed and high pressures seem to come from very minor changes in components and dimensions so be on your toes or it will bite you on the ass.
It nowhere near as easy to work up or as forgiving as many other cals out there but that depends on just how much of a OCD ballistic geek you are...

Its interesting to me to hear about others experience with ADI 2209.. only a very light load of it shot remotely well ( MOA or better) in my rifle. I also favoured the 2208 over it as I knew it not only was a lower case fill it produced tighter groups and had a better chance of retaining the higher velocities in the cut down barrel. To be honest I havent revisited either of those powders since the RL16 turned up and I have cut the tube down to 20". Maybe its worth a few loads on paper next time Im out.
Out of all the powders and projectiles I tested in the beginning the 2209 was by far the most unstable in my rifle and the only powder that spiked the pressure fast enough to cause a stiff bolt lift and ejector smear with as little as 41.5gr which seems to be a mild load for this powder for many others loading this cal. Just revisiting my range note book and both the 143gr ELDX and 139gr Lapua Scenar with the same 41.5gr load was noted as "too hot, stiff bolt, do not excede 41gr".

The final chapter in my story (not likely to be a sequel) was addressing the bullets over all length with the hope to gain back some more space in the case it was getting apparent to me that all of the tested powders were reacting badly to a full case or compressed loads.
I am running the AI style mags in my pup chassis and selected the steel Accurate-Mag brand without the front block to get a total allowable total load length of 2.965".

My loads till then however were loaded to give me a 20 thou jump to my lands which was just a starting point at the time, I was yet to revise this when I got to the fine tuning stage of the load.
However, I decided to test a few of my new pet loads of 43gr RL16 behind the 139gr Lapua with a shorter jump of 10 thou to test my powder capacity v/s high pressure issue theory.

Bingo! 40fps gain in velocity just like that with none of the pressure signs a 0.4gr powder increase would have induced at that velocity.
Now I got thinking...

I was not sure what the std measurement of the throat length is on the SAAMI specs and didnt think to look it up at the time but I now knew how to ditch a lot of pressure...
Im not sure if the Remington 700s throat is shorter than some other manufacturers throats but I didnt go searching either.. Im guessing it is a happy medium of matching with an average bullet weight and length to ogive and the M700s pathetic internal mag length.
At the time I just put it down to the fact the case was designed to run out of an AR10 upper which limits the overall bullet length to the std AR10 magazine internal dimensions. Again I still havent chased all those figures.
Without knowing all these figures I can only speculate that this is the reason for such a variation of results documented by other Creedmoor owners.

THE FIX: I seated some my rifles prefered projectiles to my max mag length of 2.965" and took some careful measurements from base to ogive and then took an average over the three 130gr TMK, 136gr Scenar L and the 139gr which gave me 100 thou to play with. This meant a minimum jump of 10 to 20 thou was possible with all three bullets loaded to full mag length.
In the lathe it went and out came 100 thou of the factory cut lands with a piloted throat reamer.

You can picture excitement as the first few test loads went over the chrono.. and yes you guessed it, another big drop in velocity but also a very low pressure load. I gained 100 thou of air space between the powder and the back of the projectile! This meant I could work my loads up further with additional powder and not see any adverse effects on the pressure until it got close to compression again.

To cut a long story short this lead me to many more load tests to find a consistent tight sub 1/2" group and eventually had me decide on the 136gr Scenar over the 139gr scenar due to ever so slightly better groups at 200y and a fraction higher speed or slightly less pressure than the 139gr bullets.
I backed my speed off to a AV of 2910fps which gives crazy little ragged hole groups at 100y and a slightly better SD than the faster loads did.

For the safety of those who will have skipped to this end of my thread to try the load at the end, I will keep my selected powder weight to myself but I will encourage you to at least try the Aliant RL16 and Peterson brass because its a big part of the battle behind you. Check your maximum load length in corolation to your lands and you magazine and find the best relation there too. Work your loads up slowly and stop at the first signs of pressure.

All the other details of my pet load are as follows:

Peterson Match brass OAL 1.916", CCI BM-4 primer, Aliant RL16 powder, Lapua 136gr Scenar L bullet, OALL 2.965", 0.015" jump to lands.

Originally Posted by 10-Ring

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.

Thank you for those OAL figures buddy, that goes to confirm my theory of various throat lengths from the various manufacturers.
I can now make sense of how you fit larger 2209 charges without the high pressures I was seeing in early testing.
My modified throat now take loads almost the same dimensions you have given me and Id have no doubt if I replicated your loads now they would be safe in this rifle "hypothetically speaking and considering all other variables such as barrel internal diameters twist rates and rifling design and drag were equal.."

When the Remington was set up in its std tupperware stock with the internal mag, the internal mag dimension was 1.80" give or take but there was no way you could seat your bullets out even that far in this rifle because even if you could get them to feed past the feed ramp they logged well into the lands at that length.
I think it would be fair to say even certain factory loads in this rifle would be running too much pressure. The Hornady super performance for one would be a brass killer should someone want it to feed to one of these std factory chambered Remingtons.

Great thread, I wonder what the RL16 would perform like in 6.5x55SE. I have a Sako AV in this caliber, which appears to have a very short throat compared to others I have owned, and is giving similar pressure issues in what is not usually a "finnicky" caliber to reload.

@10-Ring, what does the Tikka CTR magazine you are using allow as a maximum COAL?
@Wingman, my Howa Varmint allows a maximum COAL of 2.910” seated 0.010” off the lands, with the 143gr ELD-X. The action dimensions though only allow a COAL of 2.850” for ease of top loading and feeding. This doesn’t have any ill effects though.

I found Lapua brass in 6.5x47 seemed to stretch more on first firing with a moderate load than expected, giving the impression of high pressure on extraction. This may have been behind your AR2209 experience? Perhaps your brass is similar in composition and manufacturing process (as the cases are in design) and prone to the the same behaviour? For a given load it affected some cases more than others in a way that could have been interpreted as "spiking". QuickLoad couldn't match the velocity and powder charge to the pressure signs by a large margin so I knew something odd was up. It settled down on a repeat firing, and then I lightly annealed and that fixed it completely.

Originally Posted by Puffin

I found Lapua brass in 6.5x47 seemed to stretch more on first firing with a moderate load than expected, giving the impression of high pressure on extraction. This may have been behind your AR2209 experience? Perhaps your brass is similar in composition and manufacturing process (as the cases are in design) and prone to the the same behaviour? For a given load it affected some cases more than others in a way that could have been interpreted as "spiking". QuickLoad couldn't match the velocity and powder charge to the pressure signs by a large margin so I knew something odd was up. It settled down on a repeat firing, and then I lightly annealed and that fixed it completely.

A very likely theory, I didnt measure the virgin brass before the first firing and compare it to resized dimensions but that is very likely. However I fired about half that virgin brass with 2208 and hotter loads than the milder 41gr 2209 loads without any sticky bolt at all.. I would have thought the 2208 would have produced higher pressures than the 2209. This Is why I first suspected the full case was lifting pressure beyond what it should be as the 2208 had a lot of empty space under the projectile.
I should try a few more 2209 loads with the same original deep seated COAL at some stage to try and replicate the initial results.

@Wingman, your AR2209 lot is different to mine. Mine is MEM5675. Its been used in Creedmoor and 243 without issues.

Originally Posted by Flyblown

@10-Ring, what does the Tikka CTR magazine you are using allow as a maximum COAL?.

Flyblown - My Tikka 6.5 CM is a 24" barrel SS T3x Lite not the CTR. The magazine cartridge space is 75mm or 2.9527". Tikka did their homework on this model and have made available plenty of mag length and throat length to seat the longer 6.5 bullets out where they don't interfere with case capacity. They can do this as the Tikka T3/X action only comes in one standard, do all cartridges length.

@Wingman, interesting thread

assuming you mean BR-4 primer (not BM)

did you go back to check 2209 / Lapua brass combination with the longer throat ?

Originally Posted by ebf

@Wingman, interesting thread

assuming you mean BR-4 primer (not BM)

did you go back to check 2209 / Lapua brass combination with the longer throat ?

Yes sorry.. brain fart.. too many late nights... yes CCI BR-4.

No I havent revisited the 2209 at all since I got such great results with the RL16. Im off to punch some paper with it shortly so will load a few up and give them a go.