Jump to content
UKV - The Place for Precision Rifle Enthusiasts
VarmLR

Reload Swiss RS62: Actual V's QL for 6.5 Creedmoor

Recommended Posts

6 hours ago, VarmLR said:

horizontal = wind?  I do initial testing at 100 yds then test the chosen load at 300 or 400 yds.  That shows up the importance of low ES/small vertical spread better than at 100.  Have a look at your ES figures for that 46 load...are they low there and either side for one interval?

This 147gr OCW was shot in virtually no wind (I'd waited nearly two months to shoot this batch that I made up last November, having passed up a number of shooting days due to learning the hard way by twice wasting lead doing OCW in choppy conditions).

The real point I made earlier is that with these pretty small groups from a factory rifle on a small tactical bipod, a tiny rear bag and about 10 minutes cooling after each group, I reckon I'm not prepared to believe either rig or I am good enough to resolve POI causes and effects further. We're all fallible (as demonstrated by the big flyer on the last group). If I did try to draw conclusions further from the resulting groups I think I could easily be chasing shadows. (See the pic below where I've just overlaid the whole set in Photoshop. Note that discounting the 2 "flyers" at top & left, that all 16 remaining rounds lie in a 8.5mm x 12mm group. At 100 metres and across a whole grain of powder, you got to be happy with that... ;))

Anyway... I've just checked back in my Loading/Firing Records and note I actually speed tested 10 of that 46.86gr load last month. They were shot in 5°C conditions (hence slightly lower MVs than indicated by an earlier RS70 and 147gr ELDM speed ladder shot last October) and ranged 2808 - 2823 fps for an ES of 15 and an SD of 4.9. As mentioned, I'm pretty happy with that, especially given the potential for inconsistencies in my batch 2 brass from which this OCW was shot.

OCW_Hornady147ELDM_Merged.jpg

Share this post


Link to post
Share on other sites

That's not a bad way to do the overlays...shows up the group clusters POI nicely.

Share this post


Link to post
Share on other sites
On 26/02/2018 at 1:59 PM, VarmLR said:

A)   139 Lap Scenar/Lap small primer brass/Murom KVB Magnum small rifle primers/COAL 1.842"

Load (gr)           MV  (fps)       ES                   Group (inch)       Vert spread(inch)

43.70              2597                41                     0.47                         0.25

43.85             2612                 47                     0.60                        0.36

44.00              2633                15                      0.54                        0.26

44.15              2629                16                      0.29                        0.20

44.30              2652                 21                     0.45                        0.03 

44.45              2655                16                      0.26                        0.24

46.00              2656                 22                      0.40                       0.13

VarmLR,  is that last value correct? (46 grains)  It seems like a very large step, or was it supposed to read 44.6?

Share this post


Link to post
Share on other sites

Yes, well spotted. It should read 44.6.   Any more is getting into compressed loads 

Share this post


Link to post
Share on other sites
Quote

AS it happens, I tested some 1F cases of another brass batch (still Lapua) today using the OCW identified node of 44gr plus the 139 Scenar.

...........   Zero pressure signs and a light bolt lift.

I did shoot a few of the 2F with Muron KVB 223 primers (non magnum) in the same load but experienced ejector marks on brass and a slightly sticky bolt lift....go figure!

I find this an interesting point.  It seems counterintuitive for the magnum primer to provide less pressure, could it be that the 2F fired brass was not bumped back to the same length as the 1F brass, causing a tighter fit in the chamber before firing?   However, I would expect to see the non magnum primers to show signs of cratering as they generally have a thinner cup, maybe Laurie would have an insight as to what is going on here

Tom

Share this post


Link to post
Share on other sites

Insofar as SR primers go, there is NO relationship between so-called 'magnum' primers and 'magnum' (hotter) performance. Magnum SR (and BR types) primers have thicker cups but often have the same pellet as the standard grade inside. Some individual models (including non-magnums) are slightly warmer than others.

See first conclusion (commentary on Table 1) in:

http://www.targetshooter.co.uk/?p=2662

What I increasingly see is the difference SR primers can make to performance - not in MVs but in matching the rest of the load and changing group sizes. This has two results. First some experimentation with primers may be necessary during load development to get best results, and 2) once you've settled on a primer model stick with it. Changing primer (sometimes even buying a new lot of an existing one) often requires the load to be fine-tuned again.

Share this post


Link to post
Share on other sites

Thanks for the reply Laurie,  that is interesting to know about the SR magnum vs standard primers.  So the question remains what could have caused the tight bolt lift and ejector marks?  VarmLR  are you FL resizing, or just neck sizing?  If only neck sizing perhaps om the 3rd firing the case has expanded to the point , and work hardened enough that it doesn't contract back enough for a smooth extraction .

Tom

Share this post


Link to post
Share on other sites

I FL resize all my brass (using Redding dies) as I see no benefit in neck sizing and only issues on the horizon as they'll eventually need FL resized anyway.  I anneal each firing and try to keep things as consistent load to load as I can.  I also use a Lee factory crimp die but only to give a very slight crimp to try and uniform neck tension for each round.  I have found differences between several batches of muroms I used, more with SR standard which I no longer use.  For 6.5CM I use either KVB-223M or CCI-450 (being tried for my next batch to see if there is any improvement in MVs and SDs over the KVB-M primers).

Share this post


Link to post
Share on other sites

Hello Varm

I've been reading your results with interest as I'm trying load development with a new 6.5 CM using the same powder in a 26 '' barrel. what COAL or jump were you using for the scenars? I understand that this round is fond of a bit of jump, say 30 - 40 thou, is that the ballpark area you're in?                                                                                                                                              I'm not going the Scenar route (no pun intended) but thought I'd try the Nosler 140 RDF's in my Savage 12 LRP to see how they perform, but even with a 30 thou jump, this puts them under a 2.800'' COAL (2.796'' actual)  while touching the lands obviously makes them 2.826 COAL, so I guess I've possibly got a short throat?

Share this post


Link to post
Share on other sites

Hi ezmobile

 

I use a 30 thou jump for mine as I saw no real benefit in chasing the lands and only potential problems.  For my barrel this equates to a COAL of 2.842" for my TAC A1.  I think I read somewhere that SAAMI optimum COAL was 2.820" so mine could be throated quite long.

Share this post


Link to post
Share on other sites

Well, I had an interesting morning yesterday at Bisley testing out some homeloads at 300 yds. Loading 44.3 grains of RS62 behind some Nosler 140 RDF's. COAL of 2.815'' (giving a .009 thou jump to lands). The rifle was chucking them all over the bloody board. I was getting velocities from 2791 fps, up to 2829 fps and everywhere in between ( a little too fast I think)! but I've never shot like that before. I know it wasn't me as the other two rifles I took were consistent V & 5 shooters to 300, 900 & 1k all day long, and in excellent conditions too.

But here's the rub. Its a new rifle, Savage mod 12 LRP, which is supposed to be a pretty good factory rifle. Mated to a new MDT chassis and very decent scope and is a peach to shoot, so I'm a little perplexed and don't know what to look at first, but suspect it may be down to the ammo?? These bullets have a wide array of opinions from really good to not that great and powder is good for this caliber (6.5 Creed).

Any thoughts anyone? 

Share this post


Link to post
Share on other sites

Do you have access to a borescope? I've seen a new 223 Savage barrel that was deeply pitted in the last 12 inches before the muzzle. There were gaps in the lands and a very poor crown................ this didn't shoot.

Re-Pete

 

 

Share this post


Link to post
Share on other sites
On 6/4/2018 at 1:23 PM, ezmobile said:

But here's the rub. Its a new rifle, Savage mod 12 LRP, which is supposed to be a pretty good factory rifle. Mated to a new MDT chassis and very decent scope and is a peach to shoot, so I'm a little perplexed and don't know what to look at first, but suspect it may be down to the ammo?? These bullets have a wide array of opinions from really good to not that great and powder is good for this caliber (6.5 Creed).

Any thoughts anyone? 

I'd check all the usual suspects;

1.Scope ring screws locking down the scope 

2. Rings to base/rail screws

3. Rail to action screws

4. Action to chassis screws, front and rear

5. If using a moddy or muzzle brake, check how well it's locked down. Or try without it on.

if none of the above resolves the issue, check rifle with a different scope and set of rings to rule this out.

Failing that, try some factory ammo to check there's nothing wrong with the home loads.

If all else fails, get it checked by a rifle smith.

Share this post


Link to post
Share on other sites

That must have been disappointing for you ezmobile and such things can be perplexing but sometimes the causes are thankfully not too hard to track down.  I'd start (as above) with the obvious things.  Action screw torque, scope rings/scope, brass prep and consistency etc etc.  When this has happened with me it has usually been down to one specific issue.  Also,  to state the blindingly obvious, what were your load development results initially?  You mention a load of 44.3gr behind the Nostlers (SRP brass or LRP brass???)...in SRP brass this would seem in the right ball-park but sounds quite a stiff load for the LRP brass.  

Share this post


Link to post
Share on other sites

Thanks for the input fella's, much appreciated.

Everything was as it should be re; the rifle, scope etc. It's funny though, as a few days before I had just finished running the barrel in with its original H-S Precision stock and I was using cheapo S&B 140 grain FMJ's, VV N150 loaded low at around 38 grains, and it was shooting o.k. not brilliant, but I was still running the barrel in as mentioned, and so far has only had 60 rounds through it. The brass I was using was once fired Hornady with large primers (using CCI BR primers).

As for load development, this was to be a starting point for me. I made up this small batch to see how they would go and take it from there. I agree that the velocities were a tad high (highest recorded was 2829 fps) and should be looking at 2750 or thereabouts, so that'll be easy to take care of.

Cheers

 

Share this post


Link to post
Share on other sites

I think there's your answer.  You're not on a node and you'll find that 1F brass, that load of 44.3gr on LR 1F brass may be well into high pressure territory and most definitely not a load I would want to start at.   I would strongly advise starting lower, at 41.5gr RS62 in LR primer brass and working up to say 43.5.  You'll find several nodes in that range.  43.5 should be giving you 2800fps or close to.  A chap a few weeks ago was firing 43gr with RS62 and 139 Scenars from his 24 inch barrel and achieving very close to that.

Share this post


Link to post
Share on other sites

Cheers for that Varm, I'll have a go  with that and work it from there. I wasn't trying to get high velocities in the first place, I was only working from multiple articles I'd read to give me a ballpark figure to start off, and while "Quickload" is helpful, I've learned from experience not to trust their predictions on loads too faithfully, as they're quite often way off the mark.

A morning down on Short Siberia will be needed me thinks!

Share this post


Link to post
Share on other sites
On 3/8/2018 at 5:13 PM, VarmLR said:

horizontal = wind?  I do initial testing at 100 yds then test the chosen load at 300 or 400 yds.  That shows up the importance of low ES/small vertical spread better than at 100.  Have a look at your ES figures for that 46 load...are they low there and either side for one interval?

I was wondering if you’ve done any detailed testing re temp sensitivity and how groups/ES/SD evolve at material changes in temp ? Thx

Share this post


Link to post
Share on other sites

As a matter of fact, I did and found (much as expected) that it wasn't at all that temperature sensitive.

I took the exact same load tested at 24 degrees ambient (although powder temp was higher as the bullets had time to cook a little in the sun) which delivered a shade over 2700 fps from 44gr.

I re-tested at 20 degrees (a little under) and this time the rounds were kept in the shade and fed one at a time into the rifle.  The average from 6 shots was exactly 2700fps, so pretty conclusively it is the barrel that has speeded up for the first 500 rounds down the tube and has now stabilised at this velocity for this load.  My very first firings from it were considerably lower at 2633fps (new brass) and 2655fps (1F, 150 rounds down the barrel) to now where I have 500 rounds fired.  There has been no change in velocity from 400 to 500 rounds and for an ambient temperature range of about 6 or 7 degrees.  No change in 100 yd groups (still close on 1/4 moa for 5 shots).  ES rose slightly with temperature, and rose a little more than SD, but to be fair, I hadn;t batched the last lot of brass, just cleaned, annealed and loaded so it wasn't a fair conparison with earlier outings (my 24 degree ES/SD rose from single figure to ES 33(!!!) but SD was around 10.  I'm usually not happy unless both are single figure, so next time out I'll be far more careful with brass prep.  

The ES/SD of my 129gr loads were much tighter for the same conditions, coming in at ES6, SD4.

The same cannot be said of my Viht rounds which exhibit far greater changes in velocity with temperature, especially for anything north of a moderately warm load (pardon the pun).

 

 

Share this post


Link to post
Share on other sites
27 minutes ago, VarmLR said:

As a matter of fact, I did and found (much as expected) that it wasn't at all that temperature sensitive.

I took the exact same load tested at 24 degrees ambient (although powder temp was higher as the bullets had time to cook a little in the sun) which delivered a shade over 2700 fps from 44gr.

I re-tested at 20 degrees (a little under) and this time the rounds were kept in the shade and fed one at a time into the rifle.  The average from 6 shots was exactly 2700fps, so pretty conclusively it is the barrel that has speeded up for the first 500 rounds down the tube and has now stabilised at this velocity for this load.  My very first firings from it were considerably lower at 2633fps (new brass) and 2655fps (1F, 150 rounds down the barrel) to now where I have 500 rounds fired.  There has been no change in velocity from 400 to 500 rounds and for an ambient temperature range of about 6 or 7 degrees.  No change in 100 yd groups (still close on 1/4 moa for 5 shots).  ES rose slightly with temperature, and rose a little more than SD, but to be fair, I hadn;t batched the last lot of brass, just cleaned, annealed and loaded so it wasn't a fair conparison with earlier outings (my 24 degree ES/SD rose from single figure to ES 33(!!!) but SD was around 10.  I'm usually not happy unless both are single figure, so next time out I'll be far more careful with brass prep.  

The ES/SD of my 129gr loads were much tighter for the same conditions, coming in at ES6, SD4.

The same cannot be said of my Viht rounds which exhibit far greater changes in velocity with temperature, especially for anything north of a moderately warm load (pardon the pun).

 

 

Very interesting although a 7 degree spread isn’t perhaps wide enough to measure esp at the extremes of temp change. I’ve been testing VV N550 at 20F to 95F and found quite a lot of sensitivity with the same load lot / same number of rounds through the barrel with ES/SD remaining very constant. Just trying to understand if RS62 behaves consistently / linear at the extremes or whether it exaggerates at either end ? It sounds pretty stable in the mid-range for sure. 

Good thread btw. 

Share this post


Link to post
Share on other sites

From all of my load development to date, if you plotted a graph of load increment V's velocity, the N140/N150 powders are relatively linear lower in the load range but once past half-way and approaching 3/4 max they tend to curve upwards with some the biggest jumps near the top of the load range, exactly what you don't want if the powders are also temperature sensitive.  My own experience of them is that they are.

RS50/62 (the only RS powders I've so far used) both show a remarkably linear increase on load V's velocity without the same big spikes towards max loads.  Coupled with their relative lack of temperature sensitivity this makes them very consistent and stable powders which makes load development much easier and less fraught at the extremes, although I generally try and avoid loads right at the top end of what is safe, preferring to work in the range of max minus 2 to 5%.

Share this post


Link to post
Share on other sites

Yesterday I started my own load development with my new Tikka T3 TAC A1 in 6.5 Creedmoor with virgin Lapua SR brass, 139 Lapua Scenars, CCI450 primers and RS62.  I used my new magnetospeed v3 to gather velocity data, focussing on finding a velocity plateau from where I can tinker with OAL to fine tune precision.

The rifle had fired 20 rnds of factory to start breaking it in and for me to get a feel for normal levels of recoil, extraction etc.

Brass was chamfered and then neck sized using Lee collet neck sizing die (with decapping pin turned down) and bullets were seated to an OAL of 2.853 (CBTO 2.304) to be 30 thou off the lands in my rifle using a Redding Competition seater. (This gave very good concentricity all less than 1.5 thou)

I worked up from 41.6 to 44.6 in 0.3 gn steps and then from 44.8 to 45.2 in .2 gn steps then added one for luck at 45.3gn

There were no signs of pressure, easy bolt lift, no cratering/blanking and only moderately flattened primers with only a barely discernible difference between 44 and 45.3gn (image of 45.3gn primer is shown below)

The groups were all pretty respectable with half being <0.5 MOA and the rest < 1 MOA, but this was not the purpose of this exercise,  I was time limited so could not let the barrel cool as much as I wanted between strings, and I could have put more effort into better technique.

I plotted the velocity data along with SD and ES from the tests in Excel which seem to concur with the consensus that 44gn is a good node (in virgin SR Lapua brass.)

ES and SD were a bit all over the place,  Hopefully these will come down with a couple of fire formings and weight batching of the brass.

I noted that Velocities were slightly higher than those reported by VarmLR, possibly due to a faster barrel.

Tom

  

RS62.jpg

primer.jpg

Primer from 45.3gn load

Share this post


Link to post
Share on other sites

Thanks for posting your data froggy. I particularly like the way you've plotted SD and ES alongside the velocities.

I'd go with the plateau at about 43.7gn for 2700fps.  With a slippery bullet like the Scenar, I think you're needlessly chasing velocity if you use the higher charge weights.

Triffid

Share this post


Link to post
Share on other sites

Good data froggy.  That 44gr load seems to be a universally respectable load for SRP brass and the 139 scenar.  My current velocities match yours almost exactly from the same rifle (my velocities increased with around 400 rounds down the tube).  My last two outings have shown averages of 2703 and 2707fps from two 10 shot strings with ES around 15 (my brass prep to blame) and SD of 10, but that will come down with a little more care.  Accuracy is pretty acceptable.  Your data matches mine and confirms that RS62 (and 50 for that matter) is exceptionally linear wrt charge/velocity, exhibiting none of the spikes that Viht powders tend to IME.

45gr is quite a compressed load in my rifle at 30 thou jump.  Not sure the extra powder is worthwhile as for both the 44 and 45gr loads I found little difference in grouping at 900m. (probably more me than the load) so I stick with the lower load to be a little kinder on the barrel.

The group below was shot using 43.9gr....I have found that to consistently give the best groups and low ES of all my loads across a fairly wide temperature range. the 0.25moa is pretty typical of what I am getting (usually 5 shot but the picture shows a 4 shot group...for some odd reason I can't remember!).

139ScenarGP1.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

By using this site, you agree to our Terms of Use and Privacy Policy