Thread: RL26 loads 7mm Saum

Can’t speak to 180 loads, but the 162ELDMs speeds look very slow ? I get 3000 fps with RL26 in 22in bbl.
Any pressure signs at top end of ladder ?
If not & given low speeds observed I wonder if your scales are out of whack ? Have you calibrated them recently?

Originally Posted by chainsaw

Can’t speak to 180 loads, but the 162ELDMs speeds look very slow ? I get 3000 fps with RL26 in 22in bbl.
Any pressure signs at top end of ladder ?
If not & given low speeds observed I wonder if your scales are out of whack ? Have you calibrated them recently?

Hi Chainsaw, no pressure signs - checking the scales is a good idea I have not done that for years. I am on grandad duty tonight (babysitting) so will have a look tomorrow.

Cheers

AMac

Nope scales are fine.

The drop in the ladder can come from primer selection, that is confusing what bbl length were you? 62gns gives me right on 2900fps 20” barrel 180eldm

Originally Posted by Kelton

The drop in the ladder can come from primer selection, that is confusing what bbl length were you? 62gns gives me right on 2900fps 20” barrel 180eldm

20” barrel fed 215 primers

Well after the last trip to the range in December and results that were disappointing to say the least, I did a bit of research and spied a Bryan Litz article that discussed the Effects of eating Depth/COAL on Pressure and Velocity. So went back and measured the last loads 3.005" and remeasured the point a 180ELDM engaged with the lands 3.145". So I produced loads for ladder testing with the 180's and 162's at a COAL of 3.137".

Made a couple of other changes - firstly given Kelton's advice re using 210's instead of 215 primers, I grabbed some of the white river LRP - nearest thing I could find to 210's.

Secondly, I sold the Magneto Speed and brought a Garmin Xero - and what a great wee bit of kit that is!

Very different results this time
RL26 180ELDM LRP Norma brass
62.5 2841
63.0 2858
63.5 2882
64.0 2907 stiff bolt slight extractor mark, decided to stop there.

let the rifle cool down then did a 3 shot group at 63.0 produced 0.608 moa. Happy days.

Small ladder with the 162 ELDM but with 215's
64.0 2952
64.5 2963
65.0 2992
65.5 3055
Only loaded 4 rounds so no groups shot. No sticky bolt lift of extractor marks.

I came away much happier this time - 2850 with the 180 is where I had been hoping to get near.

Cheers

AMac

Never tried to shoot a 10 shot group before. Loads are 63.5 rl26 average 2869fps. ES of 60.3 SD of 16.6.
Reckon I will back this off by .5 or 1.0 gn to see if i can reduce the ES and tighten the group up a tad or so.
Still probably ok for inside 500yd.
Cheers
AMac

Originally Posted by AMac

Attachment 248109
Never tried to shoot a 10 shot group before. Loads are 63.5 rl26 average 2869fps. ES of 60.3 SD of 16.6.
Reckon I will back this off by .5 or 1.0 gn to see if i can reduce the ES and tighten the group up a tad or so.
Still probably ok for inside 500yd.
Cheers
AMac

Try 62grains 62gn and wre primers give me 2930 sd of 6 over 10 shots

Need a thick barrel to shoot a fast 10shot group
Those that i know shoot them generally do cold bore + 3*3 shot groups over a bit of time to save cooking the barrel.

then another guy i know just burns the house down, o wait that was me

Originally Posted by 199p

Need a thick barrel to shoot a fast 10shot group
Those that i know shoot them generally do cold bore + 3*3 shot groups over a bit of time to save cooking the barrel.

then another guy i know just burns the house down, o wait that was me

I here you I never have the patience when shooting groups with my own rifles fast or last round hete

Originally Posted by AMac

Ok ran a ladder test with the RL26 and the results were a tad confounding!
180ELDM in norma 300 Saum cases necked to 7mm 1x fired and FLRS fed 215 primers.
Using a magnetospeed crono
gn fps
60.0 2511
60.5 2462
61.0 2509
61.5 2570
62.0 2578
62.5 2634
63.0 2622

162 EDLM same cases as above
62.0 2630
62.5 2590
63.0 2674
63.5 2707
64.0 2696

These velocities are well down on what I am getting with Superformance 62.5 = 2950
2 groups with the 180's
60gn - 2495/2466/2495 SD 28 - 1.05moa
61gn - 2536/2529/2536 SD 3.8 - 0.6moa

162's
62.0 - 2636/2637/2605 - 1.0moa

No cratering/flattening of primers, extractor mark etc.

Hmm - I have not seen an increase in powder by a grain resulting in a drop in velocity before. Any suggestions as to the rookie error I might be making?

Cheers AMac

It will just be a case that the ES for each load is actually quite wide, and you happen to get a high value from the range on one step and then a low value from the range on the next, the range of velocities for each step will overlap substantially. you're making a less than 1% change in powder charge per step, you'd expect about a linear less than 1% change in speed