6.5 PRC Ladder Test (1st Time) 143 ELD-X New Rifle Thoughts On Next Steps

[GBOGH]

Ok so first time looking at a load ladder test and decided to look at the 143g ELD-X (as i had a lot of them ). Powders were RL26, RL19, RL17. Results are below with load data, graph, and shot grouping at 200yds. (unfortunately i was rushed to get through these as our range was about to go to a tourney so i had to get through the three 10 rd groups per 5 min range hot / range cold (so 5 min on 5 min rest )

i am curious where people would go next? i am thinking of dialing up the RL19 only in 0.2 increments now but maybe its worth looking at another or all other powders again in 0.2 increments. Just learning how to interpret data so happy to hear thoughts etc.

bo

		G1	G7
Bullet	143g ELD-X	0.625​	0.315​
Powder	RL-26
Barrel	26" Bartlein
Twist	1:8
Brass	Hornady
Primer	Federal Lg
Shot	Load-gr	Speed-FPS
1​	52​	2907​
2​	52.4​	2894​
3​	52.8​	2913​
4​	53.2​	2940​
5​	53.6​	2943​
6​	54​	2972​
7​	54.4​	3002​
8​	54.8​	3008​
9​	55.2​	3058​
10​	55.6​	3054​

		G1	G7
Bullet	143g ELD-X	0.625​	0.315​
Powder	RL-19
Barrel	26" Bartlein
Twist	1:8
Brass	Hornady
Primer	Federal Lg
Shot	Load-gr	Speed-FPS
1​	47​	2634​
2​	47.4​	2657​
3​	47.8​	2694​
4​	48.2​	2697​
5​	48.6​	2694​
6​	49​	2739​
7​	49.4​	2739​
8​	49.8​	2762​
9​	50.2​	2828​
10​	50.6​	2864​

		G1	G7
Bullet	143g ELD-X	0.625​	0.315​
Powder	RL-17
Barrel	26" Bartlein
Twist	1:8
Brass	Hornady
Primer	Federal Lg
Shot	Load-gr	Speed-FPS
1​	45​	2805​
2​	45.4​	2785​
3​	45.8​	2802​
4​	46.2​	2825​
5​	46.6​	2851​
6​	47​	2884​
7​	47.4​	2907​
8​	47.8​	2933​
9​	48.2​	2982​
10​	48.6​	2979​

 

[mildot326]

Well first off, excellent layout and posting info, I'm about to do this for the first time for my 300WM in about a week, so I really don't feel confident to comment on your results. That said, what was your COAL with respect to the lands? I've decided to start @ .020. I'm going to say that the RL26 looks to be the best with the "better" group size IMO and MV. Good job. Cheers

 

[GBOGH]

I’m at 2.905 length for all loads. I was going to work on coal once I found a sweet spot on loads. So at this point I actually don’t know my coal.

 

[mildot326]

I’m at 2.905 length for all loads. I was going to work on coal once I found a sweet spot on loads. So at this point I actually don’t know my coal.

OK, well it's my understanding that once you have the "node" you can fine tune the accuracy to some extend using the COAL. While you have a few "flyers" with the RL26, IMO you have excellent MV and if you can tighten the group , you have done your job. Good luck.

 

[GBOGH]

It’s likely I found a good upper node on rl26 but never hit a peak with rl19.
I may push rl19 a bit and also fine tune rl26 and take my time

ill Be measuring my coal in next few days. Wish i could find hornady prc for their coal

 

[mildot326]

BTW, did you experience any over pressure signs? also, I bought the Hornady gauge and modified cartridge, so I could get the exact COAL for my chamber and adjust from there. I'm running a Bartlein barrel as well & I'm impressed with it's performance so far. He's a 3 shot group with Norma 170 Tipstrike factory ammo, after about a 30rd "break in" .

 

[Bwhntr53]

I would love to find some Hornady 143 eldx bullets to load in my6.5 creedmoor. At least every I have checked. None available.

 

[GBOGH]

nice shots. I can not find the prc load cartridge for the hornady. I do have the creedmoor though. Prc anything hard to find these days

 

[Rumlover]

I'm going down this path as well. Based on what you have above, I'd focus on RE26 at 54.6. Then start playing with the CTBO/OAL. I've found the ELD-M&X, 140/143gr respectively, seem to like the 0-0.020 range for jump in my 6.5 PRC. That said, load 3-5 rounds at 0, 0.020, 0.040, 0.060 off the lands and shoot for groups....one of those should stand out by producing a tighter group. If you have to choose a load/COL based on either a tight vertical or horizontal spread, go for the load that produces the tightest vertical spread.

Couple other options... I've settled in on Retumbo for my PRC with 135 A-Tips, 144 Berger LRHT's, and 140 ELD-M's. Retumbo is hard to come by, but it's close twin is IMR 8133 and it's easier to find. For IMR 8133 and 140 ELD-M's, I'm using 59.4 gr, seated just off the lands and getting 3140 in a 26" proof with an SD of 9.

 

[GBOGH]

Thanks all for the comments...building on this i went out and did two loads at each of the following with RL26:
55.2, 55.4, 55.6,55.8,56.1, 56.4, 56.7, 57.0, 57.3, 57.6

two loads and then took avg of two shots and plotted it

got the following: (shots 1 and 10 were removed on each. shot at 57.3 was heavy bolt lift with ejector mark. primer was fine so stopped and did not fire 57.6)

Shot	Load-gr	Speed-FPS
1​	55.4​	3040
2​	55.6​	3061
3​	55.8​	3068
4​	56.1​	3081
5​	56.4​	3109
6​	56.7​	3128
7​	57​	3136
8​	57.3​	3163

Based on this data i see a few options:

i can run a node at 54.6, 55.7, or maybe even 56.8 or so. i may load 5 rounds of each of these and do a grouping at 200 and take a feel of the bolt etc. and also see the group. if one of the three stands out i can then move on to the lands testing

 

[GBOGH]

Next step in sequence... I ran the three load grains of RL26 based on "nodes" I thought I was seeing. I ran 5 shots of 54.6, 55.4, and 56.8 grains.
Photos are as follows: (ALL 200 yard groups)

They are in order of the loads above.

note that the first load 54.6 showed more sporadic velocities and spread.
the second pic, minus one shot (last one) had a decent spread
third again minus one shot was not bad either.

I shot the 5 rounds in about 20 seconds or so for each round of five. basically was not really taking too much time to steady etc.

the following are the numbers then in order of the three loads:

Now one thing that was curious to me. the last round at 56.8 showed a lot of smoke in the action area. but there was zero primer issue zero heavy bolt or ejector mark. is this a primer pocket being expanded and gas escaping from over pressure of the primer pocket???

I lean towards the 56.8 load but if the smoke is a sign of an issue seems the 55.4 is not bad either.

either way I will be measuring my lands next and doing 0.015 to start and maybe 0.025 and 0.035 away to see if there are any changes.

 

[GBOGH]

OK so interesting findings now .... so after a ton of checking etc, turns out my CBTO is 2.301 ... turns out factory ammo is 2.305 or so. interesting to begin.

all my testing above was of course with 2.305 as my length as I had not received the Hornady case to check the CBTO so assumed factory would not be right out on there.

so then when I backed off those and ran tests using the 55.4 grains of RL 26 Igot the following with a lot of pressure signs on the first two/three lengths:

Clearly shortening the chamber of course though not thought of at the time increased pressure . LOL. so my plan is to go to 2.85 length (seems the longer 2.275 was starting to look good) load a ladder test again just to confirm that my load is still around the 55.4 and then run a 6 shot group.

several of these casings noticeably had rough ejector marks on the back not just shiny but literally rough to the touch so I am disposing of those cases unless they are still ok?

 

[GBOGH]

did a ton of experimenting and playing around with the factory ammo and the CBTO measurement etc. What I found was this:

after numerous tries and measuring of bullets in the lot of 143 eld-x etc, it does appear I am at 2.300 for my CBTO.

after numerous measurements of a full lot of 143 factory ammo I got 2.950 for OAL. so this is

I loaded six rounds each of 2.295, 2.290, and 2.285 CBTO. these roughly roughly measure 2.943, 2.938, and 2.933 respectively in OAL.

The factory round measured 2.95 OAL and 2.303 on avg for CBTO. so pretty pressed on lands.

I will be running these three lengths (2.295, 2.290, 2.285) in the next few days. hopefully I will see the 3070 or so speed I was seeing before with a better grouping etc.

 

[GBOGH]

ok so here is the data....ran 143g ELD-X with a current COBT of 2.300 on my rifle and tested running at 55.4g RL26 and 2.285, 2.290, and 2.295 lengths.

First here is the data in a spread sheet:

Overall I am definitely looking into the 2.295 now...I may drop powder down just a hair...55.3 or so ... still in the node... but I liked the grouping all things considered and loved the SD/ES...

and if I am At around 3100 as well...not a bad round at all.

and here are the groupings. now this first grouping I am at odds with...I fired 6 shots through and I only see what appears to be 3 holes (albeit some damn fine shots) but no way I have three other shots in the same holes...so likely this had a lot of other spray shots...

Now here is the next round of 6 at 2.290 ..... much much worse....

Lastly the 2.295 grouping... this one has some promise as I most definitely rushed these shots with a "cease fire in 2 minutes" called just as I was starting.

 

[GBOGH]

200yds