6.5 Creedmoor: 140 RDF & ELD M - RL16

[twwilson25]

I'm hoping that someone can help diagnose why I'm getting great velocity, zero pressure sign with RL16 + 140gr Nosler RDF's, and excessive pressure signs with the Hornady ELD. Here's where I'm at with my reloading and I'll try to be comprehensive.

Nosler RDF: Twice fired Hornady brass, clean. FL size .003" shoulder bump without the expander ball. Neck size with Sinclair carbide die. Trim all cases to 1.910, chamfer and debur. Seating depth @ .030" from lands.

Charge Velocity
42.0 0
42.2 0
42.4 2787
42.6 2807
42.8 2815
43.0 2836
43.2 2836 (don't think the labradar picked up this shot)
43.4 2877
43.6 2859 (will retest 10 loads at this charge to confirm, should be node)
43.8 2880
44.0 2905

Hornady ELD: Brand new Hornady Brass, ran through FL sizer for consistency, Sinclair Neck sizer. Trimmed cases to 1.910, chamfer and debur. The exact same charge weights as used in RDF test, 42.0-44.0gr RL16. Seating depth @ 0.020" off lands. I don't have my notebook in front of me, but I stopped shooting at 43.0gr load due to excessive pressure. Extractor marks on brass, Hard bolt lift, and noticeable increase in recoil. I'll check my notebook on velocity when I stopped but I recall it was was far less than the RDF with same charge.

Any help in diagnosing the issue would be appreciated and advice welcomed. I really like the results I'm seeing from the RDF's. This is the second test I've done with them with the exact same charges, to confirm velocities. Two solid nodes with 43.0 and 43.6 with single digit ES and SD's.

Thanks
Tyler

 

[Gohring65]

You have two different bullets in different sized cases.

 

[twwilson25]

Gohring65 - ok, so what do you suggest? Fire form the new brass so it's consistent in size, and/or is the difference in ELD that would cause the pressure spike? I can load the ELD in the, now fired and prepped brass, and see if that fixes the issue. If that's the case I don't understand having to fire form new brass for a 6.5CM. If I wanted to do that much work I wouldn't gone with another cartridge.

 

[918v]

Back the ELD off the lands some more and the pressure signs will go away.

 

[arnie19]

I had the same problem . The Hornady has a longer bearing surface so use lower charge . I found the Nosler RDF to shoot better for me .

 

[twwilson25]

Velocity wise the RDF is great. The ELD I haven't been able to get out of 2700's so if that doesn't improve, I won't be using it. I've got 200 of them so I hope this changes.

 

[mikehotel]

Loaded up the Nosler 140 RFD's for the first time Friday. Using the same powder charge that I use for the 140 ELD's , the RFD's finally came in at 0.60 off the lands in my RPR. Velocities were ~2750.

 

[Gohring65]

Gohring65 - ok, so what do you suggest? Fire form the new brass so it's consistent in size, and/or is the difference in ELD that would cause the pressure spike? I can load the ELD in the, now fired and prepped brass, and see if that fixes the issue. If that's the case I don't understand having to fire form new brass for a 6.5CM. If I wanted to do that much work I wouldn't gone with another cartridge.

Contrary to popular tecnhniqes you're going to have to work back up.
I have ran into pressure problems with new brass vs fireformed brass. But the two different bullets, different bearing surface length and ogive profile. One has a hybrid profile, (RDF) and one has a traditional secant (Hornady).
You shouldn't be surprised at all that they would work up different.

 

[twwilson25]

Well I have plenty to use up so I'll start low with ELD's and work up. When I did the load work up with RDF's I started low and loaded in .5gr increments to 44.0, not expecting to get there but it's not showing pressure at all. I'm not seeing a node around 44 and I'm not willing to push it higher so I'm sticking in the 43.0-43.6 range. Thanks for the info I figured it wouldn't hurt to ask.

 

[308Gunner]

I found with the RDF that I had to go up .1 to .2 grains to get the same velocity in my 6.5Super LR