7 mm ELD-M Weak tip leads to seating depth issue

[Ripa]

First, since I am more of a reader and not a writer in this forum, thank you all for your contributions.

I have a theory I want to check with you, when I am seating the 7mm ELD-M 162 in a slightly compressed case with powder, the seating depth is within +/- 0.05 mm. This might not be a problem if the sweet spot was further from the lands. The bullets is measured are sorted base to oligve.


With the 7 mm Scenar 150 it’s within +/- 0.01mm with harder compressed loads add am beginning to think that it is the tip of the ELD that flexes where the seating stem touches’ the bullet (this bullet must be laser guided in my 708).


After measuring the total top to ogive the ES was 0.08 mm, doing that wound not give a significant improvement even though I think the tip would be more rigid


My solution is to bed the stem in order to enlarge the surface where the stem is touching the bullet.


What do you think, am I riding the bike in the wrong direction, what are your experience?


Looking forward for your response.


Regards Mats

 

[Laurie]

With the 7 mm Scenar 150 it’s within +/- 0.01mm with harder compressed loads add am beginning to think that it is the tip of the ELD that flexes where the seating stem touches’ the bullet (this bullet must be laser guided in my 708).

Many standard seater dies are supplied with stems whose cavities aren't deep enough to handle long-nose match bullets without the tip 'bottoming' in the cavity. Tip-to-stem contact gives guaranteed poor runouts, inconsistent COALs and in the case of synthetic tip designs like the Hornady ELDs, risk damaging the tip or in severe cases breaking it off. It's essential for the stem to bullet contact to be evenly on the nose well below the tip. If the bullets are too long for the stem cavity, the stem either has to be replaced with a factory 'VLD' version or machined / reprofiled a little deeper to accommodate the bullet tip or top end of the nose/meplat in a HP match design. This looks like your problem in that the relatively short/blunt nose 150gn Scenar (9.75 calibre-radius) suffers no problems whilst the longer nose and radius form ELD (17.29 calibres-radius secant ogive and a true VLD shape with Rt/R = 0.50 value).

Remove the seater stem from the die body and push a bullet into the cavity seeing if the tip makes contact before the lower stem surface provides all-round contact on the bullet nose. Light pressure and some turns on the bullet should leave an all-round symmetric contact mark on the nose that is parallel with the base.

Opening the stem mouth won't in itself solve the problem, in fact would make it worse as the stem would then contact the bullet nose further down making meplat contact more likely.

 

[Lefty Trigger]

What die are you using to seat your bullets? I load a lot of the 150gr Scenar's and the 162gr ELD's and my RCBS competition seater has a bunch of depth to spare on bullet tips.

 

[Laurie]

There are a couple of older Daily Bulletin features on this issue:

http://bulletin.accurateshooter.com/?s=VLD+bullet+seater+stems&submit=Search

 

[Ripa]

Thanks Laurie, much appreciated for this answer but more for the inspiration and knowledge regarding the 708 that you have given on forums.


The tip doesn't touch the serm, my Redding Competition seater works if I measure and correct every load. My Wilson does not work at all but my plan is to modify the stem in my lathe and enlarge the surface that touches the bullet. Probably also bedding the stem inside but I haven't figured out how the ensure that the bullet is centered.

FYI Laure
My new T3 is a 708, .315 neck, 1:9 Krieger, 700 mm, in a single fed aluminium F-open stock of my on design that also can be used with a bi-pod;
- 150 Scenar shot bungholes in a 300 m competition last Saturday (when i did my wind reading). It was the last kernels of H4650 but I think the RS62 will work. 0,25 mm from the lands, Norma cases, KVB7, 880 m/s
- 162 ELD-M shows real promise, I shot 3x5 groups today, all was within 0.4 MOA at 300m. 0,10-0,20 mm from the lands, Palma cases, RS62, BR-4, 840 m/s
- The 168 VLD is a no go.

 

[Laurie]

FYI Laure
My new T3 is a 708, .315 neck, 1:9 Krieger, 700 mm, in a single fed aluminium F-open stock of my on design that also can be used with a bi-pod;
- 150 Scenar shot bungholes in a 300 m competition last Saturday (when i did my wind reading). It was the last kernels of H4650 but I think the RS62 will work. 0,25 mm from the lands, Norma cases, KVB7, 880 m/s
- 162 ELD-M shows real promise, I shot 3x5 groups today, all was within 0.4 MOA at 300m. 0,10-0,20 mm from the lands, Palma cases, RS62, BR-4, 840 m/s
- The 168 VLD is a no go.

Thanks for the update - looks good. The 150 Scenar shoots very well in my 7mm-08. My usual powder with it is Lovex SO65 (Shooters World 'Long Rifle'), a good alternative to the 4350s, just a tad faster burning possibly.

The information on the ELD-M jump is appreciated. I've just loaded 50 rounds up using three different seating depths. I had no luck at all with the 168 Berger VLD either - when I get the opportunity, I'll try the Berger VLD jump sequence to try to find a usable setting.

I've just started a series of tests for H4350 potential replacements using my 7-08 as a test-bed with the Sierra 160 TMK as we cannot get this powder anymore. We have nine possible H4350 alternatives available here, ten once Viht N555 arrives - tested two yesterday. I'll have to see how we go though as a near 100% coronavirus lock-down threatens. Most British clubs and many ranges have already closed until the emergency abates.

 

[Ripa]

Dear Laurie

Cant get Lovex in Sweden, Norma 204 should be an alternative but I don´t like Norma (the cost performance ratio), it is Nitro powder with potential temperature sensitivity and barrel wear. According to RS own home page the RS62 should be temp. sensitive but it doesn't look that way in my winter testing below freezing point with the 162 ELD but more tests must be made.

Sorry for crashing in to my own thread.

Aim at the Corona and stay healthy
Mats

 

[Ripa]

Dear Laurie,

an update for what is is worth, best loads:

162 ELD M with RS62
Palma case
KVB 223
0,15-0,20 mm from the lands
46,7gr 837 m/s SD 2m/s 10 deg C and 845 m/s at 24 deg C
Group size appr. 12 mm with the same group size and POI between 46,7-47,1 gr.

150 Scenar with RS62
Norma case
KVB 7
0,25 mm from the lands
47,4 gr, 882 m/s, SD 1m/s at 12 deg C
Group size appr. 8 mm with the same group size and POI between 47,0-47,8 gr.

Krieger barrel 700 mm.

Normally I would not give my data on a forum but the cases is full of powder so you cant reach max pressure according to QL witch seams to be accurate with the notes i have.

Yours sincerely
Mats Nyström

 

[Laurie]

Thanks for that Mats. A lot of jump there! (Still to get back onto the range for testing - we're only just resuming matches from 1st August in my main club under social distancing rules.)

 

[Ripa]

I have waited a long time to get my hands om some more 162 ELD - M. I wasn’t happy with the result before so i started a journey into the lands and it paid off.

With the ELD 0,75 mm/ (0,029") I have shot five, four shots groups under 5 mm/0,2” at 103 (113 yards) during load development.

The 708 with 150 Scenar has delivered verry well the last two seasons, but my brain doesn’t seem to cope with the pressure from competitions, many stupid mistakes as friendly fire, not shooting enough bullets and simple shooting errors, but the scores when the bullets hit the target was nice. If the brain starts to work, I look forward to the next season with the 162 ELD.

Have a nice day

 

[Delfuego]

Friends don't let friend shoot hornady...

 

[moorepower]

Friends don't let friend shoot hornady...

I agree, shooting cheap bullets in the .2's is a waste of time!