505 Gibbs - Reloading Advice Needed

[DWB]

Good Day Gents,

I have a friend who recently acquired a 505 Gibbs.

He is getting a lot of conflicting information on reloading for it.

He has tried a 600gr Monolithic Brass bullet with 112gr N560
This gave him a speed of 1935fps with a definite click-bang effect. (Delayed firing)

Can anyone advise on the correct method of loading for this beast?
Are the use of fillers required or advisable?
If so, which fillers?

Many Thanks!

 

[John Telford]

Click bang sounds like primer. 112 gr of N560 should fill case about 81% . I would try the primer in an empty case first to see if there is still a click bang. If these are ok then up the load to87% fill and then work up from there I the usual same manner. As an example only and not verified in your rifle it could be loaded to 120gn N560 for 2000fps using 600grn woodleigh pp. I have a good recipe but it is for South African powder.

 

[DWB]

Thanks John. We are in SA, so fire away!

 

[Luederitz]

The 505 Gibbs is an overbore caliber, is you consider the enormous case capacity. In my reloading book only 525 grs bullet weight is listed.
The writer suggests very progressive powders, N165, H1000, IMR7828..
With 525grs bullet and 135 grs of N165 approx. 2200 fps should be realistic. With H1000 or IMR7828 up to 140grs powder can be used to fill the case.

If you recognized a delayed firing this could be an indication of the so called SEE (secondary explosion effect) which can be dangerous and is an indication of a fill factor, which is too low.

What is the most progressive propellant of Somchem you might buy and do you have any burn rate comparion to other powders?

 

[DWB]

Thank you. The slowest burning powder we have with Somchem is S385.
Unfortunately Somchem's powders are not available right now, but we are fortunate enough to have access to some international powders I.E. Vihtavuori, Hodgon, Reloder etc

I think he was definitely running too low a fill factor and also not far enough up the pressure curve for thins to work like they should.

 

[Ike85123]

A hotter primer is needed in most 505's ive seen reloaded. Seems the standard isnt the standard?

 

[Aussie_Hunter]

Woodleigh manual lists Alliant RL15, 19, 22 and 25 data. Which Alliant reloader do you have?

 

[DWB]

Thank you all.

We should have access to all the RL powders. I actually sent him the Woodleigh Manual's info last night as well.

They seem to have worked out a load that looks sensible on Quickload with RL16.

Any advice on fillers to use?

 

[Aussie_Hunter]

Thank you all.

We should have access to all the RL powders. I actually sent him the Woodleigh Manual's info last night as well.

They seem to have worked out a load that looks sensible on Quickload with RL16.

Any advice on fillers to use?

If you have access to All Alliant RL powders, I would use RL19, 22 or 25 and forget about fillers.

 

[DWB]

Thank you, seems like the biggest issue with the slower powders comes to the inefficiency when considering the amount of powder burnt as per QL predictions.

But I will pass on the information.

Are you all still of the thought that the max pressure for this cartridge is at 41000Psi?

 

[krish]

I have been trying on and off with 600gr woodleigh weld core with different powders. 145gr of RL25 don't give the 2200ft/sec velocity. 150gr of 50 BMG don't burn completely. Tried some military powders with no good results. I use federal 215 primer. It looks like 145 gr seem to be too much for fed 215 with slower powders. I just got few RL 23 CANS. Going to try that. I want 95 to 100% full of powder. Don't want to use fillers unless absolutely have to with a hotter. powder which will burn completely through 25 inch barrel. Again I have to try it when weather gets warmer. Is there a hotter primer ?
May try the new IMR Enduron powders.
Krish

 

[Ike85123]

I have been trying on and off with 600gr woodleigh weld core with different powders. 145gr of RL25 don't give the 2200ft/sec velocity. 150gr of 50 BMG don't burn completely. Tried some military powders with no good results. I use federal 215 primer. It looks like 145 gr seem to be too much for fed 215 with slower powders. I just got few RL 23 CANS. Going to try that. I want 95 to 100% full of powder. Don't want to use fillers unless absolutely have to with a hotter. powder which will burn completely through 25 inch barrel. Again I have to try it when weather gets warmer. Is there a hotter primer ?
May try the new IMR Enduron powders.
Krish

WLRM seem to be hotter in some applications. Would be interesting to see the heat index between them,cci250 and fed215 within the 505 case. Open space and all?

 

[Jesse1192]

I have been trying on and off with 600gr woodleigh weld core with different powders. 145gr of RL25 don't give the 2200ft/sec velocity. 150gr of 50 BMG don't burn completely. Tried some military powders with no good results. I use federal 215 primer. It looks like 145 gr seem to be too much for fed 215 with slower powders. I just got few RL 23 CANS. Going to try that. I want 95 to 100% full of powder. Don't want to use fillers unless absolutely have to with a hotter. powder which will burn completely through 25 inch barrel. Again I have to try it when weather gets warmer. Is there a hotter primer ?
May try the new IMR Enduron powders.
Krish

RL 23 is the way to go. I load 140.4gr behind the CEB solid for 2410 fps and 138gr behind a Barnes TSX for 2425 fps. No issues whatsoever. It worked better than RL22 and RL25.

 

[Jesse1192]

I have been trying on and off with 600gr woodleigh weld core with different powders. 145gr of RL25 don't give the 2200ft/sec velocity. 150gr of 50 BMG don't burn completely. Tried some military powders with no good results. I use federal 215 primer. It looks like 145 gr seem to be too much for fed 215 with slower powders. I just got few RL 23 CANS. Going to try that. I want 95 to 100% full of powder. Don't want to use fillers unless absolutely have to with a hotter. powder which will burn completely through 25 inch barrel. Again I have to try it when weather gets warmer. Is there a hotter primer ?
May try the new IMR Enduron powders.
Krish

 

[krish]

How many grain bullets ? And what kind.

 

[Jesse1192]

How many grain bullets ? And what kind.

Cutting edge bullets solid and barnes tsx. Both 525gr.

 

[CJW]

May the Schwartz be with you when you touch that thing off.