Question about Backer rod in large volume cases

[Backyardsniper]

I am about to start reloading for my 500 Jeffrey. I understand that some loads with this round require a filler, in particular it seems the 100gr of Varget with a 535gr bullet. Either way I understand a lot of people use foam backer rod as a filler. I picked up some but I want to be sure it is the correct one. This one says do not expose to heat or open flame. I want to make sure I have the correct one because I don't want to melt foam to the inside of the barrel. I don't know if that is even an issue but I'm not trying to screw up this new rifle. I will most likely be using H4350 anyway but I think the varget will work well with the 510 CEB solid and the 475 CEB Raptors since it is a faster powder. With those bullets though I expect to be in the 103-105 grain range. I'm also curious to try RL16 in it. Same burn rate as H4350 but fluffier. It does create a bit more velocity so I drop it down by about 10% from the book charge for H4350. I also ans curious if CFE223 will work. It is a bit slower than varget and is a ball powder. It is very close to BLC-2 amd W 760. I will attach a pic of the backer rod I purchased

 

[AZDAVE]

I used that kind of backer rod in a 577BPE and 500BPE with no problems. You might want to shoot one or two and then use a bore scope to inspect you barrel for deposits. Don't forget to weigh the rod as it is part of the weight of the bullet. in a 500 jeff would just skip the loads that don't fill the case enough and just shoot with the powder that gives you proper load density.

 

[AZDAVE]

I forgot to also say that in the 577 and 500 I eventually settled on a couple squares of toilet paper compressed on top of the powder as my filler.

 

[Huvius]

That is what I use for my nitro for black and reduced loads.
You may want the 5/8" for the 500 Jeff - thats what I used in my 577/500.

Also, I normally twist the backer rod into the case down to the powder and trim even with the mouth letting the bullet compress it as it's being seated.
Just easier that way rather than cutting to a specific length to meet the base of the seated bullet.
Both methods worked with no difference in performance.

 

[93marlin]

I've used backer rod and toilet paper in my 500bpe. With the TP it looks like it's snowing in front of the muzzle!
I settled on 1/2 inch backer rod. With my ancient(late 1870's) Pryce double the rifle groups around 2 to 2 1/2 inches at 50yds.

 

[Backyardsniper]

Excellent. Thanks guys. I appreciate the help. I'm headed to Lowe's now to get lumber to construct a new reloading table and mount up this Rock Chucker. I may indeed skip the ones that don't fill the case, but I have a bunch of varget. I also have a BUNCH of CFE223 which is similar in burn rate to W760 which has listed loads for the 500 Jeff. Also have H4350 and RL 16. I will keep you all posted on the progress.

 

[Aussie_Hunter]

I use around 2 grains of open cell foam in my 470 Nitro Express as a filler with RL17 and it's the most accurate load I have worked up.

 

[frog stealer]

I use around 2 grains of open cell foam in my 470 Nitro Express as a filler with RL17 and it's the most accurate load I have worked up.

I second open cell foam as well. I've used the same backer rod from Lowes as pictured above (closed cell) without any issues, but I think open cell foam (Kynoch wads) are more consistent. The Kynoch wads are expensive, but in my opinion, they are the best. I bought several hundred dollars worth through Trader Keith, and need to order some more!

 

[Backyardsniper]

I will give trader Kieth a call and order dome of those. I would rather have the right stuff.

 

[frog stealer]

I will give trader Kieth a call and order dome of those. I would rather have the right stuff.

Check out their cotton safari rifle slings as well, they are top notch!

 

[michael458]

I have a good friend that is a very serious double rifle shooter. We did quite a bit of Double Rifle work some years ago. One of those bodies of work dealt with different types of Fillers and how they effected pressures. He is a very big fan of the foam backer rod and wanted to test it against other common fillers. We did so with 470 Nitro and RL 15. Here is what we found;

 

[93marlin]

I have a good friend that is a very serious double rifle shooter. We did quite a bit of Double Rifle work some years ago. One of those bodies of work dealt with different types of Fillers and how they effected pressures. He is a very big fan of the foam backer rod and wanted to test it against other common fillers. We did so with 470 Nitro and RL 15. Here is what we found;

View attachment 473013

I think I'll keep using foam backer rod!! That's quite a difference..

 

[rdog]

Have you thought about using Trail boss powder with out the need to use filler ? i use it in my 303British & 9.3x62 for soft loads there is info on its use on line.

 

[degoins]

Very interesting and shocking at the difference between backer rod and dacron. I've used both and saw no difference in accuracy. The backer rod is much easier to use and now that I see how much less pressure than the dacron, I wont be using the dacron any more. Thanks for sharing that.

 

[Backyardsniper]

When using the backer rod has anyone had what looks like deposits from the foam on the back of the case after firing? I was working up a load to regulate my 470 today using the purple foam pictured above with 94 grains of H4350. I had some foam on the outside of the case neck after firing. I was able to wipe it off by hand and I suspect that bore solvent that is intended to melt copper will definitely clean out any deposits left from the backer rod, if any, but I was curious if anyone else had noticed that?

 

[93marlin]

That's the same backer rod that I use. I haven't noticed anything like that.
It may have something to do with larger amount of powder that you are using compared to what I'm using.
Just a thought...

 

[frog stealer]

Never had any remnants of foam after using in my .450 3-1/4”, though this was at bpe pressure levels. I was using the exact same backer rod as you are.

 

[Backyardsniper]

I figure it will be all right then. I will probably make it a point to give the barrels a little scrubbing after each outing. I can't imagine that it will hurt anything though. I will probably order some of the Kynoch ones just to test them side by side and see if there I'd any difference

 

[93marlin]

That's the same backer rod that I use. I haven't noticed anything like that.
It may have something to do with larger amount of powder that you are using compared to what I'm using.
Just a thought...

And I'm also using BPE pressure's

 

[frog stealer]

I figure it will be all right then. I will probably make it a point to give the barrels a little scrubbing after each outing. I can't imagine that it will hurt anything though. I will probably order some of the Kynoch ones just to test them side by side and see if there I'd any difference

Yeah, I think what you are seeing is harmless. NE rifles (even nitro) operate at comparatively low pressure. I think you’ll like the Kynoch wads, expensive but more convenient compared to backer rod.