Buffered Shotshell Filler In Bottleneck Cases

[enfieldphile]

Use of buffered shotshell filler under a cast boolit in bottleneck cases, to achieve 100% filling of a cartridge case has been written up by Veral Smith, articles on www.surplusrifle.com and by others.

Has anyone here used this technique? If so, what were your impressions, results etc.

[451whitworth]

I use it all the time. It keeps the powder where it needs to be which results in velocity low spreads. i use it in the 250 & 300 Savage, 30-40 Krag, 348 WCF.

[Maven]

I used to use quite a bit of it with very slow powders, e.g., WC 860 and IMR 5010 + LR Mag. primers (both propellants) in my .30-06 and 8mm Mau. Accuracy was excellent, but unchanged by the spherical shotshell buffer (SSB). However, standard deviations were markedly lower as was the amount of unburned powder left behind. Other than the extra reloading step and having to store the loaded rounds with their primers up, I encountered no problems with SSB. Nevertheless, you don't want to compress it so much that it forms a plug in the case neck. Btw, it does boost velocity, so you'll need to reduce your powder charge by several grains at the very least. Lastly, search the site's archives for Grex, Spherical Shot Buffer, etc. for [much] more information.

P.S. I used between 0.3cc and 1cc. (Lee dippers) depending on the cartridge in question.

[longbow]

I have not used shotshell buffers but have used COW and cornmeal.

I read the articles on 303british.com, surplusrifle.com, the 6.5 Swede/300 yard milkjug series of posts, Cast Bullets for Beginners and Experts and other sources.

I use filler extensively in my .303's with no problems or worries... just work up your load with filler included.

Longbow

[Wayne S]

Marven,
Other than the extra reloading step and having to store the loaded rounds with their primers up
Care to expand on this ?

[Larry Gibson]

If you read through my 6.5 Swede HV thread you'll see I use a couple kinds; Original and Grex. I also did considerable pressure testing with those loads and found no evidence that it increases pressure from being compressed. I only used it with medium and slower burning powders though. I did not nor do I recommend any filler with the faster burning pistol powders.

In a test of COW in the 45-70 I found it did increase pressures rather dramatically.

I found the use of both to be a PITA and don't use either. I use a Dacron filler which works as well if not better and is a lot easier to load.

Larry Gibson

[Maven]

Wayne S, The extra step is having, or rather choosing to add a filler. Storing the loaded rounds with the primers up is necessary because SSB/Grex will migrate into the powder charge, especially with extruded powders, if you don't (not a good thing!). SSB is a fine granular (somewhere between table salt and refined sugar) substance that's incredibly slippery to boot.

Btw, the handle is "Maven, " no r.

[35remington]

Do NOT use it with fast powders or to fill more than 50 percent of the case or you will have problems.

Prefer Dacron myself as it is much cheaper more available and does not have the fill problems granulated plastic does.

[35remington]

BTW....saying "buffered shotshell filler" is like saying "filler shotshell filler."

The buffer IS the filler. Granulated plastic or poly filler is the term you're looking for.

[Char-Gar]

I do use Precision Shotshell buffer with very slow ball powder (WC872). I would not use it with fast powders and powder charges less than about 75% of case capacity.

[Char-Gar]

Wayne S, The extra step is having, or rather choosing to add a filler. Storing the loaded rounds with the primers up is necessary because SSB/Grex will migrate into the powder charge, especially with extruded powders, if you don't (not a good thing!). SSB is a fine granular (somewhere between table salt and refined sugar) substance that's incredibly slippery to boot.

Btw, the handle is "Maven, " no r.

I would not use shotshell buffer with stick powders. With ball powders and compression it does not migrate.