doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Pressure Variance Between Fibre and Plastic Wads

I've been looking for information on loading smokeless power with fibre wads and it seems few and far between. I'm wondering if I could use fibre wads instead of plastic wads for any reload recipe. Given pressure from a fibre wad is less than plastic, all things otherwise equal, if I choose a recipe with plastic that was within the pressure range I am looking for would I be safe to say if I exchanged it for fibre the pressure would be somewhat less and still safe to shoot?

After spending much of this year learning to load fiber wads, the answer is no. We speak about fiber as if it it is all the same, and the only thing that matters is "fiber". That is not how it works. For example, I created one load that reached 18kpsi using fiber and a reasonable amount of Red Dot.

I concur that the answer is NO, you cannot simply swap fiber wad in lieu of plastic proscribe by the tested data. As the previous poster points out there are more factors at play and your swap could create the same, higher, or even pressures so low the load becomes a blooper.

Variations from tested data are possible, but they require some experience and specific knowledge.

This is interesting. Fibre wads seem less tight than plastic are more frangible so it would appear they have less resistance to sliding out of a shell. Also I have read ‘somewhere’ that fibre wads produce less pressure than plastic. What part am I not understanding ?

I’ve been loading 2.5 inch shells using 3.5 dram black powder with 1 oz shot and fibre wads for years. I’ve never measured the fps or had pressure tested but all seems okay on my guns. Now trying to experiment with smokeless powder.

On another note I know how to experiment with rifle loads and what to look for in pressure and fps. Is there not something to also look for with shotshell instead of sending them off for pressure testing?

Fiber wads are all different and it matters with respect to how well it seals the chamber. They can produce more pressure or less pressure depending on how they are made, whether they are lubed, what sort of lube is done, and all the different options for nitro cards and so forth. There is a whole lot more to worry about than just fiber vs. plastic.

As for testing, something that Tom Armbrust will tell you but Precision Reloading will not, is that the test chamber is really critical, esp with fiber loads. Precision Reloading uses 3" chambers in their 12 gauge test gun. With fiber wads, the data they produce is nothing like what you will see in your shorter chamber. In my case, 2" chambers are almost unbelievably different that 3" chambers so far as velocities produced and (presumably) pressures.

I've been told countless times that you cannot read pressure warnings from spent hulls. Loose or flatten primers mean nothing, nor are there other symptoms of being near the ragged edge of safety. So, it would be best to develop a protocol of how you are going to select starting loads, test them yourself for velocity, and then winnow down the possibilities to a somewhat large set that you will eventually send off to a testing facility.

If you are loading for short shells like 2.5s and 2" 12s, I would talk with Bruce Ducksworth in Mt. Vernon, GA first. He actually tests with short chambers (I think, but am not certain, he has a 2.5" 12b test gun). When you go with fiber, chamber length is critical. I can provide his phone and email. He is a really nice guy that will promptly test your loads for $7/shot (he likes batches of 6 per recipe).

I would like to also load fiber wad ammo for my 2.75" guns, but the amount of information out there is just short of terrible and a lot of what there is, is just bad. After investing over $500 in testing, I learned a lot, and I have good, safe loads for my 2" 12b. I'm sure I could find good loads for the other guns much easier now, but even so, I'm reluctant to take the plunge. It's a good bit of work.

In my late high school and early college days when we were loading Federal paper hulls, the trap load from the Lyman manual was 23-grains of Red Dot a nitro card & two 3/8-inch fiber wads with 1 1/8-ounce of shot. When we replaced the nitro card with the Alcan Plastic Gas Seal (PGS) we dropped the powder charge to 19- or 20-grains of Red Dot.

Reversing this from plastic to fiber and guessing you need another 3-4 grs of RD is where you can get into seriously huge trouble.

In developing 2" 12 ga. loads with all fiber and nitro cards and no plastic, we relied on pertinent information contained in Lyman's reloading manual from 1953. What was important then is important now. The fiber wad seating pressures on the powders listed (only Red Dot is available now) was surprising--up to 70 lbs. We were on a desert island regarding 2" shells--other than 2 higher pressure (8400 psi) loads at Hodgdon's site, no published data in the pressure ranges desired for our old guns. Gil

n working up and testing loads for a 2" gun I also learned quite a bit about fiber loading of shotshells. Also I came upon an interesting paragraph in the Chapter "Unraveling Rivelling" in the book Shotgun Technicana by Michael McIntosh and David Trevallion: "We also have a notion that rivelling is more likely to occur from cartridges with fiber wads than with polyethylene wads, simply because fiber is capable of setting up more friction than the slicker, smoother plastic.(This isn't to say you should avoid fiber wads, but we do recommend that you be extra diligent about keeping your bores clean if you shoot them.)

Can you explain what rivelling is? I thought you meant wrinkling the cartridge walls, which I have not had happen with fiber wads thought it does happen with plastic. But a clean bore would have nothing to do with that, so apparently I do not understand rivelling.