doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com .410 reloading question

One hundred and twenty years ago, a .40-85 primed empty was the answer --

I agree shot string does not mean longer will not pattern well on a plate and kill Dove just fine, but I do not like slow loads given a choice. I worry more about pressures. SAAMI .410 3" max. is 13,500. Based on Winchester Super X HS 3/4 ounce loads pressures run 13,100-13,500 PSI with velocity of 1100 FPS. Same hull with 11/16 ounces shot can not reach 1200 FPS without pressures reaching near max as well. You can drive 5/8 ounce shot slightly above 1250 FPS at slightly under max pressures but that load is lighter than you want.

Then the question is what will a larger volume hull give you? More room for sure, but is that going to be enough? You may need a slightly wider wad to seal the hull so you do not get blow-by. So no PC orange as they are the smallest diameter, followed by Remington, Federal and then old AA and new HSAA. I would start with the HSAA. Do not know off hand about some of the Euro wads, but in general they do run wider to seal straight wall hulls better. Hard enough shot should be OK without a full shot cup to protect it. You might get 3/4 plus, maybe 13/16 ounce to fit. But can you get velocity and keep pressures in line? After that how do they pattern?

Only way to know is load some and have them tested for pressure and velocity. It will need to be 300MP. I have found LilGun, 410 and 296/H110 loads run higher pressures than 300MP, by a lot. I do not know the pressure curve and how quickly it climbs. But you can load 3" Remington hulls with 11/16 to 1200 fps at 9000PSI with 300MP, Lil Gun will be 1175/13,500 range, 296 will 1135/12,800. So that should give you a starting powder and range of loads to work with. You could also look at 4227, 2400, Herco, Unique or 452AA none of which would be my first choice for various reasons.

The other question is what will be the difference in pressures between a brass hull and a plastic hull? Brass will not flex as much so will that increase pressures? Again the only way to know is load and test some. Also what type primers will you be shooting? That will alter pressures a lot. Do you plan on using a large rifle primer? I did read one report about wad sizes and cards to compensate for wad lack of good seal. "Whenever assembling metallic .410s with plastic shotcups an over-powder card MUST be used. This is necessary because the plastic shot cup diameter is too small to seal the interior case wall, such that omitting the over-powder card results in powder leaking past the wad, causing “bloopers.” " Again start with HSAA and you might not need a over the powder card.

All very good points, AGS and Jon. Thanks much for sharing your thoughts on this. Any untested loads would definitely be sent to Armbrust for pressure and velocity testing. Jon, you and I both have lots of experience using .410s in the field, and I respect your opinions on this. I would, however, prefer to keep the velocities at 1200 fps or less. Why? Because I have found that most of my S X Ss are regulated with heavy-for-gauge payloads at lower velocities. I have seen some drastic crossfiring of S X Ss when they are fed lighter payloads at higher velocities.

I will definitely save your loading suggestions if I decide to chase this rabbit. I may decide to be satisfied with my .73 ounce load of nickel plated 8s at 1175 fps. It has really been shown to be a clean killer for me. TBH, getting the rims cut down on a lathe and opening the primer pockets on 100 cases does not sound very appealing to me.

Thanks.

Stan, I wonder if a lighter, or heavier load will both keep convergence at the same speed? Is it the speed or weight of payload that causes the issue, or a combination? It might be fine with a lighter load, going fast, or a heavier load, going slower. You might have discovered slow and heavy is the same as lighter and fast. More likely they used 1/2 ounce loads to set convergence than the harder to find 3/4 ounce loads. If you would just learn how to pump one of my 42 pigeon grades convergence would not be a problem. But with doubles you do have it working, your sweet spot, stay there. Your seems to be about 1200 fps.

Yes, we both enjoy using a .410 for Dove. It is also my default Sporting Clays gun which gives me a lot more shooting chances than just Dove. For me I don’t think an extra 1/16 ounce shot will gain me more than 3-5 yards, if that. But I also am trying to stretch it out to begin with. You know I am happy using a full choked .410, out to a measured 30-33 yards for Dove. Sporting Clays you can take longer shots because there is no worry about not cleanly killing the bird. All hits, that make a chip or better are scored the same.

Knowing your exact distance is key. I’ve seen a lot of shooters, who pride themselves with their 50-60 yard shots, which measure 40 yards at most. Worse are those who measure to where the Dove is recovered, not where it was shot. The real math gets bigger the longer the shot. If I can keep leads in the 5-6’ range I can do well, stretch them out just a couple more feet and I don’t. The .410 patterns just whimpers out for hunting.

I agree this is an interesting problem. Guess first step is fire forming a bunch of shells. Be aware that if only the upper part is annealed the lower half will not fire form well. So you might end up with a bit of internal taper which will create a wad sealing issue. Might be inconsequential as the wad sealing in the taper should continue to seal as the shell and bore gets larger. It might even make all wads usable but I would stick to the larger diameter wads. You testing will tell you in that if the wads seals well, there will be little variance in speed and pressure because you have no blow-by. If you do get blow-by, a card over the powder may be needed under the wad.

Will Armbrust test brass loads? Precision no longer accepts brass loads. Gil

Stan,
You would be surprised how much you can do with a drill press or even a 1/2" "drill motor" in a vise and a file until you get a lathe. A lathe is a necessity of life, even if you don't hand load. Anyway, with only .005" difference, manufacturing tolerances in the rims vs. the chamber/headspace may allow 9.3 cases to fit (cases have to be the same or smaller and the chamber has to be the same or larger than the listed standards).
Mike

Maybe the solution is to install a cup into the shot load at the top of the shell with the open end in the shell to contain more shot. Don't ask me how to keep the shot from spilling out as you install the cup. Possibly slotting the cup, installing shot through the slot, then pushing the cup into the shell with the slot inside the shell? This method would eliminate the use of a different case. Jon's suggestion to try Unique, Herco, or AA452 is a bit confusing since all are way faster burning than the 410 powders and would raise pressures into the stratosphere with a 3/4 ounce load or heavier.

You can use those powders to fireform. There also are loads for shot using them. I think 300MP is a much better powder to start off with.

Might be sort of fun to try 40-50 grains of Swiss 3fg. The larger volume would be especially useful for black powder loads.

I use 300MP, Win 296 (H110?) in .410 TSS loads. Lead/TSS load recipes aren't interchangeable. An equal weight of TSS is almost half the stack height of lead due to density disparity, Gil