doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Source for low pressure 2.5" 16 gauge?

Larrry, his gun was built in 1878--144 years old. The loads you mentioned are most likely right up to SAAMI limits and I bet a dollar to a donut that his gun isn't built to take them. Gil

I have a Brit 16 gauge (Harkom) that has 2-1/2 chambers and is proofed for 3 tons. Have owned this gun for years and have experimented with 2-3/4" and 2-1/2" hulls and loads. Frankly, a low pressure load, regardless of whether it is loaded in a 2-1/2", 2-9/16", or 2-3/4" hull, is still a low pressure load. Loads for a 16 bore can produce pressures as low as 7000 psi.

In Fact, Stanbury and Carlisle in their book, Shotgun Marksmanship (page 35) stated, "...The length of a cartridge is not the same as the length of the chamber, but, with rolled turn over cartridges, the length of the FIRED case is the same as the length of the chamber. With some crimp closure cartridges the length of the fired case is actually longer than the gun chamber; for instance, a number of 12 bore cartridges intended for 2-1/2-inch chambers have cases which are 2-3/4-inches long. {...} the finished cartridge is only 2-1/16-inches long when crimp closed, as some of the tube is used in the closure..."

It is reasonable to assume from this that one may load a 2-1/2-inch LOAD into a 2-3/4-inch case and that this is, in fact, commonly done with factory 2-1/2-inch cartridges. I have done this for years for both my 16 bore guns, including the 2-1/2" Harkom. If you want to play it extra safe - cut the hulls off at 2-9/16" and use a roll crimper and overshot card.

Here's a recipe that I use for LP 16's in 2-3/4" WW16 CF hulls...

WW CF 1 oz. SR 7625 20.0 gr WW 209 Rem R-16 1155 fps 7,000 lup HSR

Any 16 gauge shooter, if he does not handload, is at the mercy of manufacturers and the market. Doubly true for those who own guns with short chambers.

Keep checking with RST. They have had 16's and 20's off and on for a month now

My reference is to the empty hulls, not to the factory loads contained in those hulls. If we're talking American factory loads, I wouldn't recommend shooting any of them in that gun other than the 2 1/2" shells from RST. However, I had a 7/8 oz load using the previous Herters hull tested. Average pressure: 7420 psi. That's well below 16ga SAAMI limits. With the new (and shorter) Herters hulls, I've reloaded them as well--compensating for the shorter hull by dropping down to the next smaller powder bushing. Everything else in the load the same as in the old Herters. I've shot them in a vintage Parker with 2 9/16" chambers and the hulls don't show any damage due to the slightly shorter chamber.

Being more careful is ok, and preferred over gambling blind.

While the min wall maybe .040, another consideration is min wall at the chamber. While different recommendations exist and it does depend on the steel itself my recommendation is to not lengthen chambers if you would reduce to .095 or less, in a Damascus 16, further more wall thickness is good, if were fluid steel you might go to .090 but I would not.

Thin walls, which you do not appear to have down the barrels, are not in you face, thinner walls created by lengthening the chamber are in your face literally when you shoot.

Much has been written about shooting 2 3/4 in 2 1/2 chambers and the potential increase in pressure. Will it be a increase of 1-200 PSI or more, I can’t say, I don’t know and neither does anyone else for an individual gun of a particular bore size, different forcing cone, the particular Shotshell material etc. Have I shot longer hulls in short chambers, of course I have; Mostly in blissful ignorance.

Today I cut down longer hulls and roll crimp with a harbor freight drill press, cheap but effective.

Most 1oz 2 3/4 loads can be done in a cut down hull roll crimped. Longshot appears to be easier to come by though you may be able to find anything at gun shows if you are will to pay high prices.

As for a load I recommend for 16 2.5 in:

Cheddite hull 2.5 inch roll crimped, 21.0 Longshot, SG16 wad, 1oz lead, Cheddite Primer, 7,600 PSI, 1190 FPS

REM Black hull 2.5 inch roll crimped, 20.0 Longshot, SP16 wad, 1oz lead, Cheddite Primer, 7,500 PSI, 1210 FPS (might need some cheerios in the wad cup to fill space)

Fed 16 hull 2.5 inch roll crimped, 19.0 Longshot, Activ G28 wad (also called SG16 wad), 1oz lead, REM STS Primer, 6450 PSI, 1170 FPS

Make sure you properly crimped, a roll crimped under done turns into a blooper.

Unfortunately with ammo choices and availability reloading is the best way to go.

If you really get into shooting this gun then buy 30 RMC 2.5 inch brass hulls. I have found them addictive, but very expensive. Further they will expand (fire form) to your chambers and if you have a variety of 16s you may find them usable once fired in only a few of your guns. That said, they last forever and I have some reloaded hundreds of times.

Haven’t had 1oz 16,s

I have no intention of lengthening the chambers. I currently reload 16 g 2.5" for a fluid steel Rigby, but was hoping for the extra margin of safety of using factory ammo. Reloading my own ammo was my fall back option

I have Cheddite hulls & primers, I've been using the BPI SG16S wads and roll crimp using a drill press. I've been using Clays (just recently opened the 8lb jug) for the loads for the Rigby and I have about 4-5 lbs of Longshot. I've shot the gun with 2f black powder. Hopefully I won't shoot the gun TOO well, the current plan is to shoot a round or 2 of skeet with maybe once a month. I have other options for higher volume skeet shooting.

I ordered a case of RST, with my luck they'll show up Monday, the day after the 5 Stand shoot

Ross Sefried & Hodgdon Ballistic Labs, DGJ Summer 2021. Ten 16g loads that will work just fine.

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Thanks for the reminder, I had sort of forgotten that article contained 16 g articles. Definitely miss DGJ