View Full Version : What are the reloading differences between a 10-12 gauge?
May 10, 2010, 08:00 PM
What is the difference between a 12 gauge 3.5" using 1-3/8 oz shot-2 shot at 1550fps
and a 10 gauge 3.5" using 1-3/8 oz shot-2 shot at 1450fps?
These are both steel shots.
Do they both have the same amount of steel pellets in each shell?
Do they both have the same amount of powder?
If you were to reload these shells how would they be different?
I would assume the 12 gauge is more powerful here but I thought the 10 gauge was suppose to be more powerful.
May 10, 2010, 08:18 PM
Just ask the goose that got hit with the 10 guage whether it kilt him any deader than the 12 guage with the same 1-3/8 oz. load of #2 shot. I doubt he noticed the 100 fps velocity difference.
I know nothing about the 10 guage, I load 12, 16, and 20. Just yankin' yer chain a bit up there, but one can load as light or as heavy as you choose, within limits of the gun. I'm guessin' that one could load the 10 up even further than 1-3/8 oz, in fact my LYMAN shotshell book starts 10 guage loads at 1-5/8 oz., and the heaviest 12 loads are 1-3/8 oz. So one is comparing the upper end of the 12 with the lower end of the 10 loads. You can do the same comparisons with light 12 loads and heavy 20 loads.
May 10, 2010, 08:42 PM
Greetings reelfisher10, and welcome aboard.
If you're going to load a 3-1/2" 10-ga with steel, why would you restrict it to a 12-ga equivalent load? For a comparison (from the Alliant Powder Guide), how about a 10 ga. with 1-5/8 oz. at 1310 fps and 10100 psi using 37 gr of Steel powder versus a 12's 1-3/8 oz at 1485 fps and 12600 psi using 41.5 gr of Steel.
The 3-1/2" 10-ga is more efficient than the 3-1/2" 12-ga. I uses less powder at lower pressure. Since it's most likely going to be in a heavier gun, the 10-ga delivers more with a lower kick. If you're wanting reload a lot of steel, then the 10-ga is your better bet.
Powerful? Does that extra 1/4 oz of steel make a big difference?... As okiefarmer said, ask the goose.
May 10, 2010, 09:11 PM
I restricted it because I was comparing two MANUFACTURED shot shells.
I have looked at the heaviest 12 gauge manufactured and it was 2 3/8 oz at 1210 fps. And the heaviest 10 gauge was 2 1/4 oz at 1210 fps. I am not understanding how the 10 gauge is more POWERFUL. So I assume by manufactured shells the 12 gauge is more powerful but for whatever reason if you wanted to you could SAFELY make the 10 gauge more powerful through reloading?
Also whats the reason for a 12 gauge 3" 1 3/8 oz shot at 1450fps and a 12 gauge 3.5" at 1 3/8 oz shot at 1500fps. These are both the same brand. What is that extra .5" doing? Giving it the extra 50 fps? That's what everyone is always complaining about when shooting a 3.5"? Or this this just a bad example and not all manufactures are this retarded? because the 3.5" is like $5 more just for 50fps.
So if it says 1 1/4 oz shot that just simply means that the weight of the shot (pellets) weighs 1 1/4 ounces?
Oh and I am not trying to say the 12 gauge will pattern better or saying a goose will say oh **** that is a 12 gauge remington shooting at me with 1 3/8 oz shot with a winchester primer. Just simply trying to understand which one is more powerful.
May 11, 2010, 02:39 AM
reelfisher10, sorry if I misunderstood your initial question, I thought you were thinking of re-loading with steel shot. Your question seems to be: Why do 12 ga 3-1/2" shells seem to be more powerful than than the 10 ga (3-1/2") loads? You've observed that with similar maximum loads, the 12s are at a higher velocity. An interesting observation and question.
By outward appearance, the average shooter will assume the larger diameter 10 ga is obviously more powerful that the smaller 3-1/2" 12 ga. But, what is meant by powerful? Obviously, the easiest way to make a comparison is using the muzzle energy of the maximum load from each shell. Given the same load weight, the faster one will have a greater muzzle energy and thus is more powerful.
I have looked at the heaviest 12 gauge manufactured and it was 2 3/8 oz at 1210 fps. And the heaviest 10 gauge was 2 1/4 oz at 1210 fps. I am not understanding how the 10 gauge is more POWERFUL. So I assume by manufactured shells the 12 gauge is more powerful but for whatever reason if you wanted to you could SAFELY make the 10 gauge more powerful through reloading?It all has to do with the allowable pressures. The 12 ga 3-1/2" Super-mag is a much newer shell than the 10 ga. So, the newer guns chambered for the new shell are capable of higher working pressures than old 10 ga guns. Typically the bigger the bore, the lower the alllowable working pressure of a shotgun -- the new 12 ga 3-1/2" is an exception.
Here are the SAAMI specs for Shotshell Maximum Average Pressure (MAP) in PSI.10 gauge 11,000
12 gauge 11,500 (except 3-1/2")
12 gauge 3-1/2" 14,000
16 gauge 11,500
20 gauge 12,000
28 gauge 12,500
.410 bore 2-1/2" 12,500
.410 bore 3" 13,500
The loads you'll find in reloading manuals take the MAP specs as Gospel. Since the 12 ga 3-1/2" Super-mag can be safely loaded (or re-loaded) to higher pressures than the 10 ga, it's quite understandable that it can accommodate more powerful loads. (It's a similar situation with the new compact 7mm mag rifle cartridges being more powerful than the larger, but ancient, 7mm Mauser -- the newer rounds are safely loaded to much higher pressures.)
Back to your specific questions:
So if it says 1 1/4 oz shot that just simply means that the weight of the shot (pellets) weighs 1 1/4 ounces?Exactly. But, for "equal" loads you have to be talking of an ounce of lead to an ounce of lead. Once the load clears the muzzle, lead, steel, and the non-toxics will behave differently.Do they both have the same amount of powder?Not necessarily. Different powders release there energy at different rates. For Steel Powder, in some loads, the 12 ga takes more powder than a similar 10 ga load. With Blue Dot, it may be the opposite.If you were to reload these shells how would they be different?It's basically the same process. Since the 10 ga are a little larger in diameter they may be easier to handle and go a little faster. However, popular high-volume re-loaders like the MEC 9000 and Grabber are not available in 10 ga.
As you intimated, don't base you selection by "power" alone. How the gun fits, handles and performs on the patterning board are important factors to be considered. Shooting 12 ga 3-1/2" Super-mag high pressure loads is an experience many choose to avoid.
I hope this answers your questions satisfactorily.
May 11, 2010, 11:57 AM
Ok that makes sense. But you said the OLD 10 gauges.. What about a new 10 gauge browning bps? I would assume they use better material or methods now for making those barrels but will the CURRENT 10 gauge barrels handle higher pressures than that of the 12 gauge 3.5"? So in other words a browning bps 10 gauge barrel is made a lot different than the bps 12 gauge barrel in terms of NOT allowing as much pressure?
May 11, 2010, 01:34 PM
What I meant by "old 10 ga" was the standard ammunition specification. The commercial ammo available has to be safe in all 10 ga guns, new and old. Of course, you can re-load 10 ga shells to exceed a MAP of 11,000 PSI that may function flawlessly in a modern 10 ga like the BPS. However that same ammo could prove catastrophic if used in an old 10 ga gun. Like new factory ammo, the reloading data observes the MAP specs, too. To load above those levels, you're on your own.
…will the CURRENT 10 gauge barrels handle higher pressures than that of the 12 gauge 3.5"?Quite possibly. Something similar happened with the old .38 S & W Special revolver cartridge cartridge. Many owners of newer guns re-loaded to higher pressures than allowed under the standards. This became so popular that the reloading data started listing the hot loads with the proviso that it be used in only certain newer guns. I'm sure you've seen such loads in the reloading guides. Eventually the manufacturers became aware of the practice and re-wrote the SAAMI standards to include .38 +P loadings. Quite often, it's the re-loaders who are responsible for the development of new cartridges and loadings.
At many gun clubs, there is a group of trap shooters known as the Boomer Boys, or something similar. Their specialty is extra-long yardage trap shooting. They will frequently make their appearance after the regular trap shooters are done for the day. A few dollars may be tossed in a pot by each shooter to reward to best shot of that event, hence the term pot shooting.
Many of the pot shooting Boomer Boys are of the opinion that the data in the reloading guides is too conservative. And, as you speculated, they load to the capacity of their specific gun, not the SAAMI specs. You'll often hear references to quantities of Blue Dot powder that are greater than can be found in any guide. Who knows, we may someday see +P shotshells.
So in other words a browning bps 10 gauge barrel is made a lot different than the bps 12 gauge barrel in terms of NOT allowing as much pressure?
I suspect there is not much difference between a BPS 10 ga and 12 ga barrels' actual construction. Remember, it's the loading of the shell that determines the pressure. There's nothing in the barrel that allows or prevents pressure, either it functions within it's design parameters or if over-stressed it may fail. Remember, it's not just the barrel that resists the pressure, but the entire assembly. With pump guns, like the BPS, I suspect the manufacturers purposefully design them to fail at the bolt locking device. That way an overpressure incident results in the bolt latch failing within the receiver, not the barrel bursting. The only incidents of burst barrels, that I'm aware of, were do to an obstructed barrel, not an over-pressure load.
I've personally had only one over-pressure failure: A fellow shooter wanted me to try his O/U and give him my impression of his re-loads. He neglected to tell me that he was experimenting with boomer loads. It was at Skeet's high-7, an easy incoming target -- I pulled the trigger, there was a loud bang, I felt a hard kick, and the target vanished in a cloud of vapor. When I tried to open the action, the lever wouldn't move and there was a significant gap at the breech. The gun was toast, but there was no sign of overpressure in the barrel.
May 11, 2010, 08:36 PM
If a person was asking about 10ga reloads compared to 12ga. The modern 10ga will outperform the 3 1/2" 12ga. 1600fps 10ga 1 3/8oz loads are out there in reloading books in the 10,000psi range. in the 3 1/2" 12ga there are 1600fps 1 1/4oz loads at 13,000psi out there. the 10ga is better suited for large shot BBB is what i use most of the time. But i load #1 steel for ducks on combo days. For factory 10ga ammo the 1 1/2oz federal 1450fps loads are the best steel loads. I also have reloading data for 1 1/2oz 10ga at 1500fps plus. It comes down to patterns and recoil, brutal recoil from the 1 1/2oz loads and modified patterns. The 1 3/8oz loads are not bad on recoil and they pattern extra full. Ineffect you get more pellets on target with higher velocity with the 1 3/8oz 10ga loads.
May 12, 2010, 07:55 PM
How much powder would you use for a 1450fps 1.5 oz steel shot? I want to know so I could run a calculation to see how much each shell would cost. And what type of powder do you use? I've read you want to use a slow burning powder when shooting steel out of a 10 gauge (or any gauge I guess). Longshot or HS-6?
I have also read bad things about steel loads going over 1500fps in gun loading books. They all seem to say it does nothing positive for patterning or it can do slight damage overtime to your barrel.
May 12, 2010, 09:21 PM
The reloading guides don't always give you exactly what you're looking for. Here's what the Alliant Reloader's guide has that's closest to your spec:
For 1-1/2 oz Steel shot:
RemPlastic SP hull, Rel Spec SAM 1 10-ga wad, Fed 209A primer, 1/8 spacer and 45 grs of Steel powder will give you 1479 FPS and 10100 PSI
Fed Integral BW hull, Rel Spec SAM 1 12-ga wad, Fed 209A primer, 1/4 spacer and 39 grs of Steel powder will give you 1390 FPS and 13300 PSI
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