Turning your 12 Gauge Into a 410 Shotgun.
- Thread starter Frontier Firearms
- Start date
well, 41mag 210gr ammo (1/2oz) doubles it's velocity from 2" to 20" so yes, I expect that
hannibal.black98
CGN frequent flyer
Sub gauge inserts are quiet common...they are made for single shot or double barrel shotguns. I have used a 12g to 20g adapter and to me, it shoots just as good as a stand alone 20g shotgun!!!
The ones I used had an o-ring to hold tight into the chamber, had to manually pull out the empty 20g hauls tho.
The ones I used had an o-ring to hold tight into the chamber, had to manually pull out the empty 20g hauls tho.
I feel like thats not a fair comparison though? Wouldn't the gases start blowing by the wad shortly after the forcing cone, negating the potential increase in velocity caused by a longer barrel? A bullet seals the bore until it exits, which allows the expanding gases to continue to accelerate the bullet until it reaches the end of the barrel but I didn't think shotgun wads seal nearly as well which would make a longer barrel mean less for velocity?
With the 12 ga load the pressure behind the wad is still pushing for the entire length of the barrel. 20" of acceleration gets more fps than 2" of acceleration.
But i'd expect the 410 wad fired in a 12 ga barrel would not receive that boost in velocity from a longer barrel. Blow by would be quite severe for a .40" wad in a .70" bore.
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Bluebulldog
Regular
- Location
- Constance Bay ON
But it would be incrementally less as it traveled down the barrel.
A sub-gauge wad and cup with a large gap around it would not allow anywhere near the pressure a regular one would. In the case of a .410 insert in a 12 gauge barrel, there would literally be 1/8 of an inch. Laws of physics would dictate that the gas pressure behind the wad would seek and find the path of least resistance ( around the wad). So, unlike actual full barrel inserts like the ones made by Briley, these essentially are relying on a short amount of travel developing pressure, before essentially having the shot and wad bounce around for the remaining 20" worth of barrel.
An interesting test on the effects of barrel length. Doesn't really help here because their shortest barrel is a 20" and they aren't using chamber inserts but there is definitely some additional velocity with a longer barrel.
https://www.theboxotruth.com/barrel-length-shotgun-affect-velocity/
If these are still in stock next time I order from Frontier I'll definitely get one and try to remember to report back.
I'd love to get both a 20ga and 410cal adapter for my single shot. Any plans to bring in a 12ga to 20ga adapter?
https://www.theboxotruth.com/barrel-length-shotgun-affect-velocity/
If these are still in stock next time I order from Frontier I'll definitely get one and try to remember to report back.
I'd love to get both a 20ga and 410cal adapter for my single shot. Any plans to bring in a 12ga to 20ga adapter?
Probably not?
If I'm not mistaken, 45lc is a bigger caliber, and while they're about the same size chamber as a 410 they are not the same bore size and the guns that can use both have a 452 bore diameter not 410.
- Location
- Prince Albert, Saskatchewan
We only have available the 12 to 410s right now.
Ballistics by the inch is a great resource: http://www.ballisticsbytheinch.com/calibers.html
No data for shotguns but it gives you an idea of how having a barrel that is too short, or indeed too long, can dramatically affect velocity.
maltextract
Regular
- Location
- Rural Manitoba
How about a 12 to 20?
My oldest kid has stared hunting. we have lots of 12 & 20 ga around but no 410.
He has shot a 20 and flinched a bit on the recoil. i know as he gets better form and a bigger body frame this will go away. but if put 410 in he can go for grouse now and not flinch.
I could see using this as a stepping stone to bigger gauges
that's correct, less then 3" ammo in a 3" chamber may lose some velocity if the shotcup+wad+seal is shorter then the gap. (gap = shotshell expanded length - chamber length)
but, in 410, the shortest shotcup easily covers the gap. My reloads take that into account too.
whereas with the inserts, after 2" (my approximation of the shown inserts) there's only "gap". Gases blow by while the shot ....
do you want to pattern some loads with me?
in the bush?
