Managed recoil......???

[bswiv]

Was looking at the Remington 20ga Managed Recoil Buckhammer loads with a view towards using them in a OLD 20ga SXS I have.

Not so much concerned about the recoil as the potential that they generate signifiantly less chamber pressure.

I am assuming that is the case but then I know how assuming can get one in trouble so I figured I see if there is spicific knowledeg out there???

 

[zippy13]

Remington (and other ammo manufacturers) typically don't publish their chamber pressures because they may fluctuate -- there are obvious legal implications. Unlike components for re-loaders, factory components may vary from lot to lot. The ammo manufacturer will adjust his recipe, from lot to lot, to maintain advertised velocity while remaining under the maximum allowed pressure. Your assumption that the Rem. Managed Recoil loads have a lower pressure is most likely correct, except it might not be what you define as significantly lower.

From your post, it seems you are looking for a lower pressure load because you question your old SxS's ability to operate safely at the maximum allowable pressure. If this is the case, IMHO, seeking a lower pressure load is a risky gamble. Have the gun checked by a competent gunsmith, you'll sleep easier.

 

[Lee Lapin]

You only have one set of eyes and fingers. Shotguns are cheap by comparison. Get the gun checked by someone competent to evaluate its safety, and if there is any doubt about it, make it a wallhanger and get a gun that's proofed to be safe with modern loads to shoot.

jmho. ymmv.

lpl

 

[bswiv]

Been shooting target loads through it, light 7/8 oz stuff, for years with no problems. Just don't want to stress the old girl with slugs that may generate more pressure.............

I'm figuring that I could simply replace the 7/8 oz shot with a 7/8 oz slug and be fine but wanted to just go with FACTORY ammo because will not be shooting more than a few.

 

[zippy13]

Here's the numbers for energy...

For 7/8-oz loads, 20-ga Remington Managed Recoil target loads have an advertised velocity of 1100 fps, Premiere target loads are at 1200 fps and the Managed Recoil slugs are at 1290 fps.

Energy varies with the square of the velocity. So, increasing from 1100 to 1290 fps represents an energy increase of 37.5% That seems significant to me.

[SIZE=-2]1290^2 = 1664100
1100^2 = 1210000
1664100-1210000=454100
454100/1210000=0.375289256198347 (37.5%)
check: 1.375289256198347x1210000=1664100[/SIZE]​

 

[bswiv]

That's the kind of information needed......

So you think the pressure is 37% more...?

 

[Dave McC]

Maybe not 37%.

Maybe 30%, maybe 60% in THAT barrel.

I'm with Lee. Good, modern slug shooters are cheap and plentiful.

Let the old soldier be....

 

[oneounceload]

For an OLD gun, especially a SxS, try shooting some of the low-pressure loads from Polywad. They make low-pressure Vintager-type loads especially for older guns. Depending on the age of the gun, are you sure it is a 2-3/4" chamber and not 2-1/2"?

 

[zippy13]

bswiv
So you think the pressure is 37% more...?
Dave McC
Maybe not 37%.
Maybe 30%, maybe 60% in THAT barrel.

Dave's correct, from the info provided by Remington, we know nothing of the internal ballistics. Different powders have different burning rates with significantly different pressure profiles. That's why there is so much work involved in assembling re-loading manuals: internal and external ballistics are evaluated.

Actually shot-shells are easier than metallics because there are just 6, or so, gauges/bores. So, the labs needs only a small collection of test shotgun barrels. With metallics there are all of those different bullets in many, many different cartridges/calibers. Right now, there's probably some lab tech rigging a barrel to evaluate another new metallic cartridge.