?? 870 From H--l ???possible?

[cpileri]

Just out of sheer curiosity, what psi can an off-the-rack Rem 870 pump gun take? diff btw regular and 'Express'? Wondering abt the potential of a 870 in one of these 12ga Big Shot chamberings? Or even just regular plastic cases but loaded w slower powders?

870's cycle so reliably even w longer shells that there is potential there. Although the factory barrels are pretty thin and there isnt alot of room to modify ejection ports.

Anyway, just asking...

C-

[Duckiller]

Shotguns are not made for high pressure. Are you asking" Can an 870 handle 25000psi?" . I doubt it. Why would you want to do that to a nice gun. Blowing up guins is not something one should try to do unless you work for a factory and you are teating to failure. With shotguns, even more than rifles and handguns you should follow the reloading manuals. Minor changes can cause major pressure changes. If this is not what you are asking then my post is for general information. From memory the max. pressure for shotguns is no more than 15,000psi, if you double that to 30,000 psi you are probably going to do serious damage to something. Problem may develop at pressurethat is less than double the normal max.

[hubel458]

The only 20---30000 psi loads we run are the hotter ones in 12ga brass cases,
allstrong plastic loads we have are 15,00 and less.....

You can use our slow powder loads in 3" plastic cases for 870
If barrel heavy enough....... 90gr 4759 max
with our sabots and 500gr or less slugs. 50g rmax Steel with sabot and 500gr.
55gr max Steel with sabot and 440gr.
They Will be about 14,000 psi load based on various lab tests.
Slug barrel, newer ones, not old thin low alloy barrels. Ed

[Zymurgy50]

The only difference between "Express and Regular" is the finish on the metal and stock.

[cpileri]

Thanks again, Mr. hubel!

Duckiller: No, what I was asking is: given the construction of the 870 unmodified, what can be done within safe pressure limits using slower powders and modern components. I think Mr. Hubel answered it: need a heavier barrel than normal 870's then can take advantage up to 14kpsi with IMR 4759 or similar. (re-17? 4227?)

Zymurgy, thank you.

C-

[JIMinPHX]

From SAAMI website:
http://www.saami.org/specifications_...wnload/209.pdf

There is a lot of mumbo jumbo in that 100+ page PDF, but the spot checking that I just did in there seems to agree with my hand written notes. They say that the following are SAAMI max pressures for shotshells:

12ga - 11,500psi
12 ga 3.5"- 14,000psi
20 ga - 12,000psi
.410 bore 2.5" - 12,500psi
.410 bore 3" - 13,500psi

Shotgun barrels tend to be pretty thin. I would not want to push my luck on the pressure limits in that type of barrel.

14,000psi loads are for 3.5" 12ga barrels only.

[hubel458]

The 14,000 psi loads will work in newer slug barrels that have .92"
minimum muzzle diameter. Not for thinner barrels. Even in the 3"
cases like we did our 4759 loads that were lab transducer tested, 5 shots,
averaged 14,700 psi with 600gr fullbore slugs.You get a newer slug
barrel of right size for 870 you will do ok.Ed

[Greg5278]

Stick with SAAMI spec loads as Jim in PHX gas suggested. Trying to go over that can result is injury or Death. A shotgun is not designed to funtion with higher pressure, and a ruptured head could cause injury with the venting gases. If in doubt about the load have Tom Armbrust pressure test it for you. He is very reasonable for a 3 or 5 shot pressure test.
Greg
AKA 12 Bore

[SuperBlazingSabots]

Hello Brother Cpileri,
1. My Remington 1100 Magnum has a rifled barrel made by Ithica measuring .870" at the muzzle.
2. My Two Savages 12 gauge F212 and F210 measure .910 at the muzzle.
3. My TC Pro Hunter SS 12 gauge barrel measures .994" at the muzzle.
4. My TC Pro Hunter SS 20 gauge barrel measures .880" at the muzzle.
5. My 20 ga SS Savage barrel measures .810 at the muzzle.

I can safely say all my guns are good to 12,000 psi max and powerfull enough to kill any game in North America with a proper load!

My TC Pro Hunter in 12 gauge with a .994" barrel would have been good to 14,000 psi but the company goofed by cutting a dovetail slot and turned a well made strong gun into a chicken rifle, what a shame when designer's spend more time at the neighborhood bar than Research Dept.

That's why they say " The bigger the guy the harder they fall "

I'm getting a H & R Ultra Slug Hunter.
The Very Best BANG for my money ! ! ! !
Can't beat that.

I'm proud to be a Elite Musketeer, among other Elite Musketeer's here, even tho we are just a few ! ! !
" One for all & All for one "

Best regards,
Ajay
www.BlazingSabots.com
BlazingSabots@Gmail.com
Blazing Sabots, LLC
Join me on FaceBook here:
http://www.facebook.com/BlazingSabots?ref=hl
http://slugshooting.accountsupport.com/ ... wforum.php
http://castboolits.gunloads.com/showthr ... ot!/page1
view...f=118&t=196961
http://www.deeranddeerhunting.com/fo...p?f=43&t=39246
http://www.go2gbo.com/forums/slug-gu...old-is-gold-!/

[hubel458]

The guy who gave me the 90gr 4759 that we tested at Tom's Armbrust's lab
with 600gr , that tested 14700 said they shot them in 870s with slug barrels ok for
quite a while before I got the info.

The thing is the amount of strain on a casehead and bolt thrust
is as much of the function of the speed that a powder gets to peak pressure,
as the amount of the peak pressure. 4759 takes 3 times longer to get
to peak pressure as most fast shotgun powders do.And Steel
powder 1.5 to 2 times as long as the fastest shotgun powders..Ed

[cpileri]

Darnit, i gotta find some 4759!!!
C-

[OnHoPr]

I never got around to trying the 4759. Ed, will the 4759 push a 440 gr or less projectile in cold temps?

[JIMinPHX]

My fondness for buying used shotguns has now diminished.

[hubel458]

So far 4759 has worked great in cold temps , We tried 4227 and it gives about same results in
hot weather and guys like it, but misfired almost all the time when cases were cold
long enough to make powder cold. Very dangerous.
If you like pumps and get a bargain on used you may save enough to put on
good slug barrel. More guys like pumps than other styles, I favor
single shots in 12ga. Ed

[cpileri]

Ok, so the 870 taken as a unit, off the rack, is a SAAMI-spec operation. Got it.
Now, some spectacular loads have been developed that do maintain normal presures, as described, but because of the longer peak pressure curves; require a heavier barrel for which some of the rifled barrels may be adequate.

thats really all i was interested in knowing.

C-