.410 platic vs fibre wad pressures?

[rbrowning2]

What your saying .. and I don't doubt your advice at all ... is that the RC factory loads I have which are blowing the ends of the shells and some of the Eley as well are all over pressure ?

Are these fibre or plastic wad factory cartridges and what gauge? I would guess fibre.

 

As for John and powder delivery , don't know as I am able to collect so not needed a delivery, enjoy a day in Kent.

 

Reloading is not without risk.

 

I have been reloading for many a year, rifles shotguns and when we had them pistols and the advice has always been the same work a load up. It is frequently not the maximum loading data that give the best accuracy or shot pattern.

 

When we reload used shotgun cases then in my experience looking at some proof house testing I had done then they open at less presure than a new case so when looking at load data tables this needs to be considered as most from the eu assume new cases.

 

Then ask do we need to load to the maximum pressure/velocity? When in general sensible observed velocities 1100 to 1200 feet per second give excellent patterns and with the correct choice of shot size and choke the down range energy and pattern to get the task done, clays or game and has done for over a hundred plus years.

 

Load sensibly and their is a good safety margin, so a few bar extra due to a different in performance due to a different batch of powder or primers will not put you at risk.

 

The biggest risk is accidentally using the wrong powder, picking up the wrong bottle and substituting a fast powder for what should have been a slow one, which is what destroyed the cylinder and top strap on a friends Colt revolver being used for long range pistol, when we were allowed pistols, how I miss them days.

Edited August 18, 2017 by rbrowning2

[Continental Shooter]

right, ok,i had missed the once fired part of it from your original post

 

so, it might well be that they'd been previously damaged (bear in mind any tear will rip under pressure)

 

For the RC and Eley, i wouldn't expect any brand new factory load to blow off their heads; this is a definite sign of overpressure. This might be caused by a change in the chemical compounds in the powder as a result of them being kept in a room too hot which dries the powder and makes it burn faster than it should.

 

I proofed a 20 bore load with Lovex D002 (also known commercially as Sipe N) 1,17 x 27 which returned 790 bar; i switched to 1,20 x 26 for all last year's shooting and this returned 720 bar

 

Used the left overs from last year on a pigeon quest early spring and seen they had the brass a bit marked so, sent a few to proof test and they returned 810 bar.... same shells as last year; just being kept in an hot place.... that's nearly 90 bar

 

This wouldn't normally be a problem in the bigger bore, but given the powder used and the bore section pressure changes are exasperated in the .410

 

below i added the standard closures heights for .410 cartridges (you're right; it's the finished height after you passed the spinner)

 

36/51------------- 47,5mm
36/63,5 ---------- 60,0 mm.
36/65------------- 61,5mm.
36/73------------- 68,0mm.
36/76 ------------- 71,0mm.

 

For once fired hulls the height is 1 mm lower than the above

 

Also, what spinner have you got? is it GAEP N 2?

 

cheers,

[neutron619]

This wouldn't normally be a problem in the bigger bore, but given the powder used and the bore section pressure changes are exasperated in the .410

 

Well you say that, but remember that the proof pressure for a 3" .410 is about 160% that of a 12 gauge (c. 5 tons against 3-3¼ tons). Not to mention the requirement for chamber thickness, which is usually significantly greater on a .410. I wouldn't be worried about 90 bar over pressure anywhere, really, but if it was going to be a problem, it would be in a "fine" 12 gauge with thin walls, not the average .410. Just my opinion, of course.

Edited August 18, 2017 by neutron619

[Continental Shooter]

Sorry, What i meant is that if it's 90 bar in a 20 bore, proportionally, is gonna be more on a 410.

[Stonepark]

 

Well you say that, but remember that the proof pressure for a 3" .410 is about 160% that of a 12 gauge (c. 5 tons against 3-3¼ tons). Not to mention the requirement for chamber thickness, which is usually significantly greater on a .410. I wouldn't be worried about 90 bar over pressure anywhere, really, but if it was going to be a problem, it would be in a "fine" 12 gauge with thin walls, not the average .410. Just my opinion, of course.

 

 

Your are correct in that an extra 1300psi (90 bar) is not going to suddenly endanger the shooter with a modern gun (or likely even an older gun proofed and in good condition) but the risk is those with pitting or dents that could cause early failure.

 

Tom Roster experimented with increasing pressures until barrels blew up (Mossberg 870 12 bore) and it took 55,000psi to cause barrel wall failure, with no evidence of lasting damage even up to 50,000psi. iraquiveteran8888 did a series on you tube trying to blow up a break barrel 410 (The little 410 that could) using a variety of different 410, pistol and rifle loads and it survived up to 55,000psi.

 

I am more concerned with extra pressure wrecking the pattern due to all the shot being significantly deformed due to excessive pressure upon firing as depending on what shot you use 1300psi increase can make a significant difference and require higher antimony shot to be used.

[Continental Shooter]

using a variety of different 410, pistol and rifle loads and it survived up to 55,000psi. am i reading correctly? is this 3800 bar?

 

 

I am more concerned with extra pressure wrecking the pattern due to all the shot being significantly deformed due to excessive pressure upon firing as depending on what shot you use 1300psi increase can make a significant difference and require higher antimony shot to be used.

 

Agreed, but we're loosing sight of what i meant with that: the 90 bar in 20 bore are in excess of 150 in .410 bore; still, not properly dangerous (on modern guns) but not recomended and not useful in terms of pattern

[Stonepark]

using a variety of different 410, pistol and rifle loads and it survived up to 55,000psi. am i reading correctly? is this 3800 bar?

Yes, you are reading it correctly, both sources were testing to destruction inexpensive shotguns to see where they failed.

 

In the 410, it took 45 colt, 444 marlin and multiple standard 454 rounds with no damage.

 

It eventually took a 454 casull 405grain over powdered load (using random rifle powders) to blow the breach.

Edited August 19, 2017 by Stonepark

[neutron619]

Yes, you are reading it correctly, both sources were testing to destruction inexpensive shotguns to see where they failed.

 

In the 410, it took 45 colt, 444 marlin and multiple standard 454 rounds with no damage.

 

It eventually took a 454 casull 405grain over powdered load (using random rifle powders) to blow the breach.

 

Yep - I read the article too. That was the day I stopped worrying about pressure in shotgun loads and started chasing pattern exclusively - the point about pressure being unhelpful to pattern notwithstanding.