Does it matter if GC comes off after Boolit leaves the muzzle?

[Case Stuffer]

Standard GC design Boolits with Alu. or Copper gas checks.


I have read that once the Boolit leaves the barrel its' job is done .

I have also read that many have retrieved boolits with the GC still attached and they seem to feel this is a very good sign.

I have read that many feel that accuracy was improved just by adding GCs.

It would seem to me that if the GC comes off in flight that it could cause a disturbance which could effect accuracy.

I admit that I have only been using gas checks for a very short period of time and only on 55 gr. .225 dia Boolits in a AR15 M4 1:7 twist . I powder coat but till use gas checks as I have no desire to lead up the barrel and until I get a Chrony I really have no idea how fast my H 335 19 gr. load is. I know it runs on the dirty side which may mean that it needs bumping up.

[1Shirt]

Years back when Lyman made slip on GC's, compaired with Hornady crimp ons, there was a lot of controversy on this subject. Today, most every thing including do it yourself alum gc's are crimp on, so it doesn't make much difference. I don't expect the gas check to come off if at all until impact.
1Shirt!

[runfiverun]

soooo when one flies off to the left at 30' and one straight down at 30 yds.....
what do you think will happen?

[williamwaco]

In a word, yes.

It matters.

you might get a few shots off with good accuracy now and then but in the long run accuracy will suffer.

[Case Stuffer]

1Shirt a snip from your post

Today, most every thing including do it yourself alum gc's are crimp on, so it doesn't make much difference.

You did say most but checking site here

http://vulcanchecks.com/gas-check-store it seems most if not all are slip on per their discription

Snip

. Our slip on style checks are applied to the base of your bullets utilizing any of the major resizing dies or gas check.

Perhaps I am confused and need someone to explain the difference between a slip on and a crimp on GC.

[elwood4884]

Slip fit gas checks don't have the thickened lip of the check designed to bite into the bullet (crimp style). Slip fits are designed to fit tightly onto the shank of the bullet without digging. By adjusting material thickness you can get optimal fit.

[MT Chambers]

Back in the day of "slip-on gas checks" from Lyman, the thought was that as long as they all either stay on or all come off, you were good to go but if just some stayed on your group would be toast.

[376Steyr]

The "slip-on" checks would sometimes "slip-off" and remain in the barrel, with bad things happening with the next shot. I have some of the old Lyman slip-on type squirreled away, and I'm reserving them for emergency use only.

[country gent]

Gas checks are similar to Paper Patches or under bullet wads. If they all come off the same at the muzzle or just past fine if they all stay on fine. If one comes off at the muzzle the next stays on to the target and then it comes off at half way point accuracy will suffer. Worst would be ones that partialy came off sticking out off the base like a rudder.

[JeffinNZ]

The "slip-on" checks would sometimes "slip-off" and remain in the barrel, with bad things happening with the next shot. I have some of the old Lyman slip-on type squirreled away, and I'm reserving them for emergency use only.

Have you witnessed a gas check left in the barrel? No disrespect but that takes some believing.

[Ballistics in Scotland]

[QUOTE=MT Chambers;3285555]Back in the day of "slip-on gas checks" from Lyman, the thought was that as long as they all either stay on or all come off, you were good to go but if just some stayed on your group would be toast.[/QUOTE

That is the situation exactly. If they all stayed on it would be fine, and this is what usually happens with checks purchased nowadays. The edges are burred over so that sizing crimps them onto the bullet. If they all fell off exactly on emerging from the muzzle, the chances are that that would be very nearly fine too. (As something spinning so fast is liable to be hurled off to one side, it might give a sideways kick to the bullet in doing so.

I used to shoot the Portuguese Guedes, and one idea advanced during the design, but not in production, was a bullet patched with copper foil. It was found that it was irregular in detaching itself, with extremely adverse effect on accuracy. My guess is that this was caused by soldering to the lead alloy through friction-induced heat, and that the same thing would happen some but not all the time with slip-on gas-checks.

I have a great fondness for the Swiss M1889 rifle, despite its relatively weak, enormously long action. It used the 7.5x53.5 round, which is actually the same chambering as the later 7.5x54.5 except for a greatly oversized chamber neck. The bullet was paper-patched lead alloy with a steel cap on the ogive alone, and it was greatly oversize for the rifling, with a heel to fit the case neck. My guess was that it was originally designed to hold a bullet of that full diameter, but swaging it down so much in the lead caused "finning" at its rear edge, which they decided to keep at the heel step where it would be relatively harmless.

It would be desirable for optimum accuracy and brass life to use a bullet with a full-diameter base. A project I have never got around to would be to do so with an 8mm., with a 1/16in. thick disc cut from 8mm. aluminium rod inside the patch, and possibly glued to it. As aluminium doesn't solder anywhere near as easily as copper, I think this would separate reliable, and take any rear-edge finning with it.

[Ballistics in Scotland]

Have you witnessed a gas check left in the barrel? No disrespect but that takes some believing.

I agree that it must be at most a very great rarity. But it only takes the one...

[mold maker]

But has anybody ever seen it happen even once?
With the pressure involved behind it, how does the GC just stop in the bore, while the bullet it's pushing, attains velocity? We're not talking about GCs previously lost in the powder, but those leaving the throat attached.
I think this is another old wives tale that needs to die, or be proved.
This is like saying a double charge produces a squib.

[too many things]

I have them come off and stick in barrel. it was from squib loads. they also will destroy a crony too. I have never had a Gator come off YET. I don't like a check that is below the neck. the 150gr 270 cal is one that I had problems with. "wasn't using Gators" was old Lyman in the tin can. I quit using the 150gr also
the squibs came from either bad primers or a damp case that wasn't dry inside.

[376Steyr]

But has anybody ever seen it happen even once?
With the pressure involved behind it, how does the GC just stop in the bore, while the bullet it's pushing, attains velocity? We're not talking about GCs previously lost in the powder, but those leaving the throat attached.
I think this is another old wives tale that needs to die, or be proved.

This is like saying a double charge produces a squib.

I note your hedge there. I think we can all agree that a GC being pushed squarely down the bore while pushing a bullet isn't going to remain in the bore if the bullet leaves the muzzle. It is prior to that when it could come adrift and allow gas to flow past it that the possibility of it becoming a bore obstruction arises. As for has anybody ever seen it happen, Skeeter Skelton once wrote that he blamed a loose gas check for a ringed barrel in a 44 Special, and so he switched to using the crimp-on style only. I don't know if he was correct, but it seems like a reasonable precaution. I personally take a dim view of loads in bottleneck cartridges that let the GC dangle unsupported in the powder space.

[W.R.Buchanan]

I have read a considerable amount on this subject. Unless someone comes up with a way to photograph the boolit thru it's entire flight I don't think we will ever know..

I think I can say this without reservation,,, If you hit what you are shooting at what difference does it make?

Optimally I would want the check to stay on all the way to the target.

Seems like a crimp on style check should do that, but I don't know for sure. I know I shoot virtually every Boolit I shoot lately with GC's installed.

My results are acceptable, so I don't over think this.

Randy

[mold maker]

As far as cameras photographing the boolit, they can read license plates from 300 miles in space.
Anything is possible, but I'm not convinced the marriage ends within the bore. If separation happens within the chamber, or before firing, that's a whole new ballgame.
I too have read accounts of this phenomenon for years, but most were the excuse for a squib ringing a barrel. Many times multi stacked squibs.
Of course on exit from the bore, there is a terrific gas release that evolves into a vacuum behind the GC. Being light weight, and having compression spring back, its grip on the boolit is all that prevents it's release. Having a forward cupped shape, it is like a parachute, and it's mass would not maintain velocity.
I have several thousand of the 7 Mag slip on checks and am afraid to use them for fear of them turning loose within the case. Would a dot of super glue be enough of a guarantee?

[bstone5]

I have found 40 S&W bullets with cola can gas checks that were shot from a SIG 239 and the gas checks were still on the bullets.
THE BULLETS WERE SHOT INTO A DIRT PILE BEHIND THE TARGET.

[robertbank]

I have read a considerable amount on this subject. Unless someone comes up with a way to photograph the boolit thru it's entire flight I don't think we will ever know..

I think I can say this without reservation,,, If you hit what you are shooting at what difference does it make?

Optimally I would want the check to stay on all the way to the target.

Seems like a crimp on style check should do that, but I don't know for sure. I know I shoot virtually every Boolit I shoot lately with GC's installed.

My results are acceptable, so I don't over think this.

Randy

Randy you have a way with words. I agree.

My plain base GC's are coming off in flight. Some do, some don't. I have found them just in front of where I am shooting and also on the bullet when they are dug from the back of the berm and points in between. None in the bore something I seriously doubt would or could happen. I have not noticed my shooting has deteriorated by using them nor have I any reason to book a flight to the next IDPA Nationals either,. What the GC's do for me is eliminate leading which is one of their primary functions. Beyond that aluminum GC's if nothing else give me a reason to have a coke or a beer in the evenings ans something to do in the morning before I have a chance to think of all the things I can put off until tomorrow so I can go shooting today.

Take Care

Bob

[Ballistics in Scotland]

As far as cameras photographing the boolit, they can read license plates from 300 miles in space.
Anything is possible, but I'm not convinced the marriage ends within the bore. If separation happens within the chamber, or before firing, that's a whole new ballgame.
I too have read accounts of this phenomenon for years, but most were the excuse for a squib ringing a barrel. Many times multi stacked squibs.
Of course on exit from the bore, there is a terrific gas release that evolves into a vacuum behind the GC. Being light weight, and having compression spring back, its grip on the boolit is all that prevents it's release. Having a forward cupped shape, it is like a parachute, and it's mass would not maintain velocity.
I have several thousand of the 7 Mag slip on checks and am afraid to use them for fear of them turning loose within the case. Would a dot of super glue be enough of a guarantee?

Bullet photography doesn't even involve very high expenditure nowadays. It can be done with the Camera Axe device and some ordinary commercial flash-guns.

http://www.cameraaxe.com/

Even more informative on this subject, though, is photography by the light from a single-point spark passing through to a photographic plate. It forms an image of the pressure waves in the air, just like the sun can cast an image of whisky and water, with different densities, mixing in a glass. This one was taken by Professor Boys of the Imperial College of Science in 1893. It bears out what you say, not with a vacuum, because there are no pressure patterns in a vacuum, but with an area of lowered pressure which does impose suction on the base of the bullet.

Attachment 142633

As to whether superglue would help, it might, and I think your chances might be better with a tiny dab of epoxy. But I don't know if you could count on it. Heat passes through jackets to produce core melting in high velocity rifles, and although that is frictionally induced heat of greater intensity, it only gets intense near the muzzle. Combustion heat is applied for longer. To look on the bright side though, copper subjected to this heat may not have the springiness of the same stuff cold.

You could always make a hole in a piece of sheet steel which will just accommodate the slip-check, and slightly thinner than its length. Then you can form a slightly T-shaped lip on the checks by hitting them with a light hammer. (A press will only shorten the complete wall of the check.) Of course you can buy a lot of checks with whatever you would earn in gainful employment, during the time this would take. But then it isn't employment. It's a hobby, and winning a small victory.