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Gas checks & bottleneck cases.

This topic can be found at:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/8721043/m/1311054072

18 April 2022, 20:02
Bill73
Gas checks & bottleneck cases.
Recently I read on a forum somebody warning against using a gas checked style bullet in bottleneck style cases,problems could arise if the gas check separates from the bullet ? lodge somehow in the case & cause pressure spikes? I have shot plenty of gas checked bullets in calibers 450 Alaskan & 475 Turnbull without any problems,any comments on this?what has been your experience?thanks.


DRSS
19 April 2022, 03:25
JFE
I’ve read similar comments but my experience is that as long as there is a tight crimp on the GC shank, it seems to make no difference.

I have not experienced any issues in leverguns in a 348 Win or 35 Rem or in bolt guns (375 H&H) where the GC is seated below the neckline. The 35 Rem and 375H&H have short necks and it’s almost impossible not to have a GC bullet sit below the neckline.
19 April 2022, 04:27
eagle27
There must have been millions of gas checked bullets fired in bottle necked cases without issue so a statement such as that on a forum is just silly. I haven't read anywhere in reloading manuals especially say Lyman's Cast Bullet Handbook, of warnings about gas checks coming away from the bullet base in a case of any sort.

In my experience with loading gas checked bullets the check is usually clipped and or crimped on quite firmly to bullet bases and I can't see any reason why they would come away from the base while sitting in a case below the case neck in general carriage and loading of the cartridge before firing.

Yes they can come away and stay in the case or case neck if the bullet is pulled for some reason but this is a different situation than checks coming away from the bullet base while seated in a case before firing.

On the odd occasion where I have had the need to pull cast bullets from my 404 Jeffery cartridges the gas check does stay in the case neck but is easily removed by flipping it over and pulling out with needle nosed pliers. They do slip out easily and I imagine in the unlikely event of one coming off the base before firing it wouldn't cause an obstruction if fired out loose behind the bullet.
19 April 2022, 04:41
rcraig
I've never had it happen far as I can tell.
19 April 2022, 04:47
Hipshoot
Have shot thousands and thousands of rounds through rifles in .222,30-30, 300 Sav, .30-40, 30-06 .35 Rem. .358Win and others over a period of at least 40 yrs. with ZERO problems.

Hip
19 April 2022, 04:54
JFE
Some older GC’s were of the slip on variety and could easily be removed from the GC shank, so perhaps comments possibly relate to those sort of GC’s. No doubt if the GC did shake loose it might cause an issue but these types of GC’s are no longer made.

Another point is that some calibres have narrower GC shanks than others. For example, 458 GC shanks could do with being a little larger in diameter as there is little interference fit compared to other calibres. When sizing bullets for large groove diameter 458 barrels, I sometimes resort to first sizing using a 0.461 sizer die and follow up with sizing the GC only using a 0.457 sizer.
19 April 2022, 06:51
crshelton
Guess that GC are not needed in straight wall cases ?
I have heard of them but never used one.


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19 April 2022, 15:33
JFE
GC’s are also used in straight wall cartridges but as by definition they’re not bottlenecked, there is no issue with the GC falling off as it’s held captive by the case walls.
19 April 2022, 16:16
arkypete
I use nothing but gas checked bullets in all of my lever actions. The one bottle necked is a Model 95 Winchester. I had two molds made by Mountain molds both are bore riding, with the first driving band engaging the rifling. The first mold weighed in at 203 grains and the second came in a 175 grains. It's my experience that the bullet needs to be 1/1000 larger then the bore diameter and the gas check needs to be annealed for a tight grip on bullet base.
The same scheme workes on 45-70, 405 Winchester. 45 Colt, 375 Whelen.
.


"Whensoever the General Government assumes undelegated powers, its acts are unauthoritative, void, and of no force." --Thomas Jefferson

19 April 2022, 18:46
Bill73
quote:
Originally posted by crshelton:
Guess that GC are not needed in straight wall cases ?
I have heard of them but never used one.


Cr,
I have shot a lot of gas checked lead bullets in straight wall cases,most of these were single shot Sharps rifles,45-70,your beloved 45-90 & my favorite 45-110,I was shooting smokeless,the velocities were much higher than BP loads,the gas checks prevented lead deposits in the barrel.


DRSS
20 April 2022, 01:18
crshelton
OK, big differences understood.

I have shot very few lead bullets in my lever action rifles.
.357, 405, .458 calibers most all jacketed bullets.


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20 April 2022, 03:10
eagle27
Another thought is that often when loading cast bullets a filler is used between the powder charge and the bullet base so in this case a filler would help prevent any propensity for a gas check to come away from the bullet base.
20 April 2022, 06:08
cal pappas
Never heard of this and I've been shooting cast bullets since the 1970s. I would imagine the powder gas would blow out a gas check that came off the bullet.


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20 April 2022, 20:23
JFE
This topic came up a few years back:

http://forums.accuratereloadin...521047062#1521047062
20 April 2022, 20:37
Bill73
I just read it & nobody agrees with the poster,I can only think of one scenario that might cause issues? a very low powder charge as one poster suggested,or if the gc has fallen on the powder column & there is a lot of airspace maybe some problems might occur? ring in the chamber etc.


DRSS
22 April 2022, 03:09
JFE
I don’t know the answer but if a little tuft of Dacron can cause a ringed chamber, a loose GC could potentially cause a problem too.
03 May 2022, 08:32
450 Fuller
A loose GC on top of powder in a bottle neck cartridge CAN and WILL potentially cause
a pressure spike.

Then-you just might want a Weatherby action
to handle the pressure spike. First hand experience says no more GCs for me except straight wall cases.

What you do with your firearm is your risk.


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