Gas check boolits seated past neck

[thehouseproduct]

Are there any issues shooting boolits seated deeper than the neck?

[Loudenboomer]

In some instances lube groves in the powder can de-grade the powder especially in hot weather. Usually not a serious problem.

[fryboy]

unless ur using the slip fit gas checks that lyman used to sale ...only what Loudenboomer stated
as for the slip fit gas checks ...dont do it

[geargnasher]

It can be done, but is not ideal.

Gear

[NuJudge]

One of the NRA publications from years ago showed a cast bullet that had been shot in a rifle cartridge, with a good bit of the bullet below the shoulder. The portion that had been below the shoulder had this wierd erroded look.

I will set up cast bullet loads such that the gas check protrudes below the neck, but nothing more.

[Bret4207]

I've been doing it for years, decades actually. It's not the ideal thing because of powder contamination, that's my biggest concern. And I used Lyman checks, still do sometimes, and had no problem. That's not saying you won't, but the idea I've seen espoused that pressure in the case somehow builds, runs to the shoulder, turns and forces the GC off the base, then turns again and pushes the boolit out the case is really pretty silly. With a poorly fitting GC of any kind it can fall off the base. If you have that issue I wouldn't recommend seating the GC below the neck unless you have a filler of some sort to support the check.

[Bass Ackward]

Don't let your urgency to be frugal over run your common sense and you will have no problem. Learn to identify the cause.

Understand lead will deform when pressure exceeds it's ability to resist it. The only thing that keeps it intact is the steel that restrains it. Free floating lead doesn't have the luxury and the base " CAN " rivet on extreme situations.

So depth below the neck, powder pressure and more importantly the rate of pressure is what "can" cause problems if you are not careful or do not understand.

Understanding eliminates your need to rely on luck.

[1Shirt]

I?ve had no problem when the base w/gc is below the neck, but I would not do it with other than Hornady GC's., and usually a dac filler.
1Shirt!:coffee:

[thehouseproduct]

I am in fact using Hornady gas checks. This is a pretty low pressure plinking load for my 300 Whisper. I guess based on what people are saying, this setup will be fine given that it meets my accuracy needs. (paper plates at 25 yards)

[Larry Gibson]

Powder contamination, loose GCs, erosion and the fact that the bullet base can indeed "rivit" (as Bass correctly mentioned) are all reasons to not do it. This is espeically the case with the higher end cast bullet loads.

Larry Gibson

[Bret4207]

Oh no, I hate to do this, but I'm gonna.

Bass, it's my understanding pressure in a cylinder rises more or less equally within the cylinder which would mean no riveting can take place. I've also heard the base can "rivet". Both can't be true, or can they? And what evidence would we see that it does occur within the case?

[Bass Ackward]

You are a smart guy; Ask yourself why the industry likes short necks on bottle necked case designs these days? Even for jacketed.

More food for thought. Why did Lyman quit selling PB and tapered Loverin rifle designs when they were so wildly popular and so easy to fit up? All you had to do was seat out until they touched the lands no matter how long your freebore was. Idiot proof really. Lyman and RCBS all went the way of the bore ride and about the same time too huh? Was it superior fit or design? Why would they do this when they KNEW they did nothing but have customers constantly complaining about fit for decades?

And the truth be known, the only danger to a large nose on a bore ride is that it would have to be seated deep in the case just .... like .... a Loverin huh?

Who knows for sure what happens in a case? But by golly, this should be an easy one to test. Mold soft and raise pressure slowly, monitor your case neck length. Necks don't stretch today with better dies, right? Use Red Dot or something fast. And don't forget to choke. Be careful you don't get too high too quickly, the brass might not be able to perform the resize operation and you will lose a neck.

That is a head scratcher; especially when you can't find it in the gun. :grin:

[Larry Gibson]

Bret

Laws of physics; objects at rest tend to stay at rest.

The rear of the bullet is being pushed forward and the front of the bullet doesn't want to move. Something will "give" if it isn't supported if the pressure is high enough (well with in cast bullet psi's). If the base of the bullet isn't supported in the neck it can easily rivit before the whole bullet gets moving. It s not theory, it is documented and can easily happen.

Larry Gibson

[Char-Gar]

The question about seating part of the bullet in the boiler room is one that reoccurs on this board with great regularity. I asked it myself a dozen years ago.

There are several reasons who doing so is not a good idea and all have been mentioned in this thread. However, the reality is I have done so many times with no ill effect at the target.

None-the-less it still makes me queasy to do so. I had good result with 311467 which stuck way down in the boiler room. I had Buckshot make me a .302 nose sizing die and sized the first two bands that diameter. That allowed me to seat the bullet out enough to keep it's feet out of the fire. Accuracy went from "good" to "great". At least I think so.

IMHO a Loverin bullet does it's best when the first band or two rides the grooves.

[geargnasher]

Agree fully there, Chargar, my experience mirrors yours, and I nose-size in two different cases to keep the GC in the neck to improve accuracy.

Pascal demonstrated and explained what happens to what when gas pressures rise in a closed system, there is a lot more going on than the inertia of the resting boolit.

Gear

[grouch]

I can't see why the bullet base would rivet inside the case - the pressure on the sides of the bullet is the same as the pressure on the base, isn't it?

[Bret4207]

Ditto what grouch said. There's just as much likelihood the boolit diameter would be reduced as riviting the base. Or is there another explanation I'm missing?

[Bass Ackward]

I can't see why the bullet base would rivet inside the case - the pressure on the sides of the bullet is the same as the pressure on the base, isn't it?


Riveting is maybe the wrong word and the hangup here. That would be from more of a complete blockage. Could it happen?

As Larry pointed out, when the bullet begins movement, the base tries to pass the nose causing obturation or swelling. Obturation that is normally controlled by steel if the bullet is far enough forward. But not in our example with the bullet suspended in air.

Now we know that brass has strength limits and is in fact designed and sized to release. We also know that lead likes to .... adhere to copper. Maybe cartridge brass too.

That neck is going to elongate under those pressure applications and hit the end of the chamber and try to stop. Pressure is still there and now increasing rapidly with what looks like a blockage.

Can the perfect storm occur? The old rifle mix was 10-1. That's only about 10/11 BHN.

And remember, Lyman HAD published a reloading manual for cast that used pretty much nothing but ultra fast shotgun powders that they HAD NOT used in previous manuals. The manuals I have before those, the 30 cals began with 2400 as the fastest powder recommended.

So did shotgun powders cause the demise of the tapered Loverin designs? Had to be "some" reason.

[DIRT Farmer]

I have no clue as to what happens, but when I started paper patch, I had the 311284 way down in the case. Digging bullets out of the ground, some of them looked like gummy worms. Cupped bases and one of them was compressed to about .20 diamater. As I stated I don't know what happens, but that is what I dug up.

[geargnasher]

Google Pascal's laws or the Noble Gas Laws and get a cup of coffee if you want the answer. Pressure is almost equal throughout the system except for pressure waves. There is also a good reason that Mr. Weatherby radiused his neck angles and the WSSSSSSSSSM case craze got started.

Gear

[jhalcott]

I tried this on several calibers. The accuracy was ALWAYS better with the check in the neck NOT in the powder room! 30-30, 30-06 ,7mm Mauser, or 280! Even when I shot Sillywets with a 7TC/U accuracy suffered IF ithe check was below the neck! NEVER did have a check come off(as far as I know) in the case or barrel.

[rayg]

Just saw this thread. Wouldn't one way to see if the bullet base rivets that is seated below the neck, is to compare the ID diameters of fired cases with the same bullet and charge between those seated above and below the case. It would seem that if there was an enlargement of the bullet below the base, it might also expand the dia of the case neck a bit more then the above seated bullets as the larger base is forced through the neck. Of course this wouldn't work if all the fired cases expanded to the full chamber size. But from firing cast bullets I know some case neck expansions vary and may not fully expand to chamber dia. So one might be able to tell the difference. However for it to happen, I would think, all the brass should be of the same neck thickness.
Anyway, maybe not a good idea but just a thought. Ray