Will Pressures Go Up, Down Or Stay The Same As Projectile Is Loaded Further Down The Barrel?

[DizzyJ]

It'll blow yer face clean off!

 

[dangerranger60]

I would not expect blowback of gases to ever be very dangerous when it comes to ill fitting cases or cases that don't expand properly. Eye protection should be sufficient to protect against most blowback issues.

If you don't believe, Do a search on the early experiments in converting .22 lr guns to 17 MACH 2. If they did not get the weight of the bolt and the spring rate right to keep the bolt closed until the chamber pressure had dropped it would grenade the case as it was being extracted, and blow the magazine out the bottom of the gun. With brass case bits and mag shrapnel flying everywhere. The easiest place to find this is on Rimfire Central , and do a search including the word Kaboom. Starting in the late 90's there were a lot of these. Most of the major manufactures turned out semi auto guns and had to recall them. Even the guns setup right would Kaboom if there was any bore fouling.
I don't remember any deaths but there were stitches required!
It wasn't till SAvage made a delayed opening bolt, that anythone had a successful semi auto 17 HMR. I think that was the A100.

 

[Howard1955]

My guess is that you'll eventually find the correct placement in the barrel for your projectile, and create an impressive pipe-bomb.

You probably want to stand far away from the rifle, behind something solid, and pull the trigger with a string.

Be sure to have a couple of cameras taking videos of your experiments. Whatever happens, it's going to be interesting to see.

Just try not to kill yourself.

 

[arakboss]

If you don't believe, Do a search on the early experiments in converting .22 lr guns to 17 MACH 2. If they did not get the weight of the bolt and the spring rate right to keep the bolt closed until the chamber pressure had dropped it would grenade the case as it was being extracted, and blow the magazine out the bottom of the gun. With brass case bits and mag shrapnel flying everywhere. The easiest place to find this is on Rimfire Central , and do a search including the word Kaboom. Starting in the late 90's there were a lot of these. Most of the major manufactures turned out semi auto guns and had to recall them. Even the guns setup right would Kaboom if there was any bore fouling.
I don't remember any deaths but there were stitches required!
It wasn't till SAvage made a delayed opening bolt, that anythone had a successful semi auto 17 HMR. I think that was the A100.

Sorry, I was addressing blow back in a locked breech firearm as was mentioned farther up the thread. I agree that premature opening of bolt could be catastrophic which is partly why I want my AR blow back bolts to stay closed until I open them.

 

[Yarome]

If you don't believe, Do a search on the early experiments in converting .22 lr guns to 17 MACH 2. If they did not get the weight of the bolt and the spring rate right to keep the bolt closed until the chamber pressure had dropped it would grenade the case as it was being extracted, and blow the magazine out the bottom of the gun. With brass case bits and mag shrapnel flying everywhere. The easiest place to find this is on Rimfire Central , and do a search including the word Kaboom. Starting in the late 90's there were a lot of these. Most of the major manufactures turned out semi auto guns and had to recall them. Even the guns setup right would Kaboom if there was any bore fouling.
I don't remember any deaths but there were stitches required!
It wasn't till SAvage made a delayed opening bolt, that anythone had a successful semi auto 17 HMR. I think that was the A100.

The mechanics involved are a completely different animal. One does not translate into the other so direct comparisons and resultant risks don't really apply.

 

[RX-79G]

If you don't believe, Do a search on the early experiments in converting .22 lr guns to 17 MACH 2. If they did not get the weight of the bolt and the spring rate right to keep the bolt closed until the chamber pressure had dropped it would grenade the case as it was being extracted, and blow the magazine out the bottom of the gun. With brass case bits and mag shrapnel flying everywhere. The easiest place to find this is on Rimfire Central , and do a search including the word Kaboom. Starting in the late 90's there were a lot of these. Most of the major manufactures turned out semi auto guns and had to recall them. Even the guns setup right would Kaboom if there was any bore fouling.
I don't remember any deaths but there were stitches required!
It wasn't till SAvage made a delayed opening bolt, that anythone had a successful semi auto 17 HMR. I think that was the A100.

That was in a blowback operated gun, not a locked breech one like he's talking about.

 

[arakboss]

That was in a blowback operated gun, not a locked breech one like he's talking about.

I edited my previous post to indicate I was talking about locked breech firearms.