Help - Serious pressure and ruined my bolt

[Ryan55555]

Looking for a little help. Here is some info:

Remington VSSFII .204
Handloaded Remington Brass
CCI 450 primers
H335 powder 27.0g
Sierra 39 bullets
COAL 2.400 (yes it is long, I have modified the mag to fit. Still not even close to the lands)

I have shot several hundred rounds with this gun and bullet combo will no problems.

Went out prairie dog hunting yesterday and about 40 shots into it I pulled the trigger and felt some blow back from the cartridge in my face. Scared me a bunch as this has never happened to me before. The bolt was stuck and I mean stuck, I was able to wrestle the bolt open and pull the bolt from the action. The case had expanded into the extractor and it took me several minutes to wiggle it loose. I looked down the barrel and it looked normal, but the bolt is ruined. As I was wiggling the stuck case from the extractor a few steel slivers come off the bolt and it is not good. The shots before this do not show any pressure signs and I never felt a sticky bolt.

What can cause this?

I use my RCBS chargemaster to load every round that I shoot. 27.0 g of H335 fills the case probably 90% full so a double charge is not likely.

I have shot this combination with 27.7g before with no excessive pressure signs.

Could a short charge cause this?

I use a Lee collet die to neck size only, what if I did not get the neck tight enough and when feeding the round into the chamber the bullet is pushed back into the case. Would this cause this problem?

Any insight would be great.

[lanenebraska]

Looking for a little help. Here is some info:

I use a Lee collet die to neck size only, what if I did not get the neck tight enough and when feeding the round into the chamber the bullet is pushed back into the case. Would this cause this problem?

Any insight would be great.

Yes, This will do it.

[Bayou City Boy]

Something else to consider............

Hodgdon shows a starting load of 25.5 grains of H335 and 26.8 grains at the top end for the Hornady 40 grain VMax. Granted its not the 39 grain Sierra bullet, but in the real world they are close enough to compare. At 27 and+ grains of powder you might have been floating on a cloud as far as pressure is concerned for a long time with your rifle. Even with stable powders, hot temps like found when PD shooting can make pressure jump even more.

If you don't have one, you might want to invest in a chrony to assist you in building loads. My guess is a chrony would have shown you reached top velocity in your rifle with your load recipe well before you got to 27 grains of powder... Adding more powder just kept upping the pressure ante without any benefits. Finally one popped. Don't rely on all of the "normal signs of high pressure" to help you. They can easily fool you, too.

Flirting with top end loads in small high pressure cartridges like the 204 Ruger can be a risky business, and very little change in the recipe can cause problems under the right conditions. A chrony will quickly and easily show you when you are at the top end for a specific rifle in any chambering. Adding more powder only increases barrel wear and pressure with no positive change in velocity.

JMO - BCB

[Jim White]

Yes, under charged rounds can cause this.

In echoing what BCB wrote, I hand load every .204 round. While it is a very accurate round it is a unforgiving round, meaning a .1 or .2 grain deviation can effect accuracy and perhaps safety depending on where your load is in the pressure band. Also, as BCB, pointed out, you can't always (visually) judge by a fired case because some primers and cases have different properties and thicknesses, even between LOTS.

When you hand load every round you can feel the primer pocket and the neck tension. If something isn't right just set that round off to the side and come back to it later.

HTH,

[Fred_C_Dobbs]

When I first began using the Lee collet dies, I sometimes would find a round with a bullet seated a loose enough I could turn it with my fingers. I got lucky because I figured out what was going on before I'd managed to fire one with the bullet pushed back. I started testing every case after neck-sizing with a sacrificial bullet to make sure I couldn't stick it in any further than the boattail. Once you're past that point in the reloading process, it would be very easy never to notice that there's too little neck tension.

[Silverfox]

Ryan55555--First, let me say I am happy you didn't get hurt in this incident. I have felt the blowback from a blown primer a couple times and it really makes the heart stop for an instant and then begin beating 190 miles per hour.

One other thing that has not been mentioned that can cause a situation like you experienced is if you have been shooting several shots and the barrel/chamber are hot and you chamber a round and then let it sit in the hot chamber for a long time and then fire it, the heat from the hot chamber can cause extremely high pressures when you fire the round and you could get the result you described.

I, too, use a ChargeMaster 1500 to measure my powder charges, but I DO NOT TRUST THE CHARGEMASTER TO BE 100% ACCURATE!!! I weigh every charge on my Denver Instruments MXX-123 to be sure I'm not over or under my desired powder charge weight. While the ChargeMaster isn't off by much, I have found that once in a great while it can be off by as much as .3 to .5 of a grain. That last little turn of the tube might have a big gob of powder granules out at the end and they all fall in at once. I ALWAYS let the ChargeMaster give me the count of the loads it has thrown and then make sure I check what it says is the final weight of the charge before pouring the charge into the pan of my DI MXX-123. I assume you check that final powder weight on every charge before pouring it into your casing as well.

Since you are .2 of a grain above the Hodgdon Powder Company January 30, 2010, suggested Max load of 26.8 gr. of H335 listed for a 40 gr. V-Max bullet, and if you don't periodically check the accuracy of your ChargeMaster, you might have a load or two with enough powder in the casing to be very dangerous. Just my thoughts on what might have gone wrong.

[tawnoper]

Just taking in to account all you said, was this using new brass? Could you of maybe gotten a hold of a slightly annealed case?

[Ryan55555]

All brass had been fired 1 or 2 times in this gun. Then neck sized with my collet die.

I had actually pulled out 2 or 3 pieces of brass because the primer pocket felt a little loose, not bad but different than the others.

I have pulled the bullets in all of my remaining loads and individually weighed the powder charge. All of the loads were +/- .1 with most of them being 27.0g exact.

I checked all of the bullets for movement due to lack of neck tension and was unable to find any that would move, they all looked good.

Not sure what to do now, first of I am going to lower my load. Second, I plan to invest in a chrono to help in my load development. Third, I am going to spend more time with "extreme powders" (IMR 8208, H4895, etc.) because most of my load development is done in the winter when it is 30 degrees outside but it is closer to 90 degrees when I was prairie dog hunting.

Anyone know were to get a new bolt?

They sure are not cheap, I have talked with a local gunsmith and he is going to check things out and get me back shooting again.

Kind of scary, I am very careful when reloading and double and triple check things.

[Bayou City Boy]

...........Not sure what to do now, first of I am going to lower my load. Second, I plan to invest in a chrono to help in my load development. Third, I am going to spend more time with "extreme powders" (IMR 8208, H4895, etc.) because most of my load development is done in the winter when it is 30 degrees outside but it is closer to 90 degrees when I was prairie dog hunting......

...............Kind of scary, I am very careful when reloading and double and triple check things.

It looks like you are headed in the right direction with the above and pulling the bullets in the remaining ammo. In the internet world, there are two types of reloaders.... Those who cram powder and bullets into a cartridge and assume all is well if nothing blows up. And then there are folks who are cautious about what they are doing, but the KNOW what they have in the way of safe ammo for all situations.

JMO - BCB

[Joe O]

http://www.pacifictoolandgauge.com/ New Bolt