Remington 700 sps

[raven1776]

I recently purchased a Remington 700 sps in a 300 RUM. I have been loading 210g Berger VLD's with Retumbo powder at 89.6g. I recieved the suggested powder weights from Berger directly. They show 82.5g as the low and 92g as the high. I load at 3/4 load. I have shot probably 50 rounds of this ammo with no problem. Yesturday I went out to check my zero for a hunt tonight and tomorrow. I took one shot and the case jammed in the chamber. I had to beat the bolt open and pry the case off the bolt face. I took the rifle home, cleaned and inspected everything and did not find anything that looked out of whack. I thought that maybe it was just a bad load so I went out and shot one more round and the same thing happened. Is there a chance that maybe the action is going bad? I am very tedious when I reload calibrating my scales every 5 rounds. The last shot I took had severe blow back from around the bolt.
Any help is greatly appreciated! I bought the rifle brand new about two months ago and only have about 70 rounds down the tube.

 

[raven1776]

I justed checked the last couple rounds I fired before this happened. They did show signs of preasure. The primers are dimpled. Is there a chance that damage has been done to the rifle or could I back off the powder charge and cure the problem?

 

[trebark]

Interesting you're having such pressure issues with the load. At 89.6 grains I thought your load was very low as I shoot 91 grains in mine and my reading finds that most guys are shooting 92-94 grains of retumbo.

Although I think 89.6 is a low charge, do you have another round from the batch of two you've already shot that you can pull the bullet out of and verify the charge?

Next on my check list would be seating depth. If you're jammed deep in the lands, that can cause a pressure spike.

If these two items check-out, I'm not sure what to do other than reduce the powder charge.

 

[raven1776]

Thank you for your reply. I pulled a bullet this morning and checked the charge. It was at 89.6g. I have been loading these short so that they will fit in the magazine. I intend to pull all the bullets and recheck them all. I read somewhere that fouling could cause exesive preasure but I only have about 10-15 rounds downrange since the last cleaning. I guess after checking all the bullets I will try a different charge and see if that helps. I am worried that there may be damage to the action now. This is my first time dealing with this problem so I am unsure what the effects may be.

 

[Buano]

If your cases show excessive pressure, you have excessive pressure. The question is, "Why?".

Did you change lots or cans of powder? A powder substitution is scary but history tells us such things happen even to experienced reloaders.

Yes, fouling can increase chamber pressure, as can rust. Anything that slows a bullet from escaping down the barrel will increase pressure.

Did you weigh & measure the bullets you pulled? Bullet differences could easily cause a spike in pressure.

Can't offer more insight without laying my hands on your rifle & loads.

Good luck!

 

[OLEJOE]

I would pull the bullets and start over. As mentioned earlier, it could be the powder or the bullets, but something is not right. Check bullet diameters as well as weight. also do you have any other powders sitting around ?

 

[Lefty7mmstw]

What is your case length? If it's long it'll jack up your pressures as it crimps into the bullet when you chamber it. What is your velocity? If you are going over 3K or so with a 210-225 in a 300 rum you are running pretty warm.

 

[Firecat]

I have a 300 rum sendero and I am getting severe pressure at 89 grains of retumbo. I am in fact going away from Retumbo in this set up because of pressure at such a low charge.

 

[azsugarbear]

I just had the same thing happen to me with a custom barrel in 243. I went nuts eliminating possible causes such as COL, confirming same powder used, etc. In the end, I took it back to the smith - thinking I had done something to the action. He took one look down the barrel with his borescope and told me my barrel had a minimum of one layer of carbon over a layer of copper.

I have a strict cleaning regimen using both BMG 50 for copper and GM carb cleaner for the carbon. My patches were clean at the end of my last cleaning, so I was absolutely convinced that my barrel was spotless - until he let me look down his borescope. There was the proof! Some barrels just don't clean as easily as others.

The recommended cure was a little JB borepast. And I do mean just a little! Take some of their finest grit paste and put it on a clean patch. Go back and forth only four or five times over the first 6' of the barrel. Do not repeat. This is one of those cases where a little is good, but even more is bad. Clean out JB paste with oil, then one round of your normal cleaning regimen.

Before you try any of this, clean your barrel thoroughly, then take it to a smith and have him look down the barrel. Most smiths will only charge $5-$10 for this service. You may be surprised by what you find.