Some guidance so I don't blow myself up...

liltank · #29 11-04-2009, 12:56 PM

Quote:

Originally Posted by MontanaRifleman

Interesting Tank, This last spring I loaded some 210 Bergers with RL17 in my 300 WSM expecting max to be around 61-61 g (no data available). i shot through my string with no pressure sings and upped the load 1/2 g at a time another couple of grains... still no pressure... Ended up finally seeing pressure at 66 g. At 65.5 g I was getting 2900+ fps with the 210's. These were on warm spring days, temps about 60-70.

How long is your barrel? I have a stock 26" savage ss in a 1:10. I don't think I could have gotten near that load in 60-70 degrees. I think I have a tight bore. I tried the 63.0 grns of H4350 with 208's and 210 bergers and I had pressure signs. Maybe I am not pushing my rifle hard enough in hot weather!!!

Tank

MontanaRifleman · #30 11-04-2009, 01:09 PM

My barrel is a Sako Finnlight, 24 3/8", 1:11, with a long throat. I loaded the 210's to the lands which left only about 2/3rds of the bearing surface catching the neck. This did leave a little more room in the case, but still, a lot higher charge than I expeted and good velocity.

I'll be doing some temp testing with the 17 in my 25-06 after hunting season.

Every rifle is different, dont push yours too hard

liltank · #31 11-04-2009, 01:22 PM

I had mine throated long so that the heavy pills would not eat up my casing space, but I think it hurt me. I have it where the 208 is seated about 1/2 way in. I think there is too much space and it is hard to get it to shoot consistently due to the powder flowing in the casing. My speeds are hard to get stabilized. I wish I would have had it throated for a normal SAAMI spec chamber.

Tank

ronedog · #32 11-04-2009, 09:04 PM

What are those pressure signs you are referring to and how are they noticed?

liltank · #33 11-05-2009, 08:12 AM

Quote:

Originally Posted by ronedog

What are those pressure signs you are referring to and how are they noticed?

You'll see your primers start to cave into the firing pin hole, and you can see ejector mark on the head of the casing. You will also notice that when you get to heavier loads, the bolt will start to feel stiff and hard to lift to eject. At that point it is a good idea to back down a grain and call it max. Generally when you reload these casings the primer pockets will be loose as well. If they are hit hard enough with pressure primers when you try to reload them will fall out.

Tank

MontanaRifleman · #34 11-05-2009, 09:41 AM

What Tank said is right but I'll expand a little. Pressure signs usally include sticky bolt, excessively flattened and/or cratered primers and ejector marks. Ejector marks are a shiney spot near the edge of the case made by the ejector in your bolt face. You can see these signs individually or in any combination. You can also see these signs without excessive pressure, i.e., a sticky bolt can be caused by a dirty chamber or dirty brass or overswelled case. If you're working up a load and your bolt has been functioning smoothly and all of a sudden it gets sticky, it's a good bet that your getting over pressure. Usually a combination of these signs is a good indicator of over pressure. Recognizing pressure signs is fairly straight forward and you get a better feel for it with experience. Also, different rifles with and different bullet/powder combinations may show different pressure signs. Pressuer signs can also be caused by other factors like cleaning residue or lube in your bore. This happened to me recently while I was treating my bore with a product that required "wet" firing it.

Enlarged primer pockets are a definite sign of pressure. If you're primers seat with little or no force, your pockets are getting enlarged and time to think about backing off.

Hope that helps,

Mark

liltank · #35 11-05-2009, 10:31 AM

Caution when trying to read pressure signs looking at primers. Federal primers are inherently the softest of primers due to its metal cup. You will see the primers to show pressure much sooner than the rifle is capable of. CCI primers are said to be harder and therefore handle higher pressures without showing any indication of overpressure. Like Montana said, it take some time to get use to reading the signs of overpressure and learning what they are.

Tank