300RUM brass life????????

[JustC]

Ok guys,....Boyd,..338-378,.....everyone else,...what are you getting? I got 4 firings with wayyyy under max load,..as did two other individuals who own them as well. I felt the primers go in just a bit too easy on the 5th loading,..but thought I would try them again anyway. The first one,...loaded with 88gr of RL25 and a SMK 200gr,...I had to smack the bolt open. I know the bullet was seated out to far from the pressure of closing the bolt,..but I don't think the charge was too much. I think the case was just expanded too much. The last time around,...It was all I could do to get them out of the Wilson seater die,....and even if I body size them,...the primer pockets pretty much dictate that being a waste of time.

Is there something I have missed? I DO NOT shoot max loads unless the gun likes them,...which I can't tell because I have gotten .250" groups from H1000 and RL25 thus far,..and much before max charges,...so it's not my powder.

Anyone?

 

[Darryl Cassel]

Hello Just C

I have the Tomahawk which is the 300 RUM improved.

I shorten the case by .010" to start with.
I turn the necks to .012" thickness.

I full length resize after "EVERY" firing.

I shoot VERY stiff loads using the 240 gr Sierra MK.

Have got up to 7 firings/loadings from the brass so far.

I felt that 7X loading with stiff loads and 240 gr bullets was great, considering how inexpensive the Remington brass is.

What bullet are you using?

Later
DC

 

[JustC]

Hey Darryl.

I am using the 200gr matchking in a 30" 10twist tube. I have turned the high spots on the neck,...and they are at about a .335 loaded round +/-. I am using a .332 bushing,..federal 215M primers,...and so far have only worked with H1000 and RL25. I have given up on the H1000 after chronographing 88gr against 87gr of RL25 at 250FPS faster!!!!

I loaded some H870,...but have only fired 4 rounds so far,..and have no opinion at this point. I also have Retumbo and have not yet opened the can.

May I ask why you full length them every time? Mine shoot well fireforming,..but better when neck sized and once fired. They formed brass is in the .250" range when I do my part.

 

[Darryl Cassel]

Hello


Anytime I work with a large case and with potent loads using heavy bullets, I have always had the best results when full length resizing the cases. Results range from, the brass holding up much longer to better accuracy "most" of the time.

Many matches have been won while shooting in 1000 yard competitions while the person is fireforming or using brand new brass that was full lengthed sized.

This is not true when talking about the PPC size cases but, for large cases such as the 300 RUM, it seems to be true.

Resizing and bumping the shoulder back sometimes helps with accuracy also.

Later
DC

 

[JustC]

So If I have a body die,...should I be running the cases through it every time? And how should I set it up?

Thanks

Also,...how does this affect my primer pocket life?

 

[Mountain Man]

i'm on about round 8-9 so far with my brass. they're still shooting sub MOA groups without problem, and i havent had one go bad yet. all i do is trim length, but i do full size every one as well. ran 89gr RL25 and 91gr of H1000 with 200SMK's already, and now my working load is 90 with 220SMK's using retumbo. fed 215 primers in all of them. probably should switch brass out here soon, but they keep shooting around 3/4MOA groups and thats good enough for me. primers have been seating fairly easy, but i havent lost any accuracy because of it. are your cases lubed at all when you shoot? that might allow too much expanding- make sure they're dry.

-brian

 

[JustC]

Mountain Man,...my cases are lubed to be able to get them out of the wilson dies. I have always been told that neck sizing is the way to go for accuracy,..and now Darryl has thrown me for a loop. I hope he expounds upon his statement (Hint,..Hint)

I do wipe them down before I take them to the range.

I had to smack the bolt open yesterday on a case on it's 5th firing that should have shown NO pressure signs,...as I had shot that load before with no problems. It was also DIFFICULT to get it out of the die. After the 3rd firing,..you have to lube them well,..anc still must be carefull prying them from the wilson die,..or you can bend the rims.

[ 07-28-2003: Message edited by: JustC ]

 

[Mountain Man]

justc-

lubing them for the die is fine, just make sure they're dry before you shoot. otherwise, it lets the brass expand too much, and it'll weaken them between expanding and getting resized in your die. i've heard both full sizing and neck sizing leads to better accuracy. i believe S1 had a real good post about why you should full size on bigger rounds, and i hope it wasnt taken down in the recent episode. DC might be able to give all the technical specs on it. cases fit my chamber and dies real close, so even with full sizing, so there isnt much resistance. your chamber vs die sizes might be a little off, causing the sticking problem.

-brian

 

[Darryl Cassel]

Just C

Neck sizing is NOT always the best way to go for large magnum sized cases when trying for the best accuracy.
Brass has a tendency to flow more rapidly with additional pressure and heat that the larger mag cases produce.

With small cases such as the PPC and 222 style cases just necking is the way to reload and shoot for accuracy.

Big mag cases are a different ball game and we have found that, the best accuracy for 1000 yard match shooting is with full length sized cases.

I knew of one fellow that won the aggregate a few years ago that fired brand new brass in every match. It was never reloaded and fired the second time.

That showed a lot of us that the neck sizing only is NOT the way to go in long range target or hunting situations.

This is especially true with the Remington brass that seems to flow a lot under pressure when fired. You will get quite a bit of stretching in the standard 300 RUM.
In the Tomahawk and it's 35 degree shoulder, this is not as drastic.

I wish Lapua or Norma made 300 RUM brass.

Check your overall length and cut it back .010" from factory specs.
Keep your cases clean and "full length" size after "every" firing.

There are several of us getting many firings out of our cases by using this method.

Later
DC

 

[JustC]

Darryl,..so would an "s" series FL die be of benefit to me? or some other type?

Would I set it to completely re-size (i.e. small gap between sheel holder and die body) or set it to partial size and then neck size with the wilson neck die?

Also,..I have found RL25 to be the best so far for my 200gr pills,..am I on the right track with that? Retumbo?

Also,...with the FL sizing,..when do your primer pockets start to become "easy".

Thanks

 

[barry206]

JustC,the 300rum is a tempermental sob.After reading Darryls remarks on the Tomohawk,the shoulder angle change may be the way to go.
To get me going in the right direction I purchased a Redding instant indicator in 300rum.This allowed me to see exactly where the headspace was located in relation to the dummy round.Mine was .007 longer than the dummy before I could feel contact with the shoulder[firing pin out]I have to bump the shoulder back to .002 after each firing or the bolt wont open..[005 headspace]The headspace measured .001 after firing.In other words necksizing was out of the question.I use the type s full lenght die now,sizing about half the neck.You can not partial resize this round.When you squeeze the sides of the brass and dont bump the shoulder,you actually make the brass longer decreasing headspace.Or I guess I should say I cant.You can see this clearly using the indicator.As for brass life,after about three firings I can tell the primer pockets are loosening up.Ive been doing 5 loads then trashing them after I had case head seperation on the 7th firing a while back.
I bought a new Rem police model two years ago.After only getting 1.250in groups I decided to put a shilen match barrel on.Dont get me wrong,it shoots great.I just cant get nowhere near max loads as has been printed. 85grs of H-4831 will push a 175 berger at 3336 and a stiff bolt.89grs of H-1000 will push a 200SMK 3220fps.After firing this I trashed that piece of brass,I could put the primer in by hand.Needless to say my loads are down a bit now but this round isnt for the easily ****ed-off.Has anyone eles had this happen with a Shilen barrel?

 

[JustC]

Barry,..your brass life is spot on with mine so far. Darryl has been kind enough to help me,..and I will see what I get doing it his way.

My brass closes in the chamber fine (pacnor 30" finished at 1"). The brass wants to stay in the die at aroud the 4th loading. The lube must be increased in order to have the shell pry out without ruining the rim. This is of course due to the fact that my wilson die was ordered as a blank by my gunsmith and reamed with the chamber reamer,..therefore it is basicaly THE chamber with a seater plug in it.

I inquired of Darryl as to the die to go with,..and the "s" sereis is what I had in mind. One more die isn't gonna break the bank after all this $$ i have already invested in this rig.

 

[Boyd Heaton]

I had ten loading's on my Match Brass last year.....Full length resize everytime

 

[Mysticplayer]

JustC and Barry, Did you have your action lugs lapped for 90% or higher contact? During lockup, does the BOLT face touch the rear of the barrel?

Be design or luck, my Enfields that I have built my cannons on have very firm lock up. Brass life so far has been pretty good (about 8 reloads). If there is any slop in the lugs, then the bolt may be bending a smidge allowing for the case to grow and not rechamber. When dealing with these big case magnums, there is a lot of bolt thrust.

I have wondered about brass growth and our actions. I really don't think it can happen if there is zero tolerance at lock and no movement during firing. How could the brass expand? So neck sizing would work in this instance.

My guess is that there is a "gap" somewhere either in the action or during firing that allows the brass to expand. This expanded brass is very hard to extract (under extreme compression from the action returning to its original size) and usually will not chamber (springs to the new expanded size when extracted). The above symptoms are used to indicate over pressure but could it also indicate action/bolt flex?

Would explain why brass life is pretty much forever in a PPC BR rifle. I agree with Darryl that the higher and longer burn of these magnums stresses the brass much harder leading toshorter life. But, I also feel that there must be some give in the action to really accelerate the expansion/stretching.

I am comparing both neck and FL sizing with my new RUM. Too hot to shoot right now but when it cools off will let you guys know.

The test will compare brass life (number of firings before something breaks), ease of chambering and extraction, accuracy at 250yds. Will use the same amount of powder. Will also FL resize some of the neck sized brass after they no longer chamber and see if I get any head separation.

Jerry

Jerry