pressure signs

[youngbuck]

Ive been working up a load for my 300RUM. The last two loads I shot were 88 and 89.5grns of h1000. I'm shooting 208 gr A-max, 215 match primers, and FL sized Rem brass. Both loads looked the same; flattened, squared off primers and some cratering from the firing pin. I have not gotten any sticky or hard bolt lifts. The groups are shrinking with the charges increasing. My last 3 shot group was a little under an inch @ 1ooyds. The 89.5gr chronographed right at 3000fps w/ a ES of 14. I'd like to keep increasing the charge to see if the groups continue to shrink or get worse. I don't want to stop short of a "super load". The gun is a factory Rem700 w/ factory 26" tube. The rifle has always been a shooter. My previous load was a 180gr AB w/ IMR4350 shooting about 3/4" @ 100. The 89.5gr h1000 load is good enough to play with to be my load now. Should I quit while I'm ahead? I'm happy w/ a factory rifle shooting under 1MOA, but would be happier with it shooting 1/2 MOA. I know there's a few hot rod loaders on here and wondering what you look for for your the max load.

[jeffro]

First off, Im not a hot rod reloader at all, but 3000fps is slow with the 300RUM. Im getting 2955fps with a 24in 300WM. No press at all, and good brass life. I would let the rifle tell you what it likes, within reason. Was your barrel slow with other loads, or fast. Some bolts will crater way before the pressure is to high. This is particularly true with some of the new REM700s. The 208 should shoot much better than 1moa with a decent barrel.

 

Another idea is to run a ladder test, and the rifle will tell you where it is happy.

[youngbuck]

My gun was never slow or fast according to any manuals on any of my other loads, pretty much in line. My gun has always cratered 215m primers. I know some guys are getting more speed with less pressure with the Retumbo. I would rather have the low velocity spread instead of a little speed w/ H1000. There isn't very much published info on 208/210 in the RUM. Walt Berger sent me some data on the 210 VLDs. He shows max load of 91.6grs h1000 @ 3036fps. I'm almost there with 89.5grs, but my primers make it seem I'm pretty close to max. I've thought about the latter test, but what charge do I stop at? I would be in the same spot, just making smaller increases. I'm not trying to run a super hot load, and velocity comes after accuracy and extreme spread for me. I just want to know where my max will be, and what other signs would indicate when I'm there.

[elkhunter]

I have had the same issues as you, increasing powder loads meant tigher groups. I shoot a 300winmag and discovered some bullets with tighter groups but they were slower loads which meant more of a drop at longer distance. Thats the greatest thing about reloads, my loads certainly wouldnt work well on another man's 300 win mag. I would say keep working at it, the limit is the day you can't beat your own loads. I always have to remind myself that a 1/4 inch difference at 300 yards does not mean much to a coues, but you probably shoot farther than that!

[STOMP442]

Is the rifle bedded and the barrel free floated? Doing this can increase accuracy significantly. You may have a sweet load going and external forces on the barrel from the stock may be causing your groups to open up a bit.

[azgutpile]

With my 300 RUM, my first thought was the same as yours, my primers appear to have a flattend appearance with some flow back into and around the firing pin; however, after looking at other cases fired from other RUMs, I realized that this is typical. If your still concerned, you could try another brand of primers, the 215M are one of the hotter primers out. If I were you, I would keep moving up slowly until one of the following occurs: you start getting a sticky bolt, you see a small circle form on the base of the case where the ejector plunger makes contact, the lettering starts smearing or deforming on the head of the case, you reach your book's the max load, you reach the book's max velocity, or the gun blows up...

 

 

Here is my most accurate load for my rifle.

 

Nosler Brass

215M primer

86.5 grains of H1000

Berger 210 Hunting VLD

full length sized

.02" off the lands

3,050 FPS

1/4 @ 100 yards

2.3" @750 yards

 

 

Stiller Predator action

28" Schneider P5 barrel

match grade chamber

[jeffro]

+1 azgutpile

 

Keep moving up slowly until one of the following occurs; you start getting a sticky bolt, you star seeing a small circle form on the base of the case where the ejector plunger would contact it, the lettering starts getting on the head of the case starts deforming/ smeared, you reach the max load that you have in your book

 

Looking at the primers only isnt that good of a test of pressure due to primer cups being very different in hardness. FED215 are very soft, and CCI250 are hard. They will look very different even with the same load. CCI250s will not be all that flatened and your rifle may be over pressure.

[TAM]

Sticky bolt, plunger impression on the brass, and enlarged primer pockets have always been the three biggest warning signs of high pressure for me. I have also noticed that most 300 RUM's seem to like max or near max loads. If you haven't tried Retumbo then you should! I don't know of a 300 RUM that doesn't love the stuff. It's uaually very accurate and pushes heavy bullets faster than most other powders. My pet load for a 210 grain JLK thru my 300 RUM is 92.2 grains Retumbo.

 

I spent a couple hours at the range today testing out a 180 grain JLK long boat tail bullet thru my 300 RUM. I started at 98 grains of Retumbo and got a giant 1.25" group. Next group was 98.5 grains which produced one jagged hole that measured 0.192 inches. Then 99 grains and 99.5 grains both produced about half inch size groups. All at 100 yards.

 

Every rifle, bullet, powder, brass, and primer are all going to shoot a little different. Sometimes you pull your hair out trying to find the perfect load and sometimes you get lucky like I did today. If your groups are getting smaller I'd keep burning powder until you see signs of pressure then STOP!

 

Good luck!

[firstcoueswas80]

I will always stop and back off a touch at sticky bolt lift. My 270 wsm loved 64.5 grains of H4831SC (shot .138" at 100 yards) but the bolt was sticking so I backed it off to 63.5 grans, which still shot at a half inch or so.

[youngbuck]

Thanks guys, I don't have any marks on the head stamp of the brass yet, I figured I would slowly go a little hotter and see what I get. I have tried Retumbo, but my extreme spread was 60-80. My ES w/ H1000 is less than 20fps. I was worried about my loads getting close to max because the primers were really squared off. I've never had a load that squared off the primers this much. I'll bump up the charge a little and see how my groups change at distance. Right now I'm seating the bullets just deep enough to fit them in my magazine. I'm gonna play with that and see if turning it into a single shot helps my groups any. I did play with seating depths on some empy cases. For you guys who are seating them way out there on standard magnum actions, how to you get the loaded unfired round out? I was alomst having to take the bolt out every time when I was right up against the lands.

 

TAM, I know a few guys using 180s that use around 100grs of Retumbo for their loads.

[ultra300mag]

Here is my two cents worth. I, like everyone else would love to be shooting a gun that is the fastest on the mountain but in all reality accuracy is much more important than speed. Most of us who shoot long range have a scope to dial the turret and so speed is not as critical as it used to be. We don't have to use the wild a guess of days past. Yes velocity is still important to figure how much hitting power there is but once again the bullet you choose is probably as important as the velocity. So as far as my own reloading my accuracy is much more important that squeezing out 10 more fps! Just my opinion and we all know that opinions are like a-holes. Everyone has a different one. Good luck and happy hunting.

[TAM]

TAM, I know a few guys using 180s that use around 100grs of Retumbo for their loads.

 

Yep I know a few as well but I'm not even going to bother when 98.5 grains groups less than 1/4" MOA. I did shoot a few with 99.5 grains yesterday and they did not show any signs of pressure, so I'm sure I could go higher if I wanted to.

 

 

Here is my two cents worth. I, like everyone else would love to be shooting a gun that is the fastest on the mountain but in all reality accuracy is much more important than speed. Most of us who shoot long range have a scope to dial the turret and so speed is not as critical as it used to be. We don't have to use the wild a guess of days past. Yes velocity is still important to figure how much hitting power there is but once again the bullet you choose is probably as important as the velocity. So as far as my own reloading my accuracy is much more important that squeezing out 10 more fps! Just my opinion and we all know that opinions are like a-holes. Everyone has a different one. Good luck and happy hunting.

 

I agree, but if a person is willing to spend some time working a load it is possible to achieve both!

[youngbuck]

Well I loaded 5rounds each of .5gr powder increases to max listed load. I started on what shot the best on my last outing, 89.5gr of H1000. I was only able to shoot 3 rounds. 1 fouling shot and 2 to group. I let my rifle cool down before I shot again. The wind picked up and I dedcided to wait to shoot groups untill it wasn't as windy (never clmed down that day). I went to grab my target @ 250yds and was pleasantly surprised. It is only a 2 shot group, but I was happy with it. My extreme spread was only 9fps.