300 RUM+180g btip+Retumbo

[remingtonman_25_06]

I did a little bit of shooting/testing today as well. This time I was sighting in my 220 swift with 55g FMJ's. I put a 200 yard zero on it, then busted some 1 liters at 300, then some 2 liters at 500. There going 3900fps, giving me .25" at 100 for 3 shots, and 1 inch groups at 300. I will try these on a yote, but if they run off, I"ll be switching back to my original yote buster, the 55g btip at 3925fps. I want to see if the FMJ's will kill them, so I can skin a couple pelts. Anyways, I also loaded up 2 loads with 180g btips and Retumbo. I loaded up 99g and 100g. I shot them at 300 yards. The 99g load gave me a 4 inch group and was scooting along at 3450fps. The 100g load was down to 3 inch at 3480fps. I'm thinking I'm gonna try 101g. Seems to get a little tighter with a little more powder. I'm not really seeing any signs of pressure. Probly break 3500fps. Thats 30-378 weatherby territory!!!

 

[kraky2]

Be very careful. I think that is one tough case on the 300 rum and it's very possilbe to get some really big pressure without seeing it. I've seen published data over at accuratereloading.com where a very experienced reloader pushed 165's to over 3700 fps without "pressure signs". Running thos loads past quickload (which I admit isn't always perfect) showed 88,000psi.

 

[Tim Behle]

Let me save you a lot of trouble. Don't shoot coyotes with FMJ bullets. The pencil in and pencil out and the coyote runs away. If you insist on trying, either shoot the coyote in the head, or take a trail hound with you. FMJ don't leave a blood trail to follow.

 

[Michael Eichele]

I drove a 180 ACCUBOND at 3709 out of the 300 RUM. It wasnt pretty. It busted my sako style extractor and the reducing ring around the rim of the bolt.

Indeed, be carefull. Personaly I wouldnt drive the 180 past 3300-3350 MAX!!! With a 26-27" pipe anyway.

 

[Jon A]

Unless you have a 29-30" barrel, I'd say you're a bit over pressure. Or your chronograph went whacky.

 

[remingtonman_25_06]

It doesn't seem to bad. Bolt lift is not any worse, on the can of Retumbo, it simply states that 100.5g is a MAX load. With velocity of 3300. My rounds are seated to 3.690" Maybe that has a little to do with it?? I use a crony chronograph, I know its not the best, but it has seemed to work well for me. I was shooting my swift today along with it and it was giving me my expected velocities of 3900 with 38g of IMR-4064 and 55g FMJ. I am going to try 101g tomorrow and see if I can get the group down to 2 inches or so, if not, I probly wont use that powder. I have always used H-1000 in my RUM, but I had some extra Retumbo laying around from when I loaded up my 210g VLD's. Retumbo seems to shoot better when loaded pretty hot out of my rifle, at least with the 2 bullets I've tried. I dont have quick load, so I'm not sure what kinda pressures I'm running at. My primers dont look bad either. I know your all looking out for me.

 

[EZShooter]

Remington 25 -
I second everyone's cautions.... Sierra 5th Edition lists 97.3 gr. MAX... 3,250 FPS out of a 26" barreled Savage.

Also, you probably already know this, but moly can affect pressure, are you shooting coated bullets? It tends to reduce pressure. Another thing - a lot of my BR buddies wince when I start talking about pressure signs, seems that a common opinion is that if you are shooting a custom gun (with a polished / well cut chamber) bolts don't get sticky. Depending on the primer your using, that may not show signs either... Federal usually do, Winchester are tougher, IMHO.

The only consensus I got from my buddies on pressure signs were shiny spots, shiny extractor marks on the brass case heads. BUT, if you have gotten here, you are way in (up) to far, back down a couple percent of load. Trying to remember at what PSI brass flows.... I want to say 85K Psi, not for sure.

Just my 2c.

EZ

 

[James Jones]

Out of a factory gun 26 inchish barrel, your pressure is probably very high , I would back off a bit and more than likly that will srink groups faster than adding powder.

As for the FMJ's and coyotes , I personaly think your going in the wrong direction. If your only gonna be shooting out to 300yds then I'd shoot some 35-40gr bullet out around 4000fps (Easy with yout gun)and blow the bullet up in the dog. A few guys I know that shoot for pelts use the 17 cals for this very reason tiny little entrace and no exit.
I know that I can run 40 gr bullets out of a 22" barreled 22-250 at over 4000fps easly so this should not be a problem for you gun and I have never had a bullet exit on anything bigger than a big house cat.

 

[kraky2]

I don't want to lecture or try to sound like I'm a reloading "god" but there just isn't a "free ride" for velocity. I just started reloading for friend and I've taken notice of how well that case is made....really thick everywhere. I'm not sure if primer pockets would show expansion like other cases or not. I could post the link to accurate reloading but I'm afraid others might try to use the data. The guys there are VERY EXPERIENCED and got their stock remington to do amazing speeds....I emailed them and said "guy's this just isn't right" and they said yeh but we didn't see any pressure signs.
I'm just not sure we can rely on the usual signs experiementing with this cartridge. (I've also been told that there is no freebore in most these guns which is another factor to consider when you see big velocity)
GOSH VELOCITY HAS TO COME FROM PRESSURE. I sure would like to see some pressure testing done on this big boy to help
drive home the possible seriousness of making this cartridge "sing".

 

[lerch]

I have been told to watch the primer pockets on ultra mag brass, I have heard that is where your case will go bad first.

On my Allen Mag I am on my 5th firing and primer pockets are still doing okay, this is with a 104gr load of WC872 with the big ol' 169.5 on top of it.

good luck
steve

 

[remingtonman_25_06]

I am aware of accuratereloading. I browsed there and got quite a few loads as a starting point for quite a few of my 300 RUM loads. Especially with the 200g and 220g SMK's. And yes, they are getting some smoking velocities with it, and even there 338 RUM they tested. My primer pockets are starting to get loose, but there are R-P cases and they have been fired 6 times. I dont think I'm all to out of wack here. Just look on the can of REtumbo, it plainly says that 100.5g is MAX for a 180g bullet out of a 300 RUM. So I started at 99g and went to 100g. I was just letting ya'll kow the velocities that went over my screen. THey were very consistent. The extremem spread were only 15fps for the 99g load, and 18fps for the 100g load. IT's only gonna take me 1 coyote to find out if those 55g fmj's will work as well. IF the yote runs off, i'll try my best to plug him again thats for sure. i dont like them running off after being hit with any bullet. I will try for shoulder shots as I like shoulder shots on coyote-elk. If he still runs off, then I will go back to my 2 inch exit holes that the 55g btip at 3925fps leaves. Not much of a pelt saving load there. I dont like these 40g that much cuz there to **** fast, 4500fps. And after about 300 yards, if you dont get a solid hit on them, I fear they will run off. Just not enough bullet and energy left to dump them tough dogs. Thanks for everyones comments. I'll try 101g today adn definately cronograph them. I"ll keep everyone posted.

 

[Michael Eichele]

[ QUOTE ]
Just look on the can of REtumbo, it plainly says that 100.5g is MAX for a 180g bullet out of a 300 RUM. So I started at 99g and went to 100g.

[/ QUOTE ]

Yes that is what the can sais. I started with a 178 AMAX and 95 of retumbo and locked my bolt in place. Velocity was 3450 FPS. This was not an unussualy hot lot of powder either. This was custom rifle with a tight chamber that doesnt allow for the brass to expand more than .001-.002 of an inch. When you take this expansion out it spikes the pressure. <font color="red"> 90.0 IS MAXIMUM </font> for my rifle at 3300 FPS in 180 ACCUBOND and 178 AMAX.

I am not telling you what to do just please understand that just because the can states you can load 100.5 grains behind a 180 grain bullet doesnt meen it will work for your rifle. Just please be carefull.

 

[kraky2]

The can also says START 6% LOWER. But all that aside I'm gonna try and copy over the data they show at Hogdons' website for 180 grainers. Goodness the start load is running 58,000psi and the max is only 4,000 higher for all that difference in powder. I've never seen that many grains make so little difference. I'm beginning to wish I hadn't volunteered to load my buddies gun....it looks like a project I should be doing and watching closely myself.

180 GR. SPR SPBT(Starting Loads)
DIA. .308" COL: 3.530"
H50BMG 103.0 3005 53,700 PSI
H870 103.0 3130 54,000 PSI
RETUMBO 94.0 3182 58,400 PSI
H1000 91.0 3018 52,300 PSI
H4831 84.0 2997 54,000 PSI
180 GR. SPR SPBT(Maximum Loads)
DIA. .308" COL: 3.530"
H50BMG 108.0C 3159 62,100 PSI
H870 106.0 3206 58,200 PSI
RETUMBO 100.5C 3300 62,400 PSI
H1000 96.0 3218 62,800 PSI
H4831 89.0 3167 62,500 P

 

[sambo3006]

As some of the others have stated, dimensional differences in each rifle can make a difference on max load, but also not all 180 gr bullets (or any other for that matter) are created equal. The length of bearing surface makes a big difference in pressure. I stupidly loaded up 1 gr under what was listed as max with Retumbo for a 225gr bullet behind the 230 gr 338 failsafe in my 338RUM. Sticky bolt and ejector mark on case head! Dropped 3 grains, bolt opens smooth but still ejector mark on case head. When I thought about it, the Failsafe is a flat base bullet with a long bearing surface.

The other guys are right. There is no such thing as a free lunch. The only way to generate more velocity at a given pressure (besides barrel length) is to have a load that reaches the top of the pressure curve faster and remains there longer--more area under the curve.

I know we all want to maximize velocity in our rounds, but gosh, these rounds are impressive enough without pushing the pressure limits. 3300 fps with a 180 gr 30 cal bullet is pretty awesome. Kirby's rounds really push the performance limits, but they have a huge powder capacity to reach those velocities with safe pressure.

I think a person needs to decide what velocity they want with a particular bullet, then look at which cartridge will safely achieve it. I certainly don't want to have to go to the hospital to have primer fragments dug out of my eyeball.(we all should wear our safety glasses--I know I don't always). Just some food for thought.