.300RUM over preasure?

[BigBluePup]

I have a few questions and was hoping some of the guys on here that seem to be very knowledgeable could help me out.

I have a Sendero II .300RUM With Huskemaw optics, Center shot rifle break,

I have been trying to make a load that shoots good and have found two VERY accurate loads.
My question is if the hotter of the two is in the danger zone for the barrel and action.

Load info.

185gr VLD
Case length, 2.855
primer, Fed215
I'm set deep enough to just BARELY get into the magazine
but can't remember off the top of my head the depth I'm set at but I will get that if needed.

Retumbo powder
charged at
97.0gr 3,250fps 10 round average
101.0gr 3,502 10 round average

they both shoot a ragged hole at 200yrd and I was getting 1/2" groups at 550yrds out of the sled.
(have not shot the 97.0gr charge at distance)
my question is will that be a dangerous load?

the only sign of over pressure I get is on the primers there is a little ridge around where the firing pin strikes. I thought it was from over pressure but I shot some factory loads through it the other day and got the same thing.
not QUITE as bad but still noticeable.
could it just be my firing pin is set to deep?

if someone could let me know if I am over pressure that would be great.
Or better yet if anyone knows how to calculate CUP that would also be great!
I know they have a 100.5gr for a 180gr bullet right on the retumbo label so I can't be too far off right?

Thanks!

 

[timmyatnop]

From my experience. That could be a sign of pressure problems, but not always. Do u have a heavy. Bolt lift or extractior marks on the head of the case. I have a few rifles that crater primers and are no where near Max load. Iam sure that are a lot of people on hear that know more about it it then me though. Mabey some of them will chim in and explain about creatored primers.

 

[BigBluePup]

Out of the 15 rounds I made at 101.0gr I had maybe 3 that where a little tight. Not enough to make me worried just a little sticky is all, BUT that was the 4th shot on that brass and from what I can tell I start to loose accuracy after the 3rd shot. so 3 rounds is the cap I am putting on my brass from here on out.

As for the bolt impression it didn't leave any marks. on 2 of them it left a VERYfaint shadow but that's it.

I too hope someone chimes in and tells me the something good. Because that bullet going 3,500fps has some AMAZING ballistics lol,

 

[MTBULLET]

if you noticed, the 100.5 charge wt. is for a DIFFERENT bullet/DIFFERENT weight.
call/e-mail BERGER for suggested loads for VLD'S, before something bad happens.

 

[highridge1]

Alot of the newer rem 700's do this, the firing pin hole is oversized causing this. You can have it bushed and it will stop or just keep shooting. They will do this even without hot loads.

 

[skuna boy]

I have a few questions and was hoping some of the guys on here that seem to be very knowledgeable could help me out.

I have a Sendero II .300RUM With Huskemaw optics, Center shot rifle break,

I have been trying to make a load that shoots good and have found two VERY accurate loads.
My question is if the hotter of the two is in the danger zone for the barrel and action.

Load info.

185gr VLD
Case length, 2.855
primer, Fed215
I'm set deep enough to just BARELY get into the magazine
but can't remember off the top of my head the depth I'm set at but I will get that if needed.

Retumbo powder
charged at
97.0gr 3,250fps 10 round average
101.0gr 3,502 10 round average

they both shoot a ragged hole at 200yrd and I was getting 1/2" groups at 550yrds out of the sled.
(have not shot the 97.0gr charge at distance)
my question is will that be a dangerous load?

the only sign of over pressure I get is on the primers there is a little ridge around where the firing pin strikes. I thought it was from over pressure but I shot some factory loads through it the other day and got the same thing.
not QUITE as bad but still noticeable.
could it just be my firing pin is set to deep?

if someone could let me know if I am over pressure that would be great.
Or better yet if anyone knows how to calculate CUP that would also be great!
I know they have a 100.5gr for a 180gr bullet right on the retumbo label so I can't be too far off right?

Thanks!

what was OAL on that load?

 

[thebbc]

At the standard COAL of 3.6 for the 300 RUM, a max load for the berger 185 shows 63500PSI at 97 grains of retumbo. 101 grains of retumbo at this COAL shows to be nearly 10000psi over max. This kind of overage would be more than noticeable. At a max COAL of 3.85 the same 97 grains would yield 57500PSI while the 101 grain load would yield about 66500PSI. All of this assumes you aren't stuffed into the rifling. If you are then your pressures will be much higher. FYI max SAAMI psi for 300 ultra is 64977PSI.

 

[Loner]

Another world record broken?

 

[Bart B]

Load info.

185gr VLD
Case length, 2.855
primer, Fed215
Retumbo powder
charged at
97.0gr 3,250fps 10 round average
101.0gr 3,502 10 round average

they both shoot a ragged hole at 200yrd and I was getting 1/2" groups at 550yrds out of the sled.
(have not shot the 97.0gr charge at distance)
my question is will that be a dangerous load?

Hodgdon's loading data:

180 GR. SPBT
Hodgdon Retumbo 100.5 grains
3300 fps
62,400 PSI

You load seems ok to me.

However......................................

About your half-inch groups at 500 yards.....

Is that the smallest ever shot?

Or are all of 'em that size?

How many shots per group?

How many groups that size did you shoot?

The only way I know of that folks have shot that size groups all the time is when a friend did it with a .308 Win. using spun-balance-tested bullets that spun perfectly true. His groups were about 3/4ths to 1 inch at 600 yards.

 

[Bart B]

Another world record broken?

I don't think so.

'Tain't none established at 500 yards as far as I know. And no mention of it being shot in a sanctioned IBS or NBRSA or other organization' tournaments.

Over the years, a few folks have shot long range groups testing rifles normally fired hand-held off the shoiulder and their ammo for ammo that are smaller than current benchrest records. I've done that myself, but have made no claim, nor has anyone else, that they are "records." Sierra Bullets has shot test groups in their indoor 100 and 200 yard test ranges that are benchrest record beaters.

I'm not a fan of tiny, few-shot group records. They are at the statistically lucky end of the size spectrum. And very few, if any, rifle barrels and lots of ammo ever equal them again.

The "tiny group" crowd has few folks who remember what the largest group fired was. Too bad as that's what they and everyone can count on all the time. It's the best measure of accuracy there is because it's repeatable.

 

[ken snyder]

Maybe there is a beginners forum that I should be visiting. My group sizes don't even come close to what I read about. Ive been told its because I don't know how to reload and that I need to learn how to shoot and even my gunsmith isnt very good. I even had a Gentleman that held 7 national records all at at one time build me a rifle that he was happy with neither him nor I were able to extract the accuracy I read about. Maybe some day I will measure up or maybe I need to raise my standards above what they currently are! Ive been shooting since the very best powders came in a 5 gallon bucket and was sold by the coffee can. reloading for almost that long and building my own rifles since dirt was an asteroid. My hat is off!

 

[BigBluePup]

Hey guys sorry about the delay in replies, I've been in L.A. for work and will be here till the middle of December. I will get my COAL asap,


highridge1, I've done a little research and have found this to be true and seems to be what I am seeing on my primers.

Bart B, Thanks for the info I will try and get a few more of the details when I get home to see if that changes anything what resources do you guys use to get these numbers?

I usually shoot 3-5 round groups when sighting in a round.
When building a new one (and I'm no expert) I shoot 10 rounds 2-3 at a time and
about 10min apart to not get the barrel to hot.
At 200yrds I can make clover leafs with the current round I have made that's why I wanted to make sure it's a safe round because it shoots REALLY good.

As far as the 1/2" group at 500 it was actually 550,
first thing in the morning dead calm with no wind, I shot a 3 round group at a steal gong. took a tape measure out to it when I was done and 1/2" was the farthest part center to center (of the dimples in the steal) so no it was not measured on paper or even done in the "legal target shooting" method of measuring groups, I don't target shoot so I would not no the first thing about scoring a group like that.
And I could not tell you if it was a fluke or not because I have not shot that round again since I am a little worried about it being to hot.

None the less I am more worried about having my action splatter in my face of burning up my gun in 200rnds then I am at proving my accuracy lol...

Once again thanks guys for the help I will try and get some more data and COAL once I get home.

 

[Bart B]

I usually shoot 3-5 round groups when sighting in a round. When building a new one (and I'm no expert) I shoot 10 rounds 2-3 at a time and about 10min apart to not get the barrel to hot.

If your barrel starts to have poor accuracy as the barrel heats up, I think it's probably binding too hard at one point around its shoulder that bears against the receiver face. Receivers with their receiver face squared up with the thread axis typicaly don't start shooting bad as they heat up. One should be able to shoot knots at most any range shooting 40 rounds about 30 seconds apart. But don't touch the barrel with bare skin; it'll fry skin well done in a heartbeat.

 

[BigBluePup]

If your barrel starts to have poor accuracy as the barrel heats up, I think it's probably binding too hard at one point around its shoulder that bears against the receiver face. Receivers with their receiver face squared up with the thread axis typicaly don't start shooting bad as they heat up. One should be able to shoot knots at most any range shooting 40 rounds about 30 seconds apart. But don't touch the barrel with bare skin; it'll fry skin well done in a heartbeat.

I've never really seen a decrease in accuracy with the barrel getting hot I just guess that's what I've always been told to do.
And it's a hunting riffle so I figured as close as I could get to cold bore first shot accuracy is the best scenario for that riffle.

It's been pretty hot before, I put 25 rounds through it in about 15-20 min once and it would give ya a little pink spot if you touched it like spilling hot coffee or something on your skin lol...