Need some help figuring this out

[dougduey]

Everyone,
Thanks for all the input. Just to clarify some things. First off, I pulled every bullet from my batch of rounds and checked that were the charge they were supposed to be. I used both my RCBS chargemaster scale and my Lee beam scale and everything was dead on. As far as COAL, although I listed it as 3.55", I actually measure from the ogive since I found quite a bit a discrepencey in the length of the bullets. When I did the bullet seating depth test, I used only bullets that were exactly the same length and then measured the length from the ogive. I used the Hornady gauge to find the length to the lands, too, and I've got quite a bit of jump.
So, who knows. Maybe it was that 25-30 degree drop in temp that messed with my Retumbo. I decided to switch powders and use RL26 which is pretty temp stable. I had shot a couple of velocity test rounds with it, so I've got some data to work with.
I'm shooting some tomorrow and will report back.

 

[ChrisInKY]

Hey Doug,
Please take pictures of your brass. Full length and close-ups of the necks ... before and after. How are you cleaning your brass?
Cheers,
Chris

 

[dougduey]

Hey Doug,
Please take pictures of your brass. Full length and close-ups of the necks ... before and after. How are you cleaning your brass?
Cheers,
Chris

Chris
I'll take photos of before and after. I generally clean with a tumbler. If the brass is really dirty, I'll use the ultrasonic. Sometimes I just clean the outside of the brass with a scotchbrite pad or steel wool.
Thanks

 

[dougduey]

Not sure that it is the problem, bu the problem with mono bullets has always been how big to make their dia in order to seal the bore but not create over pressure problems.

We cured this problem with our patented PDR design. We can cut our bulleta over groove dia without pressure issues and still always seal the bore. We don't see changes in pressure from day to day like other monos.

Steve

And that's why I love your bullets Steve!! I need to practice with some cheaper bullets to shoot, but your Hammer Bullets are my go to hunting bullets now

 

[dougduey]

Range report.
I switched to RL26 powder and dropped down from 87.5 gr that gave me a stiff bolt lift a couple weeks ago (velocity 2993 fps @ 74 degrees). So, I loaded rounds in 0.3 gr increments from 86.0-87.2. Not a single issue. Found a velocity "flat spot" node from 86.3-86.9 of 2937 fps with the 86.3 & 86.6 in the same hole and 86.9 to the right by 1/4". Velocities were about 20-25 fps less than what Quickload had predicted (based upon the 2993 velocity of 87.5 gr) until I adjusted the temp down to 50 degrees in Quickload......then it was pretty much dead on. So I think I'm close to being done. I'll load rounds up at 86.6 gr to check the velocity ES & SD and shoot more to see how they group.
I think the issue was the Retumbo. I had loaded up 3 rounds of the 250 SMK with Nosler's starting load of 91.0 gr. Sticky bolt on all 3. Can't tell you why Retumbo is creating so much pressure in my rifle. Maybe it's the combo of the Nosler brass and the Retumbo. I have a box of 100 Lapua cases I was saving for later. I may need to test and see if the Lapua cases makes a difference.
It won't be a total waste if I can't use the Retumbo in the 338, since my 6.5-284 Norma and 7 STW both like Retumbo. Funny thing is I've never seen much of a combined temperature & pressure issue with Retumbo in either of those rifles, which makes me want to do some testing with them now so I don't run into this issue when hunting.

 

[dougduey]

Update
Loaded up 9 rounds of RL-26 at 86.6 gr to check velocity and grouping. First 4 rounds gave me 2988, 2991, 2991, 2992 and no issues. 5th round gave me 2997 and a stuck bolt and case!! Temp was in the high 50's which is only a few degrees warmer than the last time I shot. But velocities were about 51-60 fps higher than last time with the same charge. I shot the 4 remaining grouping test rounds and got a sticky to stuck bolt on all of them. Groups were great (0.6-0.7") with both the MagnettoSpeed on and off. I guess the carbon wrapped barrels aren't really effected by the MagnettoSpeed since POI was the same and the groups were almost identical.
So, I put a call into Nosler and ended up talking to Mike Seay. He was a little perplexed on why I was having the pressure issues. His conclusion is I have a really good and tight barrel and the monolithic bullets are creating a lot of pressure with this barrel. He said that I obviously need to drop the charge down to a point where I consistently don't get any pressure issues.

 

[Barrelnut]

But back in post #19 you were having pressure issues with the 250 SMK?

 

[dougduey]

But back in post #19 you were having pressure issues with the 250 SMK?

True. It may be a very tight barrel and I get more velocity/pressure from what should be safe loads. I'm going to try some 225 gr Accubonds or the 230gr ELDX and see what happens

 

[RockyMtnMT]

The more bullets you shoot trying to figure this out the less expensive mine get.

Steve

 

[dougduey]

The more bullets you shoot trying to figure this out the less expensive mine get.

Steve

No truer words have been spoken, Steve!!!
Your 213 gr bullets shoot great in this rifle. Do the 236 or 260 gr Hammer Hunters give me any real advantage over the 213 gr Hunter, or should I just stick with the 213 gr??

 

[RockyMtnMT]

They will extend your range but not be quite as flat shooting. I used the 213 this hunting season. Thinking I may change to the 236g Hammer Hunter. Just a bit more weight and I think I like the heavier nose petals for terminal performance. The 260g Hammer Hunter would be tje highest bc and still be able to mag feed in most rifles.

They each are great bullets. Couldn't argue against any of them.

Steve

 

[dougduey]

They will extend your range but not be quite as flat shooting. I used the 213 this hunting season. Thinking I may change to the 236g Hammer Hunter. Just a bit more weight and I think I like the heavier nose petals for terminal performance. The 260g Hammer Hunter would be tje highest bc and still be able to mag feed in most rifles.

They each are great bullets. Couldn't argue against any of them.

Steve

I'm liking what you're saying about the 236 gr Hunter, with it being kinda the best of both worlds......good velocity and a little heavier.
Oh, by the way, best tag line I've seen: "To hunt...or not to hunt...? What a stupid question."

 

[HARPERC]

.....I purchased some 225gr Nosler E-tips and I'm using Retumbo. I contacted Nosler to make sure that it was ok to use the starting charge of 93.0 gr they had listed in their manual even though it wasn't one of the bullets listed in that grain.

Does anyone have an idea what the heck is going on here??........

I'll bite! Many moons ago we were trying to get a handle on the Barnes X-bullets, as we were seeing all variations of terminal performance.
We decided to play with the hollow point. Plan was to chuck bullets in a small lathe, and cut it a deeper. If I recall they were about 1 caliber deep (.338), and we planned on cutting them to 2 calibers deep.

While my memory is a bit rusty about depth, the results remain clear. The first few cut great nice soft copper peeled out of the hole. Then from the same box we would get one that couldn't be cut with a carbide bit. We went back and forth cut a couple, then a couple that wouldn't cut period, and gave up.

We gave the bullets to one of the younger guys in the group, who was on a tight budget at the time. He shot a few deer with them. The "soft" ones killed like lightning, the "hard" ones not so much.

I don't know if he tried other bullets, but eventually got rid of the rifle as it never shot as well as he would like. I've always wished he'd have brought it by so I could see if it could be sorted out.

My guess is you found the combination of a "hard" bullet, at either "maximum" tolerance, or just over. Then fired it through a barrel either at "minimum" tolerances or under.

Hammer is the only mono's I will shoot, because Steve is the only person I've met willing to take material, and tolerances seriously.

 

[RockyMtnMT]

I'm liking what you're saying about the 236 gr Hunter, with it being kinda the best of both worlds......good velocity and a little heavier.
Oh, by the way, best tag line I've seen: "To hunt...or not to hunt...? What a stupid question."

Someone a long time ago gave me a T-shirt with that on it. I always liked it.

Steve