New brass and pressure

[Varmint Hunter]

What surprises me is that the OP had .015" growth to the shoulder. I have never seen anything even close to that. Some of my new brass barely moves with a nearly full load. However, I'm not shooting belted cases.

 

[sedancowboy]

What surprises me is that the OP had .015" growth to the shoulder. I have never seen anything even close to that. Some of my new brass barely moves with a nearly full load. However, I'm not shooting belted cases.

That is not unusual for a belted mag. My 300 win mag grows about .017 with some brass.

 

[Varmint Hunter]

That is not unusual for a belted mag. My 300 win mag grows about .017 with some brass.

Interesting

 

[vancewalker007]

Starting load work on a re-barreled 7mag.
Using new nosler brass. After first firing on the new brass, the shoulder has moved .015" and I still don't think it has fully filled the chamber. I can easily chamber the once fired brass. I'm going to set up my FL bushing sizing die to just neck size it for this next firing.
My question is. How much will the pressure change. I ran a pressure test with the new brass. If the brass is not moving as much the 2nd time around. Will that increase or decrease pressure? I'm going to repeat the test on the next firing. Just curious how close I can start to the max pressure I reached in the first test?

Hopefully that makes sense..

Another issue you may run into with the 7mm Rem Mag is sizing problems near the belt. Everyone I know that has a belted mag has this issue. An easy fix to this is a special collet die. See the link below.

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

 

[QuietTexan]

Bullet seating. Will a particular bullet like a similar seating depth with a different powder in the same rifle?

Example, 175 eldx likes -.040" w/ RL26. Will it like -.040" w/ H1000 or Retumbo? Giver or take 5-10 thou.

Obviously I'll run a separate test but I could shorten it and save components if I had an area to shoot for.
RL26 is hard to come buy. I'd like to use as little of that as possible until I can locate some more.

I've found that the coarse seating interval (meaning -.040" off versus -0.125" off) is pretty resilient to powder changes. It'll need to be tuned for sure but I wouldn't run another full coarse depth test for the same bullet if the powder is a relatively small change of H1000 to Retumbo.

At a .125" off I'm. 027" longer than book

Then no waste in testing the two longer major depths with the ELD-X IMO. I tend to throw book COL into seating depth tests if it doesn't fall in the 0.010/050/090/130" range already.

This is a Berger 210 VLD in my 300 RUM, you can see how far the 3.600" book spec was jumping.

Interesting

Yeah, that's why the Peterson "long" 300WM brass is a game changer, it's built with that extra length originally to take that initial stretch out of the equation.

With the 300 PRC reamer problems it really keeps the 300 WM in the game for standard chambers. Even though the AW reamer should fix the PRC for anyone who builds a rifle, not always the case for off the shelf buyers. I'm wondering if we'll see if for the 7 Rem Mag eventually.

.300 Win Mag

Shooters that reload .300 Win Mag casings have often wished they could get more reloads from their casings. Well now you can!

www.petersoncartridge.com

 

[BillyGoatGruff]

What surprises me is that the OP had .015" growth to the shoulder. I have never seen anything even close to that. Some of my new brass barely moves with a nearly full load. However, I'm not shooting belted cases.

Well it surprised me too. I had to measure things several times to believe it. Your comment got me curious though. So I measured some factory ammunition I have laying around just as references. Fed 160 accb, a Barnes somethin and a Win 175 something. Shoulders all within 1-2 thou of my new Nosler brass. But two Hornady's are only 4-5 thou shorter than my new once fired Nosler. so much closer to actual chamber length. I also measured some older multi fired Nosler brass from the previous barrel and those are 3 thou shorter than my new once fired. So the new chamber is a touch longer than the old one. And new ammunition varies quite a lot from one brand to the other.
I'm surprised that the new Nosler brass is so short. You'd think they'd make it closer in the shoulder knowing that anyone buying it is hand loading for accuracy and want a couple thou shoulder bump. I could see 5 thou short , but 15 thou..? geez!

 

[BillyGoatGruff]

Another issue you may run into with the 7mm Rem Mag is sizing problems near the belt. Everyone I know that has a belted mag has this issue. An easy fix to this is a special collet die. See the link below.

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

I actually have that. Although I have really used it yet though. I have/had 2-3 firings on 300 pieces of nosler brass in the old barrel and never needed it. Some of the 3rd fire stuff is real close though. it fits in the go no go side of the die just barely. I would guess after the 4th firing it would need to be sized.

 

[Bob Wright]

What surprises me is that the OP had .015" growth to the shoulder. I have never seen anything even close to that. Some of my new brass barely moves with a nearly full load. However, I'm not shooting belted cases.

Mine grew .019 which is about "average". The parent case was a "dangerous game load for stuff that would eat or stomp the hunter fiddling with a case that wouldn't chamber. That's the reason the belt is headspacing until it fully blows out to the shoulder. After I annealed my 7RM brass they all came in less than .001 headspace. That was at 3 firings when I annealed. They varied .003 before annealing and 3x fired.

 

[BillyGoatGruff]

Mine grew .019 which is about "average". The parent case was a "dangerous game load for stuff that would eat or stomp the hunter fiddling with a case that wouldn't chamber. That's the reason the belt is headspacing until it fully blows out to the shoulder. After I annealed my 7RM brass they all came in less than .001 headspace. That was at 3 firings when I annealed. They varied .003 before annealing and 3x fired.

I recently picked up an annealer. I plan to anneal after every firing from here on out on all my rifles.

 

[vancewalker007]

I actually have that. Although I have really used it yet though. I have/had 2-3 firings on 300 pieces of nosler brass in the old barrel and never needed it. Some of the 3rd fire stuff is real close though. it fits in the go no go side of the die just barely. I would guess after the 4th firing it would need to be sized.

I think its a handy thing to have. We ran into it years ago when we were shooting 7mm STWs. We had plenty of brass back then so we just tossed them. I have run into a similar problem with my 6.5 PRC near the base. I guess its a common problem with them. I just bumped the should a little more and have been able to squeeze that base area down enough.

 

[Mike Matteson]

I had the same problem a great many years ago. It was in a 308 Norma Mag. The case length is somewhat different. The the shoulder it's shorter, neck length is longer. I resize 300 Win, and 7mm RM, and 338 WM to its chamber sizes. Was having case stretch problems in about 3 firing. Changed to 300 WM neck sizing die. Ended that problem. if I recall correctly I didn't have much problem with chambering either after that. It only sizers about 2/3 of the neck. Once fireformed no problems. Primer pockets were gone in about 12 firing. Annealing came into the picture about the same time. Stop the neck splitting. You kind of stop the case group by just bumping the shoulder. That were I would go. Peterson does make long 300 WM case. Have to watch when they come out again. I saw when they came out. Nothing on the market presently. I am going to get some the next time they are out for my 338 WM

 

[BillyGoatGruff]

New questions, Thought of start here vs starting a whole new thread.

1st. Repeated the upper end of my previous pressure test. 1st run had slight pressure signs at 69gr no pressure sings at 68.5gr. Started new test at 68.4, then had a .6 and a .8 loaded. Had pressure sings at 68.4 this time around.
Cause of why it started at a different charge weight this time around?
Same brass, bullet, powder and cbto length.
Only difference is I cleaned the rifle. But the rifle was also clean before previous test
#2
Seating depth test. The best two groups had straight vertical stringing. The rest were typical triangle shapes but pretty open groups.
What causes vertical stringing?

 

[vancewalker007]

New questions, Thought of start here vs starting a whole new thread.

1st. Repeated the upper end of my previous pressure test. 1st run had slight pressure signs at 69gr no pressure sings at 68.5gr. Started new test at 68.4, then had a .6 and a .8 loaded. Had pressure sings at 68.4 this time around.
Cause of why it started at a different charge weight this time around?
Same brass, bullet, powder and cbto length.
Only difference is I cleaned the rifle. But the rifle was also clean before previous test
#2
Seating depth test. The best two groups had straight vertical stringing. The rest were typical triangle shapes but pretty open groups.
What causes vertical stringing?

Have you verified that 68.4gr is in a powder node? If 68.4 is on a velocity jump point that could cause some vertical stringing if the velocity is swinging all over.

Vertical stringing can sometimes be caused by poor shooting form and/or poor rear bag stabilization. Make sure you are using a stable rest set up that allow the rifle to smoothly slide straight back on recoil instead of causing a bunch of muzzle jump. And, of course, check all the mounting screws and etc. I'd avoid using a bipod when doing this type of accuracy testing. It can induce a lot of negative muzzle movement on hard bench surfaces. Just some ideas to help you smooth it out.

 

[BillyGoatGruff]

Have you verified that 68.4gr is in a powder node? If 68.4 is on a velocity jump point that could cause some vertical stringing if the velocity is swinging all over.

Vertical stringing can sometimes be caused by poor shooting form and/or poor rear bag stabilization. Make sure you are using a stable rest set up that allow the rifle to smoothly slide straight back on recoil instead of causing a bunch of muzzle jump. And, of course, check all the mounting screws and etc. I'd avoid using a bipod when doing this type of accuracy testing. It can induce a lot of negative muzzle movement on hard bench surfaces. Just some ideas to help you smooth it out.

68.4gr was where it hit pressure today. I had hit pressure at 69gr last week. Weather conditions similar. Probably within a few degrees temperature wise.

The vertical stringing came on two depths of a seating test .050" off and .075" off. Using 67gr. But they were the best groups of the seating test. I chose 67. Because from my earlier pressure test I had from 66.5-67.5 had similar velocities. Just took the middle to perform the seating test with.
I'm going to test both sides of the better seating depth in smaller increments

Trying to get rounds down the tube so it can speed up/stabilize or whatever and get into my once fired brass before I really start fine tuning the powder charge

I have a solid rear bag and shoot off a bench rest up front.