37XC build
- Thread starter jasent
- Start date
3rd and 6th firings on brass.
Both lots. I don’t think the bottom of the case is getting sized enough.002” difference from new brass to fired and resized brass.
Both lots. I don’t think the bottom of the case is getting sized enough.002” difference from new brass to fired and resized brass.
No neither, was maybe 15 f warmer than load development but I also tried one grain less charge with same results
I may do a pressure test again just to rule everything out
I may do a pressure test again just to rule everything out
Jason
Your brass is fatigued. Start over with new stuff
I'm experimenting with the same condition with Barrett brass . Most of what I,m seeing is a lot of guys are running at the top or over to obtain velocities. Not good.
Just made up 12 pieces RWS into 416 Barrett to see what shakes out. Test run next week.
BTW, for all you cheap ass hats, I think WT C is the only bullet maker who uses an independent source for bc data.
It is'nt cheap!.
Alan
I can understand the 6th firing lot getting fatigued but why the 3rd? And why would the 6th firing lot not show signs till now and not on the it’s 3rd,4th, or 5th
Not a cheap ass. Im sorry you waste your money on independent bc testing and have to pass that on to your customers. Why are other companies numbers solid without that added cost?
Reminds me of the phrase... “we screw the next guy and pass the savings on to you!”
I love when companies call a group in the small community they sell to asshats.
I might be an assHat, but I do know my $ for bullets will stay west of the Mississippi.
Did you know the bullet makers west of the Mississippi test and confirm their bullet BC without passing the cost on to their customers...pretty neat concept.
I am wondering now if I am running things too hot for the savage action. Even the rim is .002” over size and the groove. Surprisingly primer pockets are still tight.
This is with both lots
This is with both lots
If pockets are tight, I would assume your case heads haven’t grown too much to extract. Again, it goes back to you having the same problem with 3rd and 6th firing brass with the same load. If you’re running the same load and lot of brass but one group is giving you problems at 3 and the other group at 6, but they both started having the problem on the same outing, I’m still thinking you have a different problem
That’s my suspicion
Standard action+moderately sized tenon+extra meat lost by running a barrel nut= equals prison rape level stretching.
Somewhere I found an article talking about magnums and barrel nuts.
Criterion not doing some magnums with a nut get me searching.
Gist of it was excessive side wall expansion because of the lack of barrel thickness surrounding it with a Similar mechanic as receivers stretch on firing allowed brass to grow more then the receiver shrinks back to original size(not stretched to yield but brass was) and locks the brass in
The rim and extractor groove isn't supported with any action. The brass is on it's own for the length of the bolt recess, plus the bolt to barrel end clearance, plus the chamfer on the chamber. The large shank Savage tennon is as large as most dedicated 338 Lapua custom actions and has a finer pitch thread.
I'm running a 33XC on a Savage 116 action. The pressure QL gave for some of my development loads were over 75 ksi w/o pressure signs on the brass. The brass became difficult to size as the modeled pressures approached 80 ksi, but I never saw an ejector mark. I've seen no growth in the headspace in 300 rounds.
If you post the details of your loads with their velocities, I'll set up a QL model and post it. I think you'll be surprised at the pressures. You simply can not run Cheytac velocities with less case volume without running higher pressures. My guess from the information provided is as the round count went up on the barrel, so did the pressures. Have you been tracking velocities?
I'm also wondering if your chambering method left the chamber a little undersized. Do you have the tools to measure IDs to the tenth thousandths?
I'm running a 33XC on a Savage 116 action. The pressure QL gave for some of my development loads were over 75 ksi w/o pressure signs on the brass. The brass became difficult to size as the modeled pressures approached 80 ksi, but I never saw an ejector mark. I've seen no growth in the headspace in 300 rounds.
If you post the details of your loads with their velocities, I'll set up a QL model and post it. I think you'll be surprised at the pressures. You simply can not run Cheytac velocities with less case volume without running higher pressures. My guess from the information provided is as the round count went up on the barrel, so did the pressures. Have you been tracking velocities?
I'm also wondering if your chambering method left the chamber a little undersized. Do you have the tools to measure IDs to the tenth thousandths?
I talked to another savage/37XC shooter and he is having the same issues as I am
My headspace is .030 long, I’m running 361gr flatlines with 120 gr h1000 at 3039 FPS from 32” 1:10 using fed 215m’s. No ejector swipe but primers are slightly flatter than when primed. Still round at the edges
4.780 coal
4.780 coal
One thing that comes to mind is the first 150 rounds through the barrel on the first lot of brass was all with the 350gr smk. Maybe that was lower pressures and now shooting monos I’m at higher pressure.
Hasn’t changed since I worked up the flatline load. So 78 rounds. All of the new lot and half the firings on the old lot are with flatlines
Totally forgot about the barrel break in so to speak with the smks
Totally forgot about the barrel break in so to speak with the smks
Most likely because 15 over ambient put you over what the brass will withstand. Work hardening at the bottom limits sizing via springback. The only way to try to reclaim that brass is push thru die to sweage the base diameter back to as new
Sometimes that works, sometimes not
Your extractor undercut diameter is a clue to being over pressure.
.002 is starting to reach limits.
Ya I’m thinking I am over pressure for this rifle. Can not size brass back to smooth chambering.
Just an FYI smk load was same 120gr h1000 and same lot of powder.
Just an FYI smk load was same 120gr h1000 and same lot of powder.
Just run a lower node.
The performance difference is minor and things will be stable and friendly.
Hurry up and get your load figured out.
when I get my Charlie tarac I’m driving NE!
when I get my Charlie tarac I’m driving NE!
Well I got my brass to chamber smooth as silk. Went with a double bump held for 10-15 sec each. Tossed what ever wouldn’t.
New to posting on these forums, just been a long time reader, hope I'll be accepted.
I've currently been shooting a 300 norma mag and have been getting sketchy hits and misses at 2660 yards in 15-20 mph winds at my spot. Decided to make the plunge into a 37 xc so I can shoot a heavier bullet and fight the wind. Thinking of ordering from either K&P or Schneider barrel, not sure if one is better than the other. Schneider is button cut, K&P, rifle cut. Would love to be swayed in one dirrection. I'd love to shoot the 390 Atips when they come out, with some barrel break in using the 350 smk. Not exactly sure how fast we can spin the Atips since they have not been released yet, but was wondering if I could order my barrel in a 8 or 9 twist to shoot the solids at a later date. There just so expensive, this is the route i feel comfortable in taking.
Thanks for your time,
Pat
I've currently been shooting a 300 norma mag and have been getting sketchy hits and misses at 2660 yards in 15-20 mph winds at my spot. Decided to make the plunge into a 37 xc so I can shoot a heavier bullet and fight the wind. Thinking of ordering from either K&P or Schneider barrel, not sure if one is better than the other. Schneider is button cut, K&P, rifle cut. Would love to be swayed in one dirrection. I'd love to shoot the 390 Atips when they come out, with some barrel break in using the 350 smk. Not exactly sure how fast we can spin the Atips since they have not been released yet, but was wondering if I could order my barrel in a 8 or 9 twist to shoot the solids at a later date. There just so expensive, this is the route i feel comfortable in taking.
Thanks for your time,
Pat
Little update. Tried 111gr h1000 and old brass still very hard extraction. Going to start with new brass and work up
You two are making my hesitancy to build off of a savage seem well founded
Same here, LGS just got a 112 Magnum in and I thought about snagging it but want to see what you two find with your setups...
Mine is using the whole ramp. And the claw is not letting go, it’s ripping right through the rim, it’s definitely brass sticking in the chamber and takes a pretty good thump to free it up. I still feel the brass is the issue and the load data from tubb is just too hot for my gun. Bear season just started so it’s slowing down my progress on the issue.
Still happy with the rifle and the 338lm barrel shoots great!
Just need to figure out the 37.
Good luck this weekend @Geno C.
Still happy with the rifle and the 338lm barrel shoots great!
Just need to figure out the 37.
Good luck this weekend @Geno C.
Thanks, ballistics wise, this thing is kicking ass! Fighting with the bolt is something I never like to do and messes with my flow while shooting though. But, a lot like the prs match last weekend, it might suck for scores, but I always have a good time
My Stiller has treated me perfect so far. If you’re going to change the savage stock to something else, you’re really only $100 more going with a Stiller to start with
