**6 Creedmoor**

[NH4X]

Hey Everyone, I am working up a load for my new MPA BA PMR Pro in 6CM. I have done an initial seating depth test, and found that the rifle really likes .050 - .060 off the lands, so that is where all my rounds are are seated. I just did a 12 round load/ladder test this afternoon, and want to share my results for some feedback. I dont want to go any higher in velocity and want to keep it below 3000fps, which my test has done. I am wondering if I should try out a 5 round load test between 42.2 and 42.4, or possibly between 42.8 and 43.2 (see chart). Any feedback is appreciated. Thanks!

Components are: Hornady 108 ELD-M, Hornady brass, CCI 200 primers, WinStaball 6.5 powder. Brass is all FL sized, trimmed, chamfered.

View attachment 7819205

Relaying data per 2022 Hodgdon Annual Manual : 43 gr is their max @ 3080 fps , 59,500 psi ,24" barrel ,same brass, WNLR primer ,same bullet .

Barrel may speed up ,may not as it gets rounds through it.

Some pick a speed ,and play with seating depth , others find where it groups best with powder charge ,then play with seating depth . Your choice . When I worked my load, I wanted 3000 fps or a tad over. I started .020 off ,got to speed ,but groups weren't quite as good as I expected. Set bullet .010 off ( 108 eldm ) and groups got as small as me and my rifle are capable of producing ( real small , I'm happy ).

Thoughts were asked for, and furnished ....nothing more or less. Just one man's experience. Best of luck to you ,and happy shootin .

Iffin ya already know the above ,disregard this post........I was bored.

 

[CK1.0]

Hey Everyone, I am working up a load for my new MPA BA PMR Pro in 6CM. I have done an initial seating depth test, and found that the rifle really likes .050 - .060 off the lands, so that is where all my rounds are are seated. I just did a 12 round load/ladder test this afternoon, and want to share my results for some feedback. I dont want to go any higher in velocity and want to keep it below 3000fps, which my test has done. I am wondering if I should try out a 5 round load test between 42.2 and 42.4, or possibly between 42.8 and 43.2 (see chart). Any feedback is appreciated. Thanks!

Components are: Hornady 108 ELD-M, Hornady brass, CCI 200 primers, WinStaball 6.5 powder. Brass is all FL sized, trimmed, chamfered.

View attachment 7819205

FWIW, I'm one of those "pick a speed" guys who doesn't believe in "nodes"...

...and you probably shouldn't be doing this yet unless you've already got ~150rds on the barrel (because it's going to speed up before it settles down).

So, with that out of the way: if you only shot 12 rounds, then you don't have enough data to make a determination about anything.

You do have a coarse idea of how many grains equals roughly what speed you get, pushing that bullet in that barrel (which honestly, from my point of view, is all you need really).

Traditionally, if you're looking for one of those mythical "nodes", you'd need to shoot some more strings (the more the merrier, or at least: more shots = more data) to make sure none of those speeds were flukes and/or to make sure you're getting something that you can discern as repeatable. Remember, to acquire enough data that it actually enables you to make any kind of truly informed determination you'd have to shoot the barrel out.. but don't let facts deter you, just pick a number: like... 2-3 more strings of 12 should suffice..?

Then, and only then, will you be able to discover the magic velocity flat spot that exists somewhere in there, even when a varied amount of powder (fuel) is used (of course, pay no mind to the fact that the velocity staying the same with either less or more fuel being used makes zero sense, and that no one can seem to find any evidence that any expert in combustion and/or actual Rocket Scientist, living or dead, believes in, or has mentioned such a phenomenon)? But, we're looking for nodes, not more facts, so...

...shoot a few more strings, look at your ouija board data graphs of the statistically-speaking, minuscule sample of shots you recorded, and then you can make a better guess determination of where your node is... after you've burned up some more components.

Oh yeah, if you don't already have a scale that measures to 0.002gr/0.001g resolution, chances are the small sliver of data you have collected is too imprecise to be usable, so you'll have to do the whole thing over again once you get a better scale.

I'm sorry if I sound like a snarky jerk, I don't mean to, just sharing a different point of view is all... LOL!

I advocate picking a known-safe, lower-to-middle of the road charge weight, and shooting for fun for a while, then when your barrel has settled in, figure out how fast you want to go and then do your best to make sure every charge you drop weighs the same down to the kernel (or as close as you can get to that), ...can pretty much bet you'll end up in "your own node" that way. Good luck!

 

[CK1.0]

2100rds on the barrel, not seeing anything that says it's time to pull it yet...

Lapua LRP 22-250 case (necked up with a .241 mandrel and fire-formed into 6CM)
41gr Sta-Ball
112gr Matchburner
CCI 200 LRP
CBTO 2.145" (jumping .103" to the lands)


1,250 yards IPSC

750 yards small IPSC



750 yards mini IPSC



300 yards (pulled a couple, could've been better, only shot one, it's not the barrel's fault that I suck at groups)

 

[Amazingrandy1]

Hi Everyone,

I was able to get my hands on a good amount of H4350 through Midsouth this past week, and put together an initial load test. Instead of only doing one shot per powder charge, I did 3 shot groups. All but one group shot under .5", so I was pretty pleased wit those results. Below is a chart of my results, and based on my numbers and plotting, I think it looks pretty promising between 40.2-40.4 and 41.6-41.8. I would actually prefer to stay in the 40.2-40.4 range to try and preserve some barrel life. I think these results look much better than what I was getting in my previous post, using Win Staball. Let me know your thought. All bullet, group, SD info is below. Thanks.

 

[FatBatman]

Hi Everyone,

I was able to get my hands on a good amount of H4350 through Midsouth this past week, and put together an initial load test. Instead of only doing one shot per powder charge, I did 3 shot groups. All but one group shot under .5", so I was pretty pleased wit those results. Below is a chart of my results, and based on my numbers and plotting, I think it looks pretty promising between 40.2-40.4 and 41.6-41.8. I would actually prefer to stay in the 40.2-40.4 range to try and preserve some barrel life. I think these results look much better than what I was getting in my previous post, using Win Staball. Let me know your thought. All bullet, group, SD info is below. Thanks.

View attachment 7835521

View attachment 7835753
View attachment 7835946

Few questions
1 what is the barrel length
2 how many rounds on the barrel

 

[Amazingrandy1]

Few questions
1 what is the barrel length
2 how many rounds on the barrel

24" barrel with 200 rounds

 

[Roksliding]

108eldm
Lapua brass (once fired) trimmed 1.91
Br4
38.4 h4350
2.225 to ogive
2900fps sd4 es8
1/2” at 100
26” 1 in 7.2 twist gap ppr barrel

Hoping to get 2k rounds on it.

 

[FatBatman]

24" barrel with 200 rounds

From what I am seeing there 40.0 or 40.8 shot good groups. Tring to pick a charge wieght based on an ad of 3 shots is not a great indicator. Load more of the charge wieghts you would prefer and shoot it if the groups are also good load 15+rounds to check sd

 

[Movistar]

Hey guys I’m looking for a little friendly gun guy advice if possible. Using new brass vs same lot 1x fired brass I am getting flat primers on the 1x fired with the same load as the new brass. Why would 1x fired be flat and new isn’t with the same formula? Anyone know why that is?

Just the facts ma’am:

- AI ASR
-24 inch Proof CF barrel suppressed
-60 degrees F & 2500 FASL
-brass is Lapua SRP all the same lot.
-both new and 1x fired were sized using the same Whidden bushing die.
-105 Berger hybrid
-seated to 2.795 COAL
- charge is 40.00 of RL16 all the same lot and same bottle loaded at the same time.
- CCI 450 primer
-rounds fired the same day all in succession. 1x was fired first. I fired 10 to test speed vs my new brass speed.
-all brass new and 1x fired trimmed to 1.915
-new brass is 3030 FPS and 6 SD
-1x fired brass is 3047 FPS and 9 SD
-accuracy was identical

Photo = new brass on the right. 1x (now 2x fired) on the left.

 

[CK1.0]

Why would 1x fired be flat and new isn’t with the same formula? Anyone know why that is?

Generally, on reloaded rounds, flattened primers are a sign of pressure... but, I've also heard it said that one can get flattened primers from rounds that are undersized for the chamber (this is how I've heard flattened primers with factory rounds get explained).

The theory with factory stuff and flattened primers is: that since the cases are short for the chamber, the primers get pushed back and out of the pockets and slam/compress against the bolt-face.

So, not my theory, but if that's the case, maybe you're bumping your shoulders too far back on your reloads..? Probably worth breaking out the ol' comparator and checking your bump and at least ruling that out I guess...

40gr of RL16 seems pretty normal/safe, so I'd look into your bump, and then, instead of COAL, maybe double-check your cartridge base to ogive (CBTO) just to make sure you're not unknowingly jamming the bullet into the rifling and adding any extra pressure that way..?

(FWIW, IMHO COAL isn't a dependable measurement, because the only thing most of us care about with COAL is whether it'll fit in a magazine or not lol, otherwise CBTO is more repeatable and useful, not to mention, easier to measure).

 

[Movistar]

Interesting. Thank you for the response. I am also full length resizing the new brass before using it

 

[CWik]

Im gonna run 6creed eventually (meaning in my bolt gun put a threaded barrel on). Right now I’m doing 6.5 creed on that gun and a gas ar10.

So, I’ve been stocking up on 6mm stuff (bullets, brass). Got the SAC Creedmoor dies and Redding comp bushing for the 6.5. (Have not switched to the sac yet).

This thread seems to show that most use SRP brass lapua , even Peterson. I see some using hornady LRP.

I wanted to get Peterson LRP but can’t find in stock yet.

Is it safe to say most shoot SRP for 6creed or is LRP preferred.

I have a good Amy of lapua SRP

I was gonna get some of both (I know most people just stick with one or the other BUTTT I’m trying both and wanted Peterson)?

Is large the better bet (if so why does lapua not make large)?

Hey @XikoPlavi – Just saw this post and I have a few hundred, once-fired Peterson 6.5 Creedmoor LRP brass that I don't plan on using. Love it, but I have more Lapua at the moment, so I'm sticking with that. Let me know if you're interested – looking to find a good home for these guys.

 

[MRamsey]

Posting results for IMR 4955 enduron powder. Not much info for loads out there but figured I’d share my preliminary results. Max charge listed with Hodgdon is 43.5 @ 2.770 OAL
Berger 108 BTHP 2.800 OAL
Lapua SRP (new only pushed out .003 when FF)
CCI 450
Origin action
Proof CF TL3 prefit (HLR Lug)
Rex Silentium can
Shot at 100 yrds




No pressure on any of it
**Edit**
I passed on this powder. Loaded 10 at 43.3 5 for the chrono and 5 for a group without and it was nothing spectacular. About a 9 SD and groups in the 3/4”-1” range. As reported from others just seems to want to throw a round. Another note is my suppressor would get much hotter than with the same rounds fired with H4350. Settled on 40.9 gr 4359 and got an SD of 5 with a half “ group going 3050fps. Wish I could have done more testing with this but the knowledge of how well 4350 does I didn’t see the need to burn components chasing this one.

 

[jolofree]

Now that's a good group none of that 3 round crap

 

[Snaz]

•AI AT 27" 7.5T Bartlien bbl
•112gr Barnes MatchBurner
•40.2gr RL16
•CCI 400s & Fed 205s
•Lapua SRP once fired brass
•0.040" off the lands @ CBOL: 2.205"

Only goal was accurate load over 3k fps. Hopefully, I'll get a few more rounds out of this barrel by not pushing it quite as hard.

Well, seems like I always pull a shot, no matter what I do..

 

[Baddog 0302]

Were the Fed. primers 205's or 205M's?

 

[Snaz]

Were the Fed. primers 205's or 205M's?

205

 

[Movistar]

•AI AT 27" 7.5T Bartlien bbl
•112gr Barnes MatchBurner
•40.2gr RL16
•CCI 400s & Fed 205s
•Lapua SRP once fired brass
•0.040" off the lands @ CBOL: 2.205"

Only goal was accurate load over 3k fps. Hopefully, I'll get a few more rounds out of this barrel by not pushing it quite as hard.

Well, seems like I always pull a shot, no matter what I do..

do you get slightly flattened primers with the cci 400? I am using less powder and they get flat. I’ve read it’s because of the cci 400 cup thickness rather than my load being too hot. That’s my only pressure sign. I’m right at 3000 FPS with 105 hybrid at 38.5 of RL16 and still getting them flat. They were flat at 40.0 and 39.0.

 

[Snaz]

do you get slightly flattened primers with the cci 400? I am using less powder and they get flat. I’ve read it’s because of the cci 400 cup thickness rather than my load being too hot. That’s my only pressure sign. I’m right at 3000 FPS with 105 hybrid at 38.5 of RL16 and still getting them flat. They were flat at 40.0 and 39.0.

Yes, sir. I was having issues with the CCI primers starting to crater/flow afterthe barrel warmed up, so I switched over to the 205s. Still on the hot side, but they're looking much better then the CCIs. I had no swipes, heavy bolt lift, or other pressure signs other than the primer.

I did a test with this load, only change was Primer. 10 shot groups provided the following:

CCI 400 AVG: 3046 ES: 16 SD: 8.1
CCI 41 AVG: 3048 ES: 30 SD: 10.3
CCI 450 AVG: 3057 ES: 46 SD: 16.7
FED 205 AVG: 3048 ES: 24 SD: 8.8

I'm sure the 450 ES/SD would be better if I worked back up. I was just in a hurry, trying to get a comparable load ready for a local comp. In the future, I think I'll skip the 400s in load development for this barrel.

 

[Dusojr]

this is my first LR build. After lots of reading and insight on this site I went 6CM. Rem 700 Action, KRG Bravo,
Lapua Brass
CCI 450
H4831
107 SMK
CBTO 2.219

 

[WGOMF]

In the last year or so, the bullets mentioned in this thread the most seem to be Bergers 105 & 109H, & 115DTAC.

And unless I missed it, no mention at all of the 110 Match King. Are they not a worthy contender? Or poor availability maybe?

 

[BrienM]

Probably be fine. Don’t think they’ve been available much or people aren’t bragging about them so they’re not impossible to find.?? Sounds like they may run better on tighter twist?

 

[WWJD]

In the last year or so, the bullets mentioned in this thread the most seem to be Bergers 105 & 109H, & 115DTAC.

And unless I missed it, no mention at all of the 110 Match King. Are they not a worthy contender? Or poor availability maybe?

This has been my match load for the season. The 110’s probably aren’t a top concern for Sierra. I have not seen any for a long time. I run a 7t, I’ve noticed you gotta run em fast to shoot. Just my findings so far.

 

[chiaan]

Looks like the next rifle is going to be a 6 Creedmoor instead of the 6.5 Creedmoor... Looking for some load details from you guys that are already running it...

Now I have to figure out what I'm going to do with all these loaded 6.5 Creedmoor factory loads I have sitting here... Maye time to start pulling bullets.

HI there, I use Peterson SRP, shooting a 110gr Hornady A-Tip in front of 41.2 gr Hodgdon Superformance powder, using a BR4 primer. Speed is 3025fps with an ES of 7. Pressure is non existant and accuracy is great. My rifle is a Ruger precision with a 1;7.7, 26" barrel. Hope this helps

 

[Dogtown]

So I came up with my first 6mm Creedmoor load. Shooting a 16” Bartlein 1:8 MODBB barrel in an AR10. With that short of a barrel I decided to go a tad lighter with Berger 95gr VLD TGT bullets. I gave H4350, RL17 and N555 a try. All shot well, but N555 was a bit on the slow side and I quickly ran out of useable case capacity. H4350 was good but it was unexpectedly overshadowed by the performance I got with RL17, which was just on a whim.

6mm Creedmoor
Berger 95gr VLD Target
Federal Brass
CCI #34
43gr RL17
2.799” COAL
2954fps

 

[howler]

Shot Frank’s Intro course this last weekend with hand loads, they did not disappoint. Here’s a five shot group from zeroing…

Berger 115gn Target VLD
Lapua brass
40gn H4350
Federal SRP

Something around 30 thou jump, fits perfect in a magazine. Makes 2,970fps in my 24” barrel.

 

[Dogtown]

Factory Overrun Brass 6mm Creedmoor Brass Box of 100 (Bulk Packaged)

This Factory Overrun Brass is manufactured to SAAMI specifications, but with visual imperfections that will not affect performance. This is not loaded...

www.midwayusa.com

This is a really hard to beat deal on brass. It's Federal and a little on the soft side, from what I can tell, but it's still holding up after 5 firings.

 

[CK1.0]

My barrel is toast (at least I'm pretty sure anyways)...

This is the barrel I had put on at the beginning of March last year (page 17 of this thread), purposely, it was never run over 2900fps and I used a pretty healthy jump to the lands the entire time (.100" to the lands).

I ended up getting 2350rds out of it running it this way (and I was cruel and merciless in the way I treated it the whole time... fuck waiting for the barrel to cool down lol).

Seems lots of guys will give different takes on what tells them when a barrel is dead... ask 10 different shooters and you'll likely get 10 different stories...

For me, I probably burned the last 50rds trying to confirm what I had already suspected... problem is, the barrel is still accurate often enough to make one wonder if it's really dead..? But it is.

The conditions were far from challenging yesterday and here is a 3-shot group at 300yrds (no, I didn't pull the bottom one). At one point I sent 5 downrange at a huge 10ft x 10ft sight-in target at 1000yrds, same hold, same conditions, and 2 of them were ~6" apart dead center at my point of aim, ...the other 3 didn't even impact the big-ass plate!



Another clue: it was hot as fuck yesterday (98-100degF), and I was only getting ~2840fps (which is maybe about what I should be seeing around 70-80degF).

I'm shooting Sta-Ball and while it's "temp stable" for a ball powder, it's nowhere near that good. I should have been seeing at least 2900fps (probably faster, more like ~2950ish or so).

I had the chrono out because I was planning on shooting a match Saturday morning (not anymore lol) and I like to check on my shit if I can before a match if I get the chance. I sent a handful of shots over the chrono and: it's not the ammo.

SD7 shot rapid-fire, if I waited a minute between shots that SD number may have shrunk...



Oh well, fun while it lasted, and it lasted a long time, so I'll be doing the "run it slow + big-jump thing" again.

 

[howler]

My barrel is toast (at least I'm pretty sure anyways)...

This is the barrel I had put on at the beginning of March last year (page 17 of this thread), purposely, it was never run over 2900fps and I used a pretty healthy jump to the lands the entire time (.100" to the lands).

I ended up getting 2350rds out of it running it this way (and I was cruel and merciless in the way I treated it the whole time... fuck waiting for the barrel to cool down lol).

Seems lots of guys will give different takes on what tells them when a barrel is dead... ask 10 different shooters and you'll likely get 10 different stories...

For me, I probably burned the last 50rds trying to confirm what I had already suspected... problem is, the barrel is still accurate often enough to make one wonder if it's really dead..? But it is.

The conditions were far from challenging yesterday and here is a 3-shot group at 300yrds (no, I didn't pull the bottom one). At one point I sent 5 downrange at a huge 10ft x 10ft sight-in target at 1000yrds, same hold, same conditions, and 2 of them were ~6" apart dead center at my point of aim, ...the other 3 didn't even impact the big-ass plate!

View attachment 7897577

Another clue: it was hot as fuck yesterday (98-100degF), and I was only getting ~2840fps (which is maybe about what I should be seeing around 70-80degF).

I'm shooting Sta-Ball and while it's "temp stable" for a ball powder, it's nowhere near that good. I should have been seeing at least 2900fps (probably faster, more like ~2950ish or so).

I had the chrono out because I was planning on shooting a match Saturday morning (not anymore lol) and I like to check on my shit if I can before a match if I get the chance. I sent a handful of shots over the chrono and: it's not the ammo.

SD7 shot rapid-fire, if I waited a minute between shots that SD number may have shrunk...

View attachment 7897583

Oh well, fun while it lasted, and it lasted a long time, so I'll be doing the "run it slow + big-jump thing" again.

In very basic testing I’ve also found staball not to be that great in temp stability either.

 

[CK1.0]

In very basic testing I’ve also found staball not to be that great in temp stability either.

Yeah, it's not in the same league as H4350 or R16 for sure, but it's ok.

Sta-Ball's temperature varience is consitent at least, and pretty easy to track depending on what ballistic calculater one runs (works fine with Strelok Pro in warmer weather, in the winter I just use the "consider powder temperature" feature and it's all good).

 

[CK1.0]

Yep, it was dead, new barrel on, ability to stack rounds on top of each other at ridiculous distance restored.

 

[CK1.0]

IDK? Maybe all this load-development shit is nonsense? lol

No barrel break-in (screwed it on, ran a single dry patch through it, shot 100rds so far).

No load development (rounds left over from last barrel, healthy jump, ~0.100"ish off or so).

No real idea how it groups at 100 yards other than getting 2 out of 3 to touch a few times in a row when putting an initial zero on it. (and now IDK if I care?)

5 shots at 1250 yards (literally rounds #96-100), rear bag + bipod off the bench:

...seemed to work fine at 750yrds as well (off a tank trap with a Shmedium):

 

[S3th]

For those running 105/108s in a 26” around 2,750-2,850 what barrel life are you getting?

 

[CK1.0]

Shot the last 50rds leftover from my last barrel through the new one, and decided I could probably dedicate my life to load development for the next few weeks and not come up with anything any better, so…

In my limited experience of exactly 2 barrels in a row so far, these Proof prefits are incredibly consistent. The chamber on my new barrel is exactly 1 thou tighter than my last one, so for loading, the only thing I had to do was adjust my sizing die to add .001” of bump in order to achieve a 2 thou shoulder bump.

That’s it. Everything else is the same as it was for the last barrel’s happy and longer than usual life. Turns out those leftover rounds weren’t ~.100”ish off, they were exactly .100” off the lands by some sort of cosmic intervention. So FWIW, the new barrel isn’t a perfect identical clone of my last one, but it’s damn close (the 1 thou difference could have just been the idiot at the wrench me thinks).

Still running “slow” with 41 grains of StaBall, Lapua ex-22-250 brass 8x fired, CCI 200, Barnes 112gr Match Burner.

Here is what I got before and after adjusting my BC up a tenth at 1000yrds (on a freshly painted target too lol), and it looks like it’s accurate enough for me:

300 rounds ready to go (rounds #151-450):

 

[Hickswr]

@CK1.0

How temp stable has the StaBALL been in your experience?

 

[Dogtown]

So stable it's StaBALL!

...I'll show myself out...

 

[CK1.0]

@CK1.0

How temp stable has the StaBALL been in your experience?

Well, it's not H4350 or RL16... but it's actually perfectly fine in warmer-to-hot temps IME (and I've shot a lot of it, ~30lbs or more), in fact, once dialed in (MV + BC) my first round hit ratio is pretty high, and I rarely have to dick around with my dope much once it's set (I just update my weather constantly).

It's in the colder weather where it gets a little wonky IME. Last winter I tried/used the "consider powder temperature" setting in Strelok Pro (leaving it ~60degF, about halfway between the warm truck on the drive and the cold bench at the range, bringing it down some if I was out there for a while) and it seemed to do much better than the previous winter.

The ball powder just meters amazingly though, like water. I honestly think using StaBall is faster than dicking around with an AT or anything else as long as one has a decent powder dropper, an old-school trickler, and a really good scale. Shit, with good technique, just dropping it straight into cases makes consistent enough stuff to practice with, maybe even go to a match with (I did once, for my first PRS match at K&M and finished middle of the pack), it's just super easy to live with.

 

[4O6shootist]

@CK1.0

How temp stable has the StaBALL been in your experience?

Bout 0.6-08 fps per degree in my experience when tested two times in 35 vs 80 degrees. Better than most ball powder, but not as good as a quality single base extruded.

 

[Hickswr]

Well, it's not H4350 or RL16... but it's actually perfectly fine in warmer-to-hot temps IME (and I've shot a lot of it, ~30lbs or more), in fact, once dialed in (MV + BC) my first round hit ratio is pretty high, and I rarely have to dick around with my dope much once it's set (I just update my weather constantly).

It's in the colder weather where it gets a little wonky IME. Last winter I tried/used the "consider powder temperature" setting in Strelok Pro (leaving it ~60degF, about halfway between the warm truck on the drive and the cold bench at the range, bringing it down some if I was out there for a while) and it seemed to do much better than the previous winter.

The ball powder just meters amazingly though, like water. I honestly think using StaBall is faster than dicking around with an AT or anything else as long as one has a decent powder dropper, an old-school trickler, and a really good scale. Shit, with good technique, just dropping it straight into cases makes consistent enough stuff to practice with, maybe even go to a match with (I did once, for my first PRS match at K&M and finished middle of the pack), it's just super easy to live with.

Great info! Thanks for the detailed reply.

 

[Andrew863]

So I just started with 6 CM and my first load was Hornady 108, Berger 105 hybrid, and Berger 109 hybrid. I have Lapua small rifle brass, cci 41 primers and H4350. Tried 39.5,40 and 40.5. The issue is I hit pressure sign at 39.5 and right at 3k fps. I had ejector marks and heavy bolt lift. My chamber is on the tight side but factory Hornady will chamber and fire fine. Anyone see a issue or anything I need to check? I plan to run closer to 2900 or 2950 so I'm fine with going slower but I just want to make sure I'm not over looking something.

 

[TheOfficeT-Rex]

First firing on brass?
What barrel length?

Pending those two questions, that might be right where I expect max to be with 4350.

 

[Hickswr]

So I just started with 6 CM and my first load was Hornady 108, Berger 105 hybrid, and Berger 109 hybrid. I have Lapua small rifle brass, cci 41 primers and H4350. Tried 39.5,40 and 40.5. The issue is I hit pressure sign at 39.5 and right at 3k fps. I had ejector marks and heavy bolt lift. My chamber is on the tight side but factory Hornady will chamber and fire fine. Anyone see a issue or anything I need to check? I plan to run closer to 2900 or 2950 so I'm fine with going slower but I just want to make sure I'm not over looking something.

How many rounds since you scrubbed the carbon ring out and verified with a borescope?

Lapua brass
H4350 39.2gr
CCI 450
Berger 105s
3010 fps
26” barrel
No pressure signs

 

[Andrew863]

First firing on brass?
What barrel length?

Pending those two questions, that might be right where I expect max to be with 4350.

2nd firing on brass first in my gun. 26in proof

 

[Andrew863]

How many rounds since you scrubbed the carbon ring out and verified with a borescope?

Lapua brass
H4350 39.2gr
CCI 450
Berger 105s
3010 fps
26” barrel
No pressure signs

Every time I get home the barrel goes to bare metal and verified with bore scope. This is a new barrel. I had 51rds on it before this range trip and a perfectly clean bore . Now have 84 and same cleaning when I got home. Learned from my last few precision rifles. It's much easier to toss it in the vise and clean it when I get home, then it is after a few range trips.

 

[TheOfficeT-Rex]

2nd firing on brass first in my gun. 26in proof

How far did the brass move between resized?

Speeds are in the ballpark, but powder charges are lower than I’d guess. I’d start looking at carbon ring. Failing that- checking shoulder bump and case web size, if they were fired in a looser chamber then bumped back too far that may explain the stiff lift.

 

[BuildingConceptsllc]

I am running the 108 Berger bthp and 43.25 gr of Staball and MV 3025. Pretty good SD and ES once I got it figured out. It was always a laser with groups but had to get more case fill to get the SD/ES down consistently. That's with a 24" barrel

 

[Andrew863]

How far did the brass move between resized?

Speeds are in the ballpark, but powder charges are lower than I’d guess. I’d start looking at carbon ring. Failing that- checking shoulder bump and case web size, if they were fired in a looser chamber then bumped back too far that may explain the stiff lift.

I did bump the about .006 back. I know it's a little much but I can't see that being a issue. One thing I have noticed my forster sizing die is tighter then any other die I have had. I usually use redding but wanted to give forster a try. I may grab a redding and just see if anything changes.

 

[Andrew863]

How far did the brass move between resized?

Speeds are in the ballpark, but powder charges are lower than I’d guess. I’d start looking at carbon ring. Failing that- checking shoulder bump and case web size, if they were fired in a looser chamber then bumped back too far that may explain the stiff lift.

For sure no carbon ring at all. But this does have me wondering if my die is sizing the wedding to much and causing pressure.

 

[TheOfficeT-Rex]

I did bump the about .006 back. I know it's a little much but I can't see that being a issue. One thing I have noticed my forster sizing die is tighter then any other die I have had. I usually use redding but wanted to give forster a try. I may grab a redding and just see if anything changes.

I've seen ejector marks with moderate charges when I bumped back more than 5k.

For sure no carbon ring at all. But this does have me wondering if my die is sizing the wedding to much and causing pressure.

I'd lean towards it not sizing the base enough - BR guys talk about 'clickers.' I'm always leery of brass not initially fired in that chamber. Check by resizing a case and seeing if it feeds/extracts smoothly, or if there's a hitch on primary extraction.


Failing that, I'm drunk and out of ideas.

 

[Andrew863]

I've seen ejector marks with moderate charges when I bumped back more than 5k.


I'd lean towards it not sizing the base enough - BR guys talk about 'clickers.' I'm always leery of brass not initially fired in that chamber. Check by resizing a case and seeing if it feeds/extracts smoothly, or if there's a hitch on primary extraction.


Failing that, I'm drunk and out of ideas.

After sized it does easily slide in the chamber and close silky smooth with no heavy close at all. I'll try and size the few I fired again with my usuall. 002 bump and see if there is any change at all. Thanks for the input.