Care And Feeding Of A GAP 6.5 SAUM.....

[blackfoot]

The problems continue. I am running about 2.5 thousands neck clearance, closer to 3 thousandths now. I am getting pressure signs even at 59 grains. Pressure increases significantly when the bullets are seated deeper. Shot up to 61 grains when jammed, but I didn't dare go past 60.5 with a .030" jump, 60.5 looked like it was about to pierce the primers.

Headspace is good, I will set my die closer next time but it wasn't excessive by any means, .005". I've been loading tight neck cartridges for years and never run into these issues, I don't think it's the neck turning, etc that is causing this.

Could the Krieger barrel be a tighter bore and I just need to back off and start somewhere around 57 grains? This seems pretty odd considering the claims of such low pressures with these loads.

Accuracy also sucks. Only a couple of charges seemed to show some promise but with a couple of flyers.

 

[bas402]

How much are you bumping the shoulder back? Does a bullet slide in a fired case? You can take it back to your smith to measure the bore. Have you measured your chamber length to get your trim length?

 

[FCS]

Noticed a similar pressure "issue" with a Krieger barrel on a 6 Creedmoor, went next step slower in burn rate and issue went away. Ultimately it came down to the Krieger barrel having a smaller land / groove diameter.
However, accuracy was great just pressure was high.

Do you have any Retumbo on hand to try?

 

[blackfoot]

How much are you bumping the shoulder back? Does a bullet slide in a fired case? You can take it back to your smith to measure the bore. Have you measured your chamber length to get your trim length?

I'm well under the trim length specs for the chamber. I didn't measure it but there are no signs I'm long. Bullet slides in a fired case with hand pressure. Fired case measures .295", neck diameter of the chamber is .296", loaded round measures around .2935-.294", bullets are .264 exactly.

I had a 6br tight neck chamber and pressure increased when I jammed into the lands, but pressure decreases in this case.

Smith is 3000 miles away and an expensive trip back and forth. I might just go down to 58 grains and work up from there?

 

[bas402]

Good idea start off again low and work back up and even try some Retumbo (if you have or can get) as FCS suggest, people have had good results with it. Bummer about your smith but maybe a call?

 

[blackfoot]

Got to the range again today and had better results. I'm still a little puzzled. I've never had primers crater when they weren't flattened, but even down to 58 grains I got cratered primers, but they were still round on the edges. Could this be not actually excess pressure but something else? It's a PTG bolt with standard fp hole.

I did have two decent loads, 58.5 grains and 59.5 grains. 59.5 had 4 into less than .250" with one flyer (pretty sure I jerked the trigger on that one).

Here is the primer on the 59.5 grain load

 

[steve123]

I shot my 6x47L with the primers looking like that for years with no ill affect.

A couple barrels ago I sent my PTG bolt off to GreTan to get it bushed which ended the primer flow issues.

Not saying their isn't other problem/s causing the issue!?!?


I have a 20x47L barrel that won't shoot the 55's which is why I bought the barrel. No choice but to find a different bullet and use the barrel up while hoping for better luck next time around with next barrel.

 

[waveslayer]

All my .308 rounds from my Remington 700 look like that.

 

[bas402]

I agree with steve123 the bolt face has to large of a hole and the soft cup of the federal primers is flowing past the firing pin. This to me is not a pressure sign just to much clearance. I had this in one of my Savages and DTA bolts, had them bushed and the ascetic issue was gone.

 

[blackfoot]

I almost ordered the PTG bolt with a small firing pin hole but was advised against it for the magnum. In my Stiller action 300WSM, which uses the same bolt with the same firing pin hole size, I don't get cratered primers until pressure is high and primers are flattened. I guess I won't worry about it and just shoot!!

 

[bas402]

I almost ordered the PTG bolt with a small firing pin hole but was advised against it for the magnum. In my Stiller action 300WSM, which uses the same bolt with the same firing pin hole size, I don't get cratered primers until pressure is high and primers are flattened. I guess I won't worry about it and just shoot!!

I didn't mean that you bought the wrong bolt/ firing pin but that they just made the hole on the one you have on the large side that's all it happens sometimes and they get out the door. I'm sure they would fix it for you with a call to them

 

[blackfoot]

I didn't mean that you bought the wrong bolt/ firing pin but that they just made the hole on the one you have on the large side that's all it happens sometimes and they get out the door. I'm sure they would fix it for you with a call to them

Thanks. As long as it took to get the bolt and the horror stories I've read on here as of late from there, I think I'll shoot it as is. I assume there is a reliable way to measure the firing pin hole to see if it's out of spec? I don't have the foggiest and not sure I trust any 'smiffs around here. Hate to send it in later when it's in spec.

 

[bas402]

Thanks. As long as it took to get the bolt and the horror stories I've read on here as of late from there, I think I'll shoot it as is. I assume there is a reliable way to measure the firing pin hole to see if it's out of spec? I don't have the foggiest and not sure I trust any 'smiffs around here. Hate to send it in later when it's in spec.

What brass are you using again Norma 7Saum? How many cycles do you have on these cases? Did you notice this on your first cycle with ie. Primers and bolt lift issues? If not what cycle did this start? After the stiff BL will the brass extract without issues? Sorry for thousand questions just trying to help

 

[blackfoot]

What brass are you using again Norma 7Saum? How many cycles do you have on these cases? Did you notice this on your first cycle with ie. Primers and bolt lift issues? If not what cycle did this start? After the stiff BL will the brass extract without issues? Sorry for thousand questions just trying to help

Yes Norma 7mm SAUM brass. Bolt lift was a little stiff last firing but I thought it might be from the minimum sizing and shoulder setback. Extracted just fine. 4th firing on this brass and annealed before sizing.

 

[bas402]

Yes Norma 7mm SAUM brass. Bolt lift was a little stiff last firing but I thought it might be from the minimum sizing and shoulder setback. Extracted just fine. 4th firing on this brass and annealed before sizing.

Have you measured the case web before firing virgin brass and then after?

 

[blackfoot]

.003" from virgin to 4x fired brass.

 

[bas402]

I was under the understanding that the max was the measurement of virgin, fire once and measure and that measurement should be no greater than .002" larger but I could be mistaken.

 

[blackfoot]

Well nothing much better with Remington brass. 60 grains produces stiff bolt lift and 3197 velocity. 59.5 grains shows OK accuracy and about 3160 velocity. I'm really at a loss trying to get this thing to shoot well consistently. Maybe I need to bed the rifle? It's a manners T4 BDL Mini Chassis. Going to try the 130 JLK now and give the 140's a rest for a bit, although I might try some different seating depths with a couple loads that showed potential. There is something causing pressure before I reach what most are claiming their load for the 140's is.

 

[Fongman]

How confident are you in your scale/powder measure and/or chrono? That velocity is a bit over mine suppressed with 24" barrel, Rem brass, 63 gr H1000 and 130 HVLDs.

 

[blackfoot]

How confident are you in your scale/powder measure and/or chrono? That velocity is a bit over mine suppressed with 24" barrel, Rem brass, 63 gr H1000 and 130 HVLDs.

I've considered a lot including the shooter. I've got a 6br that I shoot in the .1's to .2's, a lightweight .300 WSM sheep rifle that I shoot in the .3's to .5, a couple of 6.5 Grendels that are sub 1/2 minute, all loaded on the same equipment. Scale is a GemPro 250, measure is a Harrel but I just use it to throw close and then weigh them out.

I get cratered primers even at 58 grains H1000 with the 140 Hybrids. My .300 WSM on a Stiller Predator, using the same bolt specs as the PTG on this gun, doesn't crater primers. I'm using Fed 215M in both.

 

[steve123]

Blackfoot, I thought of something else.

I had a good load for my 30-375R with H-1000 "until" I bought another 8lb jug. The second jug was a faster burn rate, smoked primers using the old load. I did another ladder test and was a grain less for same velocity as old load.

Skeet1640 is reporting 3140 fps with 130's, that's 110 fps less than Pat's load. Skyking was getting 3190 with pressure signs as well with 130's. Someone else reported 3085 fps with 140's.

You seem to be getting very high velocities with 140's ??? If in your shoes I'd do a ladder test at 400Y and pick the high node at whatever velocity that ends up being. Concern yourself about the sticky bolt lift but not the primer flow.

 

[blackfoot]

I wonder if the shorter throat is causing pressure earlier??? Seems I have less pressure when I'm seated into the lands than when I jump .015" or .030". My chamber is with the new reamer with the .081" FB.

 

[SPAK]

I wonder if the shorter throat is causing pressure earlier??? Seems I have less pressure when I'm seated into the lands than when I jump .015" or .030". My chamber is with the new reamer with the .081" FB.

What's your actual Coal with the 140gr hybrids that you have been running? have you measured your lot of bullets? diameter and length? just to make sure they're in spec?

 

[blackfoot]

What's your actual Coal with the 140gr hybrids that you have been running? have you measured your lot of bullets? diameter and length? just to make sure they're in spec?

2.905" to touch the lands. Measured the diameter and they are .264. Don't know what the length spec is because Berger doesn't list in on their website.

 

[Papagallos]

I wonder if the shorter throat is causing pressure earlier??? Seems I have less pressure when I'm seated into the lands than when I jump .015" or .030". My chamber is with the new reamer with the .081" FB.

I would bet money that it's the barrel.

 

[blackfoot]

I would bet money that it's the barrel.

What do you think it is about the barrel? It's a Krieger 1:8.5 5R at 26"

 

[bas402]

I think it's the same as any other caliber to find loads, by that I mean your load will not work the same for me. All of the variables are the same for this caliber, powder,primers,bullets,brass,seating depths etc. It seems on this set up we are all expecting things to be very close and sometimes they will not be that way. Back to basics my friends! I don't think it's your barrel blackfoot you just haven't found the majic spot yet for your rifle. I would suggest forget about what other folks are getting and let your rifle tell you want it likes. That's what I've decided to do, i just relized that the starting point for load develpment for my rifle with the 140's is come to find out ALOT lower than what i originally thought would be a good staring point based on load info posted.

 

[Papagallos]

Back to basics my friends! I don't think it's your barrel blackfoot you just haven't found the majic spot yet for your rifle. I would suggest forget about what other folks are getting and let your rifle tell you want it likes. That's what I've decided to do, i just relized that the starting point for load develpment for my rifle with the 140's is come to find out ALOT lower than what i originally thought would be a good staring point based on load info posted.

Exactly. Barrel.

 

[bas402]

Papa I got your meaning but I think the op was thinking you were stating his barrel was no good,

 

[blackfoot]

I think it's the same as any other caliber to find loads, by that I mean your load will not work the same for me. All of the variables are the same for this caliber, powder,primers,bullets,brass,seating depths etc. It seems on this set up we are all expecting things to be very close and sometimes they will not be that way. Back to basics my friends! I don't think it's your barrel blackfoot you just haven't found the majic spot yet for your rifle. I would suggest forget about what other folks are getting and let your rifle tell you want it likes. That's what I've decided to do, i just relized that the starting point for load develpment for my rifle with the 140's is come to find out ALOT lower than what i originally thought would be a good staring point based on load info posted.

I get that, I just have never had to stray so far from the norm on load data. I feel a little goofy starting 5 grains below what others are using for a load. Seems everything that I've read about the 6.5SAUM isn't the case for me. My Remington brass has loose primer pockets after one firing of the same loads that I'm on 4 firings with Norma brass. It feels like somebody is jacking with me Not really, but it's driving me nuts.

 

[Papagallos]

My Remington brass has loose primer pockets after one firing of the same loads that I'm on 4 firings with Norma brass.

That's where Tula primers come in. If you can, get a hold of them and try them.

 

[waveslayer]

That's where Tula primers come in. If you can, get a hold of them and try them.

If you can find them... they are like Unicorns

 

[bas402]

Natchez has them in stock for the last week, but they will not help either if you don't start taking some case measurements. If you have loose pockets on a single firing on Remmy brass at 5th less powder then you need to see your smith!

 

[blackfoot]

Already taken case measurements. What more am I to measure?

 

[bas402]

Have you measured case webs of virgin then fired that case and taken the same measurement? If your web has expanded over .0005" your loads are to hot. I didn't have the correct mic so I took them to my smith, I am fortunate that my smith is at my indoor range where I work up my loads. My 60 gr load in my Norma brass the webs were expanding .0015", they would work great for 2 cycles then on my 3rd I would experience lift I have never shot brass that was so soft. I also stopped annealing my Norma brass except on it's 3rd cycle. Have you checked your chamber length? I trim mine at 2.020" and my chamber is 2.035". My 57gr load looks promising @ 3064 with 15 ES. IJMO but the short throat reamer doesn't favor the 140's but it's just a hunch. I will get it it will just take some time, and with just 180 down the tube it is still settling in.

 

[waveslayer]

Are you guys annealing your brass after sizing it down from the 300 RSAUM and trimming it? Or are you fire forming once, then annealing it? It seems like a lot of stress on the brass converting it to for the 6.5 SAUM. I could be wrong.

 

[blackfoot]

Are you guys annealing your brass after sizing it down from the 300 RSAUM and trimming it? Or are you fire forming once, then annealing it? It seems like a lot of stress on the brass converting it to for the 6.5 SAUM. I could be wrong.

Using 7mm SAUM brass. Annealing after the first firing.

 

[Raufoss]

You maybe screwed the brass with improper annealing.

 

[ChrisBCS]

Newbie question to OP, are you shooting that rifle off the bench/bags using a hard hold?

 

[blackfoot]

You maybe screwed the brass with improper annealing.

Problems before annealing. I haven't fired the second round on the Remington brass yet. Same pressure signs before and after annealing with the Norma brass.

 

[waveslayer]

I haven't annealed yet. I will after the first firing, thanks

 

[blackfoot]

59 gr H1000 and the 140 Berger at .030" jump yielded 3212 fps and .5" group. No stiff bolt but 59.5 did have stiff bolt lift. This was the once fired Rem brass.

I turned the necks down to give another thousands clearance in case that was the issue. Loaded round is now at .293" neck. I checked the chrono with my 6.5 Grendel loads and it seemed spot on so I trust the numbers, they are just very high for the load comparing to what others are getting.

Another anomaly I've noticed the last two times at the range. The first two shots after cleaning the barrel show excess pressure. Even the 57 grain loads showed pressure on the second shot, and from the third round on pressure signs go away.

Loads have a sticky bolt lift with lighter loads on the Remington brass than the Norma 7mm SAUM brass.

Picked up two pounds of Retumbo so I'm going to give that a shot now.

 

[SPAK]

Just got mine this week here's the chrono and loads from the first shots down the tube.
specs SAC bighorn tl2, Bartlein #3 24" 1:8 twist, gap new reamer .081" freebore.




h1000 Norma 7saum brass prep'd by me, coal 2.888" Berger 140gr hybrids lit with fed 215
over a magnetospeed chrono.




59.5 2934fps
60.0 2960fps
60.5 2985fps
61.0 3022fps
61.5 3054fps
62.0 3086fps
62.5 3094fps
63.0 3109fps
63.5 3146fps
64.0 3182fps




easy bolt lift on all loads, no observed pressure signs on virgin brass.
quickload estimates pressure on the 64.0gr load around 66kpsi so I didn't bother going any further. Besides I started crunching more powder than I really prefer at that point. I'll fine tune the load and report back with accuracy.

 

[Fongman]

If you want your barrel to survive it's best to get your pressure levels below 58k.
Also, you'll barrel will speed up quite a bit once you get to the 200-ish round count.

Congrats on the new gun!

 

[bas402]

Spak, congrats on your new one! How about some pic's Which one's showed the best groups and ES? I must say your lot of H1000 must be on the slower burning side than mine.

 

[SPAK]

Will post pics soon! Probably focus around 62-63gr quickload estimates right at 58kpsi. ... But that's what Showed most promise I'll post up soon.

 

[orrbull48]

Tag

 

[SPECR]

With H1000 being impossible to source, has anyone considered using H4350 or H100v as an alternative? It's listed for the 130 grn 7mm RSAUM load.

 

[steve123]

With H1000 being impossible to source, has anyone considered using H4350 or H100v as an alternative? It's listed for the 130 grn 7mm RSAUM load.

Aliant power pro 4000 MR would be in the vicinity of burn rate and is available now at Powder Valley.

The powders you listed might work better for bullets like 123's and lighter.

Retumbo is fantastic in my 29" barrel. 60.9 grains is giving me 3125 fps now and 63 was doing 3225 fps with a little over 100 rounds down the tube. The 63 grain load was warm but not hot, primers weren't even flat yet, both with 140 hybrids.

 

[SPECR]

Aliant power pro 4000 MR would be in the vicinity of burn rate and is available now at Powder Valley.

The powders you listed might work better for bullets like 123's and lighter.

Retumbo is fantastic in my 29" barrel. 60.9 grains is giving me 3125 fps now and 63 was doing 3225 fps with a little over 100 rounds down the tube. The 63 grain load was warm but not hot, primers weren't even flat yet, both with 140 hybrids.

Thanks for the suggestions, I'd like to try Retumbo one day, but I was fortunate to find some H1000 off Gunbroker this morning for $30 per lb. I'll steer clear of the other powders.