Pressure issue (HeadSpace? )

[7Saum]

Hi Everyone,new to this site,and reloading,I have been reading the articles on here and there seems to be a bunch of knowledgable people,my issue is with my custom 7saum, i I am seeing pressure signs on the head of my brass,which I have used 3 different brands (rem,factory rounds of Nosler,and now new Norma)all showing ejector marks with even starting loads..I have tried 4 different powders (r17,19,H4350,and rl 26) r17 show's the best potential but i am not doing anything more until I figure this out..I have been from 15th -50thou off the lands, and all mild-med loads and always pressure,can I be doing something wrong in the reloading process to cause this?Or could this be a HeadSpace issue?,any kind of input would be appreciated..
Thanx.. My 7SAUM is Stiller Predator action,#3 24 3/4" Benchmark fluted,McMillan Mcswirly stock,trigger tech trigger,all covered in titanium grey cerakote..

 

[gunsandgunsmithing]

Pics of what is leading you to feel like pressure is high would be helpful, as would specific load data you're using. FWIW, after initial firing, you are in complete control of headspace, as it relates to clearance between the case head and bolt face by means of how far you push the shoulder back when re-sizing.

 

[savagedasher]

Hi Everyone,new to this site,and reloading,I have been reading the articles on here and there seems to be a bunch of knowledgable people,my issue is with my custom 7saum, i I am seeing pressure signs on the head of my brass,which I have used 3 different brands (rem,factory rounds of Nosler,and now new Norma)all showing ejector marks with even starting loads..I have tried 4 different powders (r17,19,H4350,and rl 26) r17 show's the best potential but i am not doing anything more until I figure this out..I have been from 15th -50thou off the lands, and all mild-med loads and always pressure,can I be doing something wrong in the reloading process to cause this?Or could this be a HeadSpace issue?,any kind of input would be appreciated..
Thanx..

Head space after fireing has effect on how much of powder you can put in a case .
From in to .020 off build extra pressure at start . It can be as much as 5000 psi .
Simple answer know case capacity . Allow extra pressure when not jumping .
Start low and work up . Larry

 

[effendude]

A friend was fire forming dasher brass and ran into the same issue one time. His cases were thrusting back against the bolt face hard enough to leave ejector marks, even with mild loads. It does sound like an excessive head space issue to me. Have you measured your fired cases against new? Will the fired cases easily rechamber without sizing? It sounds like you have a very generous chamber.

Scott

 

[savagedasher]

A friend was fire forming dasher brass and ran into the same issue one time. His cases were thrusting back against the bolt face hard enough to leave ejector marks, even with mild loads. It does sound like an excessive head space issue to me. Have you measured your fired cases against new? Will the fired cases easily rechamber without sizing? It sounds like you have a very generous chamber.

Scott

He wasn't jamming them hard enough or his faults shoulder wasn't enough . Been there and done that . Larry

 

[dkhunt14]

Could come from different things, slow barrel, hot lot of powder, fat bullets. The thing that can also really effect it is if short freebore and bullet is taking up powder capacity. Effendude and gunsandgunsmith has good answers also.

More info needed. Matt

 

[7Saum]

Pics of what is leading you to feel like pressure is high would be helpful, as would specific load data you're using. FWIW, after initial firing, you are in complete control of headspace, as it relates to clearance between the case head and bolt face by means of how far you push the shoulder back when re-sizing.

Thanx,here is what I did pics to follow (hopefully )
52.5 gr rl17 -Norma Brass 145LRX OAL 2.96
55 gr -H4350-Rem Brass 145LRX OAL 2.96
Factory Nosler Custom 160 accubond 2.75
COAL I am touching lands at 2. 98 I put black marks on case to show(ejector mark in between ) I use Redding type S bushing style dies..
Thanx..

Pics of what is leading you to feel like pressure is high would be helpful, as would specific load data you're using. FWIW, after initial firing, you are in complete control of headspace, as it relates to clearance between the case head and bolt face by means of how far you push the shoulder back when re-sizing.

 

[7Saum]

A friend was fire forming dasher brass and ran into the same issue one time. His cases were thrusting back against the bolt face hard enough to leave ejector marks, even with mild loads. It does sound like an excessive head space issue to me. Have you measured your fired cases against new? Will the fired cases easily rechamber without sizing? It sounds like you have a very generous chamber.

Scott

My fired brass does chamber,with a little more resistance than sized..
Thanx

 

[7Saum]

Thanx,here is what I did pics to follow (hopefully )
52.5 gr rl17 -Norma Brass 145LRX OAL 2.96
55 gr -H4350-Rem Brass 145LRX OAL 2.96
Factory Nosler Custom 160 accubond 2.75
COAL I am touching lands at 2. 98 I put black marks on case to show(ejector mark in between ) I use Redding type S bushing style dies..
Thanx..

Thanx,here is what I did pics to follow (hopefully )
52.5 gr rl17 -Norma Brass 145LRX OAL 2.96
55 gr -H4350-Rem Brass 145LRX OAL 2.96
Factory Nosler Custom 160 accubond 2.75
COAL I am touching lands at 2. 98 I put black marks on case to show(ejector mark in between ) I use Redding type S bushing style dies..
Thanx..

 

[Comrade Terry]

The thing that can also really effect it is if short freebore and bullet is taking up powder capacity.

Easily overlooked. Don't ask me how I know.

 

[Sheldon N]

Have you checked neck clearance? Does a bullet drop freely into the neck of a fired case? Measurement of the neck OD of a fired case vs a loaded case?

 

[M-61]

You mention that you are new to reloading. In your original post you say: "...,can I be doing something wrong in the reloading process to cause this?Or could this be a HeadSpace issue?"

Answer is yes but it is really one question. What are you doing to the shoulders? If you are bumping them back too much because of improperly set up FL die....then your reloading process has created what you call a headspace issue. Check what your measurements are between unfired, fired, and resized brass.

 

[7Saum]

You mention that you are new to reloading. In your original post you say: "...,can I be doing something wrong in the reloading process to cause this?Or could this be a HeadSpace issue?"

Answer is yes but it is really one question. What are you doing to the shoulders? If you are bumping them back too much because of improperly set up FL die....then your reloading process has created what you call a headspace issue. Check what your measurements are between unfired, fired, and resized brass.

Hi,
Do u measure from the bottom of neck to the base?
Thanx

 

[timeout]

Hi,
Do u measure from the bottom of neck to the base?
Thanx

PM me your email address and I will send you a picture of what you need to measure from shoulder to base of the cartridge case. Once you have that measurement, adjust your sizing die to "bump", the shoulder back .001" to .002"
Looking at the pictures of your cases on my phone I don't see pressure indicated on the primers. I don't know what those other marks are. Ejector marks caused by over pressure in my Remington actions look round and shiny.

 

[timeout]

If I read your original post correctly, you state that you see pressure signs on factory ammo also. That would rule out you shoving the shoulder back too far.

 

[dkhunt14]

If I read your original post correctly, you state that you see pressure signs on factory ammo also. That would rule out you shoving the shoulder back too far.

I have seen factory brass up to .010 short on headspace. Matt

 

[Preacher]

Like timeout mentioned.. the primers do not look over pressured....
Pull the firing pin assembly and then chamber a loaded factory case, you should be able to just barely feel it close on a correct sized case, factory or other wise..

 

[7Saum]

Like timeout mentioned.. the primers do not look over pressured....
Pull the firing pin assembly and then chamber a loaded factory case, you should be able to just barely feel it close on a correct sized case, factory or other wise..

K thanx,I will check when I get home..

 

[CharlieNC]

Measure brass with your HS comparator. Partially seat a primer, chamber, and close the bolt such that it finishes seating the primer. Remove and measure HS, and the difference vs the original measure is the HS clearance. Note that the final measure is the 0 headspace, from which you want .002 - .005 clearance.

 

[BillPa]

Ejector marks caused by over pressure....

...or an ejector which doesn't retract at least flush with the bolt face for whatever reason.

Bill