Need help with 308 load, struggling
- Thread starter Shadow9mm
- Start date
typo, 2.810Col 2.280" ?? that's a typo, yes???
Again I would take some of that factory ammo it likes, get ahold of the some of the same bullets and use the same COAL. Then chrono some loads and try and match the velocity with whatever powders you can find that will work with that bullet
On the compressed loads I bet you misread the poise on that 505 and were running 5 gns high. Been there done that and had to pull 20 + bullets when I caught my error
On the compressed loads I bet you misread the poise on that 505 and were running 5 gns high. Been there done that and had to pull 20 + bullets when I caught my error
that is possible, but I know i double checked it. seating at 2.800 today there is barely any space, trying to seat at the recommended 2.735 is definitely fairly compressed.
FWIW I think that's a fantastic powder for that bullet weight in 308 . Not going to get max velocities but they should be fast enough and accuracy should be real good .
As to COAL , as long as you know you're not jammed into the lands and seated deep enough for good bullet hold not sure the books recommendation is all that important . That's for you not someone brand new at this . I will add that seating past the crimp groove does not seem right to me . It just does not sound right that there recommended COAL has the crimp groove buried in the neck . All bullets I load that have a crimp groove I either load to the groove so I can crimp into it or the COAL has the groove fully exposed and I actually never look at the recommended COAL . Never have I needed to bury the groove in the neck . Rightly or wrongly I've always assumed if it has a crimp groove " that's where you seat the bullet to or longer but never shorter .
I thought I had loaded 150gr sst's before in one of my 308's and had to go dig deep in my notes to find out . Turns out they were 165gr sst which the book recommends a COAL of 2.750 . My notes indicate I loaded them at 2.770 . This was years ago now so other then remembering I tested some , that's pretty much all I actually remember . Even after reading my notes I still don't remember actually testing them . My notes say I tested them with IMR 4895 and IMR 4350 . The 4895 gave better accuracy but only 1.75moa at 100yds from my Ruger American rifle . My notes also say I was having issues with my chrono that day so I have no velocity numbers from those loads .
FWIW I kinda remember them having a shorter ogive even though they had the pointy polymer tip . Maybe that's why they recommend such a short COAL . Maybe the baring surface is closer to the tip then there other bullets resulting in them needing to be seated shorter to fit all chambers . As stated above as long as you are gtg with the jump and bullet hold I wouldn't worry to much about there recommended COAL , As always start low and work up keeping an eye out for pressure signs .
As to COAL , as long as you know you're not jammed into the lands and seated deep enough for good bullet hold not sure the books recommendation is all that important . That's for you not someone brand new at this . I will add that seating past the crimp groove does not seem right to me . It just does not sound right that there recommended COAL has the crimp groove buried in the neck . All bullets I load that have a crimp groove I either load to the groove so I can crimp into it or the COAL has the groove fully exposed and I actually never look at the recommended COAL . Never have I needed to bury the groove in the neck . Rightly or wrongly I've always assumed if it has a crimp groove " that's where you seat the bullet to or longer but never shorter .
I thought I had loaded 150gr sst's before in one of my 308's and had to go dig deep in my notes to find out . Turns out they were 165gr sst which the book recommends a COAL of 2.750 . My notes indicate I loaded them at 2.770 . This was years ago now so other then remembering I tested some , that's pretty much all I actually remember . Even after reading my notes I still don't remember actually testing them . My notes say I tested them with IMR 4895 and IMR 4350 . The 4895 gave better accuracy but only 1.75moa at 100yds from my Ruger American rifle . My notes also say I was having issues with my chrono that day so I have no velocity numbers from those loads .
FWIW I kinda remember them having a shorter ogive even though they had the pointy polymer tip . Maybe that's why they recommend such a short COAL . Maybe the baring surface is closer to the tip then there other bullets resulting in them needing to be seated shorter to fit all chambers . As stated above as long as you are gtg with the jump and bullet hold I wouldn't worry to much about there recommended COAL , As always start low and work up keeping an eye out for pressure signs .
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I did a measurement of H4895 powder in a 308 case.
It came to .540 below the top.
Interesting the 270 SST is also .540 to the cannelure .
Its so close that with a Hornady typo it could be an issue and if the ratio is the same as a 30 cal SST, you would indeed have a powder limit.
It came to .540 below the top.
Interesting the 270 SST is also .540 to the cannelure .
Its so close that with a Hornady typo it could be an issue and if the ratio is the same as a 30 cal SST, you would indeed have a powder limit.
Why don't Sierra's cup and core match bullets have a cannelure?
Aren't virtually all jacketed bullets cup and core?
Why did military 30 caliber cup and core FMJBT match bullets made after the early 1950's no longer have a cannelure?
Such reasoning is new to me. Name one bullet brand that does that.
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Bart,I'm sure you have the answers and I will be some percentage wrong.
Why do the manufacturers do things the way they do? My guess is,There is more than one way to skin a cat.
There might be different priorities or upstream factors.
Sierra has had the priorities of sleek form and top accuracy. I do not pretend to have the bullet making knowledge of Sierra. A disruption of the smooth jacket surface may cause some turbulence.
Lead is "deader" than the copper jacket. Forming the groove may actually create clearance between the lead core and the jacket.
With match components, Sierra would control the quality of the jacket and core so a canelure might be a solution to a problem that does not exist.
Making military ball ammo will probaby have more variation so a canelure might crimp the bullet to the core.
The practice of crimping the case neck to the bullet can cost accuracy.Its not a universal practice for match ammo.
Trying to crimp a non-canelure bullet at the case neck leaves no place for the crimp to go. The seater die will produe poorly controlled distortion of the jacket and core.
Speer and perhaps others solders the core in with " hot cor" I think there are some jackets electro-plated.
In some cases,the canelure may be about terminal ballistic performance. How the bullet expands or holds together on game.
I don't know that there are simple,one answer fits all as to "Why" there are canelures.
In some cases,I'll speculate a canelure may be for no other reason than to meet a Gov't spec. In some cases,having or not having a canelure might be about marketing. What s the story behind Remington Cor-Lokt ? Its a popular bullet with loyal following.
IIRC,Speer makes a 30 cal bullet specifically for the 300 Savage,with a cannelure placed for a crimp at the right location for 300 Savage.
Given the short neck and the Rem Model 8/81 semi-autos,might be a good idea.
I would guess the elimination of the canelure on military match ammo might be related to asphaltum.
Some believe (and it may be true) that a light crimp with a collet crimp die utilized with a canelured Match King might improve uniformity of ignition.
I don't know. I'm not of the "crimp school".but it takes testing to prove.
Match bullet jackets are typically thinner. Handle with care.
I'm always grateful when you teach me something new.
Why do the manufacturers do things the way they do? My guess is,There is more than one way to skin a cat.
There might be different priorities or upstream factors.
Sierra has had the priorities of sleek form and top accuracy. I do not pretend to have the bullet making knowledge of Sierra. A disruption of the smooth jacket surface may cause some turbulence.
Lead is "deader" than the copper jacket. Forming the groove may actually create clearance between the lead core and the jacket.
With match components, Sierra would control the quality of the jacket and core so a canelure might be a solution to a problem that does not exist.
Making military ball ammo will probaby have more variation so a canelure might crimp the bullet to the core.
The practice of crimping the case neck to the bullet can cost accuracy.Its not a universal practice for match ammo.
Trying to crimp a non-canelure bullet at the case neck leaves no place for the crimp to go. The seater die will produe poorly controlled distortion of the jacket and core.
Speer and perhaps others solders the core in with " hot cor" I think there are some jackets electro-plated.
In some cases,the canelure may be about terminal ballistic performance. How the bullet expands or holds together on game.
I don't know that there are simple,one answer fits all as to "Why" there are canelures.
In some cases,I'll speculate a canelure may be for no other reason than to meet a Gov't spec. In some cases,having or not having a canelure might be about marketing. What s the story behind Remington Cor-Lokt ? Its a popular bullet with loyal following.
IIRC,Speer makes a 30 cal bullet specifically for the 300 Savage,with a cannelure placed for a crimp at the right location for 300 Savage.
Given the short neck and the Rem Model 8/81 semi-autos,might be a good idea.
I would guess the elimination of the canelure on military match ammo might be related to asphaltum.
Some believe (and it may be true) that a light crimp with a collet crimp die utilized with a canelured Match King might improve uniformity of ignition.
I don't know. I'm not of the "crimp school".but it takes testing to prove.
Match bullet jackets are typically thinner. Handle with care.
I'm always grateful when you teach me something new.
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Shawow9:
I am coming to the conclusion that with the SST x 150, it is a compressed load up past the 40 grain mark (not sure how high).
It may not hurt, but I agree it is disquiet. Hornady does not state compressed load one way or the other.
6 of their bullet sin the 150-155 group call for 2.735 COAL and one is 2.700 (out of 8)
Interesting that the A-MAX that looks to be similar is 2.800
Best course of course is to proceed for what works for you, maybe call Hornady and ask them.
I ran some tests:
Conclusion: Max load of H4895 powder is a compressed load in 308.
Methodology: Take a fired 308 case, fill to the max listed load of Hogdens 4895 (43.3 gr) for a Hornady 168 ELDM bullet (which I have of course) and measure the COAL when the bullet rests on the powder (probably a very small amount compressed)
Then measure COAL at 2.870 vs a COAL spec for that bullet of 2.800 .
Yes there may be some question on the overall accuracy, but I believe they are so small that there are some offsets (A sized case will be smaller). No cannelure n the 168 ELDM but the relative situation.
With the 150 SST cannelure so far up the bullet and that even shorter COAL, much more compressed.
Conclusion: Max load of H4895 powder is a compressed load in 308.
Methodology: Take a fired 308 case, fill to the max listed load of Hogdens 4895 (43.3 gr) for a Hornady 168 ELDM bullet (which I have of course) and measure the COAL when the bullet rests on the powder (probably a very small amount compressed)
Then measure COAL at 2.870 vs a COAL spec for that bullet of 2.800 .
Yes there may be some question on the overall accuracy, but I believe they are so small that there are some offsets (A sized case will be smaller). No cannelure n the 168 ELDM but the relative situation.
With the 150 SST cannelure so far up the bullet and that even shorter COAL, much more compressed.
When I get home I’m going to have to try this my self . I’m just not buying the case fill is to much . According to my notes I loaded IMR 4895 & 4350 with 165’s and didn’t seem to have an issue . H-4895 is much shorter cut powder then those others . It should settle in just fine . I’m going to dump max load , use drop tube and vibrate and see how each fills the case .
EDIT , the IMR 4895 load was 42gr for the 165gr sst . Notes don't say if I went higher , only what load I settled on .
EDIT , the IMR 4895 load was 42gr for the 165gr sst . Notes don't say if I went higher , only what load I settled on .
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44gr H-4895 in a 308win case
Powder depth-ish ( hard to measure ) , from mouth left to right
Left - 6" drop tube and vibration .475 - well below shoulder neck junction
Center - 6" drop tube only .400 - a tad below shoulder neck junction
Right - straight dump from funnel .300 - pretty much right at shoulder neck junction .
With out having any of the actual bullets in hand , I don't see why there wouldn't be plenty of bullet hold with any of these cases . I'd likely use the 6" drop tube and seat away . YMMV
Powder depth-ish ( hard to measure ) , from mouth left to right
Left - 6" drop tube and vibration .475 - well below shoulder neck junction
Center - 6" drop tube only .400 - a tad below shoulder neck junction
Right - straight dump from funnel .300 - pretty much right at shoulder neck junction .
With out having any of the actual bullets in hand , I don't see why there wouldn't be plenty of bullet hold with any of these cases . I'd likely use the 6" drop tube and seat away . YMMV
As noted, I dropped a 30 caliber bullet (168 gr not 150) into a fired case with the full Hornady load (43.2 gr). The 168 ELDM is a boat tail per the SST.
With it resting atop the powder (call it very minimal compression but a shade) it was longer than stated seating depth (.070)
So yes its a pretty full case and the SST 150 seems to be a rather high cannelure and seated deeper.
That SST can be used in any 30 cal case (or pretty much, though not workable in an M1 Carbine or happy in a lever 30-30)
So yea, seated to the listed depth, compressed. Its listed as a medium/large game bullet. So ensuring clearing any magazine might get it that short though that negates the reason for a cannelure (Bart B aside) as well.
I will follow up with a look at the 270 SST and see where it falls COAL in that case.
With it resting atop the powder (call it very minimal compression but a shade) it was longer than stated seating depth (.070)
So yes its a pretty full case and the SST 150 seems to be a rather high cannelure and seated deeper.
That SST can be used in any 30 cal case (or pretty much, though not workable in an M1 Carbine or happy in a lever 30-30)
So yea, seated to the listed depth, compressed. Its listed as a medium/large game bullet. So ensuring clearing any magazine might get it that short though that negates the reason for a cannelure (Bart B aside) as well.
I will follow up with a look at the 270 SST and see where it falls COAL in that case.
I did a couple of 270 comparisons. One was a Boat Tail Lead Tip bullet with cannelure, 130 gr. (unknown mfg)
the other the SST 130 gr.
SST cannelure falls about 1.5 cannelure higher (yes I now variables but interesting)
Then I seated an SST in a 270 case. The recommended or book (Hornady) COAL came right at the top of the cannelure .
It would seem for whatever reasons the SST does sit deeper per Hornady and the 270 Winchester would be the main application for the 130 gr SST.
the other the SST 130 gr.
SST cannelure falls about 1.5 cannelure higher (yes I now variables but interesting)
Then I seated an SST in a 270 case. The recommended or book (Hornady) COAL came right at the top of the cannelure .
It would seem for whatever reasons the SST does sit deeper per Hornady and the 270 Winchester would be the main application for the 130 gr SST.