jimbires
Well-Known Member
the redding competition shellholder sets make proper shoulder bump easy ,and repeatable . I have 3 different 7mm-08's , and 1 die set . I just use the proper shellholder for that particular rifle .
Seek wisdom from those wiser on brass failure
- Thread starter NeedForSpeed
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You can use a borescope to inspect the inside of cases and will see cracks forming. If you have a case with a slight visible ring on the outside it will be very large when viewed internally. Not saying this will catch everything but it will at least show definitive cracks when they are far enough along.
capona
Well-Known Member
It's a game of precision.
Know your headspace and fired brass headspace. Then know exactly how much you are bumping the shoulder relative to the fired brass, and it should be as little as possible that still allows for reliable chambering.
Know your headspace and fired brass headspace. Then know exactly how much you are bumping the shoulder relative to the fired brass, and it should be as little as possible that still allows for reliable chambering.
NeedForSpeed
Well-Known Member
Ive ordered a Hornady head space comparator guage and some new brass
Ill report back after I get it and see how badly Ive screwed it up
I have noticed that the Hornady Creedmoor brass "grows" much more than any other brass I load and I trim it before each reload so you guys most likely nailed the issue.
capona
Well-Known Member
This is probably obvious but I'll state it anyway. Be aware that a comparator gauge compares before and after.
But if you zero out your calipers on a go gauge in that is in that Hornady comparator like a Forster go gauge, then your reading will be exactly valid and relatable to saami spec. I know I'm not stating that well.
fyi...
I don't know 6.5 creedmoor saami specs but for 308win go is 1.630. so if I zero out on a 1.630 win .308go gauge inserted into the Hornady compare gauge, I know my spec with true nominal values for 308win..
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NeedForSpeed
Well-Known Member
What is a go guage? Never heard of that before
All you really need is a comparator. Measure your brass and bump it back. I have no issue with hornady brass growing excessively on firing. Then again I have a fairly tight chamber. There is a tolerance spec on chamber dimensions. If yours is on the long end its going to grow on that first firing. After that its on how much you size.
QuietTexan
Well-Known Member
PTG Headspace Go Ga 300 Remington Short Action Ultra Mag
The PTG Headspace Go Gauges are necessary when finish chambering a barrel, or when checking the chamber of a used gun to be sure the headspace...
www.midwayusa.com
Normally used when setting up a barrel for correct headspace.
NeedForSpeed
Well-Known Member
I really appreciate the link. I looked up both go and no go guages and it seems like the go guage shows minimum Sammi safe dimensions and the no go the maximum dimensionsPTG Headspace Go Ga 300 Remington Short Action Ultra Mag
The PTG Headspace Go Gauges are necessary when finish chambering a barrel, or when checking the chamber of a used gun to be sure the headspace...
Normally used when setting up a barrel for correct headspace.
I checked my chambers dimensions prior to loading with a dummy cartridge jammed into chamber until the bolt would close, then measured the base to ogive of that round. I then loaded rounds backed off of that number until I was happy with my results. Do these gages give more info than that or did I do that incorrectly?
QuietTexan
Well-Known Member
I think what capona is saying that since the go gauge is the SAAMI minimum spec that it's a more reliable measurement in the sense that you can compare an unsized piece against the spec, then a sized piece against the spec to determine actual sizing, instead of the relative change in length of a case before and after sizing.
I don't think my Hornady comparator is accurately bored enough to measure the actual datum line, so I'm not convinced that the extra step matters. But if someone thinks it does, more power to them.
I don't think my Hornady comparator is accurately bored enough to measure the actual datum line, so I'm not convinced that the extra step matters. But if someone thinks it does, more power to them.
Die mftr lawyers make them write instructions to take brass back to sammi, so loaded round will fit any gun. back your die off at least one turn and work your way down. You have to measure where your headspace is on a 2x fired round vs where you are sizing. you want 2-3 thousands shoulder bump. Mftr instructions can give you 10 thousand or more.
another thing, not all shellholders are made the same heigth even from same mftr. Use a shellholder that works with that set of dies and then keep it in the die box. Do no switch it around.
another thing, not all shellholders are made the same heigth even from same mftr. Use a shellholder that works with that set of dies and then keep it in the die box. Do no switch it around.
capona
Well-Known Member
You did it fine. You don't need to have gauges. I have gauges because I spin barrels on and off when I change calibers.
Go gauge is the Saami minimum, bolt should close on it.
No go is not the Saami max though. The max is longer than no go. But if your bolt closes on a no go it would be an indicator to have it looked over.
The value of zeroing your caliper out on a go gauge is it gives you a hard known value. In win 308, that's 1.630. So if my brass grows .003 , I know it's 1.633. It's a hard actual value.
Quiet Texan conveyed what I was trying to get to. Thanks Tex!
Go gauge is the Saami minimum, bolt should close on it.
No go is not the Saami max though. The max is longer than no go. But if your bolt closes on a no go it would be an indicator to have it looked over.
The value of zeroing your caliper out on a go gauge is it gives you a hard known value. In win 308, that's 1.630. So if my brass grows .003 , I know it's 1.633. It's a hard actual value.
Quiet Texan conveyed what I was trying to get to. Thanks Tex!
NeedForSpeed
Well-Known Member
Im using Forster dies and press
No shell holder needed but I understand what youre saying Thanks!
