Blue Dot in cast rifle loads
- Thread starter richhodg66
- Start date
Maven
Well-Known Member
You're most welcome, Ian! Btw, I searched online for Sea Fire's data (He combines the 2 words, but spell check doesn't like it!), but could only find vague references to it and his e-mail, which is no longer active. After looking in my reloading notebook and coming up empty handed, I checked a manila folder of reloading pamphlets (Hodgdon, Dupont/IMR, Winchester) near my reloading bench and sure enough came up with it. There was a bit of redundancy and contradictory phrasing in the original, but I tried to edit it with an eye to clarity. Be that as it may, I would tread very carefully when approaching 40% loads, especially in warm weather and heed his warning about accuracy rather than velocity.
It occurs to me after pondering the above that Sea Fire's data is more suitable to reduced jacketed bullet loads than CB loads. E.g, when I used B. Dot in my .243Win. with Ly. #245496 (~84gr. Loverin GC design), I certainly didn't use 20% of that case's capacity, but only 12gr. B. Dot (vs. 9.5 - 10.0gr. Unique with the same CB). Similarly, with just about any .30cal. GC CB I own, I would use no more than 15gr. B. Dot in my .30-06. In short, be safe and start at 10% of case capacity and then gradually increase it until you get the result you want.
It occurs to me after pondering the above that Sea Fire's data is more suitable to reduced jacketed bullet loads than CB loads. E.g, when I used B. Dot in my .243Win. with Ly. #245496 (~84gr. Loverin GC design), I certainly didn't use 20% of that case's capacity, but only 12gr. B. Dot (vs. 9.5 - 10.0gr. Unique with the same CB). Similarly, with just about any .30cal. GC CB I own, I would use no more than 15gr. B. Dot in my .30-06. In short, be safe and start at 10% of case capacity and then gradually increase it until you get the result you want.
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To Bee, or 223 Revisited
not sure if this link will work but if not check the article out on James Calhoon Bullets page, deals with jacketed bullets but he was one of the first people i read about using Bluedot for use in a rifle.
not sure if this link will work but if not check the article out on James Calhoon Bullets page, deals with jacketed bullets but he was one of the first people i read about using Bluedot for use in a rifle.
JonB
Halcyon member
Maven,
Thanks for the Sea Fire info, and thanks especially for posting your second thought's, that I quote here.
JonB
Halcyon member
Maven,
I have a question.
The highlighted line, "Work up slowly and in small increments above 50% of max. in magnum cases .308Win.-, and 7 x 57mm- based cases."
If I am understanding this correctly, 50% is MAX for 30-06 family
But not necessarily for Magnum cartridges or 308 family cases or 7x57 family cases ???
I ask, because two calibers I may try this with are 243win and 6.5x257R (7x57 is parent case)...using GCed CBs
While I am not really concerned with the MAX charge, especially since your later comment about this info being more suited for Jacketed...and your additional info about your experience with 243 with 84gr Loverin... But I just want to understand...because that high lighted statement doesn't seem logical...unless it's just a added warning to be extra careful when exceeding 50%.
Maven
Well-Known Member
Jon, Sea Fire's write up is a bit inconsistent and never mentions magnum cases. In high pressure cartridges such as the '06 and .308Win., I wouldn't even go as high as 50% of pre-established case capacity. To be meaningful, any testing of that data should be done using a chronograph and a thorough examination of the [fired] cases for signs of excess pressure. Btw, one of the criticisms of the data is that it hadn't been independently tested. Tread carefully if you go as high as 40%, Jon.
wquiles
Well-Known Member
Just trying to learn here, but is what we see as something being quite loud when comparing one combo to another directly related to the PSI pressure at the end of the barrel? IE, a combo with a lower (lets say, 1/2) psi pressure at end of barrel would be less loud?
If noise is sound waves I believe it has something to do with sudden pressure drops emitting waves. I also hear more of a boom with a large bore shotgun or 45-70 and a crack with a 17 Rem or 223.
It is also interesting how quiet a handgun is from a distance while firing nearly straight down vs slightly uphill. All in how the waves travel.
It is also interesting how quiet a handgun is from a distance while firing nearly straight down vs slightly uphill. All in how the waves travel.
wquiles
Well-Known Member
I get the part about the noise/sound waves - just trying to learn/find out if there is a correlation to something sounder louder vs. exit PSI out of the barrel.
HM8485
New Member
You really can't substitute the sound for a chronograph. Even a .22 LR exiting a barrel with a suppressor emits a substantial crack as the bullet is traveling over 1,000 fps and breaking the sound barrier. It doesn't just go "pfft" like in the movies. Ian's explanation is spot on. At any rate, even if it could, it would be unwise not to wear your ear protection when shooting anything more than a bb gun.
HM8485
New Member
I am grateful to all who have been posting. I get very good results in .357, .44, and 9mm. It seems to be a little dirtier than Bullseye, but I like the fact that it seems a bit bulkier. I recently did my promised test with cast bullets in 7.62X39 in my minty Tula SKS and 30.06 in my 03A3 2 groove barrel. I am writing to put out a caution. Using Seaforth's formula, I loaded 10 grains of that last batch of Blue Dot Alliant made, the same I use in my .357 and 44. I got classic signs of too much pressure. In the 03 I got flattened primers. In the SKS, I got flattened primers and stuck cases using both 115 and 150 gr gas-checked bullets cast of range scrap, in addition to failure to extract. The case necks were also a little bulged just below where the base of the bullet is when seated. I am going to start working downward and will post my findings and do some accuracy testing as well. By the way, in my O3A3 the 150 gr bullets got stuck in the first 1" of the barrel (a retrofitted Remington 1966, sharp and shiny as a new penny, with sharp rifling). The 115 gr cleared the barrel, but I was testing for function and pressure and not concerned with grouping. I didn't get any leading, and cleaning was easy with my old favorite, Hoppe's 9.
fiver
Well-Known Member
I would be very leery of any sort of bulging at the base of the bullet.
remember powder sends out pressure waves to the base of the weight it hits.
this is why steel shot shell loads are vastly different than regular lead loads with wads that have a cushion.
there is more room between the powder and the base of the weight.
of course there are other considerations to peak pressure[gas volume, burn speed etc.] but that isn't the whole story to how a load behaves.
remember powder sends out pressure waves to the base of the weight it hits.
this is why steel shot shell loads are vastly different than regular lead loads with wads that have a cushion.
there is more room between the powder and the base of the weight.
of course there are other considerations to peak pressure[gas volume, burn speed etc.] but that isn't the whole story to how a load behaves.